This thesis would not have been complete without a special mention to the following [632142]

UNIVERSITY OF
MEDICINE AND PHARMACY OF IASIʽʽGRIGORE T. POPAʼʼ

THESIS IN GENERAL MEDICINE

SECOND MEDICAL CLINIC , SF.SPIRIDON HOSPITAL
INTERNAL MEDICINE

DIAGNOSIS OF DVT IN CLINICAL PRACTICE

ABSOLVENT: [anonimizat] : LEC.DR.VICTORI TA SORODOC

IASI 2016

ACKNOWLEDGEMENTS
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ACKNOWLEDGEMENTS
This thesis would not have been complete without a special mention to the following
people who helped me immensely throughout the working process.
First and foremost, praises and thanks to God the Almighty for His ble ssings throughout
the research work to complete it successfully and satisfactorily.
I exte nd my heartfelt gratitude to Lec .Dr Victorita Sorodoc for her guidance and
continuous support during the research period. Her dynamism, vision, sincerity and motivati on
have deeply inspired me. She has taught me the methodology to carry out the research and to
present the research works as clearly as possible. It was a great privilege and honor to work and
study under her guidance. A big thank you to the staff of the second medical clinic,Sf.Spiridon
hospital for their willingness to help in every possible situation.
For the ancestors who paved the path before me upon whose shoulders I stand. This is
dedicated especially to my father Mr.Pravin Thanki and my mother Mrs. Sunita Thanki and
the extended Thanki Family for their support, love, prayers and mentorship in the c ompletion of
this work and also the ir sacrifices for educating and preparing me for my future.
Last but not least a big thank you to m y friends for lendin g their helping hand in this
venture and for their continuous supports throughout the working process. Thank you.

TABLE OF CONTENTS
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1. TABLE OF CONTENTS
ACKNOWLEDGEMENTS ………………………….. ………………………….. ……………………….. 2
1. TABLE OF CONTENTS ………………………….. ………………………….. ……………………….. 3
2. TABLE OF TABLES ………………………….. ………………………….. ………………………….. …. 5
3. TABLE OF FIGURES ………………………….. ………………………….. ………………………….. .. 6
4. ABBREVIATIONS ………………………….. ………………………….. ………………………….. ….. 11
GENERAL PART ………………………….. ………………………….. ………………………….. ……….. 13
5. INTRODUCTION ………………………….. ………………………….. ………………………….. ……. 14
6. HISTORY (BACKGROUND) OF DVT ………………………….. ………………………….. … 15
7. EPIDEMIOLOGY ………………………….. ………………………….. ………………………….. …… 17
7.1. INCIDENCE ………………………….. ………………………….. ………………………….. ………. 17
7.2. GENDER ………………………….. ………………………….. ………………………….. …………… 17
7.3. AGE GROUP ………………………….. ………………………….. ………………………….. ……… 17
8. PATHOPHYSIOLOGY OF DVT ………………………….. ………………………….. …………. 18
8.1. STASIS OF BLOOD ………………………….. ………………………….. ……………………….. 19
8.2. CHANGES IN BLOOD VESSELS ………………………….. ………………………….. ……. 19
8.3. HYPERCOAGULABILITY ………………………….. ………………………….. ……………… 20
9. HEMOSTASIS IN BRIEF ………………………….. ………………………….. ……………………. 20
9.1. PRIMARY HEMOSTASIS (PLATELET ADHESION AND AGGREGATION) 20
9.2. SECONDARY HEMOSTASIS ………………………….. ………………………….. …………. 21
9.3. FIBRINOLYSIS AND D -DIMER FORMATION ………………………….. ……………. 21
10. DIAGNOSIS OF DVT ………………………….. ………………………….. ………………………… 23
10.1. CLINICAL DIAGNOSIS ………………………….. ………………………….. ……………….. 23
10.2. CLINICAL ASSESMENT ………………………….. ………………………….. ………………. 25
10.3. LABORATORY INVESTIGATION S(BLOOD ANALYSIS) ……………………… 26

TABLE OF CONTENTS
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10.3.1. COMPLETE BLOOD COUNT ………………………….. ………………………….. …. 26
10.3.2. ADDITIONAL BLOOD TESTS ………………………….. ………………………….. .. 26
10.3.3. INFLAMMATORY MARKERS ………………………….. ………………………….. .. 26
10.3.4. D -DIMER AND OTHER FIBRIN DEGRADTION PRODUCTS ………….. 26
10.3.5. THROMBOPH ILIA SCREENING ………………………….. ………………………… 27
10.4. IMAGING TECHNIQUES ………………………….. ………………………….. ……………… 28
10.4.1. DOPPLER ULTRASOUND ………………………….. ………………………….. ……… 28
10.4.2. CONTRAST VENOGRAPHY ………………………….. ………………………….. ….. 30
10.4.3. OTHER IMAGING TECHNIQUES ………………………….. ………………………. 31
11. DIAGNOSTIC ALGORITHM IN CLINICAL PRACTICE ………………………….. 32
11.1. LOW PRETEST PROBABLITY ………………………….. ………………………….. …….. 32
11.2. HIGH PRETEST PROBABILITY ………………………….. ………………………….. …… 33
PERSONAL PART ………………………….. ………………………….. ………………………….. ……… 34
12. AIMS AND OBJECTIVES OF THE STUDY ………………………….. …………………… 35
13. MATERIALS AND METHODS ………………………….. ………………………….. …………. 35
14. RESULTS AND DISCUSSION ………………………….. ………………………….. …………… 36
14.1. EPIDEMIOLOGICAL AND DESCRIPTIVE PARAMETERS ……………………. 36
14.1.1. Gender ………………………….. ………………………….. ………………………….. ……….. 36
14.1.2. Age ………………………….. ………………………….. ………………………….. ……………. 37
14.1.3. Profession ………………………….. ………………………….. ………………………….. …… 38
14.1.4. Orthostatism ………………………….. ………………………….. ………………………….. .. 38
14.1.5. Settlement ………………………….. ………………………….. ………………………….. ….. 39
14.1.6. Drug History ………………………….. ………………………….. ………………………….. . 40
14.1.7. Pregnancy ………………………….. ………………………….. ………………………….. …… 40
14.1.8. Smoking ………………………….. ………………………….. ………………………….. …….. 41

TABLE OF TABLES
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14.1.9. BMI ………………………….. ………………………….. ………………………….. …………… 42
14.1.10. Days Of Hospitalization ………………………….. ………………………….. ………….. 43
14.1.11. Echocardiographic Findings ………………………….. ………………………….. ……. 43
14.1.12. Doppler Ultrasound Findings ………………………….. ………………………….. …… 45
14.1.13. Blood analysis ………………………….. ………………………….. ……………………….. 53
14.1.14. Wells score ………………………….. ………………………….. ………………………….. .. 61
14.2. CORRELATIVE PARAMETERS ………………………….. ………………………….. …… 62
15. DISCUSSIONS ………………………….. ………………………….. ………………………….. ………. 80
16. LIMITATIONS OF THE STUDY ………………………….. ………………………….. ………. 84
17. CONCLUSIONS ………………………….. ………………………….. ………………………….. ……. 85
18. BIBLIOGRAPHY ………………………….. ………………………….. ………………………….. ….. 86
2. TABLE OF TABLES
Table 1: Wells score,a pretest probablity for DVT. ………………………….. …………………… 25
Table 2: Various Causes of Increased DD assay ………………………….. ………………………. 27
Table 3: A table representing the statistical data regarding RDW -SD ……………………. 55
Table 4: A table representing statistical data regarding NT -PRO BNP …………………… 57
Table 5: A Table representing the statistical data for CRP ………………………….. ………… 58
Table 6: A table representing the statistical data regarding ESR ………………………….. .. 59
Table 7: A table representing the statistical data for Fibrinogen ………………………….. .. 60
Table 8: A statistical table representing the Male gender and the frequency of variable
locations ………………………….. ………………………….. ………………………….. ………………………….. …….. 64
Table 9: A table representing the statistical data for Female gender and the frequency
of variable locations involved ………………………….. ………………………….. ………………………….. …… 65
Table 10: A table representing the statistical data regarding the limb involvement in
Male gender ………………………….. ………………………….. ………………………….. ………………………….. .. 66
Table 11: A table representing the statistical data regarding the limb involvement in
Female gender ………………………….. ………………………….. ………………………….. ………………………… 67

TABLE OF FIGURES
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Table 12: A table representing the correlational statistical data regarding the presence
of thrombus and the wells score ………………………….. ………………………….. ………………………….. .. 74
Table 13: A table representing comparative statistics between the Wells score and DD
analysis ………………………….. ………………………….. ………………………….. ………………………….. ……… 75
Table 14: Chi square test comparing the nominals. ………………………….. ………………….. 75
Table 15: A table representing the statistical data for DD and NT -PRO BNP …………. 76
Table 16: A table representing the statistical collected for DD and RDW -SD ………….. 77
Table 17: A table representing the correlational Phi and Crame r’s V test performed for
the nominals,V value of 0.232 and P value of 0.223 was found be inconclusive …………………. 77
Table 18: A table representing general comparative statistical data between ESR and
CRP ………………………….. ………………………….. ………………………….. ………………………….. …………… 78
Table 19: A table representing the correlational test of Phi and Cramer’s V test for the
nominals.V values ≈1,in our study 0.555 and P values <0.05,in our study 0.008 are significant
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 78
Table 20: A table representing the general statistical data for CRP and Fibrinogen … 79
Table 21: A table representing the correlati onal test of Phi and Cramer’s V test for the
nominals.V values ≈1,in our study 0.756 and P values <0.05,in our study 0.000 are significant
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 79
3. TABLE OF FIGURES
Figure 1: The anatomy of the superficial and peripheral veins of the lower limb …….. 14
Figure 2: A diagram illustrating formation of a blood clot in DVT and embolization to
the general circulation ………………………….. ………………………….. ………………………….. …………….. 14
Figure 3: The illustrated manuscript depicting the first case of venous thrombosis.
ClicheÁBiblioteÁque National de France, Paris. ………………………….. ………………………….. ……. 15
Figure 4: Rudolf Virchow(1821 -1902) ………………………….. ………………………….. ……….. 16
Figure 5: An image depicting the estimated average annual number of hospitalization
with a diagnosis of DVT,PE or VTE by age and sex in USA between 2007 -2009. ………………. 17
Figure 6: Virchows Triad ………………………….. ………………………….. ………………………….. 18
Figure 7:Virchows Triad in a nutshell ………………………….. ………………………….. ……….. 19

TABLE OF FIGURES
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Figure 8: Primary Homeostasis at site of vessel injury. All rights reserved Casper
Asmussen ………………………….. ………………………….. ………………………….. ………………………….. …… 20
Figure 9: Secondary Homeostasis (Plasma Coagulation).From Casper Asmussen, all
rights reserved. ………………………….. ………………………….. ………………………….. ……………………….. 21
Figure 10: Fibrinolysis, From Caspe r Asmussen with all rights reserved ……………….. 22
Figure 11: D-dimer formation. Fibrinogen consisting of two D domains separated by a
central E domain. Thrombin cleavage of the fibrinopeptides results in the end -to-end
association of D domains into a fibrin clot. During fibrinolysis, plasmin cleaves the cross
linked fibrin into fibrin degradation products of which the D -Dimer is one of the resulting
products. ………………………….. ………………………….. ………………………….. ………………………….. ……. 22
Figure 12: A nurse performing the Homans sign in a suspected case of DVT . ……….. 23
Figure 13: A case of Phlegmasia Cerulea Dolens in a 85 year old woman with a newly
diagnosed metastatic non -small -cell lung cancer causing a massive left femoropopliteal DVT
which was confirmed by doppler ultrasonography. ………………………….. ………………………….. …. 24
Figure 14:A peculiar case of Phelgmasia Alba Dollens of the Right leg …………………. 24
Figure 15: An illustrated normal Doppler ultrasound of the Left Posterior Tibial vein
from the radiology department of the second Medical Clinic Sf.Spridon ………………………….. . 28
Figure 16: Doppler ultrasound of the CFV illustrating the presence of a thrombus in
the second Medical Clinic Sf.Spiridon. ………………………….. ………………………….. ………………….. 29
Figure 17: A Doppler u ltrasound illustrating the presence of thrombus and flux
abnormality in a case of complete thrombosis of the Femoral Vein in the second medical clinic
Sf.Spridon. ………………………….. ………………………….. ………………………….. ………………………….. …. 29
Figure 18: A venogram demo nstrating extensive DVT of the profound veins. Various
filling defects are present throughout the venous system which are interpreted as thrombi. … 30
Figure 19: CT Venography illustrating bilat eral DVT,arrows indicate the exact
location of the thrombus. ………………………….. ………………………….. ………………………….. …………. 31
Figure 20: MRI in a patient with a recurrent popliteal DVT,arrow indicates the
presence of Thrombus. ………………………….. ………………………….. ………………………….. …………….. 32
Figure 21: Diagnostic algorithm using D -dimer testing and ultrasound imaging in
patients with suspected DVT. ………………………….. ………………………….. ………………………….. ……. 33
Figure 22: Pie chart representing the difference in distribution of Gender …………….. 36

TABLE OF FIGURES
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Figure 23: A pie ch art representing the various age groups associated with DVT in our
study ………………………….. ………………………….. ………………………….. ………………………….. ………….. 37
Figure 24: A pie chart illustrating the distribut ion of patients according to profession
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 38
Figure 25: A pie chart illustrating the distribution of patients with orthostatism …….. 39
Figure 26: A pie chart illustrating the distribution of patients according to their
settlement . ………………………….. ………………………….. ………………………….. ………………………….. ….. 39
Figure 27: A pie chart representing the distribution of patients according to their
medical drug history ………………………….. ………………………….. ………………………….. ………………… 40
Figure 28: A pie chart illustrating the distribution of patients according to pregnancy
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 41
Figure 29 : A pie chart illustrating the distribution of ………………………….. ……………….. 42
Figure 30:A histogram illustrating the distribution of BMI against the freq uency of
patients ………………………….. ………………………….. ………………………….. ………………………….. ………. 42
Figure 31:A histogram illustrating the distribution of the number of hospitalized days
against the frequency ………………………….. ………………………….. ………………………….. ………………. 43
Figure 32: A pie chart illustrating the distribution of patients with RA dilatation . …… 43
Figure 33:A pie chart illustrating the distribution of patients with RVH. ……………….. 44
Figure 34: A histogram illustrating the grade of Tricupsid Regurgitation against the
percent ………………………….. ………………………….. ………………………….. ………………………….. ………. 44
Figure 35: A pie chart illustrating the di stribution of the locations involved …………… 45
Figure 36: A pie chart illustrating the precise limb involved in our study ……………….. 45
Figure 37: A pie chart illustrating the percentage in Brachial vein involvement ……… 46
Figure 38: A pie chart illustrating the percentage in IJV involvement ……………………. 46
Figure 39: A pie chart illustrating the percentage in Subclavian vein involvement ….. 47
Figure 40: A pie chart illustrating the percentage in Axillary vein involvement ………. 47
Figure 41: A pie chart illustrating the percentage i n CFV involvement ………………….. 48
Figure 42: A pie chart illustrating the ………………………….. ………………………….. ………… 48
Figure 43: A pie chart illustrating the percentage of PFV involvement ………………….. 49
Figure 44: A pie chart illustrating the percentage of popliteal vein involvement ……. 49
Figure 45: A pie char t illustrating the percentage of Peroneal Vein involvement ……. 50

TABLE OF FIGURES
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Figure 46: A pie chart illustrating the involvement of the ATV in percentage …………. 50
Figure 47: A pie chart illustrating the percentage of involvement of PTV ………………. 51
Figure 48: A pie chart illustrating the percentage of Thrombus presence in our study 51
Figure 49: A pie chart illustrating the percentage of Collateral Circulation in our study
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 52
Figure 50: A pie chart illustrating the percentage of flux abnormality in our study … 52
Figure 5 1: A pie chart analyzing the DD levels ………………………….. ………………………… 53
Figure 52: A pie chart illustrating the analysis of FDP levels ………………………….. …… 54
Figure 53: A pie chart illustrating the analysis of WBC levels ………………………….. …… 54
Figure 54: A pie chart illustrating the Hb levels ………………………….. ………………………. 55
Figure 55: A pie chart illustrating RDW -SD analysis ………………………….. ………………. 56
Figure 56: A pie chart illustrating INR analysis ………………………….. ………………………. 56
Figure 57: A pie chart illustrating the analysis of NT -PRO BNP in blood ……………… 57
Figure 58: A pie chart illustrating the analysis for PLT ………………………….. ……………. 58
Figure 59: A pie chart illustrating CRP analysis ………………………….. ……………………… 59
Figure 60: A pie chart illustrating the ESR analysis ………………………….. ………………… 60
Figure 61: A pie chart illustrating the analysis for Fibrinogen ………………………….. …. 61
Figure 62: A graph representing the Wells score against the percentage in our study 61
Figure 63: A graph representing the gender against the mean days of hospitalization 62
Figure 64 A graph representing the age groups against the mean days of
hospitalization ………………………….. ………………………….. ………………………….. ………………………… 62
Figure 65: A graph representin g the Wells scores against the mean days of
hospitalization ………………………….. ………………………….. ………………………….. ………………………… 63
Figure 66: A histogram illustrating the mean days of hospitali zation against the
number of locations involved in our study ………………………….. ………………………….. ……………… 63
Figure 67 A graph illustrating the mean days of hospitalizati on against the
orthostatism ………………………….. ………………………….. ………………………….. ………………………….. .. 64
Figure 68: A pie chart illustrating the percentage of variable locations involved for
Male gender ………………………….. ………………………….. ………………………….. ………………………….. .. 65
Figure 69: A pie chart illustrating the percentage of variable locations involved for
Female gender ………………………….. ………………………….. ………………………….. ………………………… 66

TABLE OF FIGURES
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Figure 70: A pie chart illustrating the percentage of precise limb involved in Male … 67
Figure 71: A pie chart illustrating the percentage of precise limb involved in Female 68
Figure 72: A pie chart illustrating the age group 18 -35 and the frequency of location
involved ………………………….. ………………………….. ………………………….. ………………………….. ……… 68
Figure 73: A pie chart illustrating the age group 35 -50 and the frequency of locations
involved ………………………….. ………………………….. ………………………….. ………………………….. ……… 69
Figure 74:A pie chart illustrating the age group ………………………….. ………………………. 69
Figure 75: A pie chart illustrating the age group >65 and the frequency of locations
involved ………………………….. ………………………….. ………………………….. ………………………….. ……… 70
Figure 76: A graph representing the correlation of Orthostatism and Gender with the
percentage ………………………….. ………………………….. ………………………….. ………………………….. ….. 70
Figure 77: A graph illustrating the correlation between age groups and orthostatism
against the percentage . ………………………….. ………………………….. ………………………….. ……………. 71
Figure 78: A graph illustrating the correla tional studies between the gender and the
wells score against the frequency ………………………….. ………………………….. ………………………….. 72
Figure 79: A graph illustrating the correlational studies between age groups and wells
score against the frequenc y ………………………….. ………………………….. ………………………….. ……… 73
Figure 80: A bar chart illustrating the correlational studies between wells score and
BMI against the frequency ………………………….. ………………………….. ………………………….. ………. 73
Figure 81: A bar graph illustrating the correlational study between the wells score and
the presence of thrombus against the frequency ………………………….. ………………………….. …….. 74
Figure 82: A bar chart illustrating the correlational studies between DD and Wells
score ………………………….. ………………………….. ………………………….. ………………………….. ………….. 75
Figure 83: A bar chart illustrating the correlation between DD and NT -PRO BNP
against the frequ ency ………………………….. ………………………….. ………………………….. ………………. 76
Figure 84: A bar chart illustrating the comparative data between DD and RDW -SD . 77
Figure 85: A bar chart illustrating the correlational data regarding ESR and CRP … 78
Figure 86:A bar chart illustrating the correlational data between CRP and Fibrinogen
………………………….. ………………………….. ………………………….. ………………………….. ………………….. 79

ABBREVIATIONS
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4. ABBREVIATIONS
APC -PCI Activated Protein C -Protein C Inhibitor complex
APTT Activated Partial Prothrombin Time
ATV Anterior Tibial Vein
BMI Body Mass Index
CFV Common Femoral Vein
COPD Chronic Obstructive Pulmonary Disease
CRP C-Reactive Protein
CT Computer Tomography
CTV Spiral -Multidetector -Row -CT-Venography
DD D-Dimer
DIC Disseminated Intravascular Coagulation
DVT Deep Vein Thrombosis
ESR Erythrocyte Sedimentation Rate
FDP Fibrin Degradation Products
FEU Fibrinogen Equivalent Units
FIX Factor IX , Factor IX
FVa Factor Va
FVIII Factor VIII
FX Factor X
FX Factor X
FXa Factor Xa , Factor Xa
FXI Factor X I
FXII Factor XII
Gp IIb Glycoprotein IIb
Gp111a Glycoprotein IIIa
GP1b Glycoprotien 1b
Hb Haemoglobin
Hct Haematocrit
HMW High Molecular Weight
IJV Internal Jugular Vein
INR International Normalized Ratio
MRI Magnetic Resonance Imaging
NT-PRO B NP The N -terminal Prohormone Of Brain Natriuretic Peptide
PAI Plasminogen Activator Inhibitor
PE Pulmonary Embolism
PFV Profound Femoral Vein
PLT Platelets
PMN Polymorphonucleated Cells
PT Prothrombin Time
PTV Posterior Tibial Vein
RA Right Atri um
RAD Right Atrial Dilatation
RBC Red Blood Cells
RDW -SD Red Blood Cell Distribution Width -Standard Deviation
RV Right Ventricle

ABBREVIAT IONS
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RVH Right Ventricular Hypertophy
TAFI Thrombin Activatable Fibrinolysis Inhibitor
TAT Thrombin Antithrombin III Complex
TF Tissue Factor
t-PA Tissue Plasminogen Activator
VTE Venous Thromboembolism
WBC White Blood Cells
VWF Von Willebrand Factor

GENERAL PART
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CHAPTER 1

GENERAL PART

INTRODUCTION
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5. INTRODUCTION
Deep Vein Thrombos is (DVT ) is a condition marked by the formation of a thrombus
(blood clot) within the lumen of profound veins of the
limbs, predominantly favoring the lower limbs. It usually
begins in the calf and propagates proximall y to the
popliteal, femoral and iliac veins. It is 10 times more
common in the lower limbs compared to the upper limbs.
Individuals experiencing their fir st DVT are at a high risk
of recurrent episodes throughout their lives especially if the
cause is idiopathic. (1)

Thromboembolism is the dislodgment of the thrombus ( when the portion of clot detaches
loose) and travels in the bloodstream. The most serious complication of DVT is PE ,the blood
clot travels to the heart and then to the lungs thus causing a partial or complete obstruction of
the pulmonary artery and its branches .PE is a serious life threatening complication accounting
for 15 to
30% of
patients
diagnosed
with lower
limb DVT
(2).DVT and
PE are
grouped
together and
commonly
Figure 1: The anatomy of the
superficia l and peripheral
veins of the lower limb
Figure 2: A diagram illustrating formation of a blood clot in DVT and
embolization to the general circulation Embolus DVT Normal Blood Flow
Deep Veins Of The Limb

HISTORY (BACKGROUND) OF DVT
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referred to as VTE (venous thromboembolism).Other potential complications of DVT include
post thrombotic syndrome which appears as a late complication after a couple of years, recurrent
DVT is very common and very rarely we could even find a paradoxical emboli (3).
6. HISTORY ( BACKGROUND ) OF DVT
The history of DVT goes as far as 2600 years B.C when a Chinese p hysician named
Huan – Ti described how thrombus affects blood circulation. This transformation of liquid blood
into solid form has fascinated observers for millions of years ( 3).According to Dexter &Folch -Pi
(1974), the first well docu mented case of DVT is depicted in an illustrated manuscript written in
the 13th century and currently pres erved in Paris at the Bibliothe que Nationale (MS Fr 2829,
Folio 87) (Fig 3). The
description includes the
case of a young man
from Normandy named
Raoul, aged 20 years
who dev eloped
unilateral edema of the
right ankle which
extended up to the
thigh. The left leg was
in a good functional
state. From the description it is clear that the young man developed a septic leg with ulceration
and fistulation. At that time the great and p opular surgeon Henri Du Perche advised him to wait
and see. This conservative attitude during that time when surgery was the main approach to
illness is now of common knowledge that in the treatment of DVT there is no room for surgical
intervention.Raouls condition yet deteriorated further with exposure of bone from fistula and
ulcers and development of gangrene. Raoul was advised to visit the tomb of Saint Louis, who was
buried in the ch urch of Saint Denis, where he spent several days confessing his sins an d praying
to the saint. Moreover he chose to collect the dust accumulating below the stone that covered the
tomb and apply it to the fistulae and ulcers of his foot. The open ings stopped running and were
rejuvenated. He was first obliged to use crutches, b ut subsequently he could walk with a cane
Figure 3: The illustrated manuscript depicting the first case of
venous thrombosis. ClicheÁBiblioteÁque National de France, Paris.

HISTORY (BACKGROUND) OF DVT
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and was eventually able to dispose of all devices, even though his foot throbbed a little. Raoul
was cured as described above in the year 1271 and was still alive and well in 1282. With our
current knowledge, it is not certain that this was a bona fide case of venous thrombosis. Septic
complications are not common features of this condition but, at that time, infections were much
more prevalent than now. It is clear that, without its religious implications, this cas e would not
have been reported in the manuscripts (4)
The mordern understanding of pathophysiology of DVT is usually attributed to Rudolf
Virchow in the mid 19th century who invented the Virchows Triad in an aid to understand t he
pathophysiology of venous thrombosis, the triad includes the vessel wall,blood flow and the
constituion of the blood itself. Virchows triad remains a useful concept for clinicians and
pathologists in u nderstanding the contributors of thrombosis (5)

Figure 4: Rudolf Virchow(1821 -1902)

EPIDEMIOLOGY
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7. EPIDEMIOLOGY
7.1. INCIDENCE
Venous thromboembolism is a known major public health problem. An annual incidence
of about 1 to 2 per 100 adults was established in the U.S.A.T he precise number of individuals
affected is unknown, although as many as 300,000 to 600,000 people could be affected annually
in the U.S.A causing a high morbidity and mortality rate among the general population. It is
estimated up to 60,000 to 100,000 de aths due to venous thromboembolism. (6)
About 10 to 30% of the population dies within one month of diagnosis while sudden
death is the first symptom in about 25% of patients who have a PE.The recurrence rate in 10
years is assu med to be in one third of the patients who have been previously diagnosed with a
venous thromboembolism. Furthermore half of the patients with a previous DVT are known to
experience long term complications. About two-thirds of patients manifest with DVT wh ile one
third manifest with PE with or without DVT. (7)
7.2. GENDER
The rates are estimated to be slightly higher in males compared to females, the causes not
well understood yet. (8)
7.3. AGE GROUP
DVT is a disease of aging, with a low rate of around 1 per 10,000 annually before the age
of 40 years and rising rapidly after the age of 45 years to an incidence of 5 -6 per 10,000 till the
age of 80. The morbidity impact of DVT on elderly seems to be more thus a h igher mortality due
to DVT is seen. Children and young adults rarely suffer from DVT. (8)

Figure 5: An image depicting the estimated average annual number of hospitalization
with a diagnosis of DVT,PE or VTE by age and sex in USA between 2007 -2009.

PATHOPHYSIOLOGY OF DVT
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8. PATHOPHYSIOLOGY OF DVT
In text three different types of veins have been described frequently. Superficial veins are
made of the thick walled muscular layer and lie just beneath the skin as per their name, pr ofound
or deep veins are composed of thin walled muscles media. Both these types of veins have
additional valves which permit unidirectional flow of blood to and back to the heart. Thus the
valves readily open and close without coming into contact with the lumen of the veins, also
allowing closure when the blood flows backwards preventing regurgitation. Furthermore the
perforating veins permit one way flow of blood connecting the superficial and deep veins.
Generally the precise pathophysiology is not full y understood yet, however we owe a lot
of this understanding to Virchow who postulated certain factors being valuable in the outcome of
DVT.He concluded that the stasis of blood ( 1), the changes in blood vessels ( 2) and
hypercoagulability ( 3)were the major factors responsible for the development of DVT.This is
famously referred to, according to his understanding, as the “ Virchow’s Triad”

Figure 6: Virchows Triad

PATHOPHYSIOLOGY OF DVT
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8.1. STASIS OF BLOOD
This includes any phenomena that would interrup t the flow of blood. This happens when
there is low blood volume and flow . Some of the many examples implicated here are venous
stasis, long surgical operations, prolonged immobility e.g. on a long plane or car ride, bed ridden
during hos pitalization and varicose veins, effects of some medic al therapy, severe conditions like
shock or cardiac failure. (9)
8.2. CHANGES IN BLOOD VESSELS
This phenomenon causes the irritation of the blood vessel and its vicinity. This is caused
by any inj uries or trauma to the endothelium arising from sheer stress or high blood pressure.
Changes in the vessel wall may occur as a result of chemical trauma as in intravenous injection s
of a drug or due to mechanical trauma. The resulting endothelial cell dama ge predisposes to
thrombosis. Post -operative venous thrombosis of the lower limbs may be a consequence of such
mechanical trauma. During anesthesia , there is a loss of normal muscle tone and the weight of
the limb in combination with a hard operating table may be sufficient to cause trauma to the
venous endothelium. Thus, surgery itself appears to be a very potent stimulus for venous
thrombosis. (10)

Figure 7:Virchows Triad in a nutshell

HEMOSTASIS IN BRIEF
20 | P a g e
8.3. HYPERCOA GULABILITY
This refers to the phenomena of blood coagulation. This includes any alterations in the
composition of blood constituents. There are numerous implications listed in this phenomena,
some of them include hyper viscosity ,platelet aggregation, throm bophilia disorders
(e.g.Antithrombin 3, Protein S, C deficiency) and plasma lipid profile may contribute to
thrombosis. There is a strong co -relation between cigarette smoking and its effect on platelet
function as it may have an effect on adhesion of plat elets to the underlying vessel wall. (10)
9. HEMOSTASIS IN BRIEF
This system contributes to essential body defense mechanism. It impedes both the loss of
blood and the disturbance of the flow of blood, as well as providing repair of injured vessels and
tissues consequently. The meaning of perfect homeostasis is no bleeding and no thrombosis.
Three main stages of homeostasis have been described as follows: –

9.1. PRIMARY HEMOSTASIS ( PLATELET ADHESION AND AGGREGATION)
Interaction between the damaged vascular wall, platelets and adhesive proteins leads to
formation of a platelet plug. After vessel injury occurs, local vasoconstriction slows blood flow
permitting platelets to adhere to the vessel wall.Thrombogenic components are exposed and
clinging of platelets occurs through platelet receptors ( GP1b ) to the exposed co llagen and to
collagen bound (VWF ).Thus the platelets change morphologically causing secretion of active
substances.
Nearby thrombocytes are recruited, activated and aggregate by fibrinogen cross linking
through binding between newly expressed fibrinogen receptors ( Gp11b /Gp111a ).Vessel injury
also leads to activation of the coagulation cascade wh ich subsequently follows . (11)

Figure 8: Primary Homeostasis at site of vessel injury. All rights reserved Casper Asmussen

HEMOSTASIS IN BRIEF
21 | P a g e
9.2. SECONDARY HEMOSTASIS
Traditionally, two separate pa thways have been described, which are the extrinsic and the
intrinsic pathway. These pathways meet at the level of factor X and the steps following after
which result in the formation of thrombin, are common in both the pathways. Deficiencies in any
of the coagulation active proteins in the pathways would delay the time of coagulation assay in
vitro(PT for the extrinsic pathway and APTT for the intrinsic pathway respective ly). It is
moreover appreciated that coagulation occurs via a network of simultaneous interactions with
regulation and modulation of these interactions during the generation of thrombin itself. (12)
The physiological activation of coagulation however is mediated by TF. Circulating small
levels of FVIIa bind to TF forming a complex which activates FX and FIX .FXa then bind s to
FVa forming a thrombin activating complex. The intrinsic fa ctor way is initiated by contact
factors FXII , HMW kinogen and prekallikrein which then activates FXI, FXI activates FIX which
together with its cofactor ( FVIII ) can activate FX. Ultimately FXa acts on prothrombin to form
thrombin (13)

Figure 9: Secondary Homeostasis (Plasma Coagulation).From Casper Asmussen, all rights
reserved.

9.3. FIBRINOLYSIS AND D -DIMER FORMATION
The main purpose of coagulation process is the form ation of a stable fibrin plug or a
thrombus which is regarded as a meshwork of fibers that seals a vascular injury. Thrombin is
adequately generated and is able to cleave fibrinogen. Fibrinogen is converted into fibrin by
enzymatic cleavage by thrombin. Tissue plasminogen activator (t -PA) convert s plasminogen to
plasmin which breaks down cross -linked fibrin to several fibrin degradation products, the
smallest of which is D -dimer .Thrombin activatable fibrinolysi s inhibitor (TAFI )prevents the

HEMOSTASIS IN BRIEF
22 | P a g e
formation of plasmin .Anti-plasmin and plasminogen activator inhibitor -1(PAI -1) inhibit plasmin
and t -PA respective ly (13).

Figure 10: Fibrinolysis, From Casper Asmussen with all rights reserved

Traces of products containing DD are detected in plasma of health individuals since 2 -3%
of fib rinogen is converted to cross linked fibrin and then degraded physiologically.

Figure 11: D-
dimer formation.
Fibrinogen consisting
of two D domains
separated by a central E
domain. Thrombin
cleavage of the
fibrinopeptides result s
in the end -to-end
association of D
domains into a fibrin
clot. During fibrinolysis,
plasmin cleaves the
cross linked fibrin into
fibrin degradation
products of which the
D-Dimer is one of the
resulting products.

Bockenstedt P N Engl J of Med icine

DIAGNOSIS OF DVT
23 | P a g e
10. DIAGNOSIS OF DVT
10.1. CLINICAL DIAGNOSIS
The clinical presentation of DVT includes swelling and tenderness of the affected
limb,pain,w armth and redness or disclouration of the skin which are clasically represent ed as the
signs of inflammation. (14)Low grade fever can al so be appreciated in some cases.Patients can
also exhibit complications like superficial thrombophlebitis on presentation to the clinic,a
palpable cordlike,tender vein is the most common finding. Alternatively DVT can be associated
without any symptoms.Ind ividual symptoms are neither sensitive nor specific for postive
diagnosis. A full physical examination isnt known to be of any particular benefit in diagno sising
DVT itself.
Homan sign is usually known to be positive in DVT,this test is performed by dorsif lexion
of the affected limb elicits pain in the posterior calf. The mechanism ought to cause the pain is
due to the exertion of traction of the posterior tibial vein. Nevertheless,it should be noted that this
test is of little diagnostic value as other cond itions have also been associated with a positive
homans signs,examples include he rniated intervertebral discs,cal f muscle spasm,neurogenic leg
pain,ruptured Bakers cyst and cellulitis among many other causes. (15).Other signs inc luding
Pratts sign,Bancrofts sign and Lowenbergs sign have been found positive in patients with DVT
but they are neither specific nor sensitive for diagnosis.

Figure 12: A nurse performing the Homans sign in a suspected case of DVT .

DIAGNOSIS OF DVT
24 | P a g e
Rare presentations include phlegmasia cerulea dollens in which the patients present with
extensive swollen and cyanotic leg due to massive iliofemoral thrombosis which could lead to a
venous gangrene.

Figure 13: A case o f Phlegmasia Cerulea Dolens in a 85 year old woman with a newly
diagnosed metastatic non -small -cell lung cancer causing a massive left femoropopliteal
DVT which was confirmed by doppler ultrasonography .

Phelgmasia alba dollens manifests as white colourati on of the leg due to arterialspasm
secondary to massive iliofemoral thrombosis,which is often mistaken for arterial occlusion. (16)

Figure 14:A peculiar case of Phelgmasia Alba Dollens of the Right leg

DIAGNOSIS OF DVT
25 | P a g e
The medical history of the patient is equally essential in current diagnosis of
DVT.Certain conditions are known to be associated with DVT.These are reffered to as risk
factors and include certain immunosurpresive medications,pregnancy, active cancer,recent history
of a major surgical intervantion ,oral contraceptive use,system ic infections
smoking,thrombophilia and certain working conditions causing orthostatism among many others.
(17)

10.2. CLINICAL ASSESMENT
Based o n the physical examination and medical history,the pretest possibility is the first
step when DVT is suspected.Patients are classified into three different categories,namely
low,intermediate and high by the evaluation of the final score.The frequently used score is the
Modified Wells score.It includes the following parameters and each finding is awarded a point if
present.The low category of patients have a score of 0,the moderate have a score of 1 or 2 and
the high have a score of >3.The Wells score and it s parameters are elaborated in the table below
(18).

Table 1: Wells score,a pretest probablity for DVT.

DIAGNOSIS OF DVT
26 | P a g e

The algorithm for the evaluation of suspected DVT will be disscussed further on the
disertation after evaluating all the probable options for diagnosis in depth with the aid of the
pretest probability using the Wells score just disscused above.

10.3. LABORATORY INVESTIGATIONS(BLOOD ANALYSIS)
10.3.1. COMPLETE BLOOD COUNT
A complete blood count includes various te sts which are performed on daily basis such as
RBC ,WBC , thrombocyte count, Hb,Hct,RDW -SD and many more. Various studies have shown
the relation of RDW -SD to DVT pathogenesis. (19)
10.3.2. ADDITIONAL BLOOD TESTS
This category includes INR ,NT-PRO BN P,coagulation profile markers such are
PT,APT T and so on. Studies have elaboarted the association of N T-PRO BNP in DVT diagnosis
(20)
10.3.3. INFLAMMATORY MA RKERS
Markers such as ESR ,CRP and fibrin ogen are of known value in DVT
pathology.Previous studies have a shown a strong correlation between the process of thrombus
formatio n and inflammation. (21)
10.3.4. D-DIMER AND OTHER FIBRIN DEGRADTION PRODUCTS
As discussed in the earlier chapter,D -dimer is one of the easies t product of fibrinolysis to
detect in blood.Monoclonal antibodies against the DD epitope are g enerated by i mmunization
with purified DD which enable s measurement of DD level in plasma or whole blood.The
numeric results of DD assays are reported as either in DD co ncentration or FEU (fibrinogen
equivalent units) i.e 2FEU=1 DD.
The available immunological techniques for DD detection in laboratory include
ELISA,latex agglutination assays and whole blood agglutination assays.
DD has a high sensitivity but a very low specific ity.DD is not a definete analyte but
rather a group of cross linked FDP . (22) The concentration could be increased in other pathologic
or non pathologic conditions apart fro m DVT such as DIC , infections or inflammations, cancers,
pregnancy, old aged individuals and trauma (23).False negative DD assays can be encountered in

DIAGNOSIS OF DVT
27 | P a g e
cases of small bloo d clots in calf veins, if the clot has matured over time and if the patient has a
defective fibrinolytic process. (24)
Other FDPs such asThrombin -Antithrombin III complex(TAT ) and APC -PCI complex
could be measured in the diagnosis of DVT.They are subjects of high interest among various
researchers (25)

Table 2: Various Causes of Increased DD assay

10.3.5. THROMBOPHILIA SCREENING
Thrombophilia is defined as a hypercoagulable state in which there is an increased
tendency of blood clot formation.They are grouped as gentically acquired or inherited or
acquired during the adult life. This screening is preserved for a certain population.Subjects that
should undergo these tests include a VTE event under the age of 40, recurrent events of VTE or
even late complications like thrombophlebitis,a thrombosis at a peculiar site like the
abdomen,relatives with certain protein defiency,familial history of venous thrombosis,certain
blood tests results like prolonged APTT.These tests are relativ ely expensive and should be
performed when a high suspicion of relation to DVT. (26)
They include Factor V Leiden , Factor II G20210A , Natural inhibitor deficiency , High
factor VIII, factor IX, or factor XI , lupus anticoagulant High thrombin act ivatable fibrinolysis
inhibitor, Hyperhomocysteinaemia , Dysfibrinogenemia or hyperfibrinogenemia , Plasminogen
deficiency and many others.

DIAGNOSIS OF DVT
28 | P a g e
10.4. IMAGING TECHNIQUES
10.4.1. DOPPLER ULTRASOUND
A compression doppler ultrasound should be the initial test in patients with an
intermediate to a high pretest probability score. It has a high sensitivity up to 96% and a high
specificity up to 99% too in symptomatic patients presenting with lower limb DVT.If results
come out as negative in intermediate to high pretest probability patients, it is insufficient alone to
rule out DVT in such cases. (27)
As all the other techniques it has some limitations as well. It has a low specificity and
sensitivity in DVT associated with calf and upper limbs. It does not reliably differentiate
between old and new clots formed in the process. The technique is simple, readily available,
quick and repeatable, all this adding up t o the low cost of the procedure (28)

Figure 15: An illustrated normal Doppler ultrasound of the L eft Posterior Tibia l vein
from the radiology department of the second Medical Clinic Sf.Spridon

The most common findings include incompressibility of the veins which suggests the
presence of a thrombus. Care should be taken when compressing the veins as a part of the clot
can dislodge and travel resulting in a thromboembolic event.

DIAGNOSIS OF DVT
29 | P a g e
The thrombus can also be seen as finding on its own, it is usually hypo echogenic and
quite challenging to visualize on a B -mode, and as it is ages it becomes even more echogenic. A
filling de fect can also be seen by the Doppler ultrasound.

Figure 16: Doppler ultrasound of the CFV illustrating the presence of a thrombus in the
second Medical Clinic Sf.Spiridon.

Flux abnormality is another finding associated with the Doppler ultrasound and the last
but not the least, collateral circulation is also appreciated by this technique. (29)

Figure 17: A Doppler ultrasound illustratin g the presence of thrombus and flux
abnormality in a case of complete thrombosis of the Femoral Vein in the second medical clinic
Sf.Spridon .

DIAGNOSIS OF DVT
30 | P a g e
10.4.2. CONTRAST VENOGRAPHY
It has been long regarded as the GOLD STANDARD in diagnosis of DVT . However it is
not recomme nded in the initial evaluation, it is indicated in situations where it is impossible to
realize rapidly a Doppler ultrasound and in cases with insufficient Doppler ultrasound diagnosis.
It is required in only 10% of cases. As specific and sensitive it may be, it has its own limitations.
It requires a skilled performer and a cooperative patient, large volumes of contrast substances are
introduced. The procedure itself has some associated adverse effects; they include pain, skin
reaction and thrombophlebitis. Severe adverse effects result into skin necrosis due to an allergic
reaction, impaired renal function and post injection DVT may also develop. It is therefore
contraindicated in patients with renal injury and severe reactions to contrast agents. (30)
The four common findings described by Rabinov and Paulin include constant filling
defects, abrupt termination of the dye column, non-filling of the entire deep veno us system and
diversion of flow (31).

Figure 18: A venogram demonstrating extensive DVT of the profound veins. Various filling
defects are present throughout the venous system which are interpreted as thrombi.

DIAGNOSIS OF DVT
31 | P a g e
10.4.3. OTHER IMAGING TECHNIQUES
10.4.3.1. CT
Computerized Tomography is an uncommon investigation used in the detection of a
thrombus. It has a specificity and sensitivity of 96% and 95% respectively (25).The f inding
commonly appreciated is an intraluminal filling d efect due to the presence of a
thrombus.CTV (spiral multidetector -row CT venog raphy) is useful for differentiating DVT and
other causes of leg swelling in patients with equivocal or insufficient Dopple r findings and
furthermore for obtaining additional information in patients with known DVT before
endovascular treatment. The procedure itself is cumbersome, exposes patients to high radiation
doses, costly and time consuming. Keeping this into mind, most hospitals have prohibited usage
of this para -clinical tool in the evaluation of DVT alone. Other frequent limitations could be
renal failure due to the high dose usage of contrast substance; some patients might present an
allergy to the contrast agent. (32)

Figure 19: CT Venography illustrating bilateral DVT,arrows indicate the exact location of the
thrombus .

DIAGNOSTIC ALGORITHM IN CLINICAL PRACTICE
32 | P a g e
10.4.3.2. MRI
It has a sensitivity and specificity of 96 % and 93% respectively. It can be performed
without the injection of a contrast medium. It helps us visualize pelvic veins and defines the
upper limit of the extension of the thrombus into the VCI and iliac veins. However as other para –
clinical tools, it has its own challenges as well. These include limited availability to all hospital
centers and required technical expertise (25)

Figure 20: MRI in a patient with a recurrent popliteal DVT,arrow indicate s the
presence of Thrombus.
11. DIAG NOST IC ALGORITHM IN CLINICAL PRACTICE
Patients with signs and symptoms of a suspected DVT should be further assesed b y a
clinical pretest score(Wells Score) which was described in the earlier part of my thesis. Patients
are g rouped into low probablity if their Wells score is less than or equal to 2 and high
probablility if its more than or equal to 3.

11.1. LOW PRETEST PROBABLITY
Patients in this group have low possibilty of a DVT,in this case a D -Dimer assay should
be performed.A normal value of D -dimer assay effecitevely rules out DVT without the need of
any other imaging techniques.If D -dimer values are raised then a compression doppler
ultrasound is mandatory to perform (33).

DIAGNOSTIC ALGORITHM IN CLINICAL PRACTICE
33 | P a g e
11.2. HIGH PRETEST PROBABILI TY
Patients in this criteria have an added probability of DVT presence.A compression doppler
ultrasound is followed up in this case.DVT is confirmed in case of presence of documented
ultrasound findings.However an unsatisfactory ultraound test doesn’t rul e out DVT and further
D-Dimer assay should be performed. If the D-dimer is elevated , imaging should be repeated
within 1 week (or earlier if symptoms are worsening) as an isolated distal DVT could be missed
initially on ultrasound might exten d into the pr oximal veins and could possibly be detected on
the second time .
In patients wit h unexplained swelling of the who le leg without satisfactory ultrasound
findings ,the possibility of pelvic vein thrombosis should be considered, in this case CT, MRI or
venogra phy may be indicated. (34)

Figure 21: Diagnostic algorithm using D -dimer testing and ultrasound imaging in
patients with suspected DVT.

PERSONAL PART
34 | P a g e

CHAPTER 2
PERSONAL PART

AIMS AND OBJECTIVES OF THE STUDY
35 | P a g e
12. AIMS AND OBJECTIVES OF THE STUDY
We intend to study exisisting cases of DVT associated patients in our clinic.The primary
objectives of the study include the following :-
 To assess the demographic characteristics of the patients w ith DVT hospit alized in the
Internal Medicine Clini c.
 To observe the frequency of variable location s of DVT .
 To detect the risk factors for DVT in our hospital -based practice
 To determine the reliability of the Wells score as a clinical tool to assess the risk of DVT .
 To evaluate the diagnostic accuracy of the D -dimer assay for DVT diagnosis .
 To study the correlation of the inflammatory markers in the pathogenesis of DVT
13. MATERIALS AND METHODS
This review was based on a retrospective observational study that included 62 patients
diagnos ed with DVT from January 2015 to June 2016. This information was obtained from the
hospital archives. The cases were selected on basi s of the patient’s diagnosis on discharge via
thorough analysis of the patient’s medical files available at the Internal Me dicine Clinic. The
data was abstracted from the medical records. Data included patients demographics ( age, gender,
occupation and residence) , social history ( smoking, drugs history) , past medical history ( active
cancer or undergoing any chemotherapy, any recent surgical history, previous DVT) , Doppler
ultrasound findings, Echocardiographic findings and results from hematological samples. When
any information was not available, it was classified as not available or missing.
The data were analyzed using SPSS for windows 19.0.For nominal variables, the Chi-
Square test and Phi and Cramer’s V test were used for comparing variables for significant
differences and the contingency coefficient was used as a measure of association. For numeric
variables, means were co mpared using one -way ANOVA, followed by Bonferroni post hoc test.
Differences were considered statistically significant for p values under 0.05.

RESULTS AND DISCUSSION
36 | P a g e
14. RESULTS AND DISCUSSION
All the statistical data collected was represented using graphical methods including
tables, pies and char ts.The significant statistical data were further evaluated in the discussion
part.
14.1. EPIDEMIOLOGICAL AND DESCRIPTIVE PARAMETERS
14.1.1. Gender
Male gender is known to be more prone to DVT .Certain clinical criteria for DVT pre -test
probability al so include male gender as one of the variables that has an increased risk of
developing DVT.The obvious reasons for this issue of the gender effect on the history of VTE is
not well known and still needs various explanations from studies . Women are prone t o DVT
during their child bearing age, however after the age of 50 men are more commonly affected.
(35) Contrary to this, in our study of 62 patients, male gender constituted of 29 patients while
female gender constituted of 33 patients. This represented 46.8% and 53.2% respectively for
male and female gender as per the pie chart illustrated below.

Figure 22: Pie chart representing the difference in
distrib ution of Gender

RESULTS AND DISCUSSION
37 | P a g e

14.1.2. Age
Advanced age is a known risk factor in the prognosis of DVT. Administrative databases
such as Medicare includes large number of patients but limited information and validation, thus
much remains to be learned about the epidemiology of VTE in the elderly. In our study the
patients were categorized into various age groups. This included 18 to 35 years represented by 2
patie nts corresponding to 3.2% , 35 to 50 years represented by 9 patients and 14.5%,50 to 75
years included 18 patients and 29% and finally >65 years represented by the highest 33 patients
and a 53.2%. This data is represented in the pie chart below. Various expla nations have been
given as per why elderly are more prone to DVT by previous studies. A study in Netherlands
suggested that various co morbidities which are associated with old age increase the risk of
thrombosis.CHF was found to increase the VTE risk by 2 .5 to 3.5 fold while COPD was found to
increase the risk 1.2 to 1.3 times. The same study suggested that age related risk factors like
muscle strength also contributed to the occurrence of DVT.The exa ct mechanism s were not very
clear but diminished function or efficacy of the calf muscle pump could lead to reflux and stasis
of blood. This would subseq uently lead to thrombosis (36). The pie chart below represents the
statist ical data.
Figure 23: A pie chart representing the various age groups associated with DVT in
our study

RESULTS AND DISCUSSION
38 | P a g e

14.1.3. Profession
In our study p atients were grouped into the following categories, working class had a
total of 19 patients and a 30.6% , retired included 41 patients and the highest percentage of 66.1%
and only 2 patients were unemployed r epresentin g a mere 3.2%. The explanation to this could be
the fact elderly who are retired are mostly at home and therefore having a sedentary lifestyle.
This short term immobility could cause stasis of blood and thus resulting in the thrombosis.
Certain studies hav e even shown that certain occupations that require prolonged sitting in
cramped pos itions and kneeling are also at a high risk of developing DVT. (37) (38).The data
discussed above is presented stat istically below.

14.1.4. Orthostatism
Orthostatism is a known risk factor in the pathogenesis of DVT. Standing or seated
immobility causes short term immobility which increases the risk of thrombus formation by
slowing down the blood circulation, increasing its likelihood to pool. This stasis of blood also
leads to hypercoagulability and inflammation. (39) This descriptive parameter was based on
whether the patient had long hours of immobility due to certain working requirements or no t. Figure 24: A pie chart illustrating the distribution of
patients according to profession

RESULTS AND DISCUSSION
39 | P a g e
Patients were grouped into a simple yes or no criterion , these included 19 patients
corresponding to 30.6% and 43 patients corresponding to 69.4% respectively. The statistical
representation is illustrated below.
Figure 25: A pie chart illustrating t he distribution of patients with orthostatism

14.1.5. Settlement
Patients were grouped into either Rural or Urban. The urban group included 29 patients
represented by a 46.8% while the rural included 33 patients and a 53.2%.This is summe d up in
the table and pie chart below. Patients from the rural area were more prone to DVT contributing
to the fact that they had comparative limited access to medical facilities.

Fig: A pie chart representing the settl ement
of patients in our Study
Figure 26: A pie chart illustrating
the distribution of patients according to
their settlement .

RESULTS AND DISCUSSION
40 | P a g e

14.1.6. Drug History
Certain drugs are associated with a high causal risk for DVT. Oral contraceptive pills
contain hormones like progesterone and estrogen which increase the risk of thrombus formation
by 2 to 8 fold. These oral contraceptive pills contain desog estrel which is known to have a higher
activated protein C resistance and higher levels of sex hormone binding globulin than those
containing gestodene which indicate a higher thrombosis risk. (40).Immunosuppressive drugs
also contain hormones which causes increased risk for thrombosis. This parameter had three
groups of variables, firstly with a positive drug history which was reported in 11 patients which
is represented by 17.7%,secondly a negative drug history which includes 50 cases and a 80.6%
and thirdly one pat ient had such details missing, represented by a mere 1.6%.This is represented
statistically belo w.

14.1.7. Pregnancy
Normal pregnancy induces pro-coagulant changes causing an increased risk of a
thrombotic event. Stu dies show that the risk for VTE increases 5 to 10 fold compared to non –
pregnant women. The postpartum period posses an even higher risk which is reported to be 15 to
35 times more than the non -pregnant woman at the same age (41). Figure 27: A pie chart representing the distribution of
patients according to their medical drug
history

RESULTS AND DISCUSSION
41 | P a g e

Female patients with current pregnancy included three ( 3) patients representing 4.8%
while the non-pregnant patients represented 59 (95.2%) .This is represented below. Our results
didn’t have any statistical significance.

14.1.8. Smoking

Smoking is a wel l known independent risk factor for pathogenesis of DVT.It increases
the risk of DVT b y multiple mechanisms,it increase s the levels of fibrinogen and certain clotting
factors.This in turn increases platelet activation and aggregation.Smoking is also implic ated in
alteration of fibrinolysis mechanism,ensuring the increasing tendency of clot formation.The risk
of DVT is increased several folds when smoking and increased levels of BMI are correlated (42)
A meta analysis in China supported that the association of VTE and smoking is mediated
by an acute mechanism supported by a dose reponse relationship for the amount of current
smoking and the higher risk in current compared to past smokers (43).Smoking is known to be
associated with a h igher fibrinogen level. It has been shown that the fibrinogen concentration
decreased rapidly after cessation of smoking and the fibrinogen concentr ation was nearly equal
in past smokers and non-smokers . (44)
Figur e 28: A pie chart illustrating the distribution of
patients according to pregnancy

RESULTS AND DISCUSSION
42 | P a g e

According to our studies , some patients were found to be current smokers while some
had previously been smokers.Our results didn’t have any conclusive statistical significance. In
this criteria, patients with a positive smoking response included 17 , with a 27.4%.Patients who
denied included 43 , with a 63.4%.Data was found missing in 2 patients, that represent s
3.2%.This is represented in the pie chart below.

14.1.9. BMI
The total number of patients who had available BMI values included 37. T he least value
noted was 18.42 and the highest was 42.The mean value of BMI was 29.73.The frequency and
the precise values of BMI a re appreciated in the histogram below .

Figure 29: A pie chart illustrating the distribution of
Patients according to smoking
Figure 30:A histogram illustrating the distribution of BMI against the frequency of
patients

RESULTS AND DISCUSSION
43 | P a g e

14.1.10. Days Of Hospitalization
A total number of 6 2 patients were included in this criterion. The least days of
hospitalization included 2 and the highest was 18.
The mean number was approximately 7 days. The histogram below illustrates the precise
frequency and the number of days hospitalized for all t he patients .

Figure 31:A histogram illustrating the distribution of the number of hospitalized days
against the frequency

14.1.11. Echocardiographic Findings
For Right Atrial dilatation ( RAD ) a total of 35 patients had available ultrasound
results.13 patients had normal dimensions, representing 37.1% while 22 patients had an
increased size of RA that evaluated for a 62.9%.35 patients had invalid ultras ound findin gs
which were disregarded in the representation below.

.
Figure 32: A pie chart illustrating the
distribution of patients with RA dilatation .

RESULTS AND DISCUSSION
44 | P a g e

For Right Ventricular hypertrophy (RVH ) a total of 34 patients had available results. This
included 23 patients with a normal RV size, contributing to a valid 67.7% while 11 patients had
increased RV dimensions, a valid 32.35 %.However 28 patients had unavailable ultrasound
results. They were however disrega rded in the pie chart below.

For tricuspid regurgitat ion, valid 69.7% had no(0) regurgitation reported.27.27% had
grade 1 regurgitation present while only a mere 3.03% had grade 2 regurgitation reported. This is
represented graphically below.

Figure 33:A pie chart illustrating the distribution of patients with RVH .
Figure 34: A histogram illustrating the grade of Tricupsid Regurgitation against the
percent

RESULTS AND DISCUSSION
45 | P a g e

14.1.12. Doppler Ultrasound Findings
A criterion was establis hed to find out whether one location, two locations or multiple
locations were involved in DVT.55 patients in general had the data readily available.19 patients
were reported having one location involved, presenting 34.5% , 18 patients had two locations
involved with a 32.7 % and lastly 18 patients had multiple locations involved resulting in the
remainder 32.7% . This is represented efficiently in the pie chart below.

A criterion was est ablished to appreciate the precise limb involved. A total of 55 patients
had appreciable findings. They were further categorized as follows , 27 patients had left leg
involvement, a 49.1%,24 patients had rig ht leg involved equaling a 43.6% while only 2 patients
had both legs involved equally representing a mere 3.64 %, 2 patients had the left arm involved
represented by 3.64 % .The remaining number of 7 patients were invalid and thus weren’t
represented in the pie chart below .

Figure 35: A pie chart illustrating the distribut ion of the locations involved
Figure 36: A pie chart illustrating the precise
limb involved in our study

RESULTS AND DI SCUSSION
46 | P a g e

Individual deep veins of the upper and lower limb were then studied and the results
represe nted in tables and pie charts.
Firstly, data concerning the intern al jugular vein involvement was reviewed .55 patients
had valuable ultrasound findings. Out of these only one patient had IJV as the location for
thrombosis; this represented a mere valid 1.8% while the other 54 patients had no IJV
involvement, accounting for a valid 98.2%.The inval id cases were 7 resulting in the
remaining total 11.3 %, which were eventually excluded from the pie chart presentation
below.
Data regarding the involvement of the brachial vein was collected. A total of 55 patients
had the ultrasound performed. Out of these only two patients had brachial vein involvement as
the location for thrombosis, this represented a mere 3.6% valid while the other 53 patients had no
brachial vein involvement, accounting for a valid 96.4% The invalid cases were 7 resulting in the
remaining total 11.3 %,which were eventually excluded from t he pie chart presentation below. Figure 38: A pie cha rt illustrating the
percentage in IJV involvement
Figure 37: A pie chart illustrating the
percentage in Brachial vein involvement

RESULTS AND DISCUSSION
47 | P a g e

The involvement of Subclavian vein was then studied. A total of 55 patients had the
ultrasound performed. Out of these only one patient had involvement present, accounting
for a mere 1.8% valid while the other 55 patients had no brachial vein involvement,
accounting for a valid 98.2% The invalid cases were 7 resulting in the remaining total
11.3%,which were eventually excluded from the pie chart presentation below.

The last profound vein of the upper limb, the axillary vein was then evaluated. A total
of 55 patients had the ultrasound performed. Out of these only two patients had axillary vein
involvement as the location for thrombosis, this represented a mere 3.6% valid while the
other 53 patients had no involvement, accounting for a valid 96.4% The invalid cases were 7
resulting in the remaining total 11.3%,which were eventually excluded from the pie chart
presentation below.

Figure 39: A pie chart illustrating the percentage in Subclavian vein involvement
Figure 40: A pie chart illustrating the
percentage in Axillary vein involvement

RESULTS AND DISCUSSION
48 | P a g e

Regarding the deep veins of the lower limbs, starting with the common femoral vein 55
patients had the ultrasound performed. Out of these 19 patients had this vein involvement as the
location for thrombosis, which represented a valid 34.5% while the other 36 patients had no CFV
involv ement, accounting for a valid 65 .5%.The invalid cases were 7 resulting in the remaining
total 11.3 %, which were eventually excluded from t he pie chart presentation below.

Secondly the femoral vein or also referred to as the superficial femoral vein was then
statistically reviewed. A total of 55 patients had ultrasound performed. Out of these , 17 patients
had this vein involvement as the location for thrombosis, which represented a valid 30.9% while
the other 38 patients had no involvement, accounting for a valid 69.1%.The invalid cases were 7
resulting in the remaining total 11.3 %, which were eventually exc luded from the pie chart
presentation below.

Figure 41: A pie chart illustrating the percentage in CFV involvement
Figure 42: A pie chart illustrating the
percentage of Femoral vein involv ement

RESULTS AND DISCUSSION
49 | P a g e

Thirdly the profound femoral vein was reviewed statistically. A total of 55 patients had
the ultrasound performed. Out of these 8 patients had this vein involvement as the location for
thrombosis, which re presented a valid 14.5% while the other 47 patients had no involvement,
accounting for a valid 85.5%.The invalid cases were 7 resulting in the remaining total 11.3 %,
which were eventually excluded from the pie chart presentation below.

Four thly, the popliteal vein was reviewed statistically. A total of 55 patients underwent
an ultrasound. Out of these 31 patients had the vein involved as the location for thrombosis,
which represented a valid 50.0 % while the othe r 14 patients had no involvem ent, accounting for
a valid 38.7 %.The invalid cases were 7 resulting in the remaining total 11.3 %, which were
included in the pie chart presentation below.

Figure 43: A pie chart illustrating the percentage of
PFV involvement
Figure 44: A pie chart illustrating the
percentage of popliteal vein involvement

RESULTS AND DISCUSSION
50 | P a g e

For the peroneal vein , a total of 55 patients had the ultrasound performed. Out of these
only one patient had involvement present, accounting for a mere 1.8% valid while the other 55
patients had no peroneal vein involvement, accounting for a valid 98.2 %. The invalid cases were
7 resulting in the remaining total 11.3 %, which were eventually exclu ded from the pie chart
presentation below.

For the anterior tibial vein, a total of 55 patients had the ultrasound performed. Out of
these only two patients had anterior tibial vein involvement as the location for thrombosis;
this represented a m ere valid 3.6% while the other 5 3 patients had no involvement,
accounting for a valid 96.4% . The invalid cases were 7 resulting in the remaining total
11.3%, which were eventually excluded from the pie c hart presentation below.

Figure 45: A pie chart illustrating the percentage of Peroneal Vein involvement

Figure 46: A pie chart illustrating the
involvement of the ATV in
percentage

RESULTS AND DISCUSSION
51 | P a g e

Finally, the posterio r tibial vein was statistically reviewed. A total of 56 patients had the
ultrasound performed. Out of these 11 patients had posterior tibial vein involvement as the
location for thrombosis, this represented a valid 19.6% while the othe r 45 patients had no
involvement , accounting for a valid 80.4%. The invalid cases were 6 resulting in the remaining
9.7% which were eventually excluded from the pie ch art presentation below.

The documented ultrasound findings were then statistically presented individua lly.
Firstly the presence of thrombus was reviewed. A total of 57 patients had the ultrasound
performed. Out of these 52 patients had the presence of thrombus reported, this represented a
valid 91.2% while the other 5 patients h ad the thrombus absent , accounting for a valid 8.8%.
The invalid cases were 5 resulting in the remaining total 8.1 % which were eventually
excluded from the pie chart prese ntation below.

Figure 47: A pie chart illustrating the percentage of involvement of PTV
Figure 48: A pie chart illustrating the
percentage of Thrombus presence
in our study

RESULTS AND DISCUSSION
52 | P a g e

Secondly the presence of collateral circulation was statistically reviewed. A total of 5 7
patients had the ultrasound performed. Out of these 30 patients had the presence of collateral
circulation reported, this represented a valid 52.6% while the other 11 patients were reported
with absent, accounting for a valid 19.3%.16 patients had this p arameter missing in their
ultrasound findings, accounting for a valid 28.1% . The invalid cases were 5 resulting in the
remaining total 8.1% which were eventually excluded from the pie chart presentation belo w.

Lastly, the presence of flux abnormal ity was observed. A total of 56 patients had the
ultrasound performed. Out of these 54 patients had the presence of the abnormality reported, this
represented a valid 96.4%% while the other 2 patients were reported with absent flux
abnormality, accounting for a valid 3.6%.The invalid cases were 6 resulting in the remaining
total 9.7% which were eventually excluded from the pie c hart presentation below, however
included in the table below.

Figure 50: A pie chart illustrating the
percentage of flux
abnormality in our study Figure 49: A pie chart illustrating the percentage of Collateral Circulation
in our study

RESULTS AND DISCUSSION
53 | P a g e

14.1.13. Blood analysis
DD is a known end product of fibrin degradatio n which could be detected in
blood using various readily available immunological tests. Various studies have
emphasized that it can be either a reliable or an unreliable tool in DVT diagnosis (45)
(46). In our study 60 patients had the assay performed, out of these 56 patients had an
increased value of DD, this represented a valid 93.3% while the other 4 patients were
reported with a normal value of DD, accounting for a valid 6.7%.The invalid cases w ere
2 resulting in the remaining total 3.2% which were eventually excluded from the p ie chart
presentation below.

FDP is a well known biomarker for diagnosis of DVT.Studies have shown that these
clot degradation products have a role in ruling out th romboembolic events (47).In a study
patients with DVT had significantly elevated levels of FDP compared to control subjects.
The technique of evaluating FDP was however into question, thus needing more studies to
improve the tech niques of FDP detection. (48) Contrary to this, in our study we failed to find
any significant results corresponding to previous studies.

Figure 51: A pie chart analyzing the DD levels

RESULTS AND DISCUSSION
54 | P a g e

Our study assessed 46 patients in general, o ut of these 15 patients had FDP present,
this represented a valid 32.6% while the other 31 patients reported with an absent FDP,
accounting for a valid 67.4%.The in valid cases were 16 resulting in the remaining total
25.8% which were eventually excluded from the pie chart presentation below.
.

Various studies have showed that leukocytes, especially PMN have a role in the
formation of the early thrombus. The exact mechanisms are understood to be complex
(49). In our st atistical study ; out of 59 patients only 15 had an increased value of WBC
count representing a valid 25.4%.44 patients had a normal count of WBC resulting in a
valid 74.6%.The invalid cases reported were 3, constituting for the remainder of the total
4.6%.They were excluded in the pie chart below. In the contrary , our study didn’t show
any significance related to previous studies.

Figure 52: A pie chart illustrating the anal ysis
of FDP levels

Figure 53: A pie chart illustrating
the analysis of WBC
levels

RESULTS AND DISCUSSION
55 | P a g e

For Hb levels, out of the total 59 patients 17 had an increased value of Hb count
representing a valid 2 8.8%.7 patien ts had a normal count of Hb resulting in a valid 11.9%, while
35 patients had a decreased count accounting for valid 59.3% .The invalid cases reported were 3,
constituting for the remainder of the total 4.8%.The y were excluded in the pie chart below.

Figure 54: A pie chart illustrating the Hb levels
Regarding RDW -SD, out of the total 62 patients , 22 had an increased value representing
a valid 38.6%.34 patients had normal val ues resulting in a valid 59.6%, while 1 patient had a
decreased count accounting for a valid 1.8% . The invalid cases reported were 5, constituting for
the remainder of the total 8.1%.They were included in the table below.
Frequency Percent Valid Percent Cumulative Percent
Valid Normal 34 54.8 59.6 59.6
Increased 22 35.5 38.6 98.2
Decreased 1 1.6 1.8 100.0
Total 57 91.9 100.0
Missing System 5 8.1
Total 62 100.0

Table 3: A table representing the statistical data regarding RDW -SD

RESULTS AND DISCUSSION
56 | P a g e

The pie chart below illustrates the s tatistical data presented in the table above. The invalid
cases are disregarded

Figure 55: A pie chart illustrating RDW -SD analysis
For INR, the following data was analyzed. Out of the total 62 patients 15 h ad an
increased value representing a valid 25.9%.43 patients had normal values resulting in a valid
74.1%.The invalid cases reported were 4, constituting for the remainder of the total 6.5%. They
were excluded in the pie chart below.

Figure 56: A pie chart illustrating INR analysis

RESULT S AND DISCUSSION
57 | P a g e
Out of the tota l 62 patients for NT -Pro BNP reviewed, 17 had an increased value
representing a valid 60.7%.11 patients had normal values resulting in a valid 39.3%.The invalid
cases reported were 34, constituting for the remainder of the total 54.8%.They were included in
the table.
Frequency Percent Valid Percent Cumulative Percent
Valid Normal 11 17.7 39.3 39.3
Increas ed 17 27.4 60.7 100.0
Total 28 45.2 100.0
Missing System 34 54.8
Total 62 100.0

Table 4: A table representing stat istical data regarding NT -PRO BNP
The pie chart below illustrates the statistical data represented in the table above. The
invalid patients have been disregarded.

Figure 57: A pie chart illustrating the analysis o f NT -PRO BNP in blood

RESULTS AND DISCUSSION
58 | P a g e
Out of the total 62 patients for PLT (Platelets ) reviewed , only one patient had an
increased value representing a valid 1.7%.49 patients had normal values resulting in a valid
83.1%.9 patients had a decr eased value of PLT , represented by a valid 15.3%.The invalid cases
reported were 3, constituting for the remainder of the total 4.8%.The y were excluded in the pie
chart below .

Out of the total 62 patients for CRP reviewed, 31 patients had an increa sed value
representing a valid 68.9%.14 patients had normal values resulting in a valid 31.1%.The invalid
cases reported were 17, constituting for the remainder of the total 27.4 %.The y were included in
the table below.
Frequency Percent Valid Percent Cumulative Percent
Valid Normal 14 22.6 31.1 31.1
Increased 31 50.0 68.9 100.0
Total 45 72.6 100.0
Missing System 17 27.4
Total 62 100.0

Table 5: A Table representing the statistical data for CRP

Figure 58: A pie chart illustrating the analysis for PLT

RESULTS AND DISCUSSION
59 | P a g e

The pie chart below illustrates the statistical data represented in the table above. The
invalid cases are disregarded.

ESR is known to have a role in pathogenesis of DVT.Various studies have supported this
notion (50). Out of the total 62 pa tients for ESR/1 HR reviewed, 18 patients had an increased
value representing a valid 60%.12 patients had normal values resulting in a valid 40 %.Th e
invalid cases reported were 32 , constituting for the remainder of the total 51.6 %.The y were
included in the table below.
Frequency Percent Valid Percent Cumulative Percent
Valid Normal 12 19.4 40.0 40.0
Increased 18 29.0 60.0 100.0
Total 30 48.4 100.0
Missing System 32 51.6
Total 62 100.0

Table 6: A table representing the statistical data regarding ESR

Figure 59: A pie chart illustrating CRP analysis

RESULTS AND DISCUSSION
60 | P a g e
The pie chart below illustrates the statistical data reperesented in the table above.The
invalid cases were disregarded.

Figure 60: A pie chart illustrating the ESR analysis
According to various studies fibrinogen is involved in the pathogenesis of DVT.There are
various mechanisms in whic h its contribution is understood (51).Out of the total 62 pa tients for
fibrinogen reviewed, 15 patients had an increased value representing a valid 55.6%.12 patients
had normal values resulting in a valid 44.4 %.Th e invalid cases reported were 35 , constituting for
the remainder of the total 56.5 %.They were included in th e tabl e. Our study found similar
results to the previously described.
Frequency Percent Valid Percent Cumulative Percent
Valid Normal 12 19.4 44.4 44.4
Increased 15 24.2 55.6 100.0
Total 27 43.5 100.0
Missing System 35 56.5
Total 62 100.0

Table 7: A table representing the statistical data for Fibrinogen

RESULTS AND DISCUSSION
61 | P a g e

The pie chart below illustrates the statistical data represented in the table above.The
invalid cases have been disregarded.

Figure 61: A pie chart illustrating the analysis for Fibrinogen
14.1.14. Wells score
Wells score is described in various literatures as a good clinical tool to assess the risk for
DVT. In the study , a total of 61 patients had the data available.9 patients had a Score of 3
representing a 14.75% , 25 patients had a Score of 4 representing a 40.98% , 19 patients had a
Score of 5 representing a 31.15% and finally 8 pat ients had a Score of 6 equaling to 13.11%.This
is represented graphically below.

Figure 62: A graph representing the Wells score against the percentage in our study

RESULTS AND DISCUSSION
62 | P a g e

14.2. CORRELATIVE PARAMETERS

For mean days hospitalization and gender,out of the total of 62 patients male gender
was found to have a higher number of days of hospitalization compared to female
gender.This was represented graphically below. The precise values of mean day s of
hospitalization for each gender is appreciated from the graph below.

Figure 63: A graph representing the gender aga inst the mean days of hospitaliz ation

For mean days hospitalization and age groups,out of the total 62 patients it was observed
that the oldest age group >65 years had the highest days of hospitalization ,equalling to
approximately 8 days .This is further represented graphically below. The exact values of the mean
days of hospitalization for the other age groups are represented in the same graph below.

Figure 64 A graph representing the age groups against the mean days of
hospitalization

RESULTS AND DISCUSSION
63 | P a g e

The mean days of hospitalization and the clinical wells score was then reviewed.Out of
the 62 patients.Wells Score of 3 and 5 had the highest mean days of hospitalization,while Score 6
had the lowe st mean days of hospitalization.The precise values of the mean days of
hospitalization is graphically presented below.

Figure 65: A graph representing the Wells scores against the mean days of hospitalization

For mean days o f hospitalization and the number of locations involved,out of the
availabale 62 patients it was noted that patients who had multiple locations involved had the
highest mean number of days of hospitalization.Patients with just one location involved had the
lowest mean days of hospitalization.This is also illustrated graphically below .

Figure 66: A histogram illustrating the mean days of hospitalization against the number of
locations involved in our study

RESULTS AND DISCUSSION
64 | P a g e
For orthostatism and mean number of days hospitalized,out of the 62 patients studied
patients with no ortostatism reported had a higher number of mean days hospit alized compared
to those who had orthostatism reported.This is represented graphically below

For correlational studies of gender and the number of locations involved,out of
the 29 M ale patients reviewed ,the highest valid 35.7% included the pati ents who had
multiple locations involved.The values of a single location and two locations are included
the table below.

Gender Frequency Percent Valid
Percent Cumulative
Percent
Male Valid One location 9 31.0 32.1 32.1
Two locations 9 31.0 32.1 64.3
Multipl e locations 10 34.5 35.7 100.0
Total 28 96.6 100.0
Missing Syste m 1 3.4
Total 29 100.0

Table 8: A statistical table representing the Male gender and the frequency of variable
locations

Figure 67 A graph illustrating the mean days of hospitalization against the orthostatism

RESULTS AND DISCUSSION
65 | P a g e
The pie chart b elow represents the statistical data represented in the tab le
above.The invalid case was also included.

Figure 68: A pie chart illustrating the percentage of variable locations involved for
Male gender

For correlational studie s of the Female patients out of the total 33 patients,the
highest valid 37% involved one location ,the precise values for other number of locations
involved were mentioned in the table below .

Gender Frequency Percent Valid
Percent Cumulative
Percent
Female Valid One location 10 30.3 37.0 37.0
Two locations 9 27.3 33.3 70.4
Multiple locations 8 24.2 29.6 100.0
Total 27 81.8 100.0
Missing Syste m 6 18.2
Total 33 100.0

Table 9: A table representing the statistic al data for Female gender and the frequency
of variable locations involved

RESULTS AND DISCUSSION
66 | P a g e
The pie chart below illustrates the statistical data represented in the t able
above.The invalid cases are also included.

Figure 69: A pie chart illustr ating the percentage of variable locations involved for
Female gender

The precise location for the occurance of DVT was then studied for both gender s.For
Male out of a total of 29 patients the highest frequency with 15 patients and a valid 53.6% was
the L eft Leg.The e xact frequencies and valid percentage for other limbs involved are summarised
in the table below.

Gender Frequency Percent Valid
Percent Cumulative
Percent
Male Valid Left leg 15 51.7 53.6 53.6
Right leg 10 34.5 35.7 89.3
Both legs 2 6.9 7.1 96.4
Left arm 1 3.4 3.6 100.0
Total 28 96.6 100.0
Missing System 1 3.4
Total 29 100.0

Table 10: A table representing the statistical data regarding the limb involvement in
Male gender

RESULTS AND DISCUSSION
67 | P a g e
The pie chart bel ow illustrates the statistical data represented in the table
above.The invalid case was included.

Figure 70: A pie chart illustrating the percentage of precise limb involved in Male

For female s, out of a total 33 patients,Ri ght Leg was the most location
accounting for 14 patients with a valid 51.9%. The e xact frequencies and valid percentage
for other limbs involved are summarised in the table below . Invalid cases are also
presented in the table below .

Gender Frequency Perce nt Valid
Percent Cumulative
Percent
Female Valid Left leg 12 36.4 44.4 44.4
Right leg 14 42.4 51.9 96.3
Left arm 1 3.0 3.7 100.0
Total 27 81.8 100.0
Missing System 6 18.2
Total 33 100.0

Table 11: A table repre senting the statistical data regarding the limb involvement in
Female gender

RESULTS AND DISCUSSION
68 | P a g e

The pie chart below illustrates the statistical data represented in the table
above.The invalid patients were included.

Figure 71: A pie c hart illustrating the percentage of precise limb involved in Female

The association between age groups and the frequency of location was reviewed .
For age group 18 -35,out of the two patients both had multiple locations involved
resulting in a 100% valid ity.

Figure 72: A pie chart illustrating the age group 18 -35 and the frequency of
location involved

RESULTS AND DISCUSSION
69 | P a g e

For age group 35 -50,with a frequency of 5 patients and a valid 55.6% two locations were
most involved. A single location constituted 33.3% and multiple locations presented 11.1%.This
data was presented in the pie chart below.

Figure 73: A pie chart illustrating the age group 35 -50 and the frequency of locations involved
For age group 50 -65,one location and two locations involv ed had an equal
35.3% .Multiple locations presented with 27.8% while invalid cases const ituted of the remaining
5.6%. This data is illustrated in the pie chart below

Figure 74:A pie chart
illustrating the age group
50-65 and the frequency of
locations involved

RESULTS AND DISCUSSION
70 | P a g e

For the age group >65 one location and multiple loc ations constituted of 30.3%
equally,two locations involved presented a 21.2% .The invalid cases were represented by
18.18% .This is illustrated below.

An association between orthostatism and gender was then established.Out of the total 62
patients for both genders,male patients had a 14.52% positive affirmation to orthostatism while
the rest 32.26 %denie d to being orthostatic.For female patients 16.13% had a positive response
to orthostatism while 37.1% denied such affirmations. This data is represented in the graph
below.

Figure 76: A graph r epresenting the correlation of Orthostatism and Gender with the
percentage
Figure 75: A pie chart illustrating the age group >65 and the frequency of locations
involved

RESULTS AND DISCUSSION
71 | P a g e
For the correlational studies of orthostatism and age groups the follo wing results were
obtained.For age group 18 -35 they all presented with a postive response to
orthostatism,accounting for the total 3.23% of them.Age group 35 -50 also had an increased
postive response to orthostatism of 11.29% to the negative response which accounted for a
valid 3.23%.For age groups 50 -65 the positive response was higher compared to the negative
response,16.13% and 12.9% respectively.Age group >65 had only a negative response to
orthostatism accounting for 53.23%.Generally all the working gr oups had a higher
comparative percent of postive response of orthostatism.This explains why the elder
population had a negative response as they are mostly retired.These results were illustrated in
the graph below.

Figure 77: A graph illustrating the correlation between age groups and
orthostatism against the percentage .

RESULTS AND DISCUSSION
72 | P a g e
For comparative st udies of W ells score and gender inv olvement,the following
data was collected.Male patients had a higher frequency than female patients for Score 4
and 6 while female patients had comparative higher frequencies for Score 3 and 5.The
precise values of each o ne of them are il lustrated in the bar chart below.

Figure 78: A graph illustrating the correlational stu dies between the gender and the
wells score against the frequency

For comparative studies of age groups and wells score the following data was
obtained.For Score 3 the age group with the highest frequency of cases was >65 years
subgroup,for Score 4 also the subgroup >65 had the highest number of cases reported.For Score
5 the subgroup with the highest frequency of cases was >6 5.Subgroup 50 -65 had the highest
cases reported for Score 6.

RESULTS AND DISCUSSION
73 | P a g e

The exact frequency for each score and group is represented statstically below .

Figure 79: A graph illustrating the correlational studies between age groups and we lls
score against the frequency

For correlational studies of BMI and Wells score the following information was
obtained.For each Score independently,the frequency of cases with an increased BMI were
reported more frequently than cases with a normal or de creased BMI.The precise frequency for
the BMI levels and Wells score are illustated below.

Figure 80: A bar cha rt illustrating the correlational studies between wells score and
BMI against the frequency

RESULTS AND DISCUSSION
74 | P a g e
For comparative studies of Wells score and presence of the t hrombus the following
results were obtained. For each Score individually,the fr equency of patie nts with a presence
of thrombus were relatively higher compared to the patients with an absence of
thrombus.Wells Score 4 had the highest frequ ency of patients with the presen ce of
thrombus.The precise data regarding each parameter is illustrated below.

Thrombus
presence Total
Yes No
Clinical wells score 3 7 1 8
4 22 3 25
5 17 1 18
6 6 0 6
Total 52 5 57

Table 12: A table representing the correlational statistical data regarding the presence
of thr ombus and the wells score

The bar chart below illustrates the statistical data described above.

Figure 81: A bar graph illustrating the correlational study between the wells score and
the presence of thrombus against the frequ ency

RESULTS AND DISCUSSION
75 | P a g e

For comparative studies of Wells score and the value of DD assay , the following
results were attained.For each Score individually,the frequency of patients with an
increased DD were relatively higher compared to the patients with a normal DD
value.Wel ls Score 4 had the highest frequency of patients with the increased DD. The
precise data regarding each p arameter is illustrated below. The chi -square test
represented below was used to correlate the nominals .There was no correlation obtained.
D DIMER type
Normal Increased Total
Clinical wells score 3 1 8 9
4 0 24 24
5 0 18 18
6 2 6 8
Total 3 56 59
Table 13: A table representing comp arative statistics between the W ells score and DD
analys is

Nominal by
Interval Eta
Clinical W ells score
Dependent .147
D DIMER type Dependent
.401
Table 14: Chi square test comparing the nominals .

Figure 82: A bar chart illustrating the correlational studies between DD and Wells score

RESULTS AND DISCUSSION
76 | P a g e
The association of DD and NT -PRO BNP was reviewed ..This is illustrated below,for
increased DD levels,61.54% of the patients had also elevated NT -PRO BNP levels while the
minority of 38.46% had normal values. The invalid cases were disregarded in the table
below. Nothing significant was obtained in correlation to previous studies.
D-DIMER type

Normal Increased Total
NT PRO BNP type Normal 1 10 1
Increased 1 16 17
Total 2 26 28

Table 15: A table representing the statistical data for DD and NT -PRO BNP

The bar chart below illustrates the statistical data presented in the table below.The invalid
cases were disregarded.

Figure 83: A bar chart illustrating the correlation between DD and NT -PRO BNP
against the frequency

RESULTS AND DISCUSSION
77 | P a g e

Vario us studies have shown a correlation between DD and RDW -SD in diagnosis of
DVT.The exact mechanisms involved are understood to be complex. Com parative studies of DD
and R DW-SD was reviewed and presented statistically in various methods as describ ed
below.Our study failed to obtain the s ame results as described previously.The table below
represents the statistical data collected .

D DIMER t ype
Normal Increased Total
RDW -SD type Normal 4 29 33
Increased 0 22 22
Decreased 0 1 1
Total 4 52 56
Table 16: A table representing the statistical collected for DD and RDW -SD

Value (V) Approx. Sig (P)
Nominal b y Nominal Phi .232 .223
Cramer's V .232 .223
No of Valid Cases 56
Table 17: A table representing the correlational Phi and Cramer’s V test performed for
the nominals,V value of 0.232 and P value of 0.223 was found be inconclu sive

The bar chart below illustrates the correlational data between these two blood
analysis.

Figure 84: A bar chart illustrating the comparative data between DD and RDW -SD

RESULTS AND DI SCUSSION
78 | P a g e
Inflammatory ma rkers are known to influence the pathogenesis of DVT.In our study we
tried to correlate the various parameters and we found a strong correlation between ESR to CRP
and CRP to Fibrinogen .
CRP and ESR were correlated as per the general statistical data and comparative data
represented below.
CRP type Total
Normal Increased
ESR/1hr type Normal 7 3 10
Increased 2 11 13
Total 9 14 23

Table 18: A table representing general comparative statistical data between ESR and
CRP

The table below shows the correlative tests performed on the se two nominals.
Value (V) Approx. Sig (P)
Nominal by Nominal Phi .555 .008
Cramer's V .555 .008
N of Valid Cases 23

Table 19: A table representing the correlational test of Phi and Cramer’s V test for the
nominals .V values ≈1,in our study 0.555 and P values <0.05,in our study 0.008 are significant

Figure 85: A bar chart illustrati ng the correlational data regarding ESR and CRP

RESULTS AND DISCUSSION
79 | P a g e
The compara tive data between CRP and Fibrinogen was then analyzed. There was a
strong correlation between these two inflammatory markers.The general statistical and
correlative data was presented below.
Fibrinogen
Type Total
Normal Increased
CRP type Normal 8 0 8
Increase d 3 11 14
Total 11 11 22
Table 20: A table representing the general statistical data for CRP and Fibrinogen

The table below shows the correlative tests performed on these two nominals
Value (V) Approx. Sig (P)
Nominal by Nominal Phi .756 .000
Cramer's V .756 .000
N of Valid Cases 22

Table 21: A table representing the correlation al test of Phi and Cramer’s V test for the
nominals .V values ≈1,in our study 0.756 and P values <0.05,in our study 0.000 are significant

Figure 86:A bar chart illustrating the correlational data between CRP and Fibrinog en

DISCUSSIONS
80 | P a g e
15. DISCUSSION S
In this study several significant results and in terpretations are analyzed individually and
comparatively below.
The gender that was more commonly affected according to the results was Female,which
had a slightly higher frequency compared to the Male.DVT is known to have a preference to
Male gender according to previous studies performed but this is still debatable and more studies
are required to elaborate this. (52).
Patients more than 65 years old were the most affected according to the study.This is
further supported by previous studies supporting DVT to be a disease of the elderly (53).The
answer to this could be the process of aging itself,which causes abnormalities in the coagula tion
cascade and also attributes to the loss of the vein struc tural intergrity (54).The elderly are in a
constant prothrombotic state.Studies have shown that certain coagulation factors,Fibrinogen and
DD are significantly high er in this population either acquired or inherited are a direct link to
occurance of thrombosis.Chronic heart failure is a common pathology in elderly patients.This is
associated with hypercoagulability and finally this leads to venous stasis which is pos tulated by
Virchow as one of the theory of understanding DVT (55).
Retired patients were of increased risk of DVT according to our study.This could be
explained by the fact that most of them were more than 65 years of age and had a sedentary
lifestyle which could have led to the occurance of DVT.Sedentary lifestyle avoidance among
many other factors is well known to be a preventive method for DVT.
Past medical drug history is a known factor as an etiology for DVT.These drugs in clude
immunosurpressive and anti -conceptional drugs containing hormones.According to our study
only limited patients had a positive drug history which accounted for the insignificance in
statistical analysis.
Pregnant women are known to be at a high risk of a thrombotic event.This is explained
by the fact that pregnancy is a hypercoagulable state.During pregnancy plasma levels of many
clotting factors increase significantly to prevent postpartum hemorrhage.Our study illustrated
minimum case s of pregnant wo men who had DVT ,thus the statistical irrelevance.

DISCUSSIONS
81 | P a g e
Smoking is a well known independent risk factor for pathogenesis of DVT.It increases
the risk of DVT by multiple mechanisms,including the increase in levels of fibrinogen and
certain clotting factors.This in turn increases platelet activation and aggregation.Smoking is also
implicated in alteration of fibr inolysis mechanism,this ensures the increase in tendency to
clot.The risk of DVT is increased several folds when smoking and increased levels of BMI are
correlated (42)According to our studies some patients were found to be current smokers while
some had previously been smokers.Our results didn’t have any conclusive statistical
significance.
BMI and DVT has a strong correlation .In our studies the mean value of BMI was 29
which was classified as being Overweight.Clinical trials suggest that TF(tissue factor) pathway is
upregulated in obesity.Thus obese patients have higher levels of coagulations factors like
F8,Thrombin and TAT c omplexes.This emaphises the point that obesity could also be classified
into a hypercoagulable state.Obesity is also related with a higher platelet activation rate thus
implicating on an overal increased risk of thrombus formation (50).
Doppler ultrasound as one of the paraclinical investigation had significant
results.Majority of the patients had one specific location involved,furthemore the Left leg was
the most frequent location of DVT in our study.Regarding the deep veins o f the upper
limb,Brachial vein and Axillary vein were the most common locations.For the deep veins of the
lower limb,Popliteal vein followed by Common Femoral vein were mostly involved.The
documented findings in a doppler ultrasound were significantly pre sent in our study.Thrombus
presence,Collateral circulation and Flux abnormality were all present in majority of the patients
with an available ultrasound. (56)
Blood tests with significant importance to our study are discussed below.DD is a know n
marker for DVT diagnosis though various studies have shown its negative predictive factor in
DVT diagnosis due to its false positive and false negative comparisions.In our study majority of
patients had an increased vale of DD assay and were confirmed later by positive ultrasound
findings.FDP is also a marker frequently associated with DVT diagnosis.However in our study
minimum patients had presence of FDP,thus of very little statistical significance.WBC count was
predicted normal in maj ority of the patients.Majority of patients had a decreased HB count in our
case study.The INR levels of majority of the patients in our study were well
regulated.Thrombocytes were also reported to be normal in our case study.

DISCUSSIONS
82 | P a g e
Acute phase reactants includin g ESR/1HR,CRP and Fibrinogen had expected increased
levels in majority of the patients in our study.According to various studies these acute phase
reactants have a relation to the pathogenesis of DVT. (21)These inflammatory cytok ines
influence the expression of TF which is the initiator of the extrinsic pathway of coagulation.This
thus enhances a trigger for future thrombotic events (57).Moreover to the inflammataory role of
Fibrinogen,other explanatio ns to the increased level of fi brinogen as an individual factor are
considered.In recent studies,Koenig came up with the idea that high levels of fibrinogen may
lead to an increase size of thrombus thus forming a compact network dimension.This compact
structure impaires fibrinolysis by interfering the binding of plasminogen to its receptor.This
hypothesis is highly debatable and more studies are required for a better understanding. (51)
The Modified Wells Score is a frequently u sed clinical pretest in various clinics.In our
study all patients had either an I ntermediate Score or a High score,varying from values of 3 to 6.
Male patients had a higher mean days of hospitalization compared to the Female
gender.Age group >65 had the hi ghest mean of number of days hospitalized.
According to our study patients with multiple locations involved had the highest mean of
number of days hospitalized.The more the number of locations involved the mor e severe the
outcome of DVT which required further reassement in the clinic .
Female patients had a higher reported percentage of orthostatism compared to
Male.Various studies have shown that orthostatism is one of the most frequent cause of DVT in
Women.Other more frequent causes include anti -contrace ptive pills and immobility. (58)
Age group 18 -35 all patients were orthostatic,for age group 35 -50 the comparative
percentage of positive response to orthostatism was higher.Age group 50 -65 also had a higher
comparative percent age of presence of orthostatism,while age group >65 had all with a negative
response.According to our study patients from the three working class groups had a history of
orthostatism,while the age group >65 had patients who were mostly retired.Orthostatism and
DVT had a well known correlation.Decreased mobility of the feet for long hours under certain
working conditions causes stasis of bl ood as explained by Virchow,which inturn causes a higher
risk of blood clots formation.
The comparative studies of Well s Score and BMI suggested that for each score
individually majority of patients had an increased BMI.This further emphesises the discussion
about obesity being a risk factor for DVT which was explained earlier in the discussion (59).

DISCUSSIONS
83 | P a g e
Our studies showed us that for each Wells score majority of the patients had a presence of
Thrombus.This shows us that our study emphasises on the Wells Criteria as b eing quite useful in
our clinic.Our study emphesises the importance of the Wells score as described by previous
studies (60).
The correlation studies between Wells Score and DD show ed us the following.For each
Wells score majority of the patients had an increased value of DD.This show us the importance
of using b oth these investigations in diagnosis of DVT cases. Various studies performed by
medical residents have shown to support the correlation of DD and Wells score to identify and
rule out DVT successfully. (59)
Accor ding to our stud y we obtained no correl ation between DD, NT -PRO BNP and
RDW. Increased levels of NT -PRO BNP is associated with a hypercoagulable state which means
a higher risk of thrombus formation (20).Further studies are required to establi sh the correlation
of these parameters. Studies show that RBC are a major components of blood clots,they are also
active in random cell trapping during cloting.They therefore participate actively in thrombus
formation.RBC contribute to blood viscosity by r eleasing pro -coagulatory factors thereby
activating the coagulation cascade.However whether this functions indipendently or with the aid
of the inflammatory cytokines is yet to be distinguished.This hypothesis needs more clarification
from scholars. (19)
A strong correlation was obtained for several inflammatory markers including ESR,CRP and
Fibrinogen from our study.Several previous studies have obtained significant results of great
value.This correlation is attributed to the f act that the process of thrombus formation and venous
wall damage induces a system inflammatory response thus resulting in the elevated inflammatory
markers independently. (21)

LIMITATIONS OF THE STUDY
84 | P a g e
16. LIMITATIONS OF THE STUDY
A retrospective stu dy is known to have a large number of cases for an influential
statistical significance.Contrary to this, our study evaluated only 62 patients thus resulting in the
insignificance of certain parameters which are of high interest to various scholars.Our st udy also
had essential data regarding blood parameters and paraclinical imaging missing for certain
patients. The study was biased on only the inpatients admitted to our clinic .Long term follow up
of the patients was disregarded due to lack to adequate tim e and limited resources.Certan criteria
were based on the objective signs and symptomns reported by the patients which could have
been false or mi sinterprated by the doctors in our practice.

CONCLUSIONS
85 | P a g e
17. CONCLUSIONS
Obesity, orthostatism, age more than 65 are high risk factors in pathogenesis of DVT.
In the majority of the patients more tha n two locations of the thrombus formation was
observed , just one third of the DVT cases involve d one location.
DVT was more frequent present in the left leg and v eins in the calf or thigh were most
commonly affected .
Wells score was confirm ed as a reliable clinical tool to assess risk of DVT in our clinic. It
is known to have a high sensitivity, high specificity and a high positive predictive value with
high accuracy. There is a significant correlation between the Wells score reflected in DVT
probablity and Doppler Ultrasound findings.
Doppler ultrasound is a good , available, non invasive and reliable method to confirm
DVT in clinical practice.
D-dimer testing were pos itive in the majority of cases and shoud be used to exclude
thromboembolic disease, as recommended by guidelines, especially in patients with low
predicted risk of deep vein thrombosis .D-Dimer testing is incorporated into a diagnostic strategy
with clinica l estimation of pretest probability and ultrasound imaging technique.
We failed to find some correlation s between the following laboratory parameter s;NT pro
BNP, D Dimer and RDW -SD.
In patients with DVT thrombus formations induce s a systemic inflammatory r eaction
which is reflected by increasing level of a cute phase reactants , as confirmed in our study too.
Increased level of red blood cell dist ribution width, a easily measurable laboratory
variable, could be considered part of the diagnostic strate rgy, a significant association between
RDW and DVT is demonstrated by some previous studies but the mechanism of association
requires further evaluation from researchers.

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86 | P a g e
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