Acute Appendicitis

Ministry of Health of the Republic of Moldova Public Institution

“Nicolae Testemițanu” State University of Medicine and Pharmacy of the

Republic of Moldova

FACULTY OF MEDICINE

Department Of Surgical Diseases No 2

DIPLOMA THESIS

ACUTE APPENDICITIS

Name and surname of scientific advisor: Toader Timiș.

Position and scientific degree: Conferențiar Universitar.

Name and surname of student : Abdallah Abu Salah

Year:6

Group:M1043

Chisinau, 2016

Declaration

I hereby declare that the diploma thesis entitled " ACUTE APPENDICITIS" is

written by me and has not been presented before at another college or institution of

higher education in the country or abroad. Also, I declare that all sources used,

including the Internet sources, are indicated in the paper, considering the rules for

avoiding plagiarism:

– all text fragments are reproduced exactly, even the proper translations from other

languages are written in quotes and have detailed reference source;

– paraphrasing in own words of text written by other authors has detailed reference;

– summary of the ideas of other authors has a detailed reference to the original text.

Name and surname of student : Abdallah Abu Salah

Date:________________ Original signature__________________

Contents

1.Introduction……………………………………………….

2. Embryology……………………………………………..

3. Anatomy…………………………………………………

3.1.General Anatomy…………………………….

3.2. Appendiceal vasculature……………..

3.3 Lymph drainage of appendix………….

3.4 Nerve supply to appendix………………

4.Histology……………………………………………..

5.Pathophysiology……………………………………..

6.Bacteriology……………………………………………..

7.Etiology……………………………………………………

8.presentation……………………………………………..

8.1.Symptoms………………………………………

8.2.Physical Examination……………………………

8.3.Accessory signs…………………………………….

8.4.Appendicitis and Pregnancy…………………….

8.5.Diagnostic Scoring………………………………….

8.6.Stages of Appendicitis……………………………….

9.Diagnostic Considerations…………………………………..

9.1.Misdiagnosis in women of childbearing age…….

9.2.Misdiagnosis in children…………………………..

9.3.Considerations in elderly patients…………………..

10.Differential Diagnoses………………………………………

11.Diagnosis……………………………………………………

11. Management ………………………………………………………

12.Complications………………………………………………………

13.Reference………………………………………………………

1.Introduction:

1.1 General consideration

All physicians should have a thorough knowledge of appendicitis. Although most patients with acute appendicitis can be easily diagnosed, there are many in whom the signs and symptoms are quite variable, and a firm clinical diagnosis may be difficult to establish. It is for this reason that the diagnosis is made rather liberally, with the full expectation that some patients will be operated on and found to have a normal appendix. It is preferable to maintain broad indications, as this tends to include the group of patients with indefinite signs and symptoms who actually have the disease but do not fulfill the classic criteria for the diagnosis.

Following this course, patients who might proceed to perforation of the appendix, with a host of possible secondary complications, are spared that fate. Therefore, patients having a diagnosis of acute appendicitis by acceptable standards in most hospitals will actually be found at operation to have a normal appendix.

2. Embyology:

The midgut elongates to form a ventral U-shaped loop of gut – the midgut loop or primary intestinal loop, which projects into the proximal umbilical cord as there is not enough room for it inside the abdominal cavity to accommodate its rapid growth (due to the large size of the liver and kidneys). This movement of the gut tube outside the abdominal cavity is known as the physiological umbilical herniation and is followed by rapid elongation of its mesentery. .[32]

The loop can best be considered as having two limbs – cranial (yellow) and caudal (orange), meeting at an apex where they attach to the vitelline duct which attaches the gut loop to the yolk sac.[32]

The cranial limb grows rapidly, developing into the distal duodenum, the jejunum and part of the ileum.

The caudal limb changes very little, except for the growth of the caecal diverticulum , a small outpouching which forms the caecum and appendix. The remainder of the caudal limb forms the lower ileum, the ascending colon and the proximal two thirds of the transverse colon. .[32]

Figure.1 .[32]

The midgut loop, while in the umbilical cord, rotates 90 ° anticlockwise (when viewed from the anterior aspect) around the axis of the superior mesenteric artery. (i.e. the cranial limb swings down and right while the caudal limb swings up and left). This process is completed around week 8.

During rotation, the cranial limb of the midgut elongates and forms jejunal-ileal loops while the expanding caecum sprouts a vermiform appendix .[32]

Figure.2 .[32]

The cranial loop (forming the small intestine) returns first, passing posterior to the superior mesenteric artery. Initially the loops pass to the left side of the back wall of the abdomen but later loops are deposited further to the right as the midgut loop undergoes a further 180 ° anticlockwise rotation.[32]

Figure.3 .[32]

The caecal diverticulum is the last part of the gut to reenter the abdominal cavity, temporarily lying in the right upper quadrant directly below the right lobe of the liver.

The caecal bud descends to the right iliac fossa, forming the appendix as it does so. This gives rise to the ascending colon and the hepatic (or right colic) flexure on the right hand side of the abdominal cavity. As the appendix forms during the caecum's descent, it frequently lies posterior to the caecum (retrocaecal) or posterior to the colon (retrocolic) .[32]

Figure.4 .[32] Figure.5 .[32]

3.1 Anatomy:

The vermiform appendix is located in the right lower quadrant, arises from the cecum, and is generally 6 to 10 cm in length. It has a separate mesoappendix with an appendicular artery and vein that are branches of the ileocolic vessels. The appendix is lined with colonic epithelium characterized by many lymph follicles numbering approximately 200, with the highest number occurring in the 10- to 20-year-old age group. After the age of 30, the number of lymph follicles is reduced to a trace, with total absence of lymphoid tissue occurring after the age of 60. The appendix may lie in a number of locations, essentially at any position on a clock wise rotation from the base of the cecum. It is important to emphasize that the anatomic position of the appendix determines the symptoms and the site of the muscular spasm and tenderness when the appendix becomes inflamed .

(Fig.6) Appendix Vermiform anatomy [34] (Fig.7)various positions of the appendix vermiform.[34]

3.2 Appendiceal vasculature

Arteries:

The appendix receives its blood supply from the appendicular artery, which is a branch of the posterior cecal artery (branch of superior mesenteric artery). It passes to the tip of the appendix in the mesoappendix.[36]

Veins:

The appendicular vein corresponds to the appendicular artery and drains into the posterior cecal vein (tributary of superior mesenteric vein). .[36]

(Fig.8) Appendix Vermiform vascularization. Cunningham, D.J. Textbook of Anatomy (New York, NY: William Wood and Co., 1903)

3.3 Lymph drainage of appendix

The lymphatics drain into one or two intermediate nodes lying in the mesoappendix and then eventually drain into the superior mesenteric lymph nodes.[36]

(Fig.9) Appendix Vermiform lymph node localization & drainage. Treves, Frederick Surgical Applied Anatomy (New York, NY: Cassell and Company, LTD, 1922)

3.4 Nerve supply to appendix(innervations):

The parasympathetic and sympathetic nerves are derived from the superior mesenteric plexus. The afferent (sensory) fibers, which are concerned with the conduction of visceral pain from the appendix, accompany the sympathetic nerves and enter the spinal cord at the level of tenth thoracic segment.[36]

(Fig.10) Appendix Vermiform innervation .

4.Histology:

The inner lining, facing the lumen of the appendix, is covered by a glandular epithelium with intestinal glands that extend into the deeper layers of the mucosa. The glands are lined with simple columnar epithelium and a high number of mucin producing goblet cells that are recognized by a large globule of mucin occupying the apical portion of the cell. The lamina propria typically contains lymphocytes that partly obscure the underlying muscularis mucosae, which separates the mucosa from the submucosa. .[33]

The submucosa is almost fully occupied by lymphoid tissue mainly arranged in lymphatic nodules. The lymphatic nodules are recognized by a circular aggregation of densely packed lymphocytes that stains dark with HE. The center of the lymphoid nodules stain lighter and are termed germinal centers. The germinal center contains the larger dividing lymphoblasts, similar to the arrangement in lymph nodes. The outer portions of the submucosa harbor larger vessels and have less dense infiltrates of immune cells. .[33]

Similar to the colon, an inner circular muscle layer and a full thin external longitudinal muscle layer comprise the muscularis externa that encircles the appendix. Outside of the muscular layers there is a subserosa containing loose connective tissue, vasculature and nerves. The outermost located peritoneum consists of a thin lining of mesothelial cells. .[33]

(Fig.11) Appendix Vermiform histological layers & tissue. .[33]

5.Pathophysiology:

It is widely accepted that the inciting event in most instances of appendicitis is obstruction of the appendiceal lumen. This may be due to lymphoid hyperplasia, inspissated stool (afecalith), or some other foreign body.

Given the correlation with the incidence of appendicitis by age and the size and distribution of the lymphoid tissue, it is likely that lymphoid obstruction or partial obstruction of the lumen is a common cause. Obstruction of the lumen leads to bacterial overgrowth as well as continued mucous secretion.

This causes distention of the lumen, and the intraluminal pressure increases. This may lead to lymphatic and then venous obstruction. With bacterial overgrowth and edema, an acute inflammatory response ensues. The appendix then becomes more edematous and ischemic. Necrosis of the appendiceal wall subsequently occurs along with translocation of bacteria through the ischemic wall. This is gangrenous appendicitis. Without intervention, the gangrenous will perforate with spillage of the appendiceal contents into the peritoneal cavity. If this sequence of events occurs slowly, the appendix is contained by the inflammatory response and the omentum, leading to localized peritonitis and everntually an appendiceal abscess. If the body does not wall off the process, the patient may develop diffuse peritonitis.[38]

(Fig.12) Pathogenesis of appendicitis.[38]

6.Bacteriology:

The flora in the noninflamed appendix is similar to the colon with a variety of facultative aerobic and anaerobic bacteria found; hence, the bacteria involved in appendicitis are the same as for other colonic disease. The incidence of obtaining positive cultures from the peritoneal cavity depends on the stage of appendicitis found. In patients with acute,nonperforated appendicitis, peritoneal fluid will culture bacteria in fewer than half of the.

However, Peritoneal cultures will be positive in more than 85% of patients with gangrenous or perforated appendicitis. The number of bacterial species that can be cultured depends on how vigorously the investigators attempt to isolate them, with some investigators showing an average of more than nine different species. In 1938, Altemeier clearly demonstrated the polymicrobial nature of perforated appendicitis, and for practical the usefulness of routine peritoneal cultures in patients with perforated appendicitis has been questioned. The flora are generally known, the results are not available for several days, and many times, no change in treatment plan is made despite culture results. It appears reasonable to avoid routine cultures and to obtain them only in patients with persisting infection or surgical site infection. .[38]

7.Etiology: اااااااااااااااااااااااااااااااااااااااااااااااااا

Appendicitis is caused by obstruction of the appendiceal lumen. The most common causes of luminal obstruction include:ااااااااااااااااااا

lymphoid hyperplasia secondary to inflammatory bowel disease (IBD) or infections .ااااااااااااااااااااااااااااااااااااا

fecal stasis and fecaliths (more common in elderly patients).ا

parasites (especially in Eastern countries).ااااااااااااااااا

foreign bodies and neoplasms(more rarely).ااااااااااااااااااااااااااااااا

اااااFecaliths form when calcium salts and fecal debris become اااااlayered around a hole of inspissated fecal material located within اااااthe appendix.اااااااااااااااااااااااااااااااااااASDASDاااااااااااا

Lymphoid hyperplasia is associated with various inflammatory and infectious disorders including Crohn disease,ااgastroenteritis, amebiasis,ااrespiratory infections,ااmeasles,ااand mononucleosis.

Obstruction of the appendiceal lumen has less commonly been associated with:اااااااااااDFDFDFD

1-bacteriaا(Yersinia species,اadenovirus,اcytomegalovirus,اactinomycosis, Mycobacteria species,اHistoplasma species).ااااااااااااااااا

2-اparasitesا(eg,اSchistosomes species,اpinworms,اStrongyloides stercoralis).

3-foreignا materialا(eg, shotgun pellet,اintrauterine device,اtongue stud,اactivated charcoal),اtuberculosisاand tumors.[39]

8.presentation

8.1.Symptoms

Abdominal pain is the major symptom of acute appendicitis. typically, pain is originally diffusely centered in the lower epigastrium or umbilical region,ااis quite severeاا,ااand is firm,ااsometimes with intermittent cramping superimposed.

After a period changeable from 1 to 12 hours,اbut usually within 4 to 6 hours, the pain localize to the right lower quadrant. This typical pain progression, although usual, is not constant.

In various patients,ااthe pain of appendicitis begin in the RUQ and residue there.ااVariations in the anatomic site of the appendix report for many of the variations in the main location of the somatic part of the pain.

For instance,ااa long appendix with the inflamed tip in LLQ causes pain in that region.ااA retrocecal appendix may cause chiefly flank or back ache,ااa pelvic appendix,ااprincipally suprapubic pain; and a retroileal appendix, testicular ache, most probably from irritation of the spermatic artery and ureter.

Intestinal malrotation also is اresponsible for mystifying pain patterns. The visceral element is in the normal locus,اا but the somatic element is felt in that part of the abdomen where the cecum has been detained in rotation.

Anorexia nearly always accompanied appendicitis. It is so steady that the diagnosis should be questioned if the patient is not anorectic. Although vomiting occurs in nearly 75% of patients, it is neither high up,ااnor prolonged,ااand most patients vomit only once or twice.اااVomiting is caused by both neural stimulation and the existence of ileus.

Most patients give a history of obstipation start before the onset of abdominal pain,ااand feel that defecation would reduce their abdominal pain.ااDiarrhea occurs in some patients,ااhowever, particularly children,ااso that the guide of bowel function is of modest differential diagnostic value.

The sequence of symptom manifestation has huge significance for the differential diagnosis.اااIn >95% of patients with acute appendicitis, anorexia is the first symptom,ااfollowed by abdominal pain,ااwhich is followed,ااin turn,ااby vomiting (if vomiting occurs).

If vomiting precede the beginning of pain,ااthe diagnosis of appendicitis should be questioned.[16]

8.2.Physical Examination

The most specific physical findings in appendicitis are rebound tenderness,ااpain on percussion,ااrigidity,ااand guarding.

Rarely, LLQ tenderness has been the main manifestation in patients with )situs inversus( or in patients with a lengthy appendix that extends into the LLQا.اااا

Tenderness on palpation in the RLQ over the McBurney point is the most significant sign in the patientاا.ااا

A cautious physical examination,ااnot limited to the abdomen,ااmust be performed in any patient with suspected appendicitisا.اا Gastrointestinalا,ااgenitourinary,ااand pulmonary systems should be studied.اMale infants and children frequently present with an inflamed hemi-scrotum due to movement of an inflamed appendix or pus through a patent processus vaginalis.ااThis is often firstly mis-diagnosed as acute testicular torsion.ااIn addition,اperform a rectal examination in any patient with an un-clear clinical picture,اand perform a pelvic examination in all women with abdominal pain.

8.3.Accessory signs

Vital signs are modestly changed by uncomplicated appendicitis.

Temperature increases is rarely >1°C (1.8°F) and the pulse is normal or a little elevated. Changes of greater degree usually indicate that a complication has occur or that another diagnosis should be considered.

Patients with appendicitis typically prefer to lie supine, with the thighs particularly the right thigh strained, because any movement increases pain. If asked to move, they do so slowly and with care .The classic RLQ physical signs are present when the inflamed appendix lies in the anterior position.

2-Tenderness frequently is maximal at or near the McBurney point.Direct rebound tenderness usually is present. In addition, referred rebound tenderness is present. This referred tenderness is felt maximally in the RLQ,

which indicates localized peritoneal irritation.

3-The Rovsing sign—pain in the RLQ when palpitation pressure

is exerted in the LLQ — also indicates the site of peritoneal irritation. Cutaneous hyperesthesia in the area supplied by the spinal nerves on the right at T10, T11, and T12 frequently follow acute appendicitis.

In patients with clear appendicitis, this sign is unessential, but in some early cases, it may be the first positive sign. Hyperesthesia is elicited either by needle stab or by gently pickingup the skin between the forefinger and thumb.

4-Muscular resistance to palpation of the abdominal wall nearly parallels the severity of the inflammatory process. Early in the disease,ااresistance,ااif present,ااconsists mainly of voluntary guarding.ااAs peritoneal irritation progresses,ااmuscle spasm increases and becomes chiefly involuntary,ااthat is,ااtrue reflex rigidity due to contraction of muscles directly below the inflamed parietal peritoneumا.اا

Anatomic variations in the position of the inflamed appendix lead to deviations in the usual physical findings.ااWith a retrocecal appendix,ااthe anterior abdominal result are less striking,ااand tenderness may be most patent in the flankاا.اا

When the inflamed appendix hangs into the pelvis,ااabdominal findings may be completely absent,ااand the diagnosis may be missed unless the rectum is examined.ااAs the examining finger exerts pressure on the peritoneum of) Douglas' cul-de-sac(,اpain is felt in the suprapubic area as well as locally within the rectumاا.اا Signs of localized muscle irritation also may be presentااااا.ا

5-The psoas sign indicates an irritative focus in proximity to that muscle. The test is performed by having the patient lie on the left side as the examiner slowly extends the patient's right thigh, thus stretching the iliopsoas muscle. The test

result is positive if extension produces pain.

6-obturator sign of hypogastric pain on stretching the obturator internus indicates irritation in the pelvis. The test is performed by passive internal rotation of the flexed right thigh with the patient supine.

8.4.Appendicitis and Pregnancy

The incidence of appendicitis is unchanged in pregnancy relative to the general population, but the clinical presentation is more variable than at other times.

During pregnancy, the appendix migrates in a counterclockwise direction toward the right kidney, rising above the iliac crest at about 4.5 months' gestation. RLQ pain and tenderness dominate in the first trimester, but in the latter half of pregnancy, right upper quadrant (RUQ) or right flank pain must be considered a possible sign of appendiceal inflammation.

Nausea, vomiting, and anorexia are common in uncomplicated first trimester pregnancies, but their reappearance later in gestation should be viewed with suspicion.[40]

8.5.Diagnostic Scoring

Several investigators have created diagnostic scoring systems to predict the likelihood of acute appendicitis. In these systems, a finite number of clinical variables is elicited from the patient and each is given a numeric value; then, the sum of these values is used.

The best known of these scoring systems is the MANTRELS score, which tabulates migration of pain, anorexia, nausea and/or vomiting, tenderness in the RLQ, rebound tenderness, elevated temperature, leukocytosis, and shift to the left (see Table 1).[19]

Alvarado scale:

(Table 1) Schwartz's Principles of Surgery, 9th Edition,page 2055

Clinical scoring systems are attractive because of their simplicity; however, none has been shown prospectively to improve on the clinician's judgment in the subset of patients evaluated in the emergency department (ED) for abdominal pain suggestive of appendicitis. The MANTRELS score, in fact, was based on a population of patients hospitalized for suspected appendicitis, which differs markedly from the population seen in the ED.

However, the principle disadvantages to this method are that each institution must generate its own database to reflect characteristics of its local population, and specialized equipment and significant initiation time are required. In addition, computer-aided diagnosis is not widely available in US EDs.

8.6.Stages of Appendicitis:

The stages of appendicitis can be divided into early, suppurative, gangrenous, perforated, phlegmonous, spontaneous resolving, recurrent, and chronic.

1-Early stage appendicitis:

In the early stage of appendicitis, obstruction of the appendiceal lumen leads to mucosal edema, mucosal ulceration, bacterial diapedesis, appendiceal distention due to accumulated fluid, and increasing intraluminal pressure. The visceral afferent nerve fibers are stimulated, and the patient perceives mild visceral periumbilical or epigastric pain, which usually lasts 4-6 hours.

2-Suppurative appendicitis:

Increasing intraluminal pressures eventually exceed capillary perfusion pressure, which is associated with obstructed lymphatic and venous drainage and allows bacterial and inflammatory fluid invasion of the tense appendiceal wall. Transmural spread of bacteria causes acute suppurative appendicitis. When the inflamed serosa of the appendix comes in contact with the parietal peritoneum, patients typically experience the classic shift of pain from the periumbilicus to the right lower abdominal quadrant (RLQ), which is continuous and more severe than the early visceral pain.

3-Gangrenous appendicitis:

Intramural venous and arterial thromboses ensue, resulting in gangrenous appendicitis.

4-Perforated appendicitis:

Persisting tissue ischemia results in appendiceal infarction and perforation. Perforation can cause localized or generalized peritonitis.

5-Phlegmonous appendicitis or abscess:

An inflamed or perforated appendix can be walled off by the adjacent greater omentum or small-bowel loops, resulting in phlegmonous appendicitis or focal abscess.

6-Spontaneously resolving appendicitis:

If the obstruction of the appendiceal lumen is relieved, acute appendicitis may resolve spontaneously [22]  [23]This occurs if the cause of the symptoms is lymphoid hyperplasia or when a fecalith is expelled from the lumen.

7-Recurrent appendicitis:

The incidence of recurrent appendicitis is 10%. The diagnosis is accepted as such if the patient underwent similar occurrences of RLQ pain at different times that, after appendectomy, were histopathologically proven to be the result of an inflamed appendix.

8-Chronic appendicitis

Chronic appendicitis occurs with an incidence of 1% and is defined by the following: (1) the patient has a history of RLQ pain of at least 3 weeks’ duration without an alternative diagnosis; (2) after appendectomy, the patient experiences complete relief of symptoms; (3) histopathologically, the symptoms were proven to be the result of chronic active inflammation of the appendiceal wall or fibrosis of the appendix.

9.Diagnostic Considerations

The overall accuracy for diagnosing acute appendicitis is approximately 80%, which corresponds to a mean negative appendectomy rate of 20%. Diagnostic accuracy varies by sex, with a range of 78-92% in male patients and 58-85% in female patients.[14]

The classic history of anorexia and periumbilical pain followed by nausea, right lower quadrant (RLQ) pain, and vomiting.

Vomiting that precedes pain is suggestive of intestinal obstruction, and the diagnosis of appendicitis should be reconsidered.

10.Differential Diagnoses:

There are a number of acute abdominal disorders producing signs and symptoms similar to those of acute appendicitis. These include acute gastroenteritis, cholecystitis, pyelitis, salpingitis, tuboovarian abscess, and ruptured ovarian cyst. Although diarrhea may occur with acute appendicitis, it is much more common with gastroenteritis.

In young children, intussusception enters the differential diagnosis. Other less common differential disordersinclude ureteral stones, cystitis, perforated peptic ulcer, ectopic pregnancy, acute regionalenteritis (particularly the first attack), epididymitis, and testicular torsion.

If a patient persists in having pain in the right lower quadrant that cannot be explained by some other definitive diagnosis, the patient should be considered to have acute appendicitis and should be operated on or at least carefully observed.

11.Diagnosis:

11.1.Approach Considerations:

imaging studies may be important but not always available. However, patients with appendicitis usually have accessory signs that may be helpful for diagnosis (see Physical Examination). For example, the obturator sign is present when the internal rotation of the thigh elicits pain (ie, pelvic appendicitis), and the psoas sign is present when the extension of the right thigh elicits pain (ie, retroperitoneal or retrocecal appendicitis).

Laboratory tests are not specific for appendicitis, but they may be helpful to confirm diagnosis in patients with an atypical presentation.

11.2.Lab Count

Mild leukocytosis, ranging from 10,000 to 18,000 cells/mm3, usually is present in patients with acute, uncomplicated appendicitis and often is accompanied by a moderate polymorphonuclear predominance. White blood cell counts are variable, however. It is unusual for the white blood cell count to be >18,000 cells/mm3 in uncomplicated appendicitis.

White blood cell counts above this level raise the possibility of a perforated appendix with or without an abscess. Urinalysis can be useful to rule out the urinary tract as the source of infection. Although several white or red blood cells can be present from ureteral or bladder irritation as a result of an inflamed appendix, bacteriuria in a urine specimen obtained via catheter generally is not seen in acute appendicitis.[24]

11.3.Urinalysis

Urinalysis may be useful in differentiating appendicitis from urinary tract conditions.

Mild pyuria may occur in patients with appendicitis because of the relationship of the appendix with the right ureter.

Severe pyuria is a more common finding in urinary tract infections (UTIs).

Proteinuria and hematuria suggest genitourinary diseases or hemocoagulative disorders.

11.4.Urinary 5-HIAA

measurement of the urinary 5-hydroxyindoleacetic acid (U-5-HIAA) levels could be an early marker of appendicitis. The rationale of such measurement is related to the large amount of serotonin-secreting cells in the appendix. The investigators noted that U-5-HIAA levels increased significantly in acute appendicitis, decreasing when the inflammation shifted to necrosis of the appendix. Therefore, such decrease could be an early warning sign of perforation of the appendix. [8]

11.5.CT Scanning

High-resolution helical CT also has been used to diagnose appendicitis.ااOn CT scan,ااthe inflamed appendix appear dilated (>5 cm)ااand the barrage is thickened.ااThere is usually data of inflammation,ااwithا"dirty fat,ا" thickened mesoappendix,ااand even an clear phlegmonاا.ااااا

Fecaliths can be easily visualize,ااbut their presence is not essentially pathognomonic of appendicitis.ااAn significant suggestive abnormality is the arrow head mark.ااThis is caused by thickening of the cecum,ااwhich funnel contrast agent toward the opening of the inflamed appendix.ااCT scanning is also an excellent technique for identifying further inflammatory processes hidden as appendicitisااا.

numerous CT techniques have been used,ااincluding focused and non-focused CT scans and enhanced and non-enhanced helical CT scanning.ااNon-enhanced helical CT scanning is significant,ااbecause one of the dis-advantages of use CT scanning in the estimation of RLQ pain is dye allergy.ااSurprisingly,ااall of these techniques have yielded fundamentally identical rates of diagnostic accuracy:اا92 to 97% ااsensitivity,اا85 to 94% specificity, اا90 to 98% accuracy,اااand 75 to 95% positive and 95 to 99% ااnegative projecting values.اا34–36 The additional use of a rectally administered contrast agent did not improve the results of CT scanning.

A number of studies have documented improvement in diagnostic accuracy with the liberal use of CT scanning in the work-up of suspected appendicitis. CT lowered the rate of negative appendectomies from 19 to 12% in one study,37 and the incidence of negative appendectomies in women from 24 to 5% in another.38 The use of this imaging study altered the care of 24% of patients studied and provided alternative diagnoses in half of the patients with normal appendices on CT scan.

Despite the potential usefulness of this technique, there are significant disadvantages. CT scanning is expensive, exposes the patient to significant radiation, and cannot be used during pregnancy.

Allergy contraindicates the administration of IV contrast agents in some patients, and others cannot tolerate the oral ingestion of luminal dye, particularly in the presence of nausea and vomiting. Finally, not all studies have documented the utility of CT scanning in all patients with right lower quadrant pain.

A number of studies have compared the effectiveness of graded compression sonography and helical CT in establishing the diagnosis of appendicitis. Although the differences are rather small, CT scanning has consistently proven superior.[25]

Fig(13) On this axial CT image there is stranding in the mesentery and a large appendicolith within a swollen ruptured appendix (yellow arrow). Disproportionate fat stranding is a diagnostic feature of acute appendicitis on CT. The ruptured appendix has formed an abscess within the right lower quadrant of the pelvis.

Fig(14) CT images 10 and 11 are magnified so you can see the appendicoliths within the appendix. These are successive images taken at 2.5 mm by 2.5 mm interval.

11.6.Ultrasonography

sonography has been recommended as an accurate method to establish the diagnosis of appendicitis.ااThe technique is inexpensive,ااcan be performed fast,ااdoes not require a contrast medium,ااand can be used even in pregnant patientsاا.

Sonographically,ااthe appendix is recognized as a blind-ending,ااnon-peristaltic bowel loop originate from the cecumااا.

With maximal compression,ااthe width of the appendix is precise in the anteroposterior dimensionااا.

Scan results are considered positive if a non-compressibleاااا اappendix ≥6 mm in the anteroposterior direction is demonstratedاااا.

The existence of an appendicolith establishes the diagnosisااا. Thickening of the appendiceal wall and the existence of peri-appendiceal fluid is highly suggestiveااا.

Sonographic demonstration of a normal appendix, which is an easily compressible, blind-ending tubular structure measuring ≤5 mm in diameter, excludes the diagnosis of acute appendicitis.

The study results are considered inconclusive if the appendix is not visualized and there is no pericecal fluid or massااا.

When the diagnosis of acute appendicitis is debarred by sonography,ااa brief survey of the residue of the abdominal cavity should be performed to establish an alternative diagnosis.ااIn females of childbearing age,ااthe pelvic organs must be adequately visualized also by trans-abdominal or endo-vaginal ultrasonography to rule out gynecologic pathology as a cause of acute abdominal painااا.

The sonographic diagnosis of acute appendicitis has a report sensitivity of 55 to ا96% and a specificity ofا 85 to 98%.

Sonography is similarly valuable in children and pregnant womenاا, even though its application is somewhat limited in late pregnancyاا.

Although sonography can simply identify abscesses in patients with perforation,ااthe technique has limitations and results are user dependent.

A false positive scan result can happen in the presence of peri-appendicitis from neighboring inflammation,ااa dilated fallopian tube can be misguided for an inflamed appendix,ااin spissated stool can mimic an appendicolith,ااand in obese patients,ااthe appendix may not be compressible because of overlying fatاا.

False negative sonogram results can occur if appendicitis is limited to the appendiceal tip,ااthe appendix is retrocecal,ااthe appendix is markedly enlarged and misguided for small bowel,ااor the appendix is perforated and then compressible.[27]

Fig(15)

Fig(16)

11.7.Abdominal Radiography

Plain films of the abdomen, although frequently obtained as part of the general evaluation of a patient with an acute abdomen, rarely are helpful in diagnosing acute appendicitis. However, plain radiographs can be of significant benefit in rulingout other pathology.

In patients with acute appendicitis, one often sees an abnormal bowel gas pattern, which is a nonspecific finding. The presence of a fecalith is rarely noted on plain films but, if present, is highly suggestive of the diagnosis.

A chest radiograph is sometimes indicated to rule out referred pain from a right lower lobe pneumonic process.

To date, there has not been enough experience with radionuclide scans to assess their utility.[26]

A)Barium Enema Study

Additional radiographic studies include barium enema examination and radioactively labeled leukocyte scans. If the appendix fills on barium enema, appendicitis is excluded. On the other hand, if the appendix does not fill, no determination can be made.

B)Radionuclide Scanning

Whole blood is withdrawn for radionuclide scanning. Neutrophils and macrophages are labeled with technetium Tc 99m (99m Tc) albumin and administered intravenously. Then, images of the abdomen and pelvis are obtained serially over 4 hours. Localized uptake of tracer in the RLQ suggests appendiceal inflammation; this is shown in the image below.

Technetium-99m radionuclide scan of the abdomen shows focal uptake of labeled WBCs in the right lower quadrant consistent with acute appendicitis.

Fig(17)

11.8.Gross and Microscopic Evaluation

In the early stages of appendicitis, the appendix grossly appears edematous with dilation of the serosal vessels. Microscopy demonstrates neutrophil infiltrate of the mucosal and muscularis layers extending into the lumen. As time passes, the appendiceal wall grossly appears thickened, the lumen appears dilated, and a serosal exudate (fibrinous or fibrinopurulent) may be observed as granular roughening. At this stage, mucosal necrosis may be observed microscopically.

At the later stages of appendicitis, the appendix grossly shows marked signs of mucosal necrosis extending into the external layers of the appendiceal wall that can become gangrenous. Sometimes, the appendix may be found in a collection of pus. At this stage of appendicitis, microscopy may demonstrate multiple microabscesses of the appendiceal wall and severe necrosis of all layers.

11.Treatment:.

11.1.Nonsurgical Treatment:

Despite the advent of more sophisticated diagnostic modalities, the importance of early operative intervention should not be minimized. Once the decision to operate for presumed acute appendicitis has been made, the patient should be prepared for the operating room.

Adequate hydration should be ensured, electrolyte abnormalities should be corrected, and pre-existing cardiac, pulmonary, and renal conditions should be addressed. A large meta-analysis has demonstrated the efficacy of preoperative antibiotics in lowering the infectious complications in appendicitis.

Most surgeons routinely administer antibiotics to all patients with suspected appendicitis. If simple acute appendicitis is encountered, there is no benefit in extending antibiotic coverage beyond 24 hours.

If perforated or gangrenous appendicitis is found, antibiotics are continued until the patient is afebrile and has a normal white blood cell count. For intra-abdominal infections of GI tract origin that are of mild to moderate severity, the Surgical Infection Society has recommended single-agent therapy with cefoxitin, cefotetan,or ticarcillin-clavulanic acid.

For more severe infections, single-agent therapy with carbapenems or combination therapy with a third-generation cephalosporin, monobactam, or aminoglycoside plus anaerobic coverage with clindamycin or metronidazole is indicated.[31]

The recommendations are similar for children.

11.2.Surgical Treatment

A)OPEN APPENDECTOMY

For open appendectomy most surgeons use each a McBurney (oblique) or Rocky-Davis (transverse) RLQ muscle-splitting incision in patients with supposed appendicitis.ااThe incision should be centered above each the point of maximal tenderness or palpable mass.ااIf an abscess is supposed,ااa laterally placed incision is essential to allow retro-peritoneal drainage and to keep away from generalized contamination of the peritoneal hole.ااIf the diagnosis is in uncertainty,ااa lower midline incision is suggested to allow a more broad examination of the peritoneal hole.ااThis is especially relevant in older patients with possible malignancy or diverticulitisا.ااا

Several techniques can be used to find the appendix.ااBecause the cecum usually is visible within the incision,ااthe junction of the taeniae can be followed to the bottom of the appendix.ااA wide lateral to medial movement can aid in delivering the appendiceal tip into the operative ground.ااOccasionally,ااlimited mobilization of the cecum is needed to help in adequate visualization.ااOnce identified,ااthe appendix is mobilized by separating the mesoappendix,ااwith care taken to ligate the appendiceal artery securely.اااا

he appendiceal stump can be managed by simple ligation or by ligation and inversion with either a purse-string or )Z( stitchاا.اااا

As extended as the stump is clearly viable and the base of the cecum is not occupied with the inflammatory process,ااthe stump can be securely ligated with a non-absorbable suture.ااThe mucosa is frequently obliterated to avoid the growth of mucoceleاا.

The peritoneal hole is irrigated and the wound closed in layers.ااIf perforation or gangrene is found in adults,ااthe cotaneous and subcutaneous tissue should be left open and permitted to heal by secondary intent or closed inh(4 to 5)hdays as a delayed primary closure.ااIn children,hwho generally have little subcutaneous fat, primary wound closure has not lead to an frequency of wound infectionh.

If appendicitis is not found,ااa methodical search must be made for an alternative diagnosis.ااThe cecum and mesentery should first be inspected.ااNext,ااthe small intestine should be examined in a retrograde way start at the ileocecal valve and extending at least 2 ft.hhhhh

In females,ااspecial awareness should be paid to the pelvic organs.ااAn attempt also should be made to examine the upper abdominal contents.ااPeritoneal fluid should be sent for Gram's staining and culture.اااااا

If purulent fluid is encountered,ااit is essential that the source be identified.ااA medial extension of the incision (Fowler-Weir),ااwith separation of the anterior and posterior rectus sheath,ااis acceptable if more evaluation of the lower abdomen is indicated.ااIf upper abdominal pathology is encountered,ااthe RLQ incision is closed and an appropriate upper midline incision is madeاا.[41]

B)LAPAROSCOPIC APPENDECTOMY

Laparoscopic appendectomy is done under general anesthesia.ااA nasogastric tube and a urinary catheter are sited before obtaining a pneumo-peritoneum.ااLaparoscopic appendectomy usually requires the use of three ports.ااFour ports may occasionally be essential to mobilize a retrocecal appendix. The surgeon usually stands to the patient's leftاا.اااااا

One assistant is necessary to operate the camera.ااOne trocar is placed in the umbilicusاا(10 mm),ااand a 2nd trocar is placed in the suprapubic location.ااSome surgeons place this 2nd port in the LLQاا. The suprapubic trocar is either )10 or 12 mm(,ااdepending on whether or not a linear stapler will be used.

The placement of the third trocarاا(5 mm) is variable and usually is either in the LLQ,ااepigastrium,ااor RUQ.ااPlacement is based on site of the appendix and surgeon preference.ااInitially,ااthe abdomen is thoroughly explored to exclude other pathology.

The appendix is recognized by following the anterior taeniae to its base.ااDissection at the base of the appendix enables the surgeon to make a window between the mesentery and the base of the appendix .اا

The mesentery and base of the appendix are then protected and divided individually.ااWhen the mesoappendix is drawn in with the inflammatory process,ioften best to divide the appendix first with a linear stapler and then to divide the mesoappendix immediately adjacent to the appendix with clips,ااelectrocautery, Harmonic Scalpel,ااor staples ا.اااااا

The base of the appendix is not reversed.ااThe appendix is removed from the abdominal cavity through a trocar site or within a salvage bag.ااThe base of the appendix and the mesoappendix should be evaluated for hemostasis.ااThe RLQ should be irrigated.اا Trocars are removed under through vision.[42]

Fig(18) [Reproduced with permission from Ortega JM, Ricardo AE: Surgery of the appendix and colon, in Moody FG (ed): Atlas ofAmbulatory Surgery. Philadelphia: WB Saunders, 1999.]

Laparoscopic resection of the appendix. Occasionally, if the appendix and mesoappendix are extremely inflamed, it is easier to divide the appendix at its base before division of the mesoappendix. A. A window is created in the mesoappendix close to the base of the appendix. B. The linear stapler is then used to divide the appendix at its base. C. Finally the mesoappendix can be easily divided using the linear stapler.

LAPAROSCOPIC APPENDECTOMY VS open APPENDECTOMY

The utility of laparoscopic appendectomy in the management of acute appendicitis remains controversial. Surgeons may be hesitant to implement a new technique because the conventional open approach already has proved to be simple and effective.

This analysis demonstrated that the duration of surgery and costs of operation were higher for laparoscopic appendectomy than for open appendectomy.

Wound infections were approximately half as likely after laparoscopic appendectomy as after open appendectomy. However,rate of intra-abdominal abscess was three times higher after laparoscopic appendectomy than after open appendectomy.

A principal proposed benefit of laparoscopic appendectomy has been decreased postoperative pain. Patient-reported pain on the first postoperative day is significantly less after laparoscopic appendectomy.

Hospital length of stay also is statistically significantly less after laparoscopic appendectomy. However, in most studies this difference is <1 day. It appears that a more important determinant of length of stay after appendectomy is the pathology found at operation—specifically, whether a patient has perforated or nonperforated appendicitis. In nearly all studies, laparoscopic appendectomy is associated with a shorter period before return to normalactivity, return to work, and return to sports.However, treatment and subject bias may have a significant impact on the data. Although the majority of studies have been performed in adults, similar data have been obtained in children.

There appears to be little benefit to laparoscopic appendectomy over open appendectomy in thin males between the ages of15 and 45 years. In these patients, the diagnosis usually is straightforward.

Open appendectomy has been associated with outstanding results for several decades. Laparoscopic appendectomy should be considered an option in these patients, based on surgeon and patient preference. Laparoscopic appendectomy may be beneficial in obese patients, in whom it may be difficult to gain adequate access through a small right lower quadrant incision.

In summary

it has not been resolved whether laparoscopic appendectomy is more effective in treating acute appendicitis than the time-proven method of open appendectomy. It does appear that laparoscopic appendectomy is effective in the management of acute appendicitis.

Laparoscopic appendectomy should be considered part of the surgical armamentarium available to treat acute appendicitis. The decision on how to treat a specific patient with appendicitis should be based on surgical skill, patient characteristics, clinical scenario, and patient preference. Additional well-controlled, prospective, blinded studies are needed to determine which subsets of patients may benefit from any given approach to the treatment of appendicitis.

12.Complications

Complications of appendicitis may include wound infection, dehiscence, bowel obstruction, abdominal/pelvic abscess, and, rarely, death. Stump appendicitis also occurs rarely.

1-Gangrenous Appendicitis: Thrombosis of the appendiceal artery and veins.

2-Perforation: perforation rate increased at both ends of the age spectrum.

3-Peri-appendiceal abscess:-most frequent complication.

4-peri-appendiceal fibrinous adhesions.

5- Peritonitis: -Bacterial peritonitis in absence of fibrinous adhesions.(Escherichia coli)

6- Bowel Obstruction

•7-Septic seeding of mesenteric vessels:infection along the mesenteric–portal venous system:

-pylephlebitis, pylethrombosis, or hepatic abscess

Clinical cases

Case 1

A 58-year-old woman was brought to our ED with the presentation of LLQ abdominal pain combined with nausea, vomiting and anorexia for 1 day. Shehad diabetes mellitus, hypertension and a history of duodenal ulcer. Her body temperature was 37.4°C, and blood pressure and heart rate were normal. examination revealed abdominal tenderness over the LLQ without muscle guarding or reboundpain, and hypoactive bowel sounds. White blood cellcount (WBC) was 12,700 /mm3 with left shift (segment, 86.6%; lymphocyte, 10%). C-reactive protein (CRP) was 0.4 mg/dL. Routine urine, electrolytes, amylase, lipase and liver function tests were all within normal limits. A plain film of the abdomen (kidney, ureter, bladder, KUB) showed no stones or free air except some fecal material over the ascending and descending colon. A bedside ultrasound examination without particular emphasis on the appendix demonstrated normal findings regarding the liver, gallbladder, pancreas, bilateral kidneys and urinary bladder.

The patient was initially treated with intravenous fluids and antibiotics and placed under observation. As the LLQ pain with localized rebound and muscle guarding persisted after 4 hours of observation, abdominal computed tomography (CT) with the impression of sigmoid diverticulitis was arranged. The long swollen appendix with wall hyperemia, measuring about 12 cm in length with the tip pointing towards the presacral region, just across the midline of the lower abdomen, was accidentally found Fortunately, no CT evidence of appendix perforation or abscess formation was identified. Emergency appendectomy was performed, and she was discharged 3 days later after an uneventful recovery.

13.Reference:

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Etilology (http://emedicine.medscape.com/article/773895-overview#showall)

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Schwartz's Principles of Surgery, 9th Edition,page 2064 &page 2065

Schwartz's Principles of Surgery, 9th Edition,page 2048 & page 2049