SURGERY_1.3 Appendix (Book).docx

I.3 – Appendix (Book) Schwartz, 9th ed July 2, 2013 BACTERIOLOGY

 Bacteriology of the normal appendix is similar to that of the normal colon.  Bacteria cultured in cases of appendicitis are therefore similar to those seen in other colonic infections such as diverticulitis.  The principal organisms seen in the normal appendix, in acute appendicitis, and in perforated appendicitis are:  Escherichia coli and Bacteroides fragilis  However, a wide variety of both facultative and anaerobic bacteria and mycobacteria may be present.  Appendicitis is a polymicrobial infection, with some series reporting up to 14 different organisms cultured in patients with perforation.  The routine use of intraperitoneal cultures in patients with either perforated or nonperforated appendicitis is questionable.  As discussed above, the flora is known and therefore broad-spectrum antibiotics are indicated.  By the time culture results are available, the patient often has recovered from the illness.  Additionally, the number of organisms cultured and the ability of a specific lab to culture anaerobic organisms vary greatly.  Peritoneal culture should be reserved for patients who are immunosuppressed, and for patients who develop an abscess after the treatment of appendicitis.  Antibiotic coverage is limited to:  24–48 h in cases of nonperforated appendicitis.  For perforated appendicitis, 7–10 days is recommended.  Intravenous antibiotics are usually given until the white blood cell count is normal and the patient is afebrile for 24 h.

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CLINICAL MANIFESTATIONS SYMPTOMS ABDOMINAL PAIN is the prime symptom of acute appendicitis. Initially, pain is diffusely centered in the lower epigastrium or umbilical area, is moderately severe, and is steady, sometimes with intermittent cramping superimposed. After a period varying from 1–12 h, the pain localizes to the right lower quadrant. This classic pain sequence, although usual, is not invariable. In some patients, the pain of appendicitis begins in the right lower quadrant and remains there. Variations in the anatomic location of the appendix = variations in the principal locus of the somatic phase of the pain. Anorexia nearly always accompanies appendicitis. It is so constant that the diagnosis should be questioned if the patient is not anorectic. Although vomiting occurs in 75 percent of patients, it is neither prominent nor prolonged. Most patients give a history of obstipation beginning prior to the onset of abdominal pain, and many feel that defecation would relieve their abdominal pain.

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 However, diarrhea occurs in some patients, particularly children, so that the pattern of bowel function is of little differential diagnostic value.  The sequence of symptom appearance has great differential diagnostic significance.  In more than 95 percent of patients with acute appendicitis:  Anorexia is the first symptom,  followed by abdominal pain,  then, vomiting.  If vomiting precedes the onset of pain, the diagnosis of appendicitis should be questioned. SIGNS  Physical findings are determined principally by:  anatomic position of the inflamed appendix,  whether the organ has already ruptured when the patient is first examined.  Vital signs are minimally changed by uncomplicated appendicitis.  Temperature elevation is rarely more than 1˚C (33.8˚F)  Pulse rate is normal or slightly elevated.  Changes of greater magnitude usually indicate that a complication has occurred or that another diagnosis should be considered.  Patients with appendicitis usually prefer to lie supine, with the thighs, drawn up, because any motion increases pain.  The classic right lower quadrant physical signs are present when the inflamed appendix lies in the anterior position.  Tenderness is often maximal at or near the McBurney point.  Direct rebound tenderness is usually present.  Additionally, referred or indirect rebound tenderness is present. This referred tenderness is felt maximally in the right lower quadrant, indicating localized peritoneal irritation.  The Rovsing sign—pain in the right lower quadrant when palpatory pressure is exerted in the left lower quadrant—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 accompanies acute appendicitis.  Muscular resistance to palpation of the abdominal wall parallels the severity of the inflammatory process.  Anatomic variations in the position of the inflamed appendix lead to deviations in the usual physical findings.  The psoas sign indicates an irritative focus in proximity to that muscle. The test is performed by having patients lay on their left side as the examiner slowly extends the right thigh, thus stretching the iliopsoas muscle. The test is positive if extension produces pain.  Similarly, a positive 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. LABORATORY FINDINGS  Mild leukocytosis, ranging from 10,000– 18,000/mm3, is usually present in patients with acute, uncomplicated appendicitis and is often accompanied by a moderate polymorphonuclear predominance.  However, white blood cell counts are variable. Page 1 of 10

 It is unusual for the white blood cell count to be greater than18,000/mm3 in uncomplicated appendicitis.  White blood cell counts above this level raise the possibility of a perforated appendix.  Urinalysis is 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 catheterized urine specimen is not seen with acute appendicitis.

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IMAGING STUDIES PLAIN FILMS OF THE ABDOMEN Although frequently obtained as part of the general evaluation of a patient with an acute abdomen, are rarely helpful in diagnosing acute appendicitis. However, plain radiographs can be of significant benefit in ruling out 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.

GRADED COMPRESSION SONOGRAPHY  Has been suggested as an accurate way to establish the diagnosis of appendicitis.  The technique is inexpensive, can be performed rapidly, does not require contrast, and can be used in pregnant patients.  Sonographically, the appendix is identified as a blindending, nonperistaltic bowel loop originating from the cecum.  With maximal compression, the diameter of the appendix is measured in the anteroposterior dimension.  A scan is considered positive if a noncompressible appendix 6 mm or greater in the anteroposterior direction is demonstrated.  The presence of an appendicolith establishes the diagnosis.  The presence of thickening of the appendiceal wall and periappendiceal fluid is highly suggestive.  Sonographic demonstration of a normal appendix excludes the diagnosis of acute appendicitis.  The study is considered inconclusive if the appendix is not visualized and there is nopericecal fluid or mass.  When the diagnosis of acute appendicitis is excluded by sonography, a brief survey of the remainder of the abdominal cavity should be performed to establish an alternative diagnosis.  In females of child-bearing age, the pelvic organs must be adequately visualized.  The sonographic diagnosis of acute appendicitis has a reported sensitivity of 55–96 percent and a specificity of 85–98 percent.  Some studies have reported that graded compression sonography improved the diagnosis of appendicitis over clinical exam, specifically decreasing the percentage of negative explorations for appendectomies from 37 down to 13percent.  Sonography also decreases the time before operation.  Sonography identified appendicitis in 10 percent of patients who were believed to have a low likelihood of the disease on physical examination.  The positive and negative predictive values of ultrasonography have been reported as 91 or92 percent, respectively.  However, in a recent prospective multicenter study, routine ultrasonography did not improve the diagnostic accuracy or rates of negative appendectomy or perforation when compared to clinical assessment. HIGH-RESOLUTION, HELICAL, COMPUTER TOMOGRAPHY  Also has been used to diagnose appendicitis.  On CT scan, the inflamed appendix appears dilated and the wall is thickened. I.3 - Appendix (Book)

 There is usually evidence of inflammation, with ―dirty fat,‖ thickened mesoappendix, and even an obvious phlegmon.  Fecaliths can be easily visualized, but their presence is not necessarily pathognomonic of appendicitis.  An important suggestive abnormality is the arrowhead sign. This is caused by thickening of the cecum, which funnels contrast toward the orifice of the inflamed appendix.  CT scanning is also an excellent technique for identifying other inflammatory processes masquerading as appendicitis.  Several CT techniques have been used, including focused and nonfocused CT scans and enhanced and nonenhanced helical CT scanning.  Surprisingly, all these techniques have yielded similar rates of diagnostic accuracy, i.e., 92–97 percent sensitivity, 85–94 percent specificity, 90–98 percent accuracy, and 75–95 percent positive and 95–99 percent negative predictive values.  A number of studies have documented improvement in diagnostic accuracy with the liberal use of CT scanning in the workup of suspected appendicitis.  Computed tomography lowered the rate of negative appendectomies from 19 down to 12 percent in one study, and the incidence of negative appendectomies in women from 24 down to 5 percent in another.  The use of this imaging study altered the care of 24 percent of patients studied and provided alternative diagnoses in half of the patients with normal appendices on CT scan.  Problems exist with routine CT scanning for suspected appendicitis. CT scanning is expensive, exposes the patients to significant radiation, and cannot be used during pregnancy.  Allergy contraindicates the application of intravenous contrast 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.  Studies comparing the effectiveness of ultrasound to helical CT in establishing the diagnosis of appendicitis have demonstrated CT scanning superior.  In one study, 600 ultrasounds and 317 CT scans revealed sensitivities of 80 and 97 percent, specificities of 93 and 94 percent, diagnostic accuracies of 89 and 95 percent, positive predictive values of 91 and 92 percent, and negative predictive values of 88 and 98 percent, respectively.  In another study, ultrasound positively impacted the management of 19 percent of patients, as compared to 73 percent of patients for CT.  Finally, in a third study, patients studied by ultrasonography had a 17 percent negative appendix rate compared to a 2 percent negative appendix rate in patients who underwent helical CT scanning.  One issue that has not been resolved is which patients are candidates for imaging studies.  The concept that all patients with right lower quadrant pain should undergo CT scanning has been strongly supported by two reports by Rao and his colleagues at the Massachusetts General Hospital.  In one, this group documented a fall in the negative appendectomy rate from 20 down to 7 percent, and a decline in the perforation rate from 22 down to 14 percent, and establishing an alternative diagnosis in 50 percent of patients.  In the second study, published in the New England Journal of Medicine, they documented that CT scanning prevented 13 unnecessary appendectomies, saved 50 inpatient hospital days, and lowered the per patient cost by $447.  In contrast, several studies failed to prove an advantage of routine CT scanning, documenting that surgeon accuracy approached that of the imaging study

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and expressing concern that the imaging studies could adversely delay appendectomy in affected patients.  The rational approach is the selective use of CT scanning. This has been documented by several studies in which imaging was performed based on an algorithm or protocol.  The likelihood of appendicitis can be ascertained using the Alvarado scale.  This scoring system was designed to improve the diagnosis of appendicitis and was devised by giving relative weight to specific clinical manifestation. LAPAROSCOPY  Can serve as both a diagnostic and therapeutic maneuver for patients with acute abdominal pain and suspected acute appendicitis.  Laparoscopy is most useful in the evaluation of females with lower abdominal complaints because appendectomy is performed on a normal appendix in as many as 30–40 percent of these patients.  Differentiating acute gynecologic pathology from acute appendicitis can be effectively accomplished by using the laparoscope. APPENDICEAL RUPTURE  Immediate appendectomy has long been the recommended treatment of acute appendicitis because of the risk of rupture.  The overall rate of perforated appendicitis is 25.8 percent.  Children younger than age 5 years (45%) and patients older than age 65 years (51%) have the highest rate of perforation.  It has been suggested that delays in presentation are responsible for the majority of perforated appendices.  There is no accurate way of determining when and if an appendix will rupture prior to resolution of the inflammatory process.  Although it has been suggested that observation and  Antibiotic therapy alone may be an appropriate treatment for acute appendicitis, nonoperative treatment exposes the patient to the increased morbidity and mortality associated with a ruptured appendix.  Appendiceal rupture should be suspected in the presence of fever greater than 39˚C (102˚F) and a white blood cell count greater than 18,000/mm3.  In the majority of cases, rupture is contained and patients display localized rebound tenderness.  Generalized peritonitis will be present if the walling-off process is ineffective in containing the rupture.  In 2–6 percent of cases, an ill-defined mass will be detected on physical examination.  This could represent a phlegmon or a periappendiceal abscess.  Patients who present with a mass have a longer duration of symptoms, usually at least 5–7 days.  The ability to distinguish acute, uncomplicated appendicitis from acute appendicitis with perforation on the basis of clinical findings is often difficult, but it is important to make the distinction because their treatment differs.  CT scan may be beneficial in guiding therapy.  Phlegmons and small abscesses can be treated conservatively with intravenous antibiotics; well localized abscesses can be managed with percutaneous drainage; complex abscesses should be considered for surgical drainage.  If operative drainage is required, it should be

I.3 - Appendix (Book)

performed by using an extraperitoneal approach, with appendectomy reserved for cases in which the appendix is easily accessible.  Interval appendectomy performed at least 6 weeks following the acute event has classically been recommended for all patients treated either nonoperatively or with simple drainage of an abscess. DIFFERENTIAL DIAGNOSIS  The differential diagnosis of acute appendicitis is essentially the diagnosis of the ―acute abdomen‖.  This is because clinical manifestations are not specific for a given disease, but are specific for disturbance of a physiologic function or functions.  Thus, an essentially identical clinical picture can result from a wide variety of acute processes within or near the peritoneal cavity.  The accuracy of preoperative diagnosis should be approximately 85 percent.  If it is consistently less, it is likely that some unnecessary operations are being performed, and a more rigorous preoperative differential diagnosis is in order.  A diagnostic accuracy rate consistently greater than 90 percent should also cause concern, because this may mean that some patients with atypical, but bona fide cases of, acute appendicitis are being ―observed‖ when they should have prompt surgical intervention.  The Haller group has shown, however, that this is not invariably true.  Before the group’s study, the perforation rate at the hospital in which the study took place was 26.7 percent, and acute appendicitis was found in 80 percent of the operations.  By a policy of intensive in-hospital observation when the diagnosis of appendicitis was unclear, the group raised the rate of acute appendicitis found at operation to 94 percent, although the perforation rate remained unchanged at 27.5 percent.  There are a few conditions in which operation is contraindicated.  Other disease processes that are confused with appendicitis are also surgical problems, or, if not, are not made worse by surgical intervention.  A common error is to make a preoperative diagnosis of acute appendicitis only to find some other condition (or nothing) at operation; much less frequently, acute appendicitis is found after a preoperative diagnosis of another condition.  The most common erroneous preoperative diagnoses— accounting for more than 75 percent—in descending order of frequency are: 1. acute mesenteric lymphadenitis, 2. no organic pathologic conditions, 3. acute pelvic inflammatory disease, 4. twisted ovarian cyst or ruptured graafian follicle, 5. acute gastroenteritis. The differential diagnosis of acute appendicitis depends on FOUR MAJOR FACTORS: 1. the anatomic location of the inflamed appendix 2. the stage of the process (i.e., simple or ruptured) 3. the patient’s age 4. the patient’s sex ACUTE MESENTERIC ADENITIS  Disease most often confused with acute appendicitis in children.  Almost invariably, an upper respiratory infection is present or has recently subsided.  The pain is usually diffuse and tenderness is not as sharply as localized as in appendicitis.  Voluntary guarding is sometimes present, but true rigidity is rare.  Generalized lymphadenopathy may be noted.  Laboratory procedures are of little help in arriving at the correct diagnosis, although a relative

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lymphocytosis, when present, suggests mesenteric adenitis.  Observation for several hours is in order if the diagnosis of mesenteric adenitis seems likely, because it is a self-limited disease.  However, if the differentiation remains in doubt, immediate exploration is the safest course of action

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GYNECOLOGIC DISORDERS PELVIC INFLAMMATORY DISEASE Infection usually is bilateral If confined to the right tube, may mimic acute appendicitis Nausea and vomiting are present in patients with appendicitis, but in only approximately 50% of those with pelvic inflammatory disease Pain and tenderness are usually lower, and motion of the cervix is exquisitely painful. Intracellular diplococci may be demonstrable on smear of the purulent vaginal discharge. The ratio of cases of appendicitis to cases of pelvic inflammatory disease is low in females in the early phase of the menstrual cycle and high during the luteal phase. The careful clinical use of these features has reduced the incidence of negative findings on laparoscopy in young women to 15%.

RUPTURED GRAAFIAN FOLLICLE  Ovulation commonly results in the spillage of sufficient amounts of blood and follicular fluid to produce brief, mild lower abdominal pain.  If the amount of fluid is unusually copious and is from the right ovary, appendicitis may be simulated. Pain and tenderness are rather diffuse.  Leukocytosis and fever are minimal or absent. Because this pain occurs at the midpoint of the menstrual cycle, it is often called MITTELSCHMERZ. TWISTED OVARIAN CYST  Serous cysts of the ovary are common and generally remain asymptomatic  When right-sided cysts rupture or undergo torsion, the manifestations are similar to those of appendicitis.  Patients develop right lower quadrant pain, tenderness, rebound, fever, and leukocytosis.  If the mass is palpable on physical examination, the diagnosis can be made easily.  Both transvaginal ultrasonography and CT scanning can be diagnostic if a mass is not palpable.  Torsion requires emergent operative treatment.  If the torsion is complete or longstanding, the pedicle undergoes thrombosis, and the ovary and tube become gangrenous and require resection.  Leakage of ovarian cysts resolves spontaneously, however, and is best treated nonoperatively. RUPTURED ECTOPIC PREGNANCY  Blastocysts may implant in the fallopian tube (usually the ampullary portion) and in the ovary.  Rupture of right tubal or ovarian pregnancies can mimic appendicitis.  Patients may give a history of abnormal menses, either missing one or two periods or noting only slight vaginal bleeding.  Right lower quadrant or pelvic pain may be the first symptom.  The diagnosis of ruptured ectopic pregnancy should be relatively easy.  The presence of a pelvic mass and elevated levels of chorionic gonadotropin are characteristic. Although the leukocyte count rises slightly (to approximately 14,000 cells/mm3), the hematocrit level falls as a consequence of the intra-abdominal hemorrhage.  Vaginal examination reveals cervical motion and adnexal tenderness  More definitive diagnosis can be established by culdocentesis. I.3 - Appendix (Book)

 Presence of blood and particularly decidual tissue is pathognomonic.  Treatment is emergency surgery. GASTROENTERITIS  Acute gastroenteritis is common but usually can be easily distinguished from acute appendicitis. Gastroenteritis is characterized by profuse diarrhea, nausea, and vomiting.  Hyperperistaltic abdominal cramps precede the watery stools.  The abdomen is relaxed between cramps, and there are no localizing signs.

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OTHER INTESTINAL MANIFESTATIONS MECKEL’S DIVERTICULITIS gives rise to a clinical picture similar to that of acute appendicitis located within the distal 2 ft of the ileum Associated with the same complications as appendicitis and requires the same treatment—prompt surgical intervention. Resection of the segment of ileum bearing the diverticulum with end-to-end anastomosis can nearly always be done through a McBurney incision, extended if necessary, or laparoscopically.

CROHN’S ENTERITIS  The manifestations of acute regional enteritis—fever, right lower quadrant pain and tenderness, and leukocytosis—often simulate acute appendicitis.  The presence of diarrhea and the absence of anorexia, nausea, and vomiting favor a diagnosis of enteritis, but this is not sufficient to exclude acute appendicitis.  In an appreciable percentage of patients with chronic regional enteritis, the diagnosis is first made at the time of operation for presumed acute appendicitis.  In cases of an acutely inflamed distal ileum with no cecal involvement and a normal appendix, appendectomy is indicated.  Progression to chronic Crohn's ileitis is uncommon. COLONIC LESIONS  Diverticulitis or perforating carcinoma of the cecum, or of that portion of the sigmoid that lies in the right side, may be impossible to distinguish from appendicitis.  These entities should be considered in older patients.  CT scanning is often helpful in making a diagnosis in older patients with right lower quadrant pain and atypical clinical presentations.  Epiploic appendagitis probably results from infarction of the colonic appendage(s) secondary to torsion.  Symptoms may be minimal, or there may be continuous abdominal pain in an area corresponding to the contour of the colon, lasting several days.  Pain shift is unusual, and there is no diagnostic sequence of symptoms.  The patient does not look ill, nausea and vomiting are unusual, and appetite generally is unaffected.  Localized tenderness over the site is usual and often is associated with rebound without rigidity.  In 25% of reported cases, pain persists or recurs until the infarcted epiploic appendage is removed. ACUTE APPENDICITIS IN YOUNG  Diagnosis of acute appendicitis is more difficult in young children than in the adult.  The inability of young children to give an accurate history, diagnostic delays by both parents and physicians, and the frequency of GI upset in children are all contributing factors.  In children the physical examination findings of maximal tenderness in the right lower quadrant, the inability to walk or walking with a limp, and pain with percussion, coughing, and hopping were found to have the highest sensitivity for appendicitis.

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 The more rapid progression to rupture and the inability of the underdeveloped greater omentum to contain a rupture lead to significant morbidity rates in children.  Children 38°C (100.4°F) and a shift to the left in leukocyte count of >76%, especially if they are male, are anorectic, or have had pain of long duration before admission.  hospital length of stay are increased in the elderly compared with younger populations with appendicitis  Elderly patients benefit from a laparoscopic approach to treatment of appendicitis.  In general, laparoscopic appendectomy offers elderly patients with appendicitis a shorter length of hospital stay, a reduction in complication and mortality rates, and a greater chance of discharge to home (independent of further nursing care or rehabilitation) ACUTE APPENDICITIS DURING PREGNANCY  Appendectomy for presumed appendicitis is the most common surgical emergency during pregnancy.  Approximately 1 in 766 births.  Occur at any time during pregnancy.

I.3 - Appendix (Book)

 The overall negative appendectomy rate during pregnancy is approximately 25% and appears to be higher than the rate seen in nonpregnant women.  A higher rate of negative appendectomy is seen in the second trimester, and the lowest rate is in the third trimester.  The diversity of clinical presentations and the difficulty in making the diagnosis of acute appendicitis in pregnant women is well established.  This is particularly true in the late second trimester and the third trimester, when many abdominal symptoms may be considered pregnancy related.  Anatomic changes in the appendix and increased abdominal laxity that may further complicate clinical evaluation.  There is no association between appendectomy and subsequent fertility.  Appendicitis in pregnancy should be suspected when a pregnant woman complains of abdominal pain of new onset.  The most consistent sign encountered in acute appendicitis during pregnancy is pain in the right side of the abdomen.  74% of patients report pain located in the right lower abdominal quadrant, with no difference between early and late pregnancy.  Only 57% of patients present with the classic history of diffuse periumbilical pain migrating to the right lower quadrant.  Laboratory evaluation is not helpful in establishing the diagnosis of acute appendicitis during pregnancy. The physiologic leukocytosis of pregnancy has been defined as high as 16,000 cells/mm3.  In one series only 38% of patients with appendicitis had a white blood cell count of >16,000 cells/mm3.  When the diagnosis is in doubt, abdominal ultrasound may be beneficial.  Another option is magnetic resonance imaging, which has no known deleterious effects on the fetus.  The American College of Radiology recommends the use of nonionizing radiation techniques for frontline imaging in pregnant women.  Laparoscopy has been advocated in equivocal cases, especially early in pregnancy; however laparoscopic appendectomy may be associated with an increase in pregnancy-related complications.  The overall incidence of fetal loss after appendectomy is 4% and the risk of early delivery is 7%.  It is important to note that a negative appendectomy is not a benign procedure.  Removing a normal appendix is associated with a 4% risk of fetal loss and 10% risk of early delivery.  Maternal mortality after appendectomy is extremely rare (0.03%).  Because the incidence of ruptured appendix is similar in pregnant and nonpregnant women and because maternal mortality is so low, it appears that the greatest opportunity to improve fetal outcomes is by improving diagnostic accuracy and reducing the rate of negative appendectomy. ACUTE APPENDICITIS IN HIV/AIDS PATIENTS  The incidence of acute appendicitis in HIV-infected patients is reported to be 0.5%.  The presentation of acute appendicitis in HIV-infected patients is similar to that in noninfected patients.  The majority of HIV-infected patients with appendicitis have fever, periumbilical pain radiating to the right lower quadrant (91%), right lower quadrant tenderness (91%), and rebound tenderness (74%).  HIV-infected patients do not manifest an absolute leukocytosis; however, if a baseline leukocyte count is available, nearly all HIV-infected patients with appendicitis demonstrate a relative leukocytosis  The risk of appendiceal rupture appears to be increased in HIV-infected patients.  In one large series of HIV-infected patients who underwent appendectomy for presumed appendicitis, Page 5 of 10

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43% of patients were found to have perforated appendicitis at laparotomy. The increased risk of appendiceal rupture may be related to the delay in presentation seen in this patient population The mean duration of symptoms before arrival in the emergency department has been reported to be increased in HIV-infected patients, with >60% of patients reporting the duration of symptoms to be longer than 24 hours. In early series, significant hospital delay also may have contributed to high rates of rupture. However, with increased understanding of abdominal pain in HIVinfected patients, hospital delay has become less prevalent. A low CD4 count is also associated with an increased incidence of appendiceal rupture. In one large series, patients with nonruptured appendices had CD4 counts of 158.75 ± 47 cells/mm3 compared with 94.5 ± 32 cells/mm3 in patients with appendiceal rupture. The differential diagnosis of right lower quadrant pain is expanded in HIV-infected patients compared with the general population. Opportunistic infections should be considered as a possible cause of right lower quadrant pain. Such opportunistic infections include cytomegalovirus (CMV) infection, Kaposi's sarcoma, tuberculosis, lymphoma, and other causes of infectious colitis. CMV infection causes a vasculitis of blood vessels in the submucosa of the gut, which leads to thrombosis. Mucosal ischemia develops, leading to ulceration, gangrene of the bowel wall, and perforation. Spontaneous peritonitis may be caused by opportunistic pathogens, including CMV, Mycobacterium aviumintracellulare complex, Mycobacterium tuberculosis, Cryptococcus neoformans, and Strongyloides. Kaposi's sarcoma and non-Hodgkin's lymphoma may present with pain and a right lower quadrant mass. Viral and bacterial colitis occur with a higher frequency in HIV-infected patients than in the general population. Colitis should always be considered in HIV-infected patients presenting with right lower quadrant pain Neutropenic enterocolitis (typhlitis) should also be considered in the differential diagnosis of right lower quadrant pain in HIV-infected patients. In the HIV-infected patient with classic signs and symptoms of appendicitis immediate appendectomy is indicated. In those patients with diarrhea as a prominent symptom, colonoscopy may be warranted. In patients with equivocal findings, CT scan is usually helpful. The majority of pathologic findings identified in HIVinfected patients who undergo appendectomy for presumed appendicitis are typical. The negative appendectomy rate is 5 to 10%. However, in up to 25% of patients AIDS-related entities are found in the operative specimens, including CMV, Kaposi's sarcoma, and M. avium-intracellulare complex. More recent series report 0% mortality in this group of patients. Morbidity rates for HIV-infected patients with nonperforated appendicitis are similar to those seen in the general population. Postoperative morbidity rates appear to be higher in HIV-infected patients with perforated appendicitis. The length of hospital stay for HIV-infected patients undergoing appendectomy is twice that for the general population. No series has been reported to date that addresses the role of laparoscopic appendectomy in the HIV-infected population.

I.3 - Appendix (Book)

TREATMENT  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 thirdgeneration cephalosporin, monobactam, or aminoglycoside plus anaerobic coverage with clindamycin or metronidazole is indicated.  The recommendations are similar for children OPEN APPENDECTOMY  For open appendectomy most surgeons use either a McBurney (oblique) or Rocky-Davis (transverse) right lower quadrant muscle-splitting incision in patients with suspected appendicitis.  The incision should be centered over either the point of maximal tenderness or a palpable mass.  If an abscess is suspected, a laterally placed incision is imperative to allow retroperitoneal drainage and to avoid generalized contamination of the peritoneal cavity.  If the diagnosis is in doubt, a lower midline incision is recommended to allow a more extensive examination of the peritoneal cavity.  This is especially relevant in older patients with possible malignancy or diverticulitis.  Several techniques can be used to locate the appendix.  Because the cecum usually is visible within the incision, the convergence of the taeniae can be followed to the base of the appendix.  A sweeping lateral to medial motion can aid in delivering the appendiceal tip into the operative field.  Occasionally, limited mobilization of the cecum is needed to aid in adequate visualization.  Once identified, the appendix is mobilized by dividing the mesoappendix, with care taken to ligate the appendiceal artery securely.  The appendiceal stump can be managed by simple ligation or by ligation and inversion with either a purse-string or Z stitch.  As long as the stump is clearly viable and the base of the cecum is not involved with the inflammatory process, the stump can be safely ligated with a nonabsorbable suture.  The mucosa is frequently obliterated to avoid the development of mucocele.  The peritoneal cavity is irrigated and the wound closed in layers. If perforation or gangrene is found in adults, the skin and subcutaneous tissue should be left open and allowed to heal by secondary intent or closed in 4 to 5 days as a delayed primary closure.  In children, who generally have little subcutaneous fat, primary wound closure has not led to an increased incidence of wound infection.  If appendicitis is not found, a methodical search must be made for an alternative diagnosis.  The cecum and mesentery should first be inspected.

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 Next, the small bowel should be examined in a retrograde fashion beginning at the ileocecal valve and extending at least 2 ft. In females, special attention should be paid to the pelvic organs.  An attempt also should be made to examine the upper abdominal contents.  Peritoneal fluid should be sent for Gram's staining and culture.  If purulent fluid is encountered, it is imperative that the source be identified.  A medial extension of the incision (Fowler-Weir), with division of the anterior and posterior rectus sheath, is acceptable if further evaluation of the lower abdomen is indicated.  If upper abdominal pathology is encountered, the right lower quadrant incision is closed and an appropriate upper midline incision is made LAPAROSCOPIC APPENDECTOMY  Semm - first reported successful laparoscopic appendectomy several years before the first laparoscopic cholecystectomy. However  Did not come into widespread use until after the success of laparoscopic cholecystectomy due to the fact that appendectomy is already a form of minimal-access surgery.  Performed under general anesthesia.  A nasogastric tube and a urinary catheter are placed before obtaining a pneumoperitoneum  The surgeon usually stands to the patient's left and one assistant is required to operate the camera.  Usually requires the use of three ports. Four ports may occasionally be necessary to mobilize a retrocecal appendix.  1ST trocar (10 mm)- placed in the umbilicus  2nd trocar - placed in the suprapubic position or left lower quadrant. The suprapubic trocar is either, depending on whether or not a linear stapler will be used.  3rd trocar (5 mm) - variable and usually is either in the left lower quadrant, epigastrium, or right upper quadrant. Placement is based on location of the appendix and surgeon preference.  Initially, the abdomen is thoroughly explored to exclude other pathology.  Appendix is identified by following the anterior taeniae to its base.  Dissection at the base of the appendix enables the surgeon to create a window between the mesentery and the base of the appendix.

A. A window is created in the mesoappendix close to the base of the appendix B. The linear stapler is used to divide the appendix at its base. C. Finally, the mesoappendix can be easily divided using the linear stapler

 The mesentery and base of the appendix are then secured and divided separately.  When the mesoappendix is inflamed, it is often best to divide the appendix first with a linear stapler and then to divide the mesoappendix immediately I.3 - Appendix (Book)

adjacent to the appendix with clips, electrocautery, Harmonic Scalpel, or staples.  The base of the appendix is not inverted. The appendix is removed from the abdominal cavity through a trocar site or within a retrieval bag.  The base of the appendix and the mesoappendix should be evaluated for hemostasis, right lower quadrant should be irrigated and Trocars are removed under direct vision.  Wound infections were approximately half as likely after laparoscopic appendectomy as after open appendectomy. However, the rate of intra-abdominal abscess was three times higher after laparoscopic appendectomy than after open appendectomy. PRINCIPAL PROPOSED BENEFITOFLAPAROSCOPIC APPENDECTOMY  Decreased postoperative pain - significantly less pain after laparoscopic appendectomy on the 1st postoperative day.  Shorter length of hospital stay - less after laparoscopic appendectomy. 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.  Shorter period before return to normal activity, return to work, and return to sports.  There appears to be little benefit to laparoscopic appendectomy over open appendectomy in thin males between the ages of 15 and 45 years. In these patients, the diagnosis usually is straightforward.  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 all obese patients in whom the procedure was completed laparoscopically the incisions closed primarily, whereas the wounds closed primarily in only 58% of obese patients who underwent open appendectomy.  There was no difference in rates of wound infection while intra-abdominal abscess rates were not reported.  Diagnostic laparoscopy - advocated as a potential tool to decrease the number of negative appendectomies performed.  Morbidity associated with laparoscopy and general anesthesia is acceptable only if pathology requiring surgical treatment is present and is amenable to treatment using laparoscopic techniques.  The availability of diagnostic laparoscopy may actually lower the threshold for exploration and thus adversely impact the negative appendectomy rate.  Fertile women with presumed appendicitis constitute the group of patients most likely to benefit from diagnostic laparoscopy. Up to one third of these patients do not have appendicitis at explorationreduced # of unnecessary appendectomy.  In most of the patients without appendicitis, gynecologic pathology is identified.  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. NATURAL ORIFICE TRANSLUMINAL ENDOSCOPIC SURGERY  A new surgical procedure using flexible endoscopes in the abdominal cavity.  Access is gained by way of organs that are reached through a natural, already-existing external orifice.  The hoped-for advantages associated with this method include the reduction of postoperative wound pain,

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shorter convalescence, avoidance of wound infection and abdominal-wall hernias, and the absence of scars.  Much work remains to determine if NOTES provides any additional advantages over the laparoscopic approach to appendectomy. ANTIBIOTICS AS DEFINITIVE THERAPY  A study analyzing time to surgery and perforation demonstrated that risk of rupture is minimal within 36 hours of symptom onset. Beyond this point, there is about a 5% risk of rupture in each ensuing 12-hour period. However, in many patients the disease will have an indolent course.  For patients assigned to antibiotic therapy, if symptoms did not improve within the first 24 hours, an appendectomy was performed.  When patients are treated with antibiotics alone it is possible that diagnoses of significant pathology such as carcinoid or carcinoma may be delayed. Because no laboratory test or clinical investigation can reliably distinguish patients whose appendicitis is potentially amenable to conservative treatment, surgery still remains the gold standard of care for patients with acute appendicitis. INTERVAL APPENDECTOMY  Treatment of appendicitis associated with a palpable or radiographically documented mass (abscess or phlegmon) is conservative therapy with interval appendectomy 6 to 10 weeks later.  Successful and produces much lower morbidity and mortality rates than immediate appendectomy but associated with greater expense and longer hospitalization time (8 to 13 days vs. 3 to 5 days). STAGES OF TREATMENT  Initial treatment - consists of IV antibiotics and bowel rest. Although this therapy is generally effective, there is a 9 to 15% failure rate, with operative intervention required at 3 to 5 days after presentation. Percutaneous or operative drainage of abscesses is not considered a failure of conservative therapy.  2nd stage of treatment - interval appendectomy carried out. The major argument against interval appendectomy is that approximately 50% of patients treated conservatively never develop manifestations of appendicitis, and those who do generally can be treated nonoperatively.  In addition, pathologic examination of the resected appendix shows normal findings in 20 to 50% of cases.  Overall, the rate of late failure as a consequence of acute disease averages 20%.  An additional 14% of patients either continue to have, or redevelop, right lower quadrant pain. Although the appendix may occasionally be pathologically normal, persistent periappendiceal abscesses and adhesions are found in 80% of patients.  Almost 50% have histologic evidence of inflammation in the organ itself. Several neoplasms also have been detected in the resected appendices, even in those of children.  Appendectomy may be required as early as 3 weeks after conservative therapy. Two thirds of the cases of recurrent appendicitis occur within 2 years, and this is the outside limit.  Interval appendectomy is associated with a morbidity rate of ≤3% and a hospitalization time of 1 to 3 days. PROGNOSIS  The mortality from appendicitis in the United States has steadily decreased from a rate of 9.9 per 100,000 in 1939 to 0.2 per 100,000 today.  Factors responsible - advances in anesthesia, antibiotics, IV fluids, and blood products.  Principal factors influencing mortality - whether rupture occurs before surgical treatment and the age of the patient.

I.3 - Appendix (Book)

 The overall mortality rate in acute appendicitis with rupture is approximately 1%.  The mortality rate of appendicitis with rupture in the elderly is approximately 5%—a fivefold increase from the overall rate.  Death - usually attributable to uncontrolled sepsis, peritonitis, intra-abdominal abscesses, or gramnegative septicemia and pulmonary embolism continues to account for some deaths.  Morbidity rates - parallel mortality rates and are significantly increased by rupture of the appendix and, to a lesser extent, by old age.  Serious early complications - are septic and include abscess and wound infection.  Wound infection - common but is nearly always confined to the subcutaneous tissues and responds promptly to wound drainage, which is accomplished by reopening the skin incision. It predisposes the patient to wound dehiscence. The type of incision is relevant, complete dehiscence rarely occurs in a McBurney incision  The sites of predilection for abscesses:  Appendiceal fossa  Pouch of Douglas  Subhepatic space  Between loops of intestine - site abscesses are usually multiple.  Transrectal drainage is preferred for an abscess that bulges into the rectum.  Fecal fistula - annoying but not particularly dangerous, complication of appendectomy that may be caused by sloughing of the portion of the cecum inside a constricting purse-string suture; by slipping of the ligature off a tied, but not inverted, appendiceal stump; or by necrosis from an abscess encroaching on the cecum.  Intestinal obstruction - initially paralytic but sometimes progressing to mechanical obstruction may occur with slowly resolving peritonitis with loculated abscesses and exuberant adhesion formation. Late complications are quite uncommon.  Adhesive band intestinal obstruction after appendectomy does but much less frequently than after pelvic surgical therapy.  Inguinal hernia is three times higher in patients who have had an appendectomy.  Incisional hernia is like wound dehiscence in that infection predisposes to it, it rarely occurs in a McBurney incision, and it is not uncommon in a lower right paramedian incision. CHRONIC APPENDICITIS  Characteristically, the pain lasts longer and is less intense than that of acute appendicitis but is in the same location.  There is a much lower incidence of vomiting, but anorexia and occasionally nausea, pain with motion, and malaise are characteristic.  Leukocyte counts are predictably normal and CT scans are generally nondiagnostic.  At operation, surgeons can establish the diagnosis with 94% specificity and 78% sensitivity. There is an excellent correlation between clinical symptomatology, intraoperative findings, and histologic abnormalities.  Laparoscopy can be used effectively in the management of this clinical entity. Appendectomy is curative. Symptoms resolve postoperatively in 82 to 93% of patients. Many of those whose symptoms are not cured or recur are ultimately diagnosed with Crohn's disease. APPENDICEAL PARASITES  Causes appendicitis  Ascaris lumbricoides - most common cause.  Wide spectrum of helminths have been implicated:  Enterobius vermicularis  Strongyloides stercoralis,  Echinococcus granulosis Page 8 of 10

 The live parasites occlude the appendiceal lumen, causing obstruction.  The presence of parasites in the appendix at operation makes ligation and stapling of the appendix technically difficult.  Once appendectomy has been performed and the patient has recovered, therapy with helminthicide is necessary to clear the remainder of the GI tract.  Amebiasis - can cause appendicitis. Invasion of the mucosa by trophozoites of Entamoeba histolytica incites a marked inflammatory process. Appendiceal involvement is a component of more generalized intestinal amebiasis. Appendectomy must be followed by appropriate antiamebic therapy (metronidazole). INCIDENTAL APPENDECTOMY  Decisions regarding the efficacy of incidental appendectomy should be based on the epidemiology of appendicitis.  Males were more likely to develop appendicitis than females.  Although incidental appendectomy is generally neither clinically nor economically appropriate, there are some special patient groups in whom it should be performed during laparotomy or laparoscopy for other indications.  These include children about to undergo chemotherapy, the disabled who cannot describe symptoms or react normally to abdominal pain, patients with Crohn's disease in whom the cecum is free of macroscopic disease, and individuals who are about to travel to remote places where there is no access to medical or surgical care.98  Appendectomy is routinely carried out during performance of Ladd's procedure for malrotation, because displacement of the cecum into the left upper quadrant would complicate the diagnosis of subsequent appendicitis. TUMORS  Appendiceal malignancies are extremely rare.  Primary appendiceal cancer is diagnosed in 0.9 to 1.4% of appendectomy specimens.  These tumors are only rarely suspected preoperatively. Fewer than 50% of cases are diagnosed at operation.  Most series report that carcinoid is the most common appendiceal malignancy, representing >50% of the primary lesions of the appendix.  A review from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program found the age-adjusted incidence of appendiceal malignancies to be 0.12 cases per 1,000,000 people per year.  Data from the SEER program:  mucinous adenocarcinoma - most frequent histologic diagnosis (38% of totalreported cases)  adenocarcinoma - (26%)  carcinoid - (17%)  goblet cell carcinoma (15%)  signet-ring cell carcinoma - (4%)  Five-year survival for appendiceal malignancies varies by tumor type.  Patients with carcinoid tumors have the best 5-year survival (83%), whereas those with signet-ring cell cancers have the lowest (18%). CARCINOID  Firm, yellow, bulbar mass in the appendix should raise the suspicion of an appendiceal carcinoid.  The appendix is the most common site of GI carcinoid, followed by the small bowel and then the rectum.  Carcinoid syndrome is rarely associated with appendiceal carcinoid unless widespread metastases are present, which occur in 2.9% of cases.  Symptoms attributable directly to the carcinoid are rare, although the tumor can occasionally obstruct the appendiceal lumen much like a fecalith and result in acute appendicitis.

I.3 - Appendix (Book)

 The majority of carcinoids are located in the tip of the appendix. They usually present with localized disease (64%).  Tumors