3 Anatomy and Functionfirst becomes visible in the eighth week of embryologic development as a protuberance off the terminal portion of the cecum.The three taeniae coli converge at the junction of the cecum with the appendix and can be a useful landmark to identify the appendix.
4 The appendix can vary in length from <1 cm to >30 cm; most appendices are 6 to 9 cm long.
6 It can be found in a retrocecal, pelvic, subcecal, preileal, or right pericolic position.
7 the appendix is an immunologic organ that actively participates in the secretion of immunoglobulins, particularly immunoglobulin A.Lymphoid tissue first appears in the appendix approximately 2 weeks after birth.Although there is no clear role for the appendix in the development of human disease, recent studies demonstrate a potential correlation between appendectomy and the development of inflammatory bowel disease.appendectomy is associated with a more benign phenotype in ulcerative colitis and a delay in onset of disease. The association between Crohn's disease and appendectomy is less clear.
8 EpidemiologyDespite newer imaging techniques, acute appendicitis can be very difficult to diagnose.Peak incidence in adolescents and youngadults, with a slight male predominancein this age group.Infants, elderly, pregnant women andimmunocompromised patients tend tohave atypical presentations and havehigher morbidity and mortality.
9 IncidenceThe lifetime rate of appendectomy is 12% for men and 25% for women, with approximately 7% of all people undergoing appendectomy for acute appendicitis during their lifetime.
10 The percentage of misdiagnosed cases of appendicitis is significantly higher among women than among men (22.2 vs. 9.3%).
11 Etiology and Pathophysiology Acute appendicitis is thought to begin with obstruction of the lumenObstruction can result from food matter, adhesions, or lymphoid hyperplasiaMucosal secretions continue to increase intraluminal pressure
12 Etiology and Pathophysiology FaecolithKinksAdhesionsWormsGallstoneHerniaEndometriosisBariumTumourObstruction of the lumen is the dominant etiologic factor in acute appendicitis.Fecaliths are the most common cause of appendiceal obstruction.
13 PathophysiologyExceptions exist in the classic presentation due to anatomic variability of the appendixAppendix can be retrocecal causing the pain to localize to the right flankIn pregnancy, the appendix ca be shifted and patients can present with RUQ pain
15 BacteriologyThe principal organisms seen in the normal appendix, in acute appendicitis, and in perforated appendicitis are Escherichia coli and Bacteroides fragilis.Appendicitis is a polymicrobial infection, with some series reporting the culture of up to 14 different organisms in patients with perforation.Antibiotic coverage is limited to 24 to 48 hours in cases of nonperforated appendicitis. For perforated appendicitis, 7 to 10 days of therapy is recommended.
16 History Primary symptom: abdominal pain ½ to 2/3 of patients have the classical presentationPain beginning in epigastrium or periumbilical area that is vague and hard to localize
17 HistoryIn some males, retroileal appendicitis can irritate the ureter and cause testicular pain.Pelvic appendix may irritate the bladder or rectum causing suprapubic pain, pain with urination, or feeling the need to defecateMultiple anatomic variations explain the difficulty in diagnosing appendicitis
18 HistoryAssociated symptoms: indigestion, discomfort, flatus, need to defecate, anorexia, nausea, vomitingAs the illness progresses RLQ localization typically occursAnorexia is the most common of associated symptomsVomiting is more variable, occuring in about ½ of patients
19 Physical Exam Findings depend on duration of illness prior to exam. Early on patients may not have localized tendernessWith progression there is tenderness to deep palpation over McBurney’s pointAdditional components that may be helpful in diagnosis: rebound tenderness, voluntary guarding, muscular rigidity, tenderness on rectal
20 Physical ExamMcBurney’s Point: just below the middle of a line connecting the umbilicus and the ASISRousing’s: pain in RLQ with palpation to LLQRectal exam: pain can be most pronounced if the patient has pelvic appendix
22 Physical ExamPsoas sign: place patient in L lateral decubitus and extend R leg at the hip. If there is pain with this movement, then the sign is positive.Obturator sign: passively flex the R hip and knee and internally rotate the hip. If there is increased pain then the sign is positive
23 Physical Exam Fever: another late finding. At the onset of pain fever is usually not found.Temperatures >39 C are uncommon in first 24 h, but not uncommon after rupture
24 DiagnosisAcute appendicitis should be suspected in anyone with epigastric, periumbilical, right flank, or right sided abd pain who has not had an appendectomy
25 DiagnosisWomen of child bearing age need a pelvic exam and a pregnancy test.Additional studies: CBC, UA, imaging studiesCBC: the WBC is of limited value.CRP and ESR have been studied with mixed resultsUA: abnormal UA results are found in 19-40%Abnormalities include: pyuria, hematuria, bacteruriaPresence of >20 wbc per field should increase consideration of Urinary tract pathology
26 Diagnosis Imaging studies: include X-rays, US, CT Xrays of abd are abnormal in 24-95%Abnormal findings include: fecalith, appendiceal gas, localized paralytic ileus, blurred right psoas, and free airAbdominal xrays have limited use b/c the findings are seen in multiple other processes
27 DiagnosisGraded Compression US: reported sensitivity 94.7% and specificity 88.9%Basis of this technique is that normal bowel and appendix can be compressed whereas an inflamed appendix can not be compressedDX: noncompressible >6mm appendix, appendicolith, periappendiceal abscess
28 DiagnosisLimitations of US: retrocecal appendix may not be visualized, perforations may be missed due to return to normal diameter
29 DiagnosisCT: best choice based on availability and alternative diagnoses.In one study, CT had greater sensitivity, accuracy, -predictive valueEven if appendix is not visualized, diagnose can be made with localized fat stranding in RLQ.
30 DiagnosisCT appears to change management decisions and decreases unnecessary appendectomies in women, but it is not as useful for changing management in men.Note the thick-walled and dilated appendixmesenteric streaking and "dirty fat"
31 Special PopulationsVery young, very old, pregnant, and HIV patients present atypically and often have delayed diagnosisHigh index of suspicion is needed in the these groups to get an accurate diagnosis
32 Differential Diagnosis Intra-abdominal conditionsAcute AppendicitisAcute CholecystitisDiverticulitis (Meckel’s)Inflammatory Bowel Disease (Crohn’s)Duodenal UlcerIntestinal ObstructionCarcinoma of the CecumNonspecific adenitis – Possible Yersinia infection
33 Differential Diagnosis (cont.) Intra-pelvic conditionsSalpingitisPelvic Inflammatory DiseaseEctopic PregnancyRuptured Corpus Luteum CystRuptured Follicular Cyst (Mittelschmerz)Ruptured Ovarian CystOvarian TorsionPyelonephritisUreteral/Renal stone
35 Treatment Appendectomy is the standard of care Patients should be NPO, given IVF, and preoperative antibioticsAntibiotics are most effective when given preoperatively and they decrease post-op infections and abscess formation
37 TreatmentThere are multiple acceptable antibiotics to use as long there is anaerobic flora, enterococci and gram(-) intestinal flora coverageAlso, short acting narcotics should be used for pain management
39 TumorsPrimary appendiceal cancer is diagnosed in 0.9 to 1.4% of appendectomy specimensrepresenting >50% of the primary lesions of the appendixmucinous adenocarcinoma (38% of total reported cases), adenocarcinoma (26%), carcinoid (17%), goblet cell carcinoma (15%), and signet-ring cell carcinoma (4%)
40 Carcinoid firm, yellow, bulbar mass in the appendix The appendix is the most common site of GI carcinoid, followed by the small bowel and then the rectum.Carcinoid syndrome is rarely. Unless widespread metastases are present, which occur in 2.9% of cases.