Cause: Arteriosclerotic disease or genetic cause (Ann IM 1999;130:637) most likely, such as Marfan syndrome; less likely due to trauma or infection [syphilis, TB (Ped Radiol 1999;29:536)].

Epidem: Male:Female 10:1.

Pathophys: Proposed that degenerative changes in the media of the arterial wall responsible for the aneurysm formation with rupture causing a surgical emergency.

Sx: Abdominal pain, radiating to or originating in the back, flank, or genital area.

Si: Presence of pulsatile mass not as significant as the width—with > 5 to 5.5 cm being significant (Can Fam Physician 1999;45:2069; J Vasc Surg 1999;29:191), loss of femoral pulses. Check for systemic vascular disease by checking for bruits.

Crs: Spontaneous rupture of this aneurysm increases with size, with aneurysms between 4 to 7 cm in diameter having a 25% chance of rupture (Circ 1977;56:II161). Elective repair of aneurysms < 5.5 cm in diameter not associated with increased long-term survival (Nejm 2002;346:1437; 2002;346:1445), but elective repair of those > 5cm in diameter may have decreased 30-d mortality (Nejm 2004;351:1607).

Cmplc: Vascular collapse resulting in death; this is higher in AAA repairs done emergently after symptoms start (Ann Vasc Surg 1999;13:613).

Diff Dx: Myocardial infarction, aortitis (J Vasc Surg 1999;30:189), pneumonia, pancreatitis, nephrolithiasis, bowel obstruction, diverticulitis, sickle cell crisis, mesenteric thrombosis, porphyria, diabetes, cholecystitis, perforated viscus, splenic infarct, incarcerated hernia.

Lab: CBC with diff with abnormal platelets (Eur J Vasc Endovasc Surg 1999;17:434), PT/PTT, type and cross 10 units PRBCs for repair, UA may show hematuria (hypothesized with dissection into renal arteries but this may occur in infrarenal aneurysms as well).

Emerg Med Clin N Am 1996;14:653; Am Fam Phys 1999;60:2027

Cause: Obstructed appendix from fecolith, lymphoid hyperplasia from viral illness or infiltrative disease.

Epidem: Seven percent lifetime risk; male to female 1.5:1; incidence is 23 per 10,000 population/yr if between second and third decade of life. Suggestion of ulcerative colitis protection if done before 20 yr of age (Nejm 2001;344:808).

Pathophys: As above.

Sx: Nausea, anorexia; periumbilical pain at first that moves to the RLQ; > 36 hr (Am Surg 1999;65:453) but < 72 hours of duration; sense of constipation and urge to defecate.

Si: Fever 37.5°-38.5°C; < 101°F (Am Surg 1999;65:453). RLQ guarding, rebound, and cough tenderness; right-sided rectal tenderness not helpful (World J Surg 1999;23:133; Ann R Coll Surg Engl 2004;86:292). Iliopsoas, obturator internus, and heel pounding signs may also be positive.

Crs: 12-24 hr.

Cmplc: Perforation with peritonitis (20-33%—pre CT) (Peds 1979;63:36); perforation increases prevalence of infertility × 5.

Diff Dx: UTI; urolithiasis; incarcerated inguinal or femoral hernia; intussusception in children < 4 yr of age; cecal mass (World J Surg 1999;23:713) including neoplasm; tuberculosis; schistosomiasis; mesenteric adenitis including Yersinia spp. pseudoappendicular syndrome; diverticulitis; epiploic appendagitis; typhilitis, a cecal colitis seen with aggressive chemotherapy for leukemia; Streptococcus throat infection in children.

Lab: CBC with diff [WBC usually 10K-13K, but not sensitive nor specific—perhaps low normal WBC helpful in excluding diagnosis, ie, < 8K (World J Surg 1999;23:133)]; +/− CRP with elevation (large grey zone between 10-50) indicative of acute complicated disease, eg, abscess or perforation (Brit J Surg 1999;86:501); UA, hematuria does not necessary implicate nephrolithiasis with appropriate history for appendicitis, or AAA—and WBCs may be seen in UA with appendicitis, but should be lacking bacteria; pregnancy test, if of childbearing age.

Cause: Inability of intraluminal intestinal contents to be moved forward via peristalsis.

Epidem: Complications and death have decreased since 1961 with more timely diagnosis, now being less than 10% if younger than 80 yr of age (Ann Surg 2000;231:529).

Pathophys: May be due to previous surgery with either defect in the mesentery or the development of adhesions causing problems; herniation through the femoral canal, inguinal area or anterior abdominal wall; inflammatory bowel disease or radiation enteritis with luminal stenosis; volvulus due to medications or loss of ganglion cells (J Surg Res 1996;60:385); neoplasm; or less likely a foreign body or gallstone ileus or ascaris.

Sx: Abdominal pain, nausea, vomiting, bloating, constipation.

Si: Diffuse abdominal pain with peritoneal signs, increased or lack of bowel sounds, distended or tympanic abdomen.

Crs: May pass spontaneously, others will require surgery.

Cmplc: Perforation.