SYB Case #3 67-year-old male with leukemia and abdominal distention. Radiographic finding: Pneumatosis Gas in the bowel wall A photograph of the mucosal surface of the necrotic bowel shows numerous air bubbles which have lifted the mucosa away from the muscularis Primary pneumatosis intestinalis (15% of cases) is a benign idiopathic condition in which multiple thin-walled cysts mm develop in the submucosa or subserosa of the colon. Secondary form (85% of cases) is associated with obstructive pulmonary disease, as well as with obstructive and necrotic gastrointestinal disease. Linear or curvilinear gas collections seen parallel to the bowel wall 1.Necrotic GI disease: Necrotizing enterocolitis Mesenteric ischemia-Life threatening emergency 50-75% mortality Caustic ingestions 2.Nonnecrotic GI disease: Obstruction/increased intraluminal pressure Inflammation/Ulceration Collagen vascular disease Abdominal trauma. Immunosuppresion Infection 3.Obstructive Pulmonary disease: Rupture of pulmonary blebs in obstructive lung disease may cause air to dissect through the retroperitoneum, into the mesentery, and, finally, to the bowel subserosa and submucosa. Signs and symptoms include diarrhea, bloody stools, abdominal pain, abdominal distention, and constipation. The physical findings are usually unremarkable. Prognosis depends on the overall clinical picture. NEC has a mortality rate of about 30%, and as many as 50% of patients may require surgery for perforation. Pneumatosis is an ominous radiographic finding in patients suspected of having bowel ischemiasigns of perforation, peritonitis, or abdominal sepsis. Mesenteric Ischemia Decreased intestinal blood flow results in ischemia and subsequent reperfusion damage at the cellular level that may progress to the development of mucosal injury, tissue necrosis, and metabolic acidosis. Acute (arterial embolism, thrombosis, vasoconstriction- sepsis/hypovolemia/cocaine, hypercoagulable states) Chronic (long-standing atherosclerotic disease of 2 or more mesenteric vessels, vasculitides, worse during meals) *Relatively normal abdominal examination in the face of severe abdominal pain.