[Ischemic colitis and mesenteric ischemia after abdominal aortic reconstruction]

Ischemic colitis is quite a rare condition, which can be subdivided into two categories, a so-called occlusive form as a complication of various vascular diseases, and a non-occlusive form caused by exogenous administration of drugs, or i.e. higher cocentrations of various endotoxines or cytokines. Besides the most serious cases with transmural ischemia, needing operation and resection, over 50% of all cases suffer from non-transmural or mucosal ischemia which can be treated conservatively. These cases usually show a rather favourable outcome. A part of these patients will suffer from bowel stenosis or strictures later on and may need secondary resections. Ischemic colitis following aorto-iliac reconstructive surgery is a rare but well known complication. Although it should be suspected much more frequently, only 1 to 2% of the patients will present a condition of clinical importance. The complication is more frequent in patients who undergo surgery as an emergency, especially reconstruction for aneurysmal disease, and it is less frequent in patients who undergo aorto-iliac reconstruction for occlusive disease; probably because the latter have already developed collateral vessels in the visceral area. A preoperative evaluation of this specific risk is rarely possible by angiography. Intraoperative strong pulsating backflow from the inferior mesenteric artery is considered as a quite reliable prognostic factor for a sufficient mesenteric circulation. Measurement of inferior mesenteric stump pressure, fluoresceine instillation and doppler ultrasound have been proposed as more reliable predictive elements. Wherever mesenteric circulation seems to be doubtful, inferior mesenteric replantation is advisable. In the postoperative course, a thorough clinical surveillance and probably systematic sigmoidoscopy especially on patients with prolonged intubation in strongly advisable in order to detect ischemic lesions in an early stage. Early operations on transmural lesions will help to improve this otherwise very serious and life threatening complication.