Mesenteric inflammatory veno-occlusive disease (MIVOD): an emerging and unsuspected cause of digestive tract ischemia.

Background: Mesenteric inflammatory veno-occlusive disease (MIVOD) is a new clinicopathological entity and an unsuspected cause of digestive tract ischemia in the 17 patients reviewed in this article. Patients and Methods: Of this series, MIVOD occurred twice as often in men as in women, and the age of affected patients ranged from 24 to 78 years. Unexplained ischemic bowel disease was the most common clinical presentation of MIVOD. All patients required surgical exploration and underwent resection of ischemic or gangrenous bowel. None of the patients had a known underlying systemic vasculitis, connective tissue disease, inflammatory bowel disease, infection, drug allergy, or ingestion of food contaminants or toxins. Results: In general, a correct diagnosis of MIVOD is possible in virtually all cases only after careful histological examination of the resected specimens because the endoscopic biopsy findings may be inconclu sive. The inflammatory infiltrate of active MIVOD may be lymphocytic, necrotizing, granulomatous, or mixed, and thrombosis is almost invariably alo present. The late changes Of MIVOD, concentric or eccentric myoin timal hyperplasia and occlusive phlebosclerosis, represent organized thrombi. Conclusion: MIVOD probably occurs more commonly than is generally recognized. To a casual observer the presence of thrombosis may overshadow the inflammatory component ofa veno-occlusive disease, especially in the absence of arterial vasculitis many cases of MIVOD can conceivably go undiagnosed.