Mesenteric venous thrombosis.

MVT is an uncommon form of visceral ischemia. Symptoms and signs of MVT are usually nonspecific and should not be relied on for accurate diagnosis. A simple, logical diagnostic algorithm can be used to manage most of these patients (Fig. 6). CT or MRI appears to be the most sensitive diagnostic test and should be obtained early for any patient suspected of harboring MVT. Patients with peritonitis require prompt abdominal exploratory laparotomy to rule out ischemic bowel. Once the diagnosis of acute MVT is confirmed, the patient should be anticoagulated with heparin. During operation, all nonviable bowel should be resected with intent for a second-look laparotomy after 24 hours if there is any question of ongoing ischemia. We recommend using fluorescein-assisted evaluation of marginally viable bowel intraoperatively. After the operation, anticoagulation is continued with heparin and then oral warfarin sodium when the patient's bowel function returns. For those patients without peritonitis, we recommend prompt anticoagulation followed by at least a 48- to 72-hour period of close observation. All patients who have had an episode of acute MVT and do not have a contraindication to anticoagulation should be anticoagulated on a life-long basis with warfarin sodium. Despite our increased awareness of acute MVT, the 30-day mortality rate remains high. Acute MVT typically has a more insidious and unpredictable course than do other forms of visceral ischemic syndromes, with a mortality rate as high as that of its arterial counterpart. Although there has been a slight improvement in survival during the last 20 years, the recurrence rate remains high and the long-term prognosis is poor in this group of patients. Survival of patients with chronic MVT is better than that of those with acute MVT and appears to be determined by the underlying disease.