Postoperative vasospasm after antegrade mesenteric revascularization: a report of three cases

Vascular reconstruction for chronic intestinal ischemia can be accomplished by endarterectomy or aortomesenteric bypass. In our practice, antegrade bypasses from the supraceliac aorta to the celiac axis and superior mesenteric artery are currently the most frequently used techniques. Such reconstructions often use multiple or bifurcated large diameter vascular prostheses and have demonstrated excellent long-term patency. Despite these salutory results, we have noted an unusual perioperative response in three of these patients, which is the subject of this report. All three patients underwent uncomplicated elective mesenteric revascularization with grafts (diameter greater than or equal to 6 mm) originating in the supraceliac aorta. Indications for operation included (1) history of postprandial pain, (2) documentation of weight loss, and (3) angiographic evidence of advanced atherosclerotic disease with appropriate collateral development. Episodes of abdominal pain occurred 5 to 20 days after operation when normal food intake was reinstituted. In two patients immediate angiograms revealed patent grafts with diffuse mesenteric vasospasm. Treatment with intravenous hyperalimentation and nifedipine for 10 days resulted in complete resolution of symptoms. In the third patient, symptoms were totally relieved by temporary reduction in oral intake and administration of nifedipine. A later angiogram revealed a patent graft. All patients have remained asymptomatic and regained normal weight. This pattern of postrevascularization pain has not been seen in our patients undergoing revascularization with small (i.e., venous) conduits originating in the infrarenal aorta. The cause appears to be a heightened myogenic response of a "protected" vascular bed when suddenly exposed to the high perfusion pressure and blood flow of large caliber antegrade conduits. Prophylaxis with calcium channel blockers and use of smaller diameter grafts (5 mm) may avoid this disturbing syndrome.