Superior mesenteric artery and vein injuries from blunt abdominal trauma.

During an 8-year period, from 1974 to 1982, 13 patients were treated for superior mesenteric vascular injury secondary to blunt abdominal trauma. Ten male and three female patients ranged in age from 18 to 68 years (average age, 42.7 years). Six patients presented in profound shock, two presented in cardiopulmonary arrest, and five presented with mild shock. The 13 patients had an average of 3.2 associated intra-abdominal injuries. Six patients had devitalized bowel as a direct consequence of injury to the superior mesenteric vessels. One patient developed intestinal necrosis postoperatively from thrombosis of the superior mesenteric vein which led to extensive small bowel resection. The blood replacement ranged from 2 to 30 units, averaging 11.7 units per patient. Operative procedures included lateral arteriorrhaphy (five patients) and venorrhaphy (11 patients). Four patients required combined vessel repair and one patient required ligation of both vessels and bowel resection. The mortality rate of 57% was primarily due to massive acute hemorrhage, which was larger than could be accounted for by the associated intraabdominal injuries. Free intraperitoneal hemorrhage from the valveless portal system, which can carry up to 60% of cardiac output, causes massive bleeding until abdominal tamponade supervenes.