Superior mesenteric venous injuries: to ligate or to repair remains the question

Superior mesenteric vein injuries are rare and incur high mortality. Given their low incidence, little data exist delineating indications for when to institute primary repair versus ligation. The purposes of this study are to review our institutional experience, to determine the additive effect on mortality of associated vascular injuries, to correlate mortality with the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury and to examine and define the indications and outcomes for primary repair versus ligation.

Retrospective 156 months study (January 1992 through December 2004) in a large Level I urban trauma center of all patients admitted with superior mesenteric vein injuries. Patients were stratified, according to surgical technique employed to deal with their injuries, into those undergoing primary repair versus ligation to determine outcomes and define the surgical indications of these methods. The main outcome measure was overall survival. Cases of survival were stratified according to surgical method: primary repair versus ligation.

There were 51 patients with a mean Injury Severity Score of 25 +/- 12. Mechanism of injury was penetrating for 38 (76%), blunt for 13 (24%), and patients undergoing emergency department thoracotomy for 4 (8%). Surgical management was ligation for 30 (59%), primary repair for 16 (31%), and 5 (10%) patients were exsanguinated before repair. The overall survival rate was 24/50 (47%). The survival rate excluding patients undergoing emergency department thoracotomy was 51%. The survival rate excluding patients that sustained greater than 3 to 4 associated vessels injured was 65%. The survival rates of patients with superior mesenteric vein and superior mesenteric artery was 55% and superior mesenteric vein and portal vein (PV) was 40%. The survival rate of patients with isolated superior mesenteric vein injuries was 55%. Mortality stratified to AAST-OIS grade III, 44%; grade IV, 42%; and grade V, 42%. Survival rates stratified to method of management consisted of primary repair (60%) versus ligation (40%).

SMV injuries are highly lethal. Multiple associated vessel injuries increase mortality. Mortality correlates well with the American Association for the Surgery of Trauma-Organ Injury Scale for abdominal vascular injuries. Patients undergoing primary repair have higher survival rates (63%) and lesser numbers of associated vascular and nonvascular injuries; whereas those undergoing ligation have a smaller survival rate (40%) and higher number of associated vascular and nonvascular injuries. Ligation appears to be safe and should be selected for hemodynamically unstable patients with a large number of associated injuries.