Background: Superior mesenteric artery (SMA) injuries are rare and devastating injuries incurring very high mortality rates. It is the purpose of this study to review our experience with these injuries, to analyze Fullen's classification based on anatomical zone and injury grade for its predictive value, and to correlate the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury with mortality.
Methods: Retrospective study was made over a 65-month period of all patients sustaining SMA injuries in an urban level I trauma center.
Results: Thirty-five patients, mean age 31, had a mean Revised Trauma Score of 5.86 and a mean Injurity Severity Score of 23. Mechanisms of injury were penetrating 27 (77%) and blunt 8 (23%). Mean admission systolic blood pressure was 85 mm Hg. Mean estimated blood loss was 8,500 mL and mean total fluid replacement 17,000 mL. Operating room findings were retroperitoneal hematoma in 34 (97%) and "black bowel" in 2 (6%). Number of associated injuries was nonvascular, mean 4.2, and vascular, mean 1.5. Surgical management consisted of ligation in 18 (51%), primary repair in 14 (40%), and interposition graft in 2 (6%). Overall mortality was 19 of 35 (54%). Mortality versus Fullen's zones was zone I, 100%, zone II, 43%, and zones III and IV, 25%. Mortality versus Fullen's ischemia grade was grade 1, 89%, grade 2, 58%, grade 3, 100%, and grade 4, 19%. Mortality versus AAST-OIS: was grade 1, 0%, grade II, 20%, grade III, 0%, grade IV, 59%, and grade V, 88%.
Conclusions: SMA injuries are highly lethal. Most deaths are due to exsanguination. A higher number of associated vascular injuries increases mortality. "Black bowel" is an uncommon finding. Both Fullen's anatomical zones and the AAST-OIS for abdominal vascular injuries correlate with mortality. Fullen's ischemia grade does not.