Multiinstitutional experience with the management of superior mesenteric artery injuries

Background-Superior mesenteric artery (SMA) injuries are rare and often let hal injuries incurring very high morbidity and mortality. The purposes of t his study are to review a multiinstitutional experience with these injuries .; to analyze Fullen's classification based on anatomic zone and ischemia g rade for its predictive value; to correlate the American Association for th e Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular in jury with mortality, and to identify independent risk Factors predictive of mortality, describing current trends for the management of this injury in America. Study design: We performed a retrospective multiinstitutional study of pati ents sustaining SMA injuries involving 34 trauma centers in the US over 10 years. Outcomes variables, both continuous and dichotomous, were analyzed i nitially with univariate methods. For the subsequent multivariate analysis, stepwise logistic regression was used to identify a set of risk factors si gnificantly associated with mortality. Results: There were 250 patients enrolled, with a mean Revised Trauma Score (RTS) of 6.44 and a mean Injury Severity Score (ISS) of 25. Surgical manag ement consisted of ligation in 175 of 244 patients (72%), first degree repa ir in 53 of 244 patients (22%), autogenous grafts were used in 10 of 244 (4 %), and prosthetic grafts of PTFE in 6 of 244 patients (2%). Overall mortal ity was 97 of 250 patients (39%). Mortality versus Fullen's zones: zone I, 39 of 51 (76.5%); zone II, 15 of 34 (44.1%). zone III, 11 of 40 (27.5%); an d zone IV, 25 of 108 (23.1%). Mortality versus Fullen's ischemia grade: gra de 1, 22 of 34 (64.7%). Mortality versus AAST-OIS for abdominal vascular in jury: grade I, 9 of 55 (16.4%); grade II, 13 of 51 (25.5%); grade III, 8 of 20 (40%); grade IV, 37 of 69 (53.6%); and grade V, 17 of 19 (89.5%). Logis tic regression analysis identified as independent risk factors for mortalit y the following: transfusion of greater than 10 units of packed RBCs, intra operative acidosis, dysrhythmias, injury to Fullen's zone I or II, and mult isystem organ failure. Conclusions: SMA injuries are highly lethal-Fullen's anatomic zones, ischem ia grade, and AAST-OIS abdominal vascular injuries correlate well with mort ality. Injuries to Fullen's zones I and II, Fullen's maximal ischemia grade , and AAST-OIS injury grades IV and V, high-intraoperative transfusion requ irements, and presence of acidosis and disrhythmias are significant predict ors of mortality. All of these predictive factors for mortality must be tak en into account in the surgical management of these injuries. (J Am Coll Su rg 2001; 193:354-366. (C) 2001 by the American College of Surgeons).