Bovine aortic arch: Predictor of entry site and risk factor for neurologic injury in acute type a dissection

Background. The aim of this study was to evaluate ifthe presence of a bovine aortic arch (BAA) the mostcommon aortic arch anomalyinfluences the location ofthe primary entry tear, the surgical procedure, and theoutcome of patients undergoing operation for type Aacute aortic dissection (AAD).

Methods. A total of 157 patients underwent emergencyoperations because of AAD (71% men, mean age 59.5± 13years). Preoperative computed tomographic scans werescreened for the presence of BAA. Patients wereseparated into 2 groups: presenting with BAA (BAAD,n [ 22) or not (BAAL, n [ 135). Location of the primarytear, surgical treatment, outcome, and risk factors forpostoperative neurologic injury and in-hospital mortalitywere analyzed.

Results. Fourteen percent (22 of 157) of all patientsoperated on for AAD had a concomitant BAA. Location ofthe primary entry tear was predominantly in the aorticarch in patients with BAA (BAAD, 59.1% versus BAAL,13.3%; p < 0.001). Multivariate analysis revealed thepresence of a BAA to be an independent risk factor forhaving the primary tear in the aortic arch (odds ratio[OR], 14.79; 95% confidence interval [CI] 4.5448.13;p < 0.001) but not for in-hospital mortality. Patientswith BAA had a higher rate of postoperative neurologicinjury (BAAD, 35% versus BAAL, 7.9%; p [ 0.004).Multivariate analysis identified the presence of BAA asan independent risk factor for postoperative neurologicinjury (OR, 4.9; 95% CI, 1.63514.734; p [ 0.005).

Conclusions. In type A AAD, the presence of a BAApredicts the location of the primary entry site in the aorticarch and is an independent risk factor for a poor neurologicoutcome.