The use of mechanical circulatory support (MCS) during repair of traumatic aortic injuries is associated with a decreased incidence of postoperative paraplegia and mortality. Historical cohort study with contemporaneous but nonrandomized controls in a tertiary care hospital from July 1, 1988, through December 31, 1999. Consecutive cases undergoing operation for traumatic aortic injuries. Use of MCS (with or without systemic heparinization) determined by surgeon preference. Incidence of postoperative paraplegia and mortality. Twenty-two patients underwent repair of traumatic aortic injuries using MCS, resulting in no paraplegia but 4 deaths, 3 of them from cerebral ischemia. Thirteen patients had their traumatic aortic injuries repaired using a "clamp-and-sew" or passive shunt technique with no deaths but paraplegia in 2. Compared with an earlier report from our group from January 1, 1975, through June 30, 1988, the annual incidence of traumatic aortic injuries has decreased, whereas the age of patients and proportion of operations using MCS have increased. A review of the recent literature on traumatic aortic injuries reveals an average postoperative paraplegia incidence of 1% with MCS and 16% without MCS. Overall mortality is similar, but others have also reported cases of cerebral ischemia after aortic repair. The use of MCS during repair of traumatic aortic injuries is associated with a decreased incidence of postoperative paraplegia. The occasional occurrence of cerebral ischemia deserves further study.