Rupture of thoracic aorta caused by blunt trauma. A fifteen-year experience. During the 15 years from 1971 through 1985, 114 patients with rupture of the thoracic aorta caused by blunt trauma were admitted to the Shock Trauma Center of the Maryland Institute for Emergency Medical Services Systems. Mean age was 31.3 years (range, 15 to 80). Ninety were male and 24 were female, a 3.75:1 ratio. Of the 114, 89 (78.1%) survived initial resuscitation in the admitting area. Twenty five of the 89 initial survivors (28.1%) died during or after surgical repair. Paraplegia occurred in 11 of the 78 operating room survivors (14.1%). Further analysis was done of the 83 patients admitted in the 10-year period from 1976 through 1985. Mean Injury Severity Score, excluding aortic injury, was 18.2. Twenty-five of the 83 (30.1%) died during resuscitation in the admitting area or operating room. Seven others died during surgical repair and 12 died postoperatively, leaving 39 survivors (39/83 [47%] of total admissions and 39/58 [67.2%] of survivors of resuscitation). Paraplegia/paresis developed postoperatively in six of 34 (17.6%) cases involving shunt and four of 17 (23.5%) without shunt. Other major complications occurred in 21 of the operating room survivors. Statistically significant risk of death or major complication was associated with female sex, higher Injury Severity Score, lower admission blood pressure, larger hemothorax on admission, less qualified surgeon, major operation before aortic repair, use of shunt, and transfer directly from scene of injury. There was no advantage in this series to using or not using a shunt in preventing paraplegia. Mortality rates are realistic for a highly developed trauma system. Better techniques are needed to manage exsanguination and prevent paraplegia. 