Safety and efficacy of hypothermic cardiopulmonary bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta

Background. Hypothermic cardiopulmonary bypass with circulatory arrest is a n important adjunct for operations on the distal aortic arch and the descen ding thoracic and thoracoabdominal aorta. Its safety and efficacy compared with other techniques (eg, simple aortic clamping, partial cardiopulmonary bypass, and regional hypothermia) are not clearly established. Methods. One hundred sixty-one patients (ranging from 20 to 83 years old) w ith descending thoracic or thoracoabdominal aortic disease had resection an d graft replacement of the involved aortic segments using hypothermic cardi opulmonary bypass usually with intervals of circulatory arrest (mean interv al, 38 minutes). Results. The 30-day mortality rate was 6.2% (10 patients). It was 41% (7 of 17) for patients having emergent operations (rupture or acute dissection) and 2.1% (3 of 144) for all other patients (p < 0.001). The 90-day mortalit y rate was 11.8% (19 patients). Paraplegia occurred in 4 and paraparesis in 1 of the 156 operative survivors whose lower limb function could be assess ed postoperatively (3.2%). Among the 91 survivors with thoracoabdominal. ao rtic disease, early paraplegia occurred in 1 of 33 patients with Crawford t ype I disease, 0 of 34 with type 11 disease, and 2 of 24 with type III dise ase. One patient (type 11 disease) had development of paraplegia on the ten th postoperative day. None of the 50 patients with aortic dissection experi enced paralysis. Renal dialysis was required in 4 (2.5%) of the 157 operati ve survivors, prolonged inotropic support (> 48 hours) in 17 (11%), reopera tion for bleeding in 8 (5%), mechanical ventilation (> 48 hours) in 31 (20% ), and tracheostomy in 13 (8%). Three patients (1.9%) sustained a stroke. Conclusions. Hypothermic cardiopulmonary bypass provides safe and substanti al protection against paralysis and renal, cardiac, and visceral organ syst em failure that equals or exceeds that of other currently used techniques b ut without the need of other adjuncts. (C) 2001 by The Society of Thoracic Surgeons.