RESUMO
The combination of deep hypothermia and circulatory arrest has been used in a variety of cardiovascular surgical techniques and is presented in this article as an elective method in the treatment of type B dissecting aneurysms that may or may not involve the distal aortic arch. Out of 190 patients operated on with acute aortic dissection, 10 patients with type B underwent surgical procedures, between January 1985 and December 1987, four with acute dissection (less than 14 days evolution), and six with chronic dissection (more than 14 days evolution). The approach was by left posterolateral thoracotomy with cardiopulmonary bypass using femoro-femoral cannulation, deep hypothermia, and circulatory arrest. The duration of circulatory arrest was between 27 and 58 minutes, mean 37 minutes. Extracorporeal circulation (ECC) lasted between 68 and 142 minutes, with a mean perfusion time of 83.7 minutes, and temperature fell to 14 degrees C and 16 degrees C. Intrahospital mortality was 20% (two patients). No long-term mortality has been recorded. Eighty percent of the patients (eight patients) are alive and showed good evolution between 10 and 44 months following surgery, with a long-term mean survival of 24 months and 23 days. The only neurological complication was a single case of right unilateral blindness followed by complete visual recuperation. Myocardial and spinal cord protection are excellent, without any incidence of postoperative infarct or paraplegia. Postsurgical blood loss ranged from 200 to 650 mL with a mean of 385 mL. Acute renal insufficiency was not detected. We believe that the combined techniques of deep hypothermia and circulatory arrest used electively, and not just out of occasional necessity, is a viable choice that allows easier surgical manipulation of type B dissection aneurysms and complete resolution of those involving retrograde dissection to the aortic arch. In addition. this combined technique does not increase postoperative mortality in this critically dangerous disease.
