Left atrial-aortic/femoral bypass with a centrifugal pump without systemic heparin during surgery on the descending...

Active or passive bypass to support the distal circulation during cross-clamping of the descending thoracic aorta has been reported to decrease the incidence of paraparesis, to reduce left ventricle afterload, and to preserve distal organ perfusion. The aim of this study was to describe and to evaluate a perfusion technique for surgery on the descending aorta in humans. Nine patients underwent surgery on the descending thoracic aorta. The left atrium was cannulated using a Carmeda bioactive surface cannula. Distal cannulation sites were the left common femoral artery or the aorta below the involved segment. The cannulae were connected to a BioMedicus centrifugal pump via Carmeda bioactive surface tubings and pump heads. No systemic heparin was used. Cross-clamp time was 51 +/- 6 min, and the pump flow was 2.3 +/- 0.2 L/min. The mean arterial pressure in the upper body was 81 +/- 4 mm Hg and 68 +/- 5 mm Hg in the lower. Seven patients were discharged from hospital. Two patients with aortic rupture died; one died on the operating table, and the other, neurologically intact, died 4 days postoperatively due to multiorgan failure. No patients suffered spinal cord injury. It is concluded that active bypass without systemic heparin during cross-clamping of the descending aorta is simple and safe.