Perfusion techniques during surgery of the thoracic and thoraco-abdominal aorta: the veno-arterial bypass

Abstract

Open repair of the descending thoracic aorta and the thoraco-abdominal aorta remains a challenging procedure. On the proximal side, pressure overload in the supra-aortic territories and pump failure are just two examples for undesirable effects of descending thoracic aortic cross-clamping which may end with a disaster. On the distal side, potential problems include among others, paraplegia, renal failure, visceral and peripheral ischemia. Finally, there are per-procedural issues like hypoxia due to single lung ventilation, uncontrollable inflow or backflow, excessive blood loss, unrealistic time constraints for systematic revascularization of intercostals arteries etc. Partial (femoro-femoral) cardiopulmonary bypass provides answers to many of the issues raised above. In addition, perfusion with heparin coated equipment allowing for significant reduction of anticoagulation has been shown to be useful for maintaining the hemostatic potential of the patient and limiting blood loss. Our current approach to perfusion for descending thoracic and thoraco-abdominal aneurysm repair has evolved into a versatile cardiopulmonary bypass strategy allowing for rapid conversion from partial cardiopulmonary bypass with peripheral cannulation to full, and if necessary, central, cardiopulmonary bypass, and all sorts of combinations including deep hypothermic circulatory arrest.