A versatile extracorporeal circuit for use during repair of descending and thoracoabdominal aortic aneurysms in high-risk patients with cardiac and/or pulmonary dysfunction: a novel approach to a significant perfusion management dilemma.
The incidence of ischemic complications associated with repair of descending and thoracoabdominal aortic aneurysms has been significantly reduced by the use of distal aortic perfusion with moderate hypothermia, cerebral spinal fluid drainage, and segmental sequential clamping techniques. However, because the maintenance of proximal perfusion, the adequacy of left heart bypass (LHB), and the ability to ventilate patients on only one lung are all dependent on ventricular and pulmonary function, high-risk patients with descending and/or thoracoabdominal aortic aneurysms in the presence of cardiopulmonary insufficiency or instability present a difficult challenge for the surgical team. Traditional closed LHB circuits become nonfunctional in the event of cardiac arrest or refractory arrhythmias that create hemodynamic instability and are unable to provide necessary pulmonary support if the patient fails to ventilate adequately on one lung during thoracotomy. Furthermore, converting a patient from closed LHB to traditional venoarterial cardiopulmonary bypass (CPB) is frequently difficult, especially when the perfusionist works without the benefit of extra personnel to assist during such crises. Consequently, a modified extracorporeal circuit was designed to provide closed LHB with desired therapeutic adjuncts while also satisfying the additional need for a rapid infusion device, a source of supplemental ventilation/oxygenation, and, if necessary, the ability to convert the patient to venoarterial CPB conveniently in the event of cardiac and/or pulmonary failure during surgery to repair descending and/or thoracoabdominal aortic aneurysms.