Retrograde cerebral perfusion during hypothermic circulatory arrest reduces neurologic morbidity

Hypothermic circulatory arrest has become an accepted technique for a variety of cardiac and complex aortic operations. However, prolonged periods (> 45 min) of hypothermic circulatory arrest in older patients is associated with marginal cerebral protection and an increased incidence of adverse neurologic events. In an effort to minimize such morbidity, we used a technique of retrograde cerebral perfusion with continuous monitoring of cerebral hemoglobin oxygen saturation during hypothermic circulatory arrest in 35 patients who underwent thoracic aortic operations or resection of intracardiac tumor. There were 27 men and 8 women (mean age 60 years, range 21 to 83 years). Sixteen patients had acute dissection, 6 had contained rupture of a thoracic aortic aneurysm, 10 had either a chronic dissection or aneurysm, and 3 had hypernephromas extending into the heart. Six patients underwent root replacement by means of an open technique for their distal anastomosis, 7 underwent root and partial arch replacement, 12 had root and total arch replacement, 7 had total arch replacement, and 3 had resection of tumor in the heart and retrohepatic vena cava. Seven patients had simultaneous coronary artery bypass grafting, 3 had replacement of one of the arch vessels, and 2 patients had a cesarean section. Sixteen cases were emergency, 6 urgent, and 13 elective. Nine (26%) were reoperations. Thirty-four patients underwent the procedure via a median sternotomy and one patient through a posterolateral thoracotomy. The mean retrograde cerebral perfusion time was 63 minutes (range 35 to 128 minutes), with 30 (86%) patients having more than 45 minutes, 12 (34%) having more than 65 minutes, and 4 (11%) having more than 90 minutes. There was 1 operative death caused by a preoperative myocardial infarction from an aortic dissection, and there were 2 late deaths (multiple organ failure and ruptured total aortic aneurysm). One patient had a stroke with a residual right hemiplegia and a pronounced aphasia. There were no other significant neurologic events or reoperations for bleeding. The average length of stay for patients having elective operations was 11 days and for those having emergency operations, 27 days. At a mean follow-up of 6 months all surviving patients (91%) are well. Hypothermic circulatory arrest is a relatively simple technique that provides a bloodless field and good visualization without the need for aortic crossclamps. Moreover, retrograde cerebral perfusion with continuous monitoring of cerebral oxygen saturation extends the "safe" time for hypothermic circulatory arrest, allowing ample opportunity to perform complicated cardiac and aortic operations with reduced risk of adverse neurologic events.