Clinical application of retrograde cerebral perfusion for brain protection during surgery of ascending aortic aneurysm--a report of 50 cases.

This study was designed to discuss the effects on the brain by different protective methods in ascending aortic aneurysm surgery retrospectively. Two hundred seventy-one surgeries of ascending aortic aneurysm have been done in the past 15 years. There were 65 patients with a dissecting aneurysm of the aortic arch or right arch. To protect the brain, deep hypothermic circulatory arrest (DHCA) combined with retrograde cerebral perfusion (RCP) through superior vena cava (N = 50) and simple DHCA (N = 15) were used during the procedure. Blood samples for lactic acid level from the jugular vein were compared in both groups. Perfusion blood distribution and oxygen content difference between the perfused blood and returned blood were measured in 5 and 10 of RCP patients, respectively. The DHCA time was 35.86 +/- 18.81 min (10 approximately 63 min) and DHCA + RCP time was 45.5 +/- 17.21 min (16 approximately 81 min). The resuscitation time was 7.11 +/- 1.59 h (4.4 - 9.4 h) in DHCA versus 5.43 +/- 2.15 h (2 approximately 9 h) in RCP patients. The operation death rate was 3/15 in DHCA group and 1/50 in RCP patients. Central nervous complication occurred in 3/12 of DHCA patients and 1/49 of RCP patients (p < .01). The overall survival rate was 96% (RCP) versus 67% (DHCA); the central nervous system dysfunction was 20% in DHCA versus 2% in RCP (p < .001). The blood lactic acid level increased significantly after reperfusion in DHCA than that in RCP. The measurement of blood distribution indicated that approximately 2Q% of the perfused blood returned from arch vessels. The difference of oxygen content between perfused and returned blood showed that the oxygen uptake was adequate in RCP group. The application of RCP can prolong the safety duration of circulation arrest. Continuous cerebral perfusion may maintain the brain at a cooler temperature and flush out particulate and air emboli while open anastomosis of the aortic arch to the prosthesis can be safely performed. Therefore, RCP is a preferable method for brain protection in our clinical practices.