[Results of open heart surgery in neonates--comparison between profound hypothermia with circulatory arrest and deep hypothermic bypass].

: To investigate factors affecting surgical outcome of open heart surgery in neonates, a retrospective review was carried out on 38 patients operated in the 9 years period from May 1981 to August 1990, in our institution (TAPVR19, TGA7, HLHS7, and others 5). In the former 3 years and 9 month period, 12 patients were operated with the use of profound hypothermia and circulatory arrest (Group I) and in the latest 5 year and 5 month period, continuous deep hypothermic bypass was used in all but for 7 patients with HLHS (Group II). In the group of neonates with TAPVR, operative mortality improved to 7% (1 of 14) in Group II compared to that of 60% (3 of 5) in Group I. CVP and LAP measured immediately after cessation of cardiopulmonary bypass (CPB) were lower in Group II and the value of CPK-MB was significantly lower in Group II. There was a significant negative correlation (r = -0.695, p less than 0.05) between CPB time and urine volume for 72 hours after operation. A significant negative correlation (r = -0.899, p less than 0.01) was also obtained between CPB time and urine volume in the group of 7 neonates with TGA. There was no significant difference in urine volume between patients with TAPVR and TGA despite of significantly longer CPB time in patients with TGA. It is concluded that, 1) improved protection of cardiac and renal function was obtained in neonates operated with the use of continuous deep hypothermic bypass, 2) surgical outcome was influenced by the method of CPB, CPB time and differences in cardiac function ascribed to primary lesions.