Eightyfive patients with severe pulmonary hypertention (Pp/Ps over 0.75) underwent various open-heart surgeries at the department of Thoracic and Cardiovascular Surgery, Sapporo Medical College and Hospital, during the period from July 1, 1973 through July 31, 1981. The cardiac diseases included were as follows (deaths in parentheses) ; ventricular septal defect (VSD + PH) 59 cases (11); complete transposition of the great arteries (TGA + VSD) 15 cases (10); coarctation of the aorta (CoA complex) 8 cases (5) ; interruption of the aortic arch (IAA + VSD) 3 cases (2). The overall mortality was 32.9%. In VSD with severe PH, the operative mortality was 18.0%. On the other hand, there was no death in 15 cases of VSD with moderate PH (Pp/PsO.6 - 0.75). of 15 cases with TGA + VSD, Mustard's operation was performed in 10 (7), Senning's operation In 3 (1), Jatene's operation in 1 (1), and Kaye-Stansel's operation in 1 (1). Of 8 cases with CoA complex, primary total correction was performed in 2 (2) and staged operation in 6 (2). In cases with IAA+VSD, a primary total correction of Muraoka's operation was successfully performed in a 2 year old boy. With use of combined hypothermia (surface and perfusion cooling) and cardiac arrest, results of primary total correction have significantly improved in the group older than 3 months of age.
