AN INDICATION OF OPERATION FOR VENTRICULAR SEPTAL DEFECT, ESPECIALLY IN TYPE 1 CASES

Ventricular septal defect (VSD), which is one of the most common cardiac malformations, sometimes leads to aortic regurgitation (AR). In this study, several conditions related to occurrence of AR were analyzed on the basis of 184 operated cases.1) VSD was divided into the following three types ;supracrystal type without (Ia) and with clonal muscular rim (Ib), and membranous type (II), which accounted for 26%, 6% and 68% of cases, respectively.2) The frequency of abnormal aortic cusps in each of the three types was 67%, 18% and 6%, respectively, and there was a significant difference between types Ia and II (p < 0.01).3) According to the cumulative curve of the occurrence of abnormal aortic cusps and AR, the 50th percentile for the former was 10 years of age, that for the later 13 years.4) There was no relationship between the frequency of abnormal aortic cusps and the size of VSD.5) Spontaneous closure of VSD was thought to occur in many cases between 6 and 15 years of age.6) Concerning the operative indications for VSD Ia, the following conclusions were obtained : i) Cases with AR should undergo the radical operation regardless of stage or age. ii) In cases without AR, patients over 10 years old should undergo the operation.However, operation for patients under 10 years old should be decided with reference to the progression of cusp abnormality and the occurrence of spontaneous closure.