Clinical Analysis of Surgical Results for Discrete Subaortic Stenosis

Yu, Song Hyeon; Lim, Sang Hyun; Hong, You Sun; Park, Young Hwan; Chang, Byung Chul; Kang, Meyun Shick

Abstract

BACKGROUND: Discrete subaortic stenosis is known to recur frequently even after surgical resection. We retrospectively reviewed the preoperative and postoperative changes in pressure gradient through left ventricular outflow tract, and the recurrence rate. MATERIAL AND METHOD: Between September 1984 and December 2004, 34 patients underwent surgical treatment. Mean age of patients was 17.1+/-15.2 years and 19 patients (55.9%) were male. 16 patients (47.1%) had previous operations and associated diseases were aortic regurgitation (11), coarctation of aorta (3), and others. RESULT: Immediate postoperative peak pressure gradient was significantly lower than preoperative peak pressure gradient (21.8 mmHg vs 75.8 mmHg, p<0.01). Peak pressure gradient measured after 50.3 months of follow up was 20.2 mmHg, which was also significantly lower than that of preoperative value but not significantly different from that of immediate postoperative value. There was no surgical mortality but one patient developed cerebral infarction. Mean follow up duration was 69.8+/-54.6 months. During this period, 5 patients (14.7%) had reoperation, 3 (8.8%) of whom were due to recurred subaortic stenosis. We found no risk factors for recurrence and survival for free from reoperation was 76.4%.
CONCLUSION
Excision of subaortic membrane combined with or without myectomy in discrete subaortic stenosis showed sufficient relief of left ventricular outflow tract obstruction with low mortality and morbidity, but careful long term follow up is necessary for recurrence, since it is not predictable.