Long-term results after excision of fixed subaortic stenosis.

Forty-nine patients underwent surgical excision of fixed subaortic stenosis (discrete fibrous ring and tunnel) between 1968 and 1984 and were followed up for 1 to 16 years (5.8 ± 4). Twenty-six patients (Group I) had isolated subaortic stenosis and 23 (Group II) had subaortic stenosis and associated cardiac defects. Discrete fibrous ring was present in 46 and tunnel type of obstruction in three patients. For the discrete ring, excision alone was done in 32 patients (four recurrences) and excision with myotomy in 17 (three recurrences). In Group I, there were no operative deaths and one late death from a noncardiac cause. In Group II, one early and two late deaths occurred. The actuarial survival rate for 10 years is 88%. Reoperations were performed in 10 patients, seven for recurrence and three for aortic valve replacement for preexisting aortic regurgitation that had progressed since the primary operation. Cardioplegia was used in 28 patients (one recurrence) and was not used in 21 patients (six recurrences). An operative residual gradient of