Resection of subaortic membrane for discrete subaortic stenosis

We reviewed the long-term results of surgery for discrete subaortic membrane (SubAM) from a single institute.

A retrospective review of medical records of all patients (n = 146) who underwent resection of a SubAM for discrete subaortic stenosis between 1990 and 2015 at the All India Institute of Medical Sciences, New Delhi, India was undertaken.

Median age at surgery was 9.0 years (9 months-47 years). There was one early death. Preoperative peak left ventricular outflow tract (LVOT) Doppler gradient was 83.4 ± 26.2 mmHg (range: 34-169 mmHg). On preoperative echocardiography, aortic regurgitation (AR) was absent in 69 (47.3%), mild in 35 (24%), moderate in 30 (20.5%), and severe in 12 (8.2%). After surgery, the LVOT gradient was reduced to 15.1 ± 6.2 mmHg (P < 0.001). Fourteen patients (9.6%) who had residual/recurrent significant gradients are currently being followed-up or awaiting surgery. There was improvement in AR for operated patients with freedom from AR of 92.6 ± 0.03% at 15 years. Kaplan-Meier survival at 25 years was 93.0 ± 3.9% (95% confidence interval: 79.6, 97.7). Freedom from re-operation at 25 years was 96.9 ± 1.8%.

Long-term results of surgery for discrete SubAM are good. Resection of the membrane along with septal myectomy decreases the risk of recurrence.