Discrete membranous subaortic stenosis: improved results after resection and myectomy.
BACKGROUND
Despite an adequate resection, a significant recurrence rate is encountered in patients undergoing operation for discrete membranous subaortic stenosis. The fibrous membrane and hypertrophied myocardium commonly are removed, but because of the involved risks, the resection may be inadequate and contribute to the recurrence rate.


METHODS
A review of the cases of 23 patients undergoing operation for discrete membranous subaortic stenosis from 1980 to 1994 was undertaken. Fourteen patients (61%) had coexisting cardiac lesions, all of which were concomitantly repaired.


RESULTS
The left ventricle-aorta gradient decreased from a preoperative mean of 63.39 +/- 7.63 mm Hg to 15.17 +/- 3.06 mm Hg postoperatively (p < .001) during a mean follow-up of 3.32 +/- 0.58 years. Aortic insufficiency decreased postoperatively in 8 patients (34.8%), remained unchanged in 6 patients (26.1%), and showed only insignificant progression in 4 patients (17.4%). There were no early deaths, and the single late death was not cardiac related. No patient had development of endocarditis or heart block or required a pacemaker. One patient (4.3%) had a recurrence, which required reoperation.


CONCLUSIONS
Our results suggest that aggressive myectomy in concert with membrane resection constitutes safe treatment for discrete membranous subaortic stenosis and is associated with low rates of endocarditis, recurrence, and progression of aortic insufficiency.
Rayburn
S T
ST
Division of Cardiothoracic Surgery, University of Mississippi Medical Center, Jackson 39216, USA.
Netherland
D E
DE
Heath
B J
BJ
D000293:Adolescent; D000328:Adult; D001024:Aortic Valve Stenosis / Q000209:etiology / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000150:complications