SURGICAL-TREATMENT OF SUBAORTIC STENOSIS AFTER BIVENTRICULAR REPAIR OF DOUBLE-OUTLET RIGHT VENTRICLE

Out of 180 patients who underwent biventricular repair of double-outle t right ventricle between 1980 and 1995, 9 (5%) required reoperation b ecause of subaortic stenosis, Two other patients who initially underwe nt operation elsewhere underwent reoperation at our institution becaus e of subaortic stenosis, The median age at biventricular repair was 4 months, Repair consisted of tunnel construction from the left ventricl e to the aorta in nine patients; the remaining two patients received a n arterial snitch operation with ventricular septal defect closure, Su baortic stenosis developed with time: the mean postoperative left vent ricle-to-aorta gradient after repair was 10 +/- 19 mm Hg (range, 0 to 50 mm Hg) and became 84 +/- 27 mm Hg (range, 40 to 124 mm Hg) in a mea n delay of 45 +/- 66 months (range, 1 to 213 months), At reoperation, the obstruction was caused by the protrusion of the inferior rim of th e ventricular septal defect into the left ventricular outflow tract as sociated with subaortic hypertrophied muscle and membrane, The 11 pati ents underwent 15 reoperations. Surgical technique consisted of an ext ended septoplasty in 6 reoperations. In this technique an incision was made in the septal patch and was extended into the muscle toward the apex until a large opening of the left ventricular outflow pathway was obtained, A new patch was then secured to streamline the left ventric ular outflow tract, None of the patients who underwent extended septop lasty had to undergo reoperation, There were no early or late deaths, At 115 +/- 85 months after biventricular repair, all patients were in New York Heart Association functional class I or II and the mean posto perative left ventricle-to-aorta gradient was 20 +/- 24 mm Hg (range, 0 to 60 mm Hg), me conclude that after biventricular repair of double outlet right ventricle, the subaortic region is at risk for the develo pment of stenosis, Surgical treatment adapted to the anatomy of the ob struction can offer good early and midterm results, It seems that an a ggressive approach by an extended septoplasty avoids multiple reoperat ions.