SUBAORTIC OBSTRUCTION IN DOUBLE-OUTLET RIGHT VENTRICLES - SURGICAL CONSIDERATIONS FOR ANATOMIC REPAIR

Background. Subaortic obstruction is one of the risk factors for anato mic repair of double outlet right ventricles (DORV). A comprehensive a pproach to such lesions has been developed in our institution since 19 81. This retrospective work analyzes the results of this approach. Met hods and Results. Between January 1981 and September 1992, 30 patients aged 15 days to 15 years (mean, 44.8 months) underwent repair of a DO RV associated with subaortic obstruction. Eighteen patients had a pall iative procedure before complete repair. The ventricular septal defect (VSD) was subaortic in 15 patients, doubly committed in 1, noncommitt ed in 9, and subpulmonary in 5. The subaortic obstruction was a result of restrictive VSD in 29 patients and of double straddling of mitral and tricuspid valves once. The preoperative peak systolic pressure gra dient between the left ventricle and the aorta (LV-Ao) was 68.7+/-23 m m Hg. Reconstruction of the left ventricular outflow tract comprised a ventral enlargement of the VSD in subaortic, doubly committed, and th ose subpulmonary VSDs scheduled for an arterial switch operation or a conal resection in noncommitted and other subpulmonary forms. Reconstr uction of the right ventricular outflow tract included primary closure of the right ventricle in 12 patients, an infundibular patch in 9, a transannular patch in 4, and insertion of a right ventricular pulmonar y valved conduit in 5. There were two early (6.6%) and two late (7.1%) deaths. Three patients required reoperation. A mean follow-up of 60.5 +/-46.8 months was achieved in all the survivors. They were all in New York Heart Association class I or II, in sinus rhythm. At last follow -up, the mean LV-Ao gradient was 7.5+/-6.2 mm Hg, and LV function indi ces were within normal ranges. Actuarial survival and freedom from reo peration rates at 8 years were 86.6% and 87.0%, respectively. Conclusi ons. Surgical relief of subaortic obstruction in DORV has to be adapte d to VSD location and spatial arrangement of atrioventricular valves a nd great vessels.