REPAIR OF COMPLETE ATRIOVENTRICULAR-CANAL DEFECTS - RESULTS WITH THE 2-PATCH TECHNIQUE

Background. Between 1983 and 1994, 115 infants and children underwent repair of a complete atrioventricular canal defect with the two-patch technique and routine mitral valve ''cleft'' closure. Methods. A retro spective review of these 115 patients was performed. Age at the time o f repair ranged from 1 month to 108 months (mean age, 14.2 +/- 16.5 mo nths; median age, 8 months). Preoperative cardiac catheterization in 1 13 patients revealed a mean pulmonary to systemic now ratio of 3.37 +/ - 1.8, a mean pulmonary artery systolic pressure of 71.1 +/- 15.7 mm H g, and a mean pulmonary vascular resistance of 4.9 +/- 3.3 units. Asso ciated anomalies included Down's syndrome (99 patients), patent ductus arteriosus (47), and coarctation of the aorta (4). Rastelli classific ation was A (76 patients), B (10), C (24), and unknown (5). Twenty-fou r patients had intraoperative epicardial or transesophageal echocardio graphy. Results. Although there was a trend toward increasing mean pre operative pulmonary vascular resistance with age from 2.1 +/- 0.9 unit s (0 to 3 months) to 4.0 +/- 2.6 units (4 to 6 months) to 5.7 +/- 3.0 units (7 to 12 months), the mean pulmonary vascular resistance of each age group was not significantly different from that of the main group . The operative survival rate was 94% (seven early deaths) and the ove rall survival rate, 91% (three late deaths). Intraoperative echocardio graphy altered the surgical therapy for 1 patient. No patient has requ ired reoperation for a residual ventricular septal defect. Four patien ts (3.5%) had heart block requiring permanent pacemakers. Eight patien ts (7%) required reoperation for mitral insufficiency; 6 of whom had s uccessful repair of a residual cleft. Conclusions. For infants with co mplete atrioventricular canal defect, repair using the two-patch techn ique with routine mitral valve cleft closure at 4 to 6 months of age r esults in a low operative mortality, a low incidence of permanent hear t block, and a low reoperation rate for mitral insufficiency.