Abstract 4566: Growth and Function of Hypoplastic Right Ventricles and Tricuspid Valves in Infants with Pulmonary Atresia and Intact Ventricular Septum
Objectives The pulmonary atresia intact septum (PAIVS) spectrum includes very hypoplastic right ventricles (RVs) and tricuspid valves (TVs) as well as RV-coronary artery connections (RV-CACs). These abnormalities are often thought irreversible and only 30 – 40% reach a 2-ventricle repair (2VR). Our hypothesis, however, has been PAIVS is a developmental defect and catch-up growth is possible. We provide up to 10 year data on RV and TV growth and function after 2VR.
Methods Follow-up echo data were sought on the 24 survivors of the 28 patients (pts) treated from 1989 –1999. Two pts with Ebstein’s anomaly and one without coronary-aorta connections were excluded. Biplane echos were required for accurately estimating RV volume, TV size, and function. Measurements were indexed (I) to determine the z-values (standard deviation of the mean from predicted).
Results All patients had an RV outflow patch and ASD reduction. Growth required complete relief of RV obstruction and a mildly restrictive (3–5 mmHg) ASD to encourage TV flow. A central shunt was placed in 38%. RV-CACs (2.7 ± 1.6/pt) were uneventfully ligated off bypass in 9/28 (32%). For the 24 survivors, 19 adequate paired biplane studies were obtained and 12 approached 10 year follow-up. No central shunts remained. The other survivors were satisfactory on local follow-up visits. The TVs, despite increased flow, grew more slowly than RVs. But even very small TVs in 10 pts went from z-values of −4.6 ± 0.4 to −0.04 ± −1.5 within 5–10 years. Normal size was achieved in 9/10 and 1 went from z = −5.2 to −3.1. Valvotomies were done in 3. RV function was high normal (EF = 74.5 ± 0.1%) because of pulmonary regurgitation in 8 pts with adequate studies.
Conclusions 1) Catch-up growth appears reliable in PAIVS pts even for TV z-values ≤ −4.0. 2) The consequences of PAIVS can be reversed by growth when RV obstruction is relieved and TV flow increased. 3) RV function was good and resembled well repaired TOF. 4) These results encourage pursuing 2VRs in PAIVS pts.