OUTCOMES IN CRITICALLY ILL NEONATES WITH PULMONARY STENOSIS AND INTACT VENTRICULAR SEPTUM - A MULTIINSTITUTIONAL STUDY

Objective. This study attempted to determine the optimal therapeutic interventions by risk-adjusted comparisons of early and intermediate-term outcomes. Background. The variety of interventions and the small case load at individual institutions have delayed the generation of reliable information concerning therapy for this condition. Methods. In this prospective 27-institution study, 101 neonates were consecutively enrolled (between January 1, 1987 and January 1, 1991). Treatment was determined by the physicians. Demographic and morphologic details were tabulated. Dimensions of the pulmonary ''anulus'' and tricuspid anulus were measured on echocardiograms, and right ventricular cavity size was estimated. Right ventricular-pulmonary trunk pressure gradients were tabulated. Numerous analyses were made. Results. Severe pulmonary valve stenosis and an intact ventricular septum were present in all patients. The right ventricular-pulmonary trunk junction (''anulus'') was severely narrowed in 15%. Right ventricular cavity size was severely reduced in 4%. The tricuspid valve was small in 15% of patients; its diameter was poorly correlated with right ventricular cavity size. Eighty-nine percent and 81% of patients survived greater-than-or-equal-to 1 month and 4 years, respectively, after the initial procedure. Multivariable analysis identified no patient-specific risk factors for death. Only open pulmonary valvotomy without a support technique was uniformly a procedural risk factor; under some circumstances, transannular patching without a shunt was a risk factor. The right ventricular-pulmonary trunk gradient immediately after valvotomy was < 30 mm Hg in 81% of patients and was similar after surgical and balloon valvotomy. In 74% of patients, no intervention was required after the first accomplished intervention. Conclusions. Marked variation in morphology is uncommon in critical pulmonary stenosis in neonates. Percutaneous balloon valvotomy and certain types of surgical valvotomy are optimal initial procedures. The unusual situation of a small pulmonary ''anulus'' may initially require a transannular patch and a systemic-pulmonary artery shunt.