New pediatric applications and techniques for balloon valvuloplasty: Tetralogy of Fallot, complex pulmonary stenosis/atresia, and pulmonary atresia with intact septum

Abstract

Palliative pulmonary balloon valvuloplasty in Tetralogy of Fallot has been proposed to promote growth of the pulmonary valve so that it can be incorporated in a later repair without transannular patch to avoid the late complications from free pulmonary regurgitation. We have used the procedure in patients with severe hypoxemia less than 3 months old. Synopsis of 141 published cases and our own experience in 15 patients shows technical success in 93%, a complication rate of 5%, cyanotic spells in 9%, and a mortality of 0.6%. Arterial oxygen saturation instantly increased from 78 to 91%. Based on the intention to treat, emergent surgery was avoided in 65%. Despite a significant increase in pulmonary valve diameter, the incidence of transannular patch was reduced in only one study, partly reflecting the surgeon's preference. Palliative pulmonary balloon valvuloplasty can also promote pulmonary artery growth in other complex cyanotic lesions. In pulmonary valve atresia with intact ventricular septum without right ventricular dependent coronary circulation, catheter valvotomy and subsequent pulmonary balloon valvuloplasty can establish right ventricle to pulmonary artery continuity. Perforation of the atretic valve can be accomplished with a bare wire (rarely), with a hot tip laser wire or with a radiofrequency wire if available. We use a standard steerable 5 French electrode catheter to deliver radiofrequency pulses at 8–26 watt with subsequent dilatation using a 7–8 mm low profile balloon. If tricuspid valve diameter or right ventricular size are below normal, additional stenting of the ductus with a flexible stent expanded to 4–5 mm diameter should be performed. In patients with severe hypoplasia, stent placement across the outflow tract is necessary. With this strategy, overall outcome should be superior to the published data on 68 attempted catheter perforations: Out of the 74% technically successful procedures, only 47% remained without surgical intervention during early follow-up.