Balloon dilation of the right ventricular outflow tract in tetralogy of Fallot: a palliative procedure

Fifteen patients requiring palliation for tetralogy of Fallot were treated by balloon dilation because of hypercyanotic spells. The mean age at dilati on was 1.9 +/- 0.7 years (range 0.5 - 3), and the mean weight 9.8 +/- 2.1 k g (range 6.0 - 13.5). Dilation of the outflow tract was combined with dilat ion of the left and/or right pulmonary arteries in 5 patients. Successful d ilation was achieved in 12 patients (80%), but failed in 3 patients with hy poplastic pulmonary arteries. In one patient, the stenosis of the right pul monary artery could not be dilated because of a very sharp angle at the sit e of the stenosis. Two of the 3 patients in whom the procedure failed died of severe cyanotic spells within 24 hours of the unsuccessful procedure. No major complications occurred during or after the procedure in the cases un dergoing successful dilation. The arterial oxygen saturation increased sign ificantly, from 71 +/- 5.7% to 89 +/- 3.9%, immediately after the procedure (p < 0.005). During a period of follow up of 6 +/- 3.7 months (range 1 - 1 3), the procedure was repeated on 3 occasions, and successfully accomplishe d in 2 of these. In conclusion, balloon dilation is a satisfactory palliati ve procedure for tetralogy of Fallot in those units in which total correcti on is not performed under 2 to 3 years of age.