Use of small stents for rehabilitation of hypoplastic pulmonary arteries in pulmonary atresia with ventricular septal defect.

Branch pulmonary artery stenosis frequently occurs in pulmonary atresia with ventricular septal defect (PA/VSD). Balloon dilation alone is often unsuccessful in patients with severely hypoplastic pulmonary arteries with residual stenoses after surgical repair. In an attempt to promote distal pulmonary artery growth, 17 stents were placed in 12 severely stenotic pulmonary artery lesions in 10 patients with PA/VSD. All had prior surgery, including pulmonary artery repair, right ventricle to pulmonary artery homograft, and, in 6 of 10, closure of VSD. Median age at stent placement was 16.8 months (range, 13.2-56). Stents were placed using 3.0, 3.5, or 4.0 mm balloons in all but one lesion, in which a 7 mm balloon was used. Following stent placement, there was an increase in the lesion diameter from 1.5 to 3.4 mm (P < 0.05) and an increase in flow to the affected lung from 27% to 34% (P < 0.05). Repeat catheterization 2 to 6 months after stenting in six patients revealed complete occlusion in two of eight lesions. In the other six vessels, there was an increase in distal vessel diameter from 2.96 to 3.94 mm (P < 0.05) even though four had severe restenosis requiring restenting. Two patients underwent surgical pulmonary artery reconstruction and stent removal because of adequate distal vessel growth. Stenting of hypoplastic pulmonary arteries in PA/VSD results in immediate improvement in vessel size and blood flow. Stent restenosis is common although distal vessel growth can be achieved. Stenting of these lesions should be reserved only for those patients unresponsive to other interventions.