Intraoperative and percutaneous stenting of congenital pulmonary artery and vein stenosis

Abstract

Background: Conventional surgical or balloon dilation therapy for pulmonary artery or vein stenosis has been unsatisfactory in many patients. Balloon-expandable stents offer a new form of treatment for these vascular stenoses and can be implanted percutaneously or intraoperatively.

Methods and results: Between July 1991 and October 1992, 20 balloon-expandable Palmaz stents (Johnson & Johnson) were implanted in 16 children at median age and weight of 3.0 years and 12.8 kg, respectively. Stent implantation was performed intraoperatively (n = 15) if the patient was less than 1 year of age or less than 10 kg in weight, in cases where limited vascular access precluded percutaneous implantation, or as an adjunct to other intracardiac surgery. Otherwise, percutaneous stenting was performed (n = 5). Vessels were tested for distensibility by dilation with balloon catheters or vascular sounds. Stents were implanted using angioplasty catheter balloons chosen to achieve desired vessel diameter and inflated to 4 to 17 atm. Acute hemodynamic and cineangiographic studies were performed in all patients immediately after the procedure to 2 months after stenting. After pulmonary artery stent implantation, mean pulmonary artery diameter increased from 5.6 to 11.5 mm (P = .001), with a decrease in mean systolic pressure gradients from 43 to 8.0 mm Hg (P = .005). Follow-up cardiac catheterization (mean, 8.7 months) in 3 patients revealed no restenosis, thrombosis, or aneurysm formation. In patients in whom pulmonary vein stents were implanted, mean pressure gradients fell from 11 to 0.3 mm Hg (P = .03), and mean pulmonary capillary wedge pressure fell from 17 to 6.3 mm Hg (P = .03) immediately after stenting. At 2- to 6-month follow-up, cardiac catheterization documented restenosis within the stent in 2 of 3 patients. The third patient died 2 months after stenting from presumed vein reocclusion.

Conclusions: When implanted intraoperatively or percutaneously, balloon-expandable endovascular stents have been efficacious in the treatment of pulmonary artery stenosis. Longer follow-up will be necessary to document the long-term effectiveness of pulmonary artery stenting. Preliminary data suggest that early restenosis is common after pulmonary vein stenting. The intraoperative approach extends stenting therapy to smaller children and to patients who have limited percutaneous access.