[Percutaneous implantation of endoprostheses in stenosis of the pulmonary branches]

Between July 1992 and October 1995. 10 Palmaz stents were implanted in 6 patients aged 2 to 25 years with stenoses of pulmonary artery branches. The stenoses were located on the right (n = 2) or left pulmonary artery (n = 3) or both branches (n = 1). Stenoses of the right pulmonary artery were secondary to a Waterston (n = 1) or Blalock-Taussig (n = 1) anastomosis or to surgical plasty with Dacron (n = 1). Stenoses of the left pulmonary artery were secondary to surgical plasty with Goretex (n = 2), pericardium (n = 1) or Dacron (n = 1): three of these patients had undergone a left Blalock-Taussig anastomosis before complete correction. After implantation of the stent, the pulmonary artery diameter increased from 4 +/- 2 mm to 11 +/- 2 mm (p = 0.0117) and the transstenotic gradient decreased from 44 +/- 18 to 15 +/- 12 mmHg (p = 0.0277). Similarly, the percentage of homolateral pulmonary perfusion at scintigraphy increased from 22 +/- 13% to 53 +/- 17% (p = 0.0431). There were no deaths. The major complication was migration of the stent, observed in three patients at the moment of implantation in two cases and in the hours following implantation in the other case. In these 3 patients, the embolised stent was left in the pulmonary arteries with no adverse consequences on pulmonary perfusion. Two of these patients later successfully underwent further catheterisation for implantation of another stent. Implantation of a stent is a therapeutic alternative in pulmonary artery stenoses which often recur after surgery and/or angioplasty. They increase the diameter of the stenosed vessel and reestablish the equilibrium of perfusion between the two lungs.