High pressure balloon angioplasty for branch pulmonary artery stenosis: early experience.

OBJECTIVES: The aim of this study was to evaluate the efficacy and safety of high pressure balloons (17 to 20 atm, Blue Max, Meditech) to dilate branch pulmonary artery stenosis.
BACKGROUND: The low success rate (50% to 60%) for angioplasty of branch pulmonary artery stenosis using low pressure balloons is due primarily to the inability to eliminate the balloon waist. Hence, higher inflation pressures may improve results.
METHODS: Hemodynamic and angiographic data from 52 patients (0.3 to 34.8 years old) who underwent high pressure balloon dilation of branch pulmonary artery stenosis between October 1990 and February 1992 were reviewed retrospectively, as were data from previous low pressure dilations in these patients. Common diagnoses included tetralogy of Fallot (n = 9), tetralogy of Fallot with pulmonary atresia (n = 23), single ventricle (n = 8) and isolated congenital pulmonary stenosis (n = 7). The 52 patients had 72 vessels dilated. Criteria for success were a > or = 50% increase in vessel diameter or a > 20% decrease in right ventricular to aortic pressure ratio.
RESULTS: Of 36 vessels with previously unsuccessful low pressure balloon dilation, 23 (63%) were successfully dilated with high pressure balloons. Of the 36 remaining vessels, 29 (81%) were successfully dilated with high pressure balloons. Factors associated with success were stenosis at a surgical anastomosis and disappearance of the balloon waist with dilation. Aneurysms developed in three vessels. Complications occurred in seven patients (13%); in two patients the distal pulmonary artery was perforated by a stiff guide wire, causing death in one.
CONCLUSIONS: Dilation of stenotic peripheral pulmonary arteries with high pressure balloons improves the success rate of angioplasty both in patients who have had unsuccessful dilation with a low pressure balloon and in those without previous attempted dilation.