Peripheral Pulmonary Artery Stenosis: Acute and Mid-term Results of High Pressure Balloon Angioplasty

Surgical angioplasty for branch pulmonary arterial stenosis (BPAS) is associated with a low success rate and a high mortality rate. The success rate of balloon angioplasty using low pressure balloon catheters is about 60%. Little data are available on the success rate using high-pressure balloon (HPB) catheters. Therefore, our goal is to report the procedural and mid-term success rates using HPB catheters for the treatment of BPAS and those factors associated with success. 38 patients (25 boys/13 girls) with BPAS underwent at least one attempt (48 procedures) of balloon angioplasty using HPB catheters. Their median age was 1.1 years (range, 0.1–22.1 year), and their median weight was 9.6 kg (range, 3.7–61 kg). Thirty patients (79%) had BPAS following surgical intervention for their cardiac defects (mostly post tetralogy of Fallot), and eight (21%) patients had the BPAS associated with Williams syndrome (2 patients), Alagille syndrome (one patient), unoperated tetralogy of Fallot (one patient), and congenital BPAS (4 patients). Twenty-six procedures involved the left pulmonary artery (LPA), and 22 procedures involved the right pulmonary artery (RPA). The overall acute success rate was 56% (27 of 48 vessels). The mean ± SD of the gradient across the stenotic segment decreased from 37 ± 20 to 23 ± 20 mmHg (P < 0.001), and the diameter of the narrowest segment improved from 3.5 ± 1.6 to 5.7 ± 2.5 mm (P < 0.001). The median RV/AO pressure ratio decreased from 0.64 to 0.52 (P = 0.009). The median ratio of balloon size to the diameter of the narrowest segment was 2.67 (range, 1.3–7.8). Lesion location (RPA) was associated with higher acute success rate (P = 0.03), but not with mid-term outcome. Acute (P = 0.006) and mid-term (P = 0.04) success were related to balloon diameter to vessel diameter ratio. At mid-term follow-up (median interval 2.5 years), 16 vessels (33%) were widely patent. Complications included perforation of a small branch pulmonary artery in one patient, resulting in hemoptysis with complete recovery. One patient developed pulmonary artery hypertension; two patients developed an aneurysm of the dilated segment; one patient developed femoral vein thrombosis; and one patient had a paradoxical embolus associated with a cerbrovascular accident. There were no procedure-related deaths. We conclude that BPAS is challenging to treat. The use of HPB angioplasty may avoid surgery or the permanence of stem implantation and should be the first intervention for this condition in the pediatric patient. Other interventions should be reserved for refractory stenosis.