Low incidence of restenosis after successful balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

Balloon pulmonary angioplasty (BPA) is now a treatment option for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, the incidence of restenosis and long-term changes in vessel diameters in pulmonary arteries after BPA are unknown. The present study investigated the incidence of restenosis by measuring changes in vessel diameter after BPA. We reviewed 58 patients (168 lesions) with CTEPH who underwent single dilation for the target lesion (type A/B/C lesions) during BPA procedure followed by selective pulmonary angiography more than 6 months after the final BPA procedure. The outcomes of BPA were assessed in terms of pulmonary artery diameters. In a median follow-up of 1.9 (1.2-2.7) years, restenosis occurred in only one case with a type C lesion after BPA (0.6%). In type A/B lesions, the minimal lumen diameter was significantly enlarged at follow-up after BPA [3.48 (2.59-4.34) to 4.22 (3.31-4.90) mm]. In type C lesions, the minimal lumen diameter was unchanged at follow-up after BPA [3.15 (1.96-3.64) to 3.28 (2.38-4.61) mm]. The present results revealed that restenosis after BPA rarely occurs in type A/B/C lesions. Minimal lumen diameters for type A/B lesions continually increased and those for type C lesions did not decrease. Stent implantation in type A/B/C lesions would be unnecessary after BPA.