Balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to result from incomplete resolution of pulmonary thromboemboli that undergo organisation into fibrous tissue within pulmonary arterial branches, filling pulmonary arterial lumina with collagenous obstructions. The treatment of choice is pulmonary endarterectomy (PEA) in CTEPH centres, which has low post-operative mortality and good long-term survival. For patients ineligible for PEA or who have recurrent or persistent pulmonary hypertension after surgery, medical treatment with riociguat is beneficial. In addition, percutaneous balloon pulmonary angioplasty (BPA) is an emerging option, and promises haemodynamic and functional benefits for inoperable patients. In contrast to conventional angioplasty, BPA with undersized balloons over guide wires exclusively breaks intraluminal webs and bands, without dissecting medial vessel layers, and repeat sessions are generally required. Observational studies report that BPA improves haemodynamics, symptoms and functional capacity in patients with CTEPH, but controlled trials with long-term follow-up are needed. Complications include haemoptysis, wire injury, vessel dissection, vessel rupture, reperfusion pulmonary oedema, pulmonary parenchymal bleeding and haemorrhagic pleural effusions. This review summarises the available evidence for BPA, patient selection, recent technical refinements and periprocedural imaging, and discusses the potential future role of BPA in the management of CTEPH.