Chronic thromboembolic pulmonary hypertension: a tribute to pulmonary endarterectomy.

O ur understanding of chronic thromboembolic pulmonary hypertension (CTEPH), in terms of both its natural history and pathophysiology, has greatly improved since the landmark descriptions given by MOSER and BRAUNWALD [1] more than 40 yrs ago. At that time, small case series were available, depicting the clinical features of patients suffering from ‘‘long-standing thromboembolic pulmonary hypertension’’, ‘‘chronic massive thromboembolic obstruction’’ or ‘‘chronic obstruction of large pulmonary arteries’’. These patients shared a history of long-term dyspnoea on exertion with normal spirometry values, evidence of pulmonary hypertension, and right ventricular dysfunction in association with the presence of marked defects at the ventilation/ perfusion scan; the occurrence of a single or multiple venous thromboembolism episodes, usually several years previously, was constantly mentioned in the diagnostic work-up [2–5]. The success of a surgical procedure, namely pulmonary endarterectomy, has transformed this lethal disorder into a potentially curable form of pulmonary hypertension [1]. As a consequence, the referral of cases suitable for surgery has gradually increased with time: at the University of San Diego (San Diego, CA, USA) there were 41 operated cases in 1980, rising to 323 cases in 1992 [6, 7]. This has enabled us to broaden our knowledge, with the help of further involvement from European centres [8–11].