[Chronic thromboembolic pulmonary hypertension: can successful thrombendarterectomy normalize exercise capacity and gas exchange?].

Chronic thromboembolic pulmonary hypertension, a rare complication of pulmonary embolism is amenable to thrombendarterectomy (TEA) and when successful, improves exercise capacity and normalizes resting pulmonary arterial pressure. To test if exercise capacity and exercise gas exchange are also normalized after successful TEA. Over a period of 4 years, 5 patients underwent TEA at Sheba Medical Center. All experienced marked clinical improvement; their functional capacity (NYHA class) improved by 1-3 stages and resting pulmonary blood pressure normalized. One to 3 years after surgery each underwent a 6 minute walking test and incremental exercise to measure maximal oxygen uptake. It was found that following TEA, the 6 minute walking distance improved by 100-215 meters and more. Maximal oxygen uptake remained below normal in 4/5 cases and ranged 42-87% of predicted values. Hemoglobin oxygen saturation that was normal after TEA at rest, fell in all with exercise to 91-96%. Exercise gas exchange remained abnormal, consistent with residual pulmonary vascuLar disease. Thrombendarterectomy in chronic thromboembolic pulmonary hypertension caused marked clinical improvement and normalized resting pulmonary arterial pressures. Exercise capacity also improved but peak oxygen uptake remained below normal and exercise gas exchange remained abnormal. Chronic thromboembolic pulmonary hypertension can be effectively treated. However, despite remarkable improvement, residual pulmonary vascular disease persists and is not relieved following successful operation.