Surgical treatment for chronic thromboembolic pulmonary hypertension under profound hypothermia and circulatory arrest in 24 patients

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious disease that induces hypoxemia and pulmonary hypertension, eventually leading to respiratory failure and right heart failure. We evaluated the results of surgical treatment in patients undergoing circulatory arrest under profound hypothermia. Methods: Between February 1995 and June 1999, 24 cases of CTEPH were surgically treated. The age of patients (11 males and 13 females) ranged from 21 to 71 years (mean 49 +/- 15 years). Because of hypoxemia, severe pulmonary hypertension (mean pulmonary artery pressure 45 +/- 7 mmHg), and low cardiac output, the functional class of these patients was New York Heart Association (NYHA) III or IV. Following a median sternotomy, profound hypothermia was induced using cardiopulmonary bypass, and pulmonary thromboendarterectomy in the bilateral pulmonary arteries was performed under intermittent circulatory arrest. Surgery was performed emergently in four patients. Results: Of these 24 patients, 2 of 20 patients who underwent elective surgery and 3 of 4 patients who underwent emergent surgery died in the hospital. Symptoms of CTEPH markedly improved in 18 patients who survived the surgery. Pulmonary arterial pressure was decreased to 16 +/- 6 mmHg, and cardiac output was increased. Conclusions: When CTEPH is resistant to medical treatment, surgical treatment is useful. When surgical indications are carefully selected, pulmonary thromboendarterectomy using intermittent circulatory arrest under profound hypothermia is quite effective for treating CTEPH.