Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension is substantially more prevalent than is generally recognized. Most patients affected with this disorder are severely symptomatic, but in the early stages, the diagnosis may be hard to make. Despite an estimated incidence of 2500 to 25,000 cases annually in the United States alone, these patients continue to be misdiagnosed. The condition results in pathologic arterial changes (in both affected and unaffected vessels) due to chronic pulmonary embolism. The disease carries a poor prognosis and a high mortality rate. Medical therapy is limited to anticoagulants, diuretics, vasodilators, and inotropes; however, because the disease is caused by fixed obstructive lesions, no medical treatment is considered curative. In general, medical treatment only transiently relieves symptoms and is ineffective in altering the prognosis. The condition is treated with pulmonary transplantation in a number of centers. Pulmonary endarterectomy has many advantages, however, including a lower operative mortality rate, excellent long-term results, and no need for chronic immunosuppression; it is now widely accepted as the most appropriate therapeutic option. With successive improvements in technique and in the postoperative management of these patients over the past decade, we can now offer this procedure to patients because there is an acceptable incidence of death and excellent anticipation of clinical improvement. Although the procedure is offered to some severely ill patients with poor risk factors, the mortality rate of this procedure at our institution remains in the range of 5% to 7%. Underrecognition remains the primary barrier to care. It is hoped that with more awareness of the efficacy of surgical treatment, more patients will be given the opportunity to be relieved of this disease.