Chronic, massive thrombotic obstruction of the pulmonary arteries. Analysis of four operated cases.

CHRONIC, massive thrombotic obstruction of the pulmonary arteries has attracted interest recurrently through the years as a neglected cause of pulmonary hypertension of obscure etiology, usually discovered at autopsy.'-10 This form of "cor pulmonale" has been regarded as a rare entity of academic rather than therapeutic interest. Such opinions now require revision. With the advent of pulmonary thromboendarterectomy as a feasible surgical procedure, chronic massive obstruction has become a potentially curable form of heart disease."' 12 Furthermore, the wider use of pulmonary angiocardiography'3 14 and other diagnostic technics'5 16 has led to the antemortem diagnosis of an appreciable number of such patients in recent years. In the last 3 years, we have encountered eight patients in whom extensive, chronic thromboembolism was the sole cause of, or the major factor in, the development of pulmonary hypertension. This experience has substantiated our prior suggestion that the possibility of surgical correction would heighten interest in this entity and lead to the discovery of additional cases." Four of our eight patients have been operated upon in an attempt to relieve the thrombotic obstruction. In two, thromboendarterectomy was successful, and the patients are alive and well more than 2 years after surgery. In two, surgical cor-