[Surgical results of pulmonary thromboendarterectomy for chronic pulmonary thromboembolism].

Chronic pulmonary thromboembolism may produce severe respiratory insufficiency and progressive pulmonary hypertension resulting in an intractable right ventricular failure. Although the pathogenesis of this syndrome has not been completely understood, medical treatment usually has little effect and only surgery can be a life saving remedy. Since 1986, seven patients with this syndrome have had pulmonary thromboendarterectomy at the First Department of Surgery, Chiba University Medical Center. Surgery is indicated mainly for patients who present with a mean pulmonary arterial pressure greater than 30 mmHg. All procedures were performed through a unilateral thoracotomy with a cardiopulmonary bypass on stand-by use. Two patients (#1 and #6) needed bilateral surgery which was carried out in two stages, in the remainder only a right side being operated on. When a major pulmonary artery was clamped, the systolic pulmonary arterial pressure rose to equalize or even exceeded that of systemic artery, however since no further hemodynamic deterioration was observed, cardiopulmonary bypass was not used in any case. Although the key feature of this procedure is commonly said to establish an exact cleavage plane between thrombus and arterial wall, it can be carried out without difficulty through thoracotomy approach. Grasping the thrombus, blunt dissection is further proceeded until the entire thrombotic material comes free as a cast of the vessels. All patients survived the operation without major complications including severe reperfusion pulmonary edema. Postoperative catheterization, performed one month following surgery, demonstrated a marked reduction of pulmonary arterial pressure with significantly reduced pulmonary arterial resistance (PAR).