Long-term evaluation of cava-pulmonary artery anastomosis.

Abstract

In 63 patients with severe malformations of the right side of the heart with diminished pulmonary blood flow, a superior vena cava-pulmonary artery (cava-PA) anastomasis was made. Fifty-six survived operation and have been followed for an average of 7.9 years. There were three late deaths, all unrelated to the shunt. The results of operation were gratifying with improved arterial oxygenation and lowering of the hematocrit for five to seven years when signs and symptoms of hypoxemia began to reappear. A thorough evaluation of all patients in this series was undertaken to determine the causes of this late deterioration, to explore methods of providing additional oxygenation in these patients, and to reevaluate the cava-PA shunt as a palliative operation. The causes of late deterioration were: (1) diminished flow through cava-PA shunt caused by an increased pulmonary vascular resistance either primary or secondary to increased viscosity of the blood and the expansion of collateral veins to inferior vena cava; (2) diminished flow to contralateral lung caused by the closure of pulmonary outflow tract and increased pulmonary vascular resistance. Additional operations to improve oxygenation were carried out when indicated. These were: (1) systemic artery-pulmonary artery shunt to contralateral lung; (2) atrial septectomy; (3) axillary-arteriovenous (AV) fistula; (4) ligation of collateral venous connections; (5) correction of cardiac defect. Upon late reevaluation, the cava-PA shunt has provided excellent palliation and low mortality rates in carefully selected cases when combined with other appropriate palliative operations. Contraindications to cava-PA anastomosis include: (1) a correctable lesion; (2) pulmonary hypertension (at any time); (3) age less than six months.