Percutaneously Adjustable Pulmonary Artery Band

Abstract

Conventional banding techniques result in up to 50% mortality as a result of improper and fixed constriction of the pulmonary artery in patients in unstable condition. We developed a percutaneously adjustable band with a fluid-filled reservoir that allows variable constriction without thoracotomy or other surgical procedures. Six pigs ranging in weight from 7 to 10 kg underwent pulmonary artery banding. Swan-Ganz catheterization, ultrasound studies, and Doppler studies were used to adjust and monitor the pressure gradient across the band. Thirty days after banding, the pigs were killed; their hearts were sectioned, weighed, and compared with hearts from a control group of six pigs weighing 11 to 13 kg. The ratio of mean total heart weight to total body weight (× 10 −3) was 6.3 ± 0.7 in the banded group and 4.4 ± 0.3 in the controls ( p < 0.001). The ratio of left ventricular weight to right ventricular weight was 0.76 ± 0.1 in the banded group and 1.6 ± 0.1 in the controls ( p < 0.001). The thickness of the right ventricular free wall was 4.9 ± 0.5 mm in the banded group and 2.6 ± 0.5 mm in the controls ( p < 0.001). Right ventricular free wall weight in the banded group was 25.9 ± 5.8 gm compared with 11.1 ± 1.3 gm in the controls ( p < 0.001). These results demonstrate the effectiveness of the band in inducing right ventricular hypertrophy. Since the band is easily placed and simply adjusted percutaneously, this device promises to be of importance clinically in improving the safety of pulmonary artery banding procedures.