Percutaneously adjustable pulmonary artery band. An experimental study.

Several forms of congenital heart lesions with increased pulmonary flow can be effectively palliated by pulmonary artery banding. In addition, banding has aroused renewed interest to induce left ventricular hypertrophy in infants with simple transposition of the great arteries. Occasionally a need arises to readjust the band to obtain an optimal degree of banding after operation. For percutaneous control of the degree of constriction after pulmonary artery banding, we developed a readjustable vessel occluder. The occluder consists of a stainless steel snare coated with polyethylene, an enveloping polyvinyl catheter (5F and 8 to 12 cm in length), and a screw adjuster, which is a stainless steel cylinder, 7 by 20 mm, containing a bolt and a nut. By means of a specially designed needle driver (1.0 mm in diameter), the screw adjuster can easily be driven percutaneously without a skin incision. The maximum stroke of the screw is 14 mm by 34 revolutions. One complete revolution of this screw corresponds to a change in diameter of 0.14 mm and to a change in circumference of 0.44 mm. Six mongrel dogs ranging in weight from 5 to 10 kg underwent banding of the pulmonary artery or the ascending aorta with this device. Follow-up evaluation by cardiac catheterization and angiocardiography was performed up to 2 months after implantation of the device. This band could be effectively and finely adjusted up to 2 months after implantation and no complication was seen. This preliminary study suggests that this new device may be applicable in patients with congenital heart disease and excessive pulmonary blood flow.