Pulmonary artery banding: long-term telemetric adjustment

Objective: Adjustment of pulmonary blood flow is difficult in pulmonary artery banding for complex congenital heart defects. A new wireless, battery free, telemetrically controlled, implantable device (RoWatch(TM), EndoArt, S.A., Lausanne, Switzerland) allowing for progressive occlusion/reopening of the device through a remote control at the wanted percentage of occlusion (adjustable pulmonary artery banding) underwent experimental evaluation. Methods: Eleven mini-pigs underwent FIoWatch(TM) implantation around the main pulmonary artery through left thoracotomy. The first group (n = 4), mean age 18.2 +/- 0.1 weeks, mean body weight 12.0 +/- 0.1 kg, underwent FLoWatch(TM) implantation as device tolerance test. The second group (n = 7), mean age 8.6 +/- 3.4 weeks, mean body weight 5.1 +/- 1.5 kg, underwent functional evaluation: at implantation, 1, 3, 5, 8 and 10 weeks after implantation, the device was progressively occluded and reopened, with Doppler evaluation of the developed pressure gradient. Results: The four mini-pigs of first group were sacrificed at mean age of 42.3 +/- 0.1 weeks, mean body weight 25.1 +/- 3.2 kg (mean interval of 24 weeks after implantation); the device was still functioning and histology revealed almost normal morphology of the pulmonary artery. In all seven mini-pigs of second group the possibility of narrowing/ releasing the pulmonary artery was confirmed at implantation and during follow-up: at last control their mean age was 20.5 +/- 2.8 weeks and the body weight 12.7 +/- 3.7 kg. Conclusions: Complete adjustment of pulmonary blood flow is now possible with an implantable device allowing for pulmonary artery banding with early and late telemetric flow control. (C) 2002 Elsevier Science B.V. All rights reserved.