Off-label use of an adjustable gastric banding system for pulmonary artery banding

Background Pulmonary artery banding is proposed as a first palliation in infants with complex congenital heart disease and high pulmonary blood flow. In addition, it may be used to retrain the left ventricle. Optimal tightening may be difficult to obtain, leading to reoperation. An implantable device for pulmonary artery banding with telemetric control was recently developed allowing for repeated adjustments, but it is presently limited to patients weighing less than 20 kg. In large animals, we tested an off-label adjustable gastric banding system for pulmonary artery banding. Methods and Results Fourteen ewes weighing 50 to 75 kg underwent implantation of the Lap-Band device (BioEnterics Corp, Santa Barbara, Calif) around the main pulmonary artery through a left thoracotomy. All had functional evaluation with progressive occlusion and opening of the device at implantation and every 2 weeks until sacrifice immediately after implantation (group 1, n=8), at 1 month (group 2, n=3), at 3 months (group 3, n=3), or death. Invasive pressure measurements in the right ventricle and aorta were carried out each time. Devices were easily implanted in all animals. Progressive occlusion and reopening were possible in all animals during each time point. Two animals died of right heart failure related to excessive tightening of the band. Retrieval of the device without any major damage was possible in 12 of 14 animals. Conclusion With this implantable device, we were able to adjust the pulmonary artery diameter in animals. Patients requiring left ventricle retraining and weighing more than 30 kg would benefit from the device's use in humans.