Development of a device for transcatheter pulmonary artery banding: evaluation in animals

Pulmonary artery banding (PAB) is the first palliation in infants with complex congenital heart disease and elevated pulmonary blood flow. In older patients with corrected transposition of the great arteries, it may be used to re-train the left ventricle. To date, the only option is surgical. We report the development and the evaluation of a device for transcatheter PAB.

We intended to implant a pulmonary artery (PA) reducer percutaneously between the native pulmonic valve and the pulmonary bifurcation. Immediately following its insertion, we planned to implant a balloon expandable stent inside the restriction to calibrate the banding. Sheep were sacrificed acutely (group 1, n=6) and after 1 month of follow-up (group 2, n=6), the reducer was implanted successfully in all animals. It allowed the PA diameter to be reduced from 25 to 10.5 mm. Bare stents were successfully delivered inside the reducer. No paraprosthetic leak was found by injecting contrast dye. After the insertion procedure, signs of intolerance to obstruction were present in all animals and prompted us to dilate the stents from 12 to 16 mm. One animal from group 1 died before a balloon dilatation could be achieved. In the animals from group 2, the mean systolic gradient was 19 and 34.8 mmHg, respectively, at early and late evaluation.

Implantation of a PA reducer is possible in sheep, through a transcatheter approach allowing intravascular PAB. Miniaturization of the device is necessary to enlarge its use from adulthood to childhood.