Pulmonary artery banding has become an infrequently used surgical technique. However, if a band was developed that could be relieved without the need for open heart surgery, it is likely that pulmonary artery banding would be used more frequently in the management of infants with congenital heart disease. Such a pulmonary artery band was placed in seven 1 week old mongrel puppies by using a loop of an absorbable suture material (Vicryl). One dog died at 2 months as a result of right ventricular failure. The remaining six dogs underwent cardiac catheterization and pulmonary balloon angioplasty at 6 months of age. After measuring pulmonary artery, right ventricular and aortic pressures and performing a right ventricular angiogram, balloon angioplasty of the band site was performed. A 20 mm balloon angioplasty catheter (Medi-Tech) was used in all dogs. Balloon angioplasty decreased right ventricular pressure from 101 +/- 19 to 42 +/- 3 mm Hg (p less than 0.05) and right ventricular systolic outflow tract gradient from 59 +/- 14 to 7 +/- 2 mm Hg (p less than 0.03), and increased the size of the band site from 8.7 +/- 0.03 to 14.9 +/- 0.5 mm (p less than 0.01). All dogs were recatheterized 2 months after angioplasty and were then killed for pathologic evaluation. At follow-up catheterization, right ventricular pressure, right ventricular outflow tract gradient and pulmonary artery size at the band site remained at the values obtained immediately after angioplasty. Postmortem examination demonstrated that there was no evidence of pulmonary artery damage. Although these studies are preliminary, they suggest that a reversible pulmonary artery band can be performed.