Can we predict the long-term function of the subclavian flap angioplasty?

Neonatal operations have improved the prognosis for newborn children with aortic coarctation. The 30-day mortality of 123 neonates with isolated coarctation of the aorta collected from nine series was found to be 0.8%. The subclavian flap angioplasty was the most frequently used surgical procedure in this collected series. This technique is relatively new, however, and many questions have yet to be answered. In this study we have done subclavian flap repair in newborn pigs and followed them up to adult ages. The pigs were killed 28 or 44 weeks postoperatively, and the aortas were reexamined. All flaps had grown symmetrically in width and length and parallel to the growth of the descending thoracic aorta. The flaps were macroscopically intact. Signs of degenerative processes were not found. The wall thickness of the subclavian flap increased by growth of the individual fibroelastic lamellar units in the tunica media. This adaptation to the increased wall stress occurred early in life. The wall strength of the flap also increased by thickening of the intimal layer. We conclude that the subclavian flap is well suited to function as a part of the aorta in adult life.