Arterial regeneration over absorbable prostheses.

Small-vessel arterial replacement by a prosthetic material elicits inflammatory and regenerative reactions that alter the patency rate of the resultant prosthesis-tissue complex. Woven absorbable polyglycolic acid prostheses, 24 mm in length, were implanted into adult rabbit aortas and followed for 7 1/2 months. At the time the animals were killed, 45 specimens were studied grossly and by arteriography, light and electron microscopy, immunohistology, and bursting-strength determinations. No rabbit died of aortic-related complications. Mild dilation occurred in 11% (five specimens), and intimal hyperplasia occurred in 13% (six specimens), with 76% (34 specimens) displaying parallel walls at the original 3- to 4-mm diameter. Microscopy showed that the prostheses were replaced by regenerating endothelialized vessels containing smooth musclelike myofibroblasts and dense fibroplasia, without thrombosis or infection. All withstood saline solution infusion at three to five times the systolic pressure. Results of these studies demonstrate conditions that permit arterial regeneration over absorbable scaffolds.