Ingrowth of aorta vascular cells into basic fibroblast growth factor-impregnated vascular prosthesis material: a porcine and human in vitro study on blood vessel prosthesis healing.

Abstract

One of the most life-threatening vascular diseases is rupture of an abdominal aneurysm. The conventional treatment is based on surgical reconstruction. An alternative treatment is endovascular aneurysm repair (EVAR). Despite many advantages, one of the problems of EVAR is endoleakage from deficient healing between the aortic neck and the fabric of the endograft. We hypothesize that better healing, achieved with induction of vascular cell ingrowth into the graft material, would lead to better graft healing. Both pig aorta and human normal and aneurysmal aortic wall were used for organ cultures. Various growth factors were evaluated for the potential to induce intimal hyperplasia (ie, platelet-derived growth factor, vascular endothelial growth factor, and basic fibroblast growth factor [bFGF]). After the most potent growth factor had been selected, a vascular prosthetic material (Dacron fabric) impregnated with collagen and heparin was incubated with this growth factor. Impregnated pieces of Dacron were fixated on top of the aortic organ cultures for study of ingrowth of the neointima formation into the graft material. bFGF was the most potent growth factor to induce neointima in aortic organ cultures. The pieces of impregnated Dacron had a release of 5 ng/24 h of bFGF for a period of at least 28 days. With fixation on top of the aortic organ cultures, the impregnated Dacron was capable of inducing neointima formation and ingrowth of the neointima into the graft material after 28 days. We showed that a Dacron prosthesis impregnated with collagen, heparin, and bFGF is capable of inducing graft healing in our in vitro model, the aortic organ cultures of pig and human aortas. These results suggest that the problem of endoleakage with EVAR may be solved with a perfect proximal healing between the aortic wall and the prosthesis.