ALBUMIN AS A SEALANT FOR A POLYESTER VASCULAR PROSTHESIS - ITS IMPACTON THE HEALING SEQUENCE IN HUMANS

Objective. Although the healing characteristics of albumin impregnated vascular prostheses have been extensively studied in animal models, t hey have never been studied in. humans, We therefore examined the heal ing sequence and the albumin degradation rate of this type of prosthes is harvested from humans, We also addressed the possible relationship between the implantation of cross-linked albumin and a specific inflam matory reaction. Methods. Thirty albumin-impregnated polyester vascula r prostheses were collected in our institution from January 1991 to Fe bruary 1993. The mean duration of implantation of the prostheses was 8 .4+/-9.7 (SD) months (range: 1 hour to 26 months). Twenty two prosthes es were patent at the time of explantation and 4 had been thrombosed f or less than 24 hours, In 18 cases, the prostheses were surgically rem oved because of a complication or a reoperation, and during an autopsy in 12 cases. Each harvested specimen was submitted to histological an d immunohistochemical studies in order to demonstrate the presence of human albumin sealant, and to determine the inflammatory cell constitu ents. Results. The albumin-impregnated prostheses were poorly infiltra ted by healing tissues after 2 years of implantation An external capsu le was constantly observed after 2 months of implantation with a nonsp ecific chronic inflammatory reaction localized between the capsule and the polyester yarns, We observed large amounts of albumin sealant aft er 2 months, a gradual degradation with time, and traces after 2 years of implantation in humans, The luminal surface of the ex-plant was ma inly covered with organized fibrin, No histological signs of a specifi c inflammatory reaction were observed. Conclusions. The healing of the albumin impregnated prosthesis was poor and the degradation rate of t he albumin sealant was significantly delayed, when compared to animal models, This difference in degradation rate could be related to inters pecies differences of phagocytic cells enzymatic machinery, Finally, i mplantation of glutaraldehyde cross-linked albumin in humans is safe, since me observed an aspecific chronic foreign body inflammatory react ion.