Concomitant dual intravascular and subcutaneous microsurgical implantation of xenograft tissue in a rodent model for evaluation of structural degeneration.

ABSTRACT

INTRODUCTION: An economical animal model to study xenograft tissue degeneration and calcification and the durability of biological vascular patch material and bioprosthetic valve leaflets is desirable. OBJECTIVE: A cost-effective model to analyze xenograft degeneration, calcification, immunologic reaction, and anticalcification treatment was developed. Furthermore, a technique for implant into the vascular lumen of the abdominal aorta in rats is presented. METHODS: Twelve Lewis rats were used as recipients. The microsurgical procedure was performed using a high-definition optical system. Anesthesia was induced and maintained with isoflurane inhalation. The suprarenal and infrarenal portion of the abdominal aorta was isolated, the abdominal aorta was cross-clamped, and a 4-mm square portion of the abdominal aorta was removed. Subsequently, a complementary-sized piece of porcine or bovine glutaraldehyde-fixed bioprosthetic valve leaflet tissue was sutured as a patch in the abdominal aorta. RESULTS: The mean operating time was 45 ± 10 minutes and the mean ischemic time was 25 ± 5 minutes. Early and 3-month survivals were 100%. One rat had intraoperative bleeding. No paralysis or thrombosis was observed. CONCLUSION: Feasibility and reproducibility of removing a portion of the abdominal aorta and replacing it with a patch of xenograft tissue was demonstrated in a rodent model with 100% survival at 3 months. Concomitant dual intravascular and subcutaneous microsurgical implantation of xenograft tissue in a small-animal (rat) model is a cost-effective approach for investigation of xenograft tissue degeneration.