Concomitant Dual Intravascular and Subcutaneous Microsurgical Implantation of Xenograft Tissue in a Rodent Model for Evaluation of Structural Degeneration

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.