Orthotopic total aortic root replacement model in adult sheep.

Prosthetic heart valves undergo mandatory preclinical animal testing prior to human clinical trials. Historically, a non-site-specific placement of a valve prosthesis has been commonly performed; however, recently site-specific placement continues to attract interest. Various animal models have been used for preclinical evaluation of both aortic and mitral valve prostheses; however, a universally accepted animal model for orthotopic total aortic root replacement with acceptable early and late mortality for long-term evaluation has been lacking. This article reports a successful orthotopic model for placement of tissue valve conduit prosthesis for total aortic root replacement in adult sheep. This model utilized preoperative echocardiographic assessment, specific intraoperative surgical techniques, and both early and late postoperative management therapies. The combination of all of these components resulted in a successful model for orthotopic placement of a tissue valve prosthesis for total aortic root replacement in adult sheep for potential long-term assessment.