Creation of aortic regurgitation model on isolated porcine heart and aortic valve-sparing root replacement using a new device for aortic valve cusps positioning

Abstract

Valve-sparing surgery in ascending aortic and root aneurysms combined with aortic regurgitation (AR) is a relevant and actively developing trend. The ways to improve these operations are the development of new devices to simplify and standardize valve-sparing procedures using animal models and testing in experiment. Objective. To review experimental methods of aortic root aneurysm and AR modeling, as well as devices simplifying aortic valve-sparing root replacement, including a new device for positioning of aortic valve (AV) cusps during valve-sparing root replacement with AV reimplantation (David procedure), which we have developed. Materials and methods. The components of the developed device were manufactured by three-dimensional printing with preliminary modeling in the parametric environment of computer-aided design with the open source code FreeCAD 0.20.1. The possibility of David procedure on the isolated swine aortic root in the experiment using the new device was evaluated. Results. During the experiments we performed aortic root replacement with AV reimplantation on the isolated porcine aortic root. We noted that the developed device provides good exposure of the surgical correction zone and reduces the probability of damage to the aortic root structures, especially to the AV cusps, in the process of reimplantation. The device eliminates the necessity to use assistants during the main stage of intervention, which reduces the probability of operator-associated complications. Conclusion. Standardization and simplification of reimplantation of AV cusps into the vascular graft during aortic root replacement with the help of the device developed by us is achieved by performing trial positioning of AV cusps and hydraulic tests at different positions of the cusps, which simplifies the search for the optimal point of coaptation and allows to keep the found best position of the cusps until their anchoring inside the graft. The directions of further research are improvement of the design of the developed device, experimental studies with evaluation of the result of valve-sparing surgery under conditions of pulsating fluid flow, testing of the technology on large laboratory animals.