Hydrodynamics in the intact and denervated aorta in experiment

Abstract

Aim. As neurogenic processes affect the cardiovascular system and change its function throughout the whole life, the study aims to simulate and study the hydrodynamics of blood flow in an intact and denervated aorta.Methods. A pulse wave going through an intact segment of a dog’s thoracic aorta, a denervated autograft, and a donor dog’s thoracic aorta allograft was assessed by using equipment for blood pressure measurement and tensiometry of longitudinal and diametrical deformations of blood vessels at the point of pressure measuring. The experiments were performed under general endotracheal anesthesia. Two series of acute experiments on replacement of the thoracic aorta by an autograft and an allograft were carried out. Each series had eight dogs. The approach was thoracotomy in the IV intercostal space on the left. A required segment was replaced after heparin infusion while using subclavian-femoral bypass and retrograde autoperfusion.Results. It was found out experimentally that the formation and propagation of a normal isolated pulse wave with preservation of a viscous laminar blood flow were impossible without preserved innervation of the aorta. The experiments showed that in an intact aorta, its diameter tends to increase (by 400–500 μm), with simultaneous shortening of the segment (by 250 μm), and this process keeps being ahead of the pressure wave by 0.02–0.04 s. The rate of aortic dilatation is faster than that of systolic pressure elevation. However, in contrast to the intact aorta, the autograft, on the contrary, becomes longer and narrows, as pressure rises.Conclusion. To create optimal hydrodynamics of aortic blood flow, there should be a neuroreflectory system to control each pulse wave, which must determine its solitonic nature and provide antiflatter stabilization of blood flow.Received 16 April 2018. Revised 3 June 2018. Accepted 7 June 2018.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest.