Surgical thoracic sympathectomy induces structural and biomechanical remodeling of the thoracic aorta in a porcine model.

Background: Sympathetic innervation exerts marked effects on vascular smooth muscle cells, including a short-term homeostatic (vasoconstrictor) and a direct trophic action promoting differentiation. However, the role of sympathetic nervous system in long-term structural and functional modulation of the aortic wall is yet undefined.

Methods: Six Landrace pigs underwent bilateral thoracic sympathectomy from the stellate to T8 ganglion, whereas 10 pigs underwent sham operation.

Local hemodynamics and intimal hyperplasia at the venous side of a porcine arteriovenous shunt.

Venous anastomotic intimal hyperplasia (IH) observed in the arteriovenous shunt (AVS) has been associated with disturbed hemodynamics. This study aims to correlate hemodynamics with wall histology and wall mechanics by examining the flow field in AVS with computational fluid dynamics using experimental data taken from in vivo experiments. Input data to the computational model were obtained in vivo one month after AVS creation; adjacent vessels were submitted to histological and mechanical examination.

Biomechanical, morphological and zero-stress state characterization of jugular vein remodeling in arteriovenous fistulas for hemodialysis.

While the role of hemodynamic variables on the development of intimal hyperplasia in arteriovenous fistulas for hemodialysis has been examined, less is known about the intramural biomechanical factors. In this study, arteriovenous fistulas were created by implantation of e-PTFE grafts between carotid artery and jugular vein in healthy pigs. In vivo recordings exhibited a three-fold pressure and flow elevation in grafted veins after fistula creation, remaining so until sacrifice.