In Vivo Analysis of Dynamic Tensile Stresses at Arterial End-to-end Anastomoses. Influence of Suture-line and Graft on Anastomotic Biomechanics

Abstract

Objective to determine the influence of an anastomotic suture line and a graft on dynamic tensile stresses of vascular end-to-end anastomoses in vivo. Material and methods the abdominal aorta of twelve 35-kg pigs was used as an experimental model. Simultaneous recordings of internal arterial diameter and pressure were performed on each pig at 3 successive stages: (1) The genuine artery (REF), (2) artery–artery (A-A) and (3) graft–artery (G-A) anastomosis at 1-mm increments in the immediate perianastomotic area. Thereby, RD (relative distension), CC (compliance coefficient), Ep(dynamic pressure-strain elastic modulus) and hysteresis loop areas could be calculated for every measuring point. Results the graft was significantly stiffer than REF. A-A and G-A anastomoses were significantly less compliant than REF. Maximum Ep, minimum CC and hysteresis loop areas were found at the anastomotic line due to minimum anastomotic RD. Downstream of the G-A anastomosis, the RD, CC, Epand loop areas were significantly different from REF, but significantly different from A-A. Conclusion an animal model for acute studies of mechanical properties of vascular end-to-end anastomoses was developed. The main determinant for anastomotic biomechanics was the suture-line itself.