In vivo analysis of dynamic tensile stresses at arterial end-to-end anastomoses. Influence of suture-line and graft on anastomotic biomechanics.
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.


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), E(p)(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 E(p), 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, E(p)and loop areas were significantly different from REF, but significantly different from A-A.


CONCLUSIONS
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.
Ulrich
M
M
Department of Thoracic and Cardiovascular Surgery and Institute of Experimental Clinical Research, Skejby Sygehus, Aarhus University Hospital, Brendstrupgaardsvej, Aarhus N, DK-8200, Denmark.
Staalsen
N
N
Djurhuus
C B
CB
Christensen
T D
TD
Nygaard
H
H
Hasenkam
J M
JM
D000714:Anastomosis, Surgical; D000818:Animals; D001012:Aorta, Abdominal / Q000502:physiology* / Q000601:surgery; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D006439:Hemodynamics; D011140:Polyurethanes; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013552:Swine; D013718:Tensile Strength
D001672:Biocompatible Materials; D011140:Polyurethanes