Effect of force on anastomotic suture line disruption after carotid arteriotomy

Static and dynamic forces exerted on 6-0 polypropylene suture material after carotid arteriotomy were measured in 22 adult mongrel dogs. Force was measured in 11 normotensive animals (Group I) before and 6 weeks after carotid artery repair. Force was measured in the remaining animals during normotension and induced hypertension before and 6 weeks after operation. The tensile strength of each suture used in the study was measured by the manufacturer. The mean force required to break a 6-0 polypropylene suture measured 436.9 +/- 2 g, whereas knotting of the suture decreased the tensile strength to 316.9 +/- 3.9 g (p less than 0.001). The static and dynamic axial forces exerted on the suture after carotid arteriotomy in Group I was in the range of 26 g and decreased to 18 g at 6 weeks, whereas the 45 degree force exerted during the static dynamic phase measured in the range of 23 g and decreased to 16 g at 6 weeks (not statistically significant). The axial and 45 degree forces exerted on 6-0 polypropylene suture material in Group II under normotensive conditions were in the range of 14 g after carotid arteriotomy and ranged between 12 to 14 g at 6 weeks. Systolic hypertension did not result in a significant increase in axial or 45 degree forces during static or dynamic measurements, both in the range of 15 g after carotid arteriotomy. Measurements were similar at 6 weeks and ranged between 14 and 16 g. Our data indicate that 6-0 polypropylene suture material is an appropriate choice for repair of the carotid artery and that the suture material has sufficient inherent tensile strength to withstand forces generated in the neck region. Furthermore, our data indicate that spontaneous carotid artery suture line disruption is most likely related to damage to the suture strand during carotid artery repair rather than an inherent weakness in the suture material.