Polypropylene suture stresses after closure of longitudinal arteriotomy

This study was performed (1) to determine the load on polypropylene (Prolene) sutures when used to close a longitudinal carotid arteriotomy and (2) to compare that load with the tensile strength of the suture material. Laboratory methods were used to determine the stress caused by pressure, the surgeon's knot, and that resulting from longitudinal extension of the sutured vessel. Results showed that the stress from the surgeon's knot accounts for more than 95% of total load on the suture, the remainder resulting from pressure and geometry. At 100 mm Hg in a 10 mm carotid artery at in situ length, 5-0 Prolene suture is loaded to 22%, 6-0 to 32%, and 7-0 to 42% of their respective breaking stresses. When the cervical spine is hyperextended, the carotid artery is stretched up to 6%. When the sutured pressurized vessel is extended 6%, 5-0 Prolene suture is loaded to 51%, 6-0 to 52%, and 7-0 to 75% of breaking stresses. These data suggest that 5-0 and 6-0 Prolene sutures should be used in preference to 7-0 sutures to close a carotid arteriotomy.