Comparison of dural repair techniques

Background context Incidental durotomy occurs in 1% to 17% of lumbar spine surgery. This is treated with watertight suture repair, often combined with a sealant. Purpose To compare the hydrostatic strength of dural repair using various suture sizes, closure techniques, and adhesives. Study design A novel in vitro hydrostatic calf spine model. Outcome measures Dural leakage as a function of hydrostatic pressure and leak area. Methods We compared surgical repair between 5-0 surgilon and 6-0 prolene suture, continuous locked versus interrupted suture, and the effectiveness of three adhesives hydrogel, cyanoacrylate, and fibrin glue. The leakage flow rate was compared among suture groups using analysis of variance (ANOVA). The percent reduction of leak area was determined for the sealants and compared using ANOVA. The study was funded from an intramural departmental grant. Results 6-0 Prolene was found to have significantly decreased leakage flow rate than 5-0 surgilon. We found no significant differences in the flow rate between the interrupted and continuous locked sutures. In most cases, leakage occurred from the needle holes around sutures. There was an 80% reduction in leak area with the hydrogel and cyanoacrylic sealants compared with only a 38% reduction with fibrin glue; however, there was no statistical difference between the leak rates using any of the sealants. Conclusion 6-0 Prolene using either interrupted or locked techniques was the best at creating watertight closure of an incidental durotomy. If a watertight seal cannot be obtained, a hydrogel or a fibrin sealant will immediately improve the strength of repair. Newer sutures that have a larger diameter of suture relative to needle should be developed for use in dural repair.