Hydrostatic Comparison of Nonpenetrating Titanium Clips Versus Conventional Suture for Repair of Spinal Durotomies

Study Design. Biomechanics. Objective. To compare the hydrostatic strength of suture and nonpenetrating titanium clip repairs of standard spinal durotomies. Summary of Background Data. Dural tears are a frequent complication of spine surgery and can be associated with significant morbidity. Primary repair of durotomies with suture typically is attempted, but a true watertight closure can be difficult to obtain because of leakage through suture tracts. Nonpenetrating titanium clips have been developed for vascular anastomoses and provide a close apposition of the tissues without the creation of a suture tract. Methods. Twenty-four calf spines were prepared with laminectomies and the spinal cord was evacuated leaving an intact dura. After Foley catheters were inserted from each end and inflated adjacent to a planned dural defect, the basal flow rate was measured and a 1-cm longitudinal durotomy was made with a scalpel. Eight repairs were performed for each material, which included monofilament suture, braided suture, and nonpenetrating titanium clips. The flow rate at 30, 60, and 90 cm of water and the time needed for each closure were measured. Results. There was no statistically significant difference in the baseline leak rate for all 3 groups. There was no difference in the leakage rate of durotomies repaired with clips and intact specimens at any pressure. Monofilament and braided suture repairs allowed significantly more leakage than both intact and clip-repaired specimens at all pressures. The difference in leak rate increased as the pressure increased. Closing the durotomy with clips took less than half the time of closure with suture. Conclusion. Nonpenetrating titanium clips provide a durotomy closure with immediate hydrostatic strength similar to intact dura whereas suture repair with either suture was significantly less robust. The use of titanium clips was more rapid than that of suture repair.