Introduction: A high rate of unintended durotomy is reported in the literature, with reports in revision surgery exceeding 10%. Methods at improving the fidelity of durotomy closure have consisted of watertight closure with fibrin sealants. One concern by physicians during cerebrospinal fluid leak (CSF) repair is using suture where the needle diameter is incompletely matched by a small suture diameter. This is commonly seen in most sutures used in dural repair, including the commonly utilized nylon-based sutures, carrying the potential for CSF leak. In an attempt to address this concern, increased use with Gortex ™ (Goremedical, Flagstaff, AZ) suture has been seen as it carries a unique design with a needle whose diameter is matched by the suture.

Methods: A comparison of dural closures was performed through a direct comparison of the peak pressure at which leakage occurred from a durotomy closure. A 1 cm durotomy was made in a latex dural tube(Fig. 1) utilized in an established CSF repair model consistent across all durotomy trials (Fig. 2) (www.sawbones.com). Trials were performed for every combination of suture and closure technique by two investigators (GG, CM). 4-0 Nurolon™, a commonly used suture with a tapered needle (Ethicon, Somerville, NJ) was compared to various Gortex™ suture sizes (CV-6™/5-0 and CV-5™/4-0). The failure pressure was determined by incremental pressure at a rate of 1cm/sec until the point of incisional leakage was observed under magnification over 3 closure techniques (interrupted, running, locked) for each type of suture. A Mann-Whitney-u test was utilized for comparison of Nylon and Gortex for significance. For Closure technique, one-way analysis of variance was performed.

Results: Thirty dural closures were performed. The mean peak pressure at which CSF drainage occurred after CSF drainage did differ significantly (P=.330) between Nurolon™(30.3) and Gortex™(30.9). The peak pressures did not differ significantly between the various closure methods (Nurolon or gortex)(table 1)(P=0.147).

Conclusions: No significant difference was noted between nylon and gortex-based suture as well as with closure method.

Patient Care: A persistant CSF leak in the lumbar spine carries a high morbidity often to routine elective procedures. This laboratory analysis serves to enhance the general understanding of strengths of various sutures and closure techniques.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand the various dural suture options for durotomy closure. 2) Understand the mean 'peak pressure to failure' among suture options for durotomy closure. 3)Understand the differences between Goretex and Nurolon sutures used in durotomy closure.

References: Comparison of dural repair techniques. Dafford EE, Anderson PA. Spine J. 2013 Aug 22.