Simple Non-Watertight Closure for Keyhole Retrosigmoid Craniotomies: Is Less More?

Introduction: The retrosigmoid craniotomy is a versatile surgical approach to the cerebellopontine angle (CPA) though cerebrospinal fluid (CSF) leak remains a concern, with a reported prevalence of 0 to 22%. Achieving a “watertight” dural closure after retrosigmoid approaches has been the neurosurgical maxim to minimize CSF leaks though is often unachievable with the native dura. A host of closure materials and strategies have been proposed to achieve this to varying degrees of success. We review our series of retrosigmoid craniotomies and describe our simple, standardized method of closure without watertight dural closure.

Methods: A retrospective review of all retrosigmoid craniotomies performed by the senior author was completed.

Surgical Technique: A post-auricular ~4 to 6 cm curvilinear incision is made. A high-speed cutting burr is then used to perform a craniectomy. No fixed retractors were used. If a large subdural space is present from CSF loss or resection of a large mass, an oversized piece of Gelfoam is placed in the subdural space reducing CSF flow toward the durotomy. A couple of interrupted Nurolon sutures are used to grossly approximate the dural edges and provide scaffolding to support onlay material. An oversized sheet of Duragen is placed as an overlay on the dura. Gelfoam is then placed in the craniectomy defect in a slightly overfilled manner and held in place with titanium mesh ([Fig. 1]). The Gelfoam expands in the craniectomy dead space to provide downward pressure on the collagen matrix graft. No dural sealants are used. The suboccipital muscles and galea-fascial plane are approximated. The skin is closed with a running sub-cuticular suture followed by skin glue.

Results: Patient demographics and surgical outcomes are outlined in Tables 1 and 2. There were two cases (2.8%) of CSF leak during the study period, both resolved with placement of lumbar drain for 5 days. The first patient had a 2.1-cm² craniectomy and microvascular decompression for hemifacial spasm. She had one defined risk factor (morbid obesity, BMI 41.0 kg/m²). The second patient had a 19.7-cm² craniotomy for resection of recurrent epidermoid tumor. Initial surgery and craniotomy, which was complicated by CSF leak and meningitis, was completed at a different institution. She had three defined risk factors (history of DM, perioperative exogenous corticosteroid use, and history of prior surgery at surgical site).

Discussion: CSF leaks are associated with significant morbidity and medical costs. The use of a variety of autografts, allografts, and dural sealants have been described. This often leads to unnecessary complexity for unclear benefits and potentially incurring autologous graft site morbidity and prolonged operative times. We evaluated our closure technique after keyhole retrosigmoid craniectomies where, as a matter of methodology, we do not attempt watertight dural layer closure. Our 2.8% CSF leak rate after a retrosigmoid approach compares favorably with the literature. Unlike most other studies, however, this was a single surgeon study with a uniform approach and without the use of adjunct or “rescue” methods resulting in a more accurate representation of the efficacy in the described technique.

Publikationsverlauf

Artikel online veröffentlicht:
12. Februar 2021