Keyhole retrosigmoid approach without watertight dural closure - Evaluation of a minimalistic approach

The retrosigmoid craniotomy is a versatile surgical approach to the cerebellopontine angle though cerebrospinal fluid leak remains a concern, with a reported prevalence of 0-22 %. A host of closure materials and strategies have been proposed to achieve a watertight dural closure to varying degrees of success. We review our series of keyhole retrosigmoid craniotomies and describe our simple, standardized method of closure without watertight dural closure.

A retrospective review of all retrosigmoid craniotomies performed by the senior author was completed. Closure was achieved by placing an oversized piece of gelatin in the subdural space. The dura is grossly approximated. An oversized sheet of collagen matrix is placed as an overlay followed by gelatin sponge in the craniectomy defect held in place with titanium mesh. The superficial layers are approximated. The skin is closed with a running sub-cuticular suture followed by skin glue. Patient demographics, cerebrospinal fluid leak risk factors, and surgical outcomes were determined.

A total of 114 patients were included. There was one case (0.9 %) of CSF leak, which resolved with placement of a lumbar drain for 5 days. The patient had one defined risk factor (morbid obesity, BMI 41.0 kg/m²).

Obtaining a watertight dural layer closure has been the generally accepted strategy in preventing CSF leaks in a traditional retrosigmoid approach. In keyhole retrosigmoid approaches it may not be necessary by utilizing a simple gelfoam bolstered collagen matrix onlay technique potentially improving outcome measures including operative time.