Radical Intracapsular Dissection Technique for Dumbbell-Shaped Spinal Schwannoma with Intradural and Extradural Components

Abstract

Dumbbell-shaped spinal schwannomas with intradural and extradural components are associated with higher complication rates. This may be in part due to epineurial dissection of the extradural component, which inevitably damages the functioning nerve fibers beneath the epineurium and may lead to dural defects that are often difficult to repair. The objective was to describe a radical intracapsular dissection technique that provides a simpler operative field with no need for dural repair and a better chance of preserving functioning nerve fibers. The technique comprised the following: 1) exposure of the tumor while preserving spinal stability; 2) a single incision encompassing the dura and epineurium; 3) microsurgical dissection of the tumor just beneath the epineurium, preserving the viable nerve fibers; and 4) primary closure of the duroepineurial incision. We describe a case series of 7 patients in whom this type of tumor was excised using this technique. Gross total excision was achieved in 5 patients. In 1 patient with a large paravertebral component, the remaining tumor was removed with an additional anterior approach. No cerebrospinal fluid leak was noted, and no recurrence was observed in the median follow-up period of 36 months. The radical intracapsular dissection technique described herein represents an alternative technique for the removal of dumbbell-shaped spinal schwannomas with intradural and extradural components.