gms | German Medical Science

Objective: To report about endoscope-assisted surgery of large skull based epidermoid cysts focusing on the application of neuro-endoscopy and the clinical outcome in cases of epidermoid cysts.

Methods: Twenty-seven consecutively operated patients (2005–2011) with an epidermoid cyst of the skull base were retrospectively analysed. Among them thirteen were giant, defined by compromising the brainstem and expanding over at least two skull fossa. Surgeries were performed both with an operating microscope (OPMI Pentero, Zeiss Company, Oberkochen, Germany) and endoscopic equipment (4 mm rigid endoscopes with 30° and 70° optics; Karl Storz Company, Tuttlingen, Germany) under continuous intraoperative monitoring (SSEP, MEP, AEP, MEP/EMG of anatomical and clinical affected cranial nerves). Surgical reports and DVD-recordings were evaluated for identification of adhesion areas and surgical details.

Results: All cases were operated through the retrosigmoid approach despite the supratentoriell extension of the epidermoid. In six cases cranial nerves I-XII could be visualized and documented through the standard approach. In all cases the endoscope was used as an adjunctive tool for inspection/ endoscope-assisted removal of microsurgical remnants. The effective time of use of the endoscope was limited to the end stage of the procedure, but very effective. Neurological deficits were all temporary; no permanent postoperative morbidity/mortality was noted. Within the follow-up time (mean 32 months, 6–84) no recurrences have been detected.

Conclusions: In a modern operative setting giant epidermoid cysts may be removed through a standardized skull based approach with excellent clinical results. The combined use of microscope and endoscope offers relevant advantages in demanding anatomical situations.