Endoscopic Assisted Resection of Prepontine Epidermoid Cysts

Abstract

Objective/Background To describe an innovative endoscopic technique to treat prepontine epidermoid cysts. These cysts are typically resected in a microsurgical fashion and can be associated with significant risks and complications. This report is the first description of an endoscopic-assisted removal of an epidermoid cyst without the use of the operative microscope and evaluates the operative findings, technique, and postoperative course.

Study Design Retrospective review at tertiary referral center.

Methods Two patients, one with rapidly progressive headache and ataxia, and another with trigeminal neuralgia were found to have mixed-intensity cystic lesions of the prepontine region consistent with an epidermoid cyst. A detailed description of the preoperative preparation, surgical approach, intraoperative technique, pre- and post-operative imaging findings and monitoring outcomes are emphasized.

Results Both patients underwent resection of the epidermoid cyst using an endoscope-assisted technique. The procedures were 3 and 4 hours in duration with an estimated blood loss of 50 cc in both operations. No intraoperative complications occurred. The patients were discharged from the hospital on postoperative days 2 and 3, respectively. Postoperative imaging revealed no edema of the cerebellum and complete resolution of the cyst. Neurological examination revealed improvement of preoperative symptoms with complete resolution of headache and ataxia of case 1, with resolution of trigeminal neuralgia in case 2. Case 2 did develop an ipsilateral cranial nerve (CN) VI paresis postoperatively that resolved over a 3-week period. The patient from case 1 remains symptom free after 24-months with magnetic resonance imaging (MRI) consistent with gross-total resection of the epidermoid cyst. Case 2 has continued resolution of trigeminal neuralgia and CN VI palsy with 12-month follow-up MRI consistent with gross total resection.

Conclusions The use of the endoscope as the sole means to access the posterior fossa to treat prepontine cystic lesions affords the surgeon excellent visualization with minimal cerebellar retraction and can be done in a safe and effective manner with little to no morbidity.

Keywords

endoscopic - skull base - retrosigmoid - cerebellopontine angle - epidermoid

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