Endoscopic Surgery for Large Posterior Fossa Arachnoid Cysts

Abstract

The authors report two cases of large arachnoid cysts of the posterior fossa treated by endoscopic surgery. One patient underwent a successful endoscopic cyst fenestration by burr hole approach after several procedures of shunt revision. In another an endoscope-assisted microsurgical intervention was necessary. Lateral (cerebellar or cerebellopontine angle) cysts, as two reported cases, may be treated through a lateral retromastoid approach by fenestration into the prepontine cistern and eventually into the cisterna magna. We advise to start the operation through a burr hole and to try to realize the fenestration by endoscopy only. If this attempt fails, an endoscope-assisted microsurgical technique may be performed by enlarging the craniectomy. In this last instance the endoscope is useful particularly deeply to fenestrate the anterior cyst wall in the prepontine or ambient cisterns, where it provides more illumination and helps to identify the nervous and vascular structures.

Endoscopic management of posterior fossa arachnoid cyst in an adult: case report and technical note

“…However, the effective treatment remains controversial, and there are reports in the literature highlighting this issue (3,6,12,14,18,21,24,26,29). These reports mostly concern the pediatric population, with the biggest series being reported by a European cooperative study that included 54 cysts at the posterior fossa from 17 institutions (27).…”

“…Less common presentations include ataxia, hearing loss, and facial nerve palsy (12,18,29). Hydrocephalus is considered very suggestive of the disease (6,8,14,19,28) and di Rocco et al found hydrocephalus in all of their eight patients with symptomatic PFAC (10). The association of other congenital anomalies is estimated to occur in 10 to 30% of cases (23,25).…”

“…These reports mostly concern the pediatric population, with the biggest series being reported by a European cooperative study that included 54 cysts at the posterior fossa from 17 institutions (27). The posterior fossa location represented the second most common location for arachnoid cysts after the middle cranial fossa (14,28). Symptomatic cases mostly present with a history of increased head size and signs of increased ICP.…”

“…The treatment modalities are open surgery with excision or marsupialization of the cyst, shunting procedure and endoscopic fenestration. New reports have demonstrated good clinical and radiological results in endoscopically-treated PFAC, with minimal invasiveness of this surgical procedure and the lack of a need for shunt implantation (6,14,21,24,26).…”

Middle Cranial Fossa Arachnoid Cyst Presenting With Subdural Effusion and Endoscopic Detection of Tear of the Cyst -Case Report-

“…2) Recently, advances in neuroendoscopic surgery have allowed treatment by endoscopic cyst fenestration. [3][4][5][7][8][9]14,16) Simple burr hole drainage has often been used in middle cranial fossa arachnoid cyst combined with subdural hematoma. However, various approaches have been selected in cases associated with subdural effusion.…”