Neuronavigation-assisted endoscopic unilateral cyst fenestration for treatment of symptomatic septum pellucidum cysts.

Background: Traditional surgical treatments for this rare disease include open surgical procedures and ventriculoperitoneal shunting. In 1995, endoscopic fenestration was first applied to treatment of cysts of the septum pellucidum (CSP). However, cyst fenestration generally takes a bilateral approach by making two burr holes leading to two fenestrations in the lateral walls of the cyst. Some disadvantages are related to bilateral fenestration. So far, there is no consensus on the surgical indications, the endoscopic approaches, and techniques for CSPs. Based on our experience with 14 cases of symptomatic CSP treated with neuronavigation-assisted endoscopic unilateral cyst fenestration via a single burr hole, we discuss the operative indications and the utility of endoscope-assisted techniques in combination with neuronavigation.

Methods: 14 patients underwent endoscopic CSP fenestration via a right frontal approach using a rigid endoscope and neuronavigation. Neuronavigation helped locating optimal skin incision, puncture point, optimal operation trajectory, and real-time operation monitoring. Postoperatively, a follow-up study on the 14 patients was performed.

Results: The follow-up period ranged from 6 months to 2 years. Postoperatively, the mass effect of the cysts and the self-reported symptoms disappeared immediately. In 7 patients with papilledema, the optic fundus examinations showed that papilledema improved. The computerized tomography (CT) or magnetic resonance imaging (MRI) scans showed significant decrease in the cyst size and no recurrence during the follow-up. In 2 patients with accompanying hydrocephalus, the hydrocephalus disappeared.

Conclusion: The results after uni- and bilateral CSP fenestration show no significant difference. Avoiding damage of contralateral tissue, the surgical trauma in unilateral fenestration is less than in bilateral fenestration. Furthermore, the unilateral approach shortens the operation time. We believe that unilateral cyst fenestration is a better therapeutic option in symptomatic CSP.