Endoscopic third ventriculostomy for treatment of tonsillar descent with hydrocephalus: CSF flow dynamics and treatment strategies

Abstract

Objective

To explore the role of cerebrospinal fluid (CSF) flow dynamics and develop treatment strategies involving endoscopic surgery for tonsillar descent with hydrocephalus.

Methods

This study included 15 patients with tonsillar descent with hydrocephalus. All patients underwent cine-magnetic resonance imaging (MRI) preoperatively to measure CSF flow at the entrance of the cerebral aqueduct and foramen of Magendie. Endoscopic third ventriculostomy (ETV) was performed.

Results

All patients exhibited abnormal CSF flow dynamics at Magendie’s foramen prior to surgery. After surgery, cine-MRI showed CSF flow through the ventriculostomy. During the follow-up period of 8–72 months, the level of tonsillar descent reduced in 9 patients, and the spinal cord syrinx was reduced in 1 patient. Clinical symptoms were improved in 14 patients. Secondary endoscopically assisted posterior cranial fossa decompression was performed in one patient whose symptoms were not improved after ETV. In no case was secondary ventriculo-peritoneal shunting performed following primary ETV.

Conclusion

ETV is a low-risk and effective method that can replace ventriculo-peritoneal shunt placement in the treatment of tonsillar descent with obstructive hydrocephalus. Preoperative cine-MRI of CSF flow dynamics in the aqueduct and Magendie’s foramen provides valuable information for determining surgical timing and strategies.

Keywords:

• Tonsillar descent
• hydrocephalus
• endoscopic third ventriculostomy
• cine-MRI
• syringomyelia

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the fund ‘The capital health research and development of special’ [No. 2011-2008-06].