Endoscopic Third Ventriculostomy With "Rescue" Fourth Ventriculocisternostomy: 2-Dimensional Operative Video

Area of Science:

• Neurosurgery
• Endoscopic Neurosurgery
• Hydrocephalus Management

Background:

• Obstructive hydrocephalus can present with normal pressure hydrocephalus-like symptoms.
• Fourth ventricular outflow obstruction is a potential cause, often managed with Endoscopic Third Ventriculostomy (ETV).
• Anatomical variations can increase surgical complexity and risk.

Purpose of the Study:

• To illustrate the challenges of ETV in the presence of anatomical variants.
• To demonstrate the utility of flexible endoscopy for lysis of fourth ventricle adhesions.
• To highlight the importance of preoperative recognition of posterior communicating artery anastomosis.

Main Methods:

• Case presentation of Endoscopic Third Ventriculostomy (ETV).
• Intraoperative use of flexible endoscopy for lysis of fourth ventricular adhesions and web.
• Preoperative imaging review to identify anatomical variants.

Main Results:

• Demonstration of a key anatomical variant: anastomosis of posterior communicating arteries medializing beneath the tuber cinereum.
• Successful lysis of a fourth ventricular web using flexible endoscopy.
• Successful completion of fourth ventriculocisternostomy after initial ETV fenestration challenges.

Conclusions:

• Anastomosis of posterior communicating arteries presents a significant challenge during ETV for obstructive hydrocephalus.
• Preoperative identification of this variant is essential for surgical planning.
• Flexible endoscopy is a valuable tool for managing fourth ventricular adhesions and webs.