Endoscopic tracking of a ventricular catheter for entry into the lateral ventricle: technical note

Tapping the ventricle with a cannula prior to introducing the endoscope is the preferred technique by many neurosurgeons in gaining ventricular access during endoscopic procedures. We have adapted this technique by passing a soft ventricular catheter into the ventricle (instead of a cannula), subsequently following this catheter into the lateral ventricle with the endoscope. Access to the lateral ventricle is planned according to trajectories selected from preoperative imaging and anatomic landmarks with or without the use of stereotactic navigation. The endoscope is introduced along the catheter tract with constant and direct visualization of the shaft of the catheter.

The authors performed endoscopic tracking of a catheter during 47 consecutive endoscopic procedures. No injuries to deep structures or mistrajectories occurred. Safe and precise access to the lateral ventricles can be achieved by using a ventricular catheter as a guide for the endoscope.

This technique was used with and without stereotactic navigation and deemed useful in both circumstances as cerebral spinal fluid (CSF) egress through the catheter verifies positioning before the introduction of a larger diameter endoscope. Moreover, once CSF is obtained, the catheter is not removed from this position so no additional error is incurred when the endoscope or rigid plastic sheath is placed. Finally, the catheter serves as a continuous marker to the ventricle allowing repeated endoscopic entries. This technique was found to be particularly useful in biportal procedures to mark specific trajectories that could be easily re-accessed in situations where intraoperative shift occurs.