Image-guidance in Ventriculoperitoneal Shunt Placement Has More Accurate Catheter Placement and Fewer Revisions

Introduction: Ventriculoperitoneal shunting (VPS) is one of the most commonly performed neurosurgical procedures. Despite this, revision rates can be alarmingly high, with some estimates reaching up to 30-40%. While a variety of navigation modalities are available, “free-hand” techniques for placing the proximal ventricular catheter based purely on anatomical landmarks are still widely used and are one potential target for reducing unnecessary and costly revisions.

Methods: We performed a retrospective review of all adult patients (age 20-85 years) who underwent placement of a frontal VPS for any indication between 2020-2021. Accuracy was assessed using Kakarla grade (KG) and linear distance from the catheter tip to the foramen of Monro (TTF). Accurately placed proximal catheters were defined as KG-I and mal-positioned catheters were defined as KG-III.

Results: 60 patients (age 20-85; females, 75%) were included in our study. Indications for VPS included post-hemorrhagic hydrocephalus (n=24, 40%) post-tumor resection (n=11, 18.3%), postoperative CSF leak (n=10, 16.7%), IIH (n=9, 15.0%), and NPH (n=4, 6.7%). The use of image guidance (n=20, 33.3%) was associated with more accurate catheter placement by both subjective (KG, p=0.001) and objective (TTF, p< 0.01) measures, with no effect on length of surgery (p=0.224). Five patients (8.3%) required revision of their proximal catheter, all placed free hand (12.5% v. 0%, p=0.099), of which 3 were in the immediate post-operative window (i.e., days 1-7) for persistent ventriculomegaly or poor neurologic exam. These catheters placements were significantly less accurate (TTF distance 27.2 mm v. 11.9 mm; p< 0.001).

Conclusion : Free-hand placement of the proximal ventricular catheter during VPS implantation can lead to increased inaccuracies and avoidable peri-operative complications. Image-guidance placement seems to overcome these issues without increasing the length of surgery. This data suggests that image-guidance should be standard-of-care.