Ommaya reservoir with ventricular catheter placement for chemotherapy with frameless and pinless electromagnetic surgical neuronavigation

Background: Accuracy in Ommaya reservoir catheter placement is critical to chemotherapy infusion. Most frameless image guidance is light emitting diode (LED) based, requiring a direct line of communication between instrument and tracker, limiting freedom of instrument movement within the surgical field. Electromagnetic neuronavigation may overcome this challenge.

Objective: To compare Ommaya reservoir ventricular catheter placement using electromagnetic neuronavigation to LED-based optical navigation, with emphasis on placement accuracy, operative time and complication rate.

Methods: Twenty-eight patients who underwent placement of Ommaya reservoirs at our institution between 2010 and 2014 with either electromagnetic (12 patients) or optical neuronavigation (16 patients) were retrospectively reviewed.

Results: Half of the patients were male. Their mean age was 56 years (range 28-87 years). Accuracy and precision in catheter tip placement at the target site (foramen of Monro) were both higher (p=0.038 and p=0.043, respectively) with electromagnetic neuronavigation. Unintended placement of the distal catheter contralateral to the target site occurred more frequently with optical navigation, as did superior or inferior positioning by more than 5 mm. Mean operative times were shorter (p=0.027) with electromagnetic neuronavigation (43.2 min) than with optical navigation (51.0 min). There were three complications (10.7%)--one case each of cytotoxic edema, post-operative wound infection, and urinary tract infection. The rate of complication did not differ between groups.

Conclusion: In contrast with optical neuronavigation, frameless and pinless electromagnetic image guidance allows the ability to track instrument depth in real-time. It may increase ventricular catheter placement accuracy and precision, and decrease operative times.