Stereotactic placement of ventricular catheters: does it affect proximal malfunction rates?

The majority of ventriculoperitoneal (VP) shunt malfunctions are due to proximal catheter failure. Ideal placement of Ommaya reservoirs is desired to avoid toxicity from intraparenchymal chemotherapy infusion.

To determine whether stereotactic placement of ventricular catheters decreases the rate of Ommaya reservoir complications and the rate of proximal VP shunt failure.

Under institutional review board approval, a review of a prospectively collected database was done identifying all patients who underwent stereotactic-guided placement of VP shunts and Ommaya reservoirs performed by a single surgeon between November 2007 and November 2009. Neuronavigation was used to preset a surgical plan consisting of an ideal entry point (usually frontal) and target point (ipsilateral foramen of Monro). The navigation probe was passed along this trajectory. After removal of the navigation probe, pre-sized ventricular catheters were passed without a stylet along the created path. Post-operative CT scans and clinical follow-up were assessed.

70 patients (mean age 44.6 years) underwent 52 VP shunt and 18 Ommaya reservoir placement procedures. Rigid cranial fixation was used in all cases. All catheters were placed in a single pass. Mean operative time was 62 min. Mean follow-up was 16.3 months. No proximal malfunctions or Ommaya complications have been seen thus far. One patient required repositioning of an Ommaya reservoir as post-operative CT showed poor placement (1.4%). One patient with hydrocephalus due to cryptococcal meningitis developed an abdominal abscess and required removal of his entire shunt with subsequent replacement. One patient was noted to have a small amount of intraventricular hemorrhage; this did not result in any clinical change and did not require any further intervention. No other surgical complications were noted.

In terms of results corroborating decreased proximal malfunction rates, we present the largest series of stereotactic-guided ventricular catheter placements to date. Though time in the operating room is increased due to navigation registration, actual operative time is comparable to procedures without navigation. A longer-term follow-up is needed to assess the longevity of our positive short-term results.