A Comparison of External Ventricular Drain Catheter Diameter on Occlusion and Replacement: A Randomized Trial

Ventriculostomy is a common neurosurgical procedure. A Nationwide Inpatient Sample (NIS) database study demonstrated a significant increase in ventriculostomy utilization from 1988-2010, with over 35,000 hospitalizations including a procedural code for ventriculostomy in 2010.

Ventriculostomy occlusion is a common complication after external ventricular drain (EVD) placement. A review of published prospective and retrospective studies indicates that approximately 1-7% of EVDs require replacement secondary to occlusion. Furthermore, in the NIS database study of over 101,000 hospitalizations in which ventriculostomy was performed, nearly 6% of patients required at least one additional ventriculostomy procedure. Studies have demonstrated non-patent EVD in 19-47% of patients, however these studies did not prospectively evaluate EVD occlusion as a primary endpoint, report on number of catheter irrigations performed, or identify risk factors for EVD occlusion.

Recently, the investigators completed a retrospective review of a prospectively collected database of patients undergoing bedside EVD placement with the primary outcome of interest being catheter occlusion. This sample included 101 patients over a 1 year period. Two Codman catheters were available for use (Clear Bactiseal 'large' catheter: outer diameter 3.4 mm, inner diameter 1.9 mm; and Orange Bactiseal 'small' catheter: outer diameter 3 mm, inner diameter 1.5 mm). The decision regarding which catheter to use was made at the time of the procedure based on resident preference and availability. Both temporary occlusion (requiring flushing but patency could be restored) and permanent catheter occlusion (requiring replacement) were common, occurring in 41% and 19% of patients, respectively. Over 25% of small catheters became occluded during the study period compared to 11% of large catheters. Small catheters were associated with a 3.4 times greater odds of occlusion than the larger diameter catheters on multivariable regression analysis. This study suggests that the preferential use of larger diameter catheters may reduce the risk of ventriculostomy occlusion and need for replacement, however the study was not randomized and catheter selection may have been biased.

Recently, a smaller retrospective study of patients with intraventricular hemorrhage performed by Gilard and colleagues demonstrated a lower rate of occlusion and no increased risk of hemorrhage with larger bore catheters. Otherwise, there is no data in the literature supporting the preferential use of catheters based on size (clinical equipoise).