Comparison of EVD Catheter Diameter on Occlusion and Replacement

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).

Inclusion Criteria:

- Adult patients (18-85 years old) with a Glasgow Coma Scale (GCS) score of 7 or higher
requiring frontal EVD placement.

- Diagnoses: spontaneous subarachnoid hemorrhage, intraventricular hemorrhage,
intraparenchymal or cerebellar hemorrhage due to aneurysm, arteriovenous malformation,
arteriovenous fistula, hypertension, or idiopathic etiology.

- Also included are patients for whom the attending neurosurgeon decides that frontal
EVD placement is indicated for patient treatment with planned cerebrospinal fluid
(CSF) drainage for 72 hours or more.

Exclusion Criteria:

- GCS of 6 or less

- Hunt and Hess subarachnoid hemorrhage grade of 5.

- Age 86 or greater, or age 17 or less.

- Patient cannot consent and next of kin cannot consent prior to procedure.

- Diagnosis of traumatic brain injury, as the EVD is often clamped for extended periods
of time.

- Patients anticoagulated prior to admission with warfarin, Effient, Plavix, therapeutic
heparin infusion, therapeutic subcutaneous lovenox, therapeutic subcutaneous arixtra,
or other therapeutic anticoagulant or antiplatelet agent (ASA not included).

- Plan for EVD placement through non-frontal burr hole.