Factors which influence the complications of external ventricular cerebrospinal fluid drainage

External ventricular drainage (EVD) is one of the most common neurosurgical procedures in emergencies. This study aims to find out which factors influence the occurrence of EVD-related complications in a comparative investigation of metal needles and polyurethane catheters. This is the first clinical study comparing these two systems.

Adult patients undergoing pre-coronal EVD placement via freehand burr hole trepanation were included in this prospective study. The exclusion criteria were the open EVD insertion and/or a pre-existing infectious disease of the central nervous system.

Two hundred consecutive patients were enrolled. Of these, 100 patients were treated by using metal EVD (group 1) and 100 patients with polyurethane catheters (group 2). The overall complication rate was 26% (misplacement 13.5%, hemorrhage 12.5%, infection 2.5%, and dislocation 1%) without statistically significant differences between both groups. Generalized brain edema and midline shift had a significant influence on misplacements (generalized brain edema: p = 0.0002, Cramer-V: 0.307, OR = 7.364, 95% CI: 2.691-20.148; all patients: p = 0.001, Cramer-V: 0.48, OR = 43.5, 95% CI: 4.327-437.295; group 1: p = 0.047, Cramer-V: 0.216, OR = 3.75, 95% CI: 1.064-13.221; group 2: midline shift: p = 0.038, Cramer-V: 0.195, OR = 3.626, 95% CI: 1.389-9.464) all patients: p = 0.053, Cramer-V: 0.231, OR = 5.533, 95% CI 1.131-27.081; group 1: p = 0.138, Cramer-V: 0.168, OR = 2.769, 95% CI: 0.813-9.429 group 2. Hemorrhages were associated with the use of oral anticoagulants or antiplatelet therapy (p = 0.002; Cramer-V: 0.220, OR = 3.798, 95% CI: 1.572-9.175) with a statistically similar influence in both groups.

Generalized brain edema has a significant influence on misplacements in both groups. Midline shift lost its significance when considering only the patients in group 2. Patients under oral anticoagulation and antiplatelet therapy have increased odds of EVD-associated hemorrhage. Metal needles and polyurethane catheters are equivalent in terms of patient safety when there are no midline shift and generalized brain edema.