Freehand Insertion of External Ventricular Drainage Catheter–Evaluation of Accuracy in a Single Centre

Abstract

INTRODUCTION External ventricular drain (EVD) placement is the gold standard for managing acute hydrocephalus. Freehand EVD, using surface anatomical landmarks is performed for ventricular cannulation due to its simplicity and efficiency. This study evaluates accuracy and reason(s) for misplacements as few studies have analyzed the accuracy of freehand EVD insertion. METHODS Preoperative and postoperative computed tomography (CT) scans of patients who underwent EVD insertion in 2014 were retrospectively reviewed. Diagnosis, Evan's ratio, midline shift, position of burr hole, length of the catheter and procedural complications were tabulated. The procedures were classified as satisfactory (catheter tip in the frontal horn ipsilateral lateral ventricle) and unsatisfactory. Unsatisfactory cases were further analyzed in relation to position of burr hole from midline and length of the catheter. RESULTS A total of 77 EVD placements in 70 patients were evaluated. Mean age of the patients was 57.5 yr. About 83.1% were satisfactory placements and 11.7% were unsatisfactory in the contralateral ventricle, corpus callosum and interhemispheric fissure. About 5.2% were in extra ventricular locations. About 2.6% EVD placements were complicated by hemorrhage and 1 catheter was reinserted. Suboptimal placements were significantly associated with longer intracranial catheter length. The mean length was 66.54 ± 10.1 mm in unsatisfactory placements compared to 58.32 ± 4.85 mm in satisfactory placements. Between the 2 groups, no significant difference was observed in Evan's ratio, midline shift, surgeon's experience, distance of burr hole from midline and coronal suture. CONCLUSION Freehand EVD insertion is safe and accurate. In small number of cases, unsatisfactory placement is related to longer catheter length.