Determinants of accuracy of freehand external ventricular drain placement by neurosurgical trainees

The external ventricular drain (EVD) placement is one of the most common neurosurgical procedures. This operation is performed by freehand technique in the majority of cases; therefore, the operator's experience plays an important role in success and possible morbidity of this procedure.

To evaluate the accuracy and safety of EVD placement by junior neurosurgery residents and factors predicting accuracy of EVD placement.

This is a prospective cohort study conducted at our academic medical center, between September 2017 and August 2018. All patients 18 years or older who required EVD placement were included. The accuracy and complications of EVD placement were assessed in the first and second year resident cohorts as well as by their level of experience, using descriptive statistics. Univariate and multivariate models were used to assess predictive factors for optimal EVD.

A total of 100 EVDs were placed in 100 patients during the study period. According to Kakarla classification, the catheter was optimally placed in 80% of cases. The first year residents had a significantly higher rate of suboptimal burr hole placement compared to the second year residents (66.7% versus 27.1%, p = 0.004). The trainees with less than 10 EVD placement experience also had a significantly higher rate of suboptimal burr hole placement (55.2% vs. 23.9%, p = 0.003), significantly longer duration of operation (43.1 min ± 14.9SD vs 34.2 min ± 9.6 p = 0.005), and significantly lower rate of optimal EVD location (85.9% versus 65.5%, p = 0.023). Optimal location of the burr hole was the only significant predictor of optimal EVD placement in multivariate analysis (OR 11.9, 95% CI 3.2-44.6, p < 0.001).

Neurosurgery residents experience and optimal burr hole placement are the main predicators of accurate EVD placement.