Implementation of real-time intraoperative ultrasound and accuracy of transfrontal primary external ventricular drain placement following high-fidelity surgical simulation training

Objective External ventricular drain (EVD) insertion can be performed using a freehand technique or by the use of intraoperative image guidance. The aim of this study was to analyse whether implementation of real-time ultrasound-guided EVD insertion using high-fidelity surgical simulation was associated with improved accuracy of transfrontal EVD placement.Methods Departmental mandatory real-time intraoperative ultrasound-guided EVD placement training using a high-fidelity surgical simulator was delivered. Retrospective analysis of operative records and medical notes was performed for all primary transfrontal EVDs 7 months before and 7 months after the provision of simulated ultrasound training. A modified Kakarla grading system was used to classify the accuracy of EVD placement. Misplacement was defined as the entire EVD tip being placed within the brain parenchyma.Results A total of 126 EVDs were included in the analysis. Pre-training 63.6% (42/66) of EVDs were placed with grade 1A/1B accuracy (optimal) whilst post-training this improved to 73.3% (44/60, p = 0.257). 21.2% (14/66) of EVDs were placed with grade-2 (suboptimal) accuracy pre-training compared to 26.7% (16/60) post-training (p = 0.533). 15.2% (10/66) of EVDs were misplaced pre-training. Post-training no EVDs were misplaced, which reached statistical significance (p = 0.002). There was no significant difference in the number of passes required to place the EVD using the landmark technique compared to real-time intraoperative ultrasound guidance (p = 0.378). The median operative duration prior to ultrasound training was 43 minutes (IQR: 23), whilst post-ultrasound training it was 40.5 minutes (IQR: 17), but this difference was not significant (p = 0.313).Conclusions A high-fidelity training simulator was used to train neurosurgeons to use real-time intraoperative ultrasound to place EVDs. There was a significant improvement in the accuracy of EVD placement without a significant difference in operative duration.