Cerebral Sulci as a Cause of Catheter Entry Point Deviation and Shunt Malposition and the Role of Surgical Navigation in Improving Accuracy

Background In ventriculoperitoneal shunting for idiopathic normal pressure hydrocephalus, optimal trepanation sites and trajectories are critical to prevent shunt malposition. However, the effect of cerebral sulci at the burr hole site on unexpected intraoperative entry point changes remains unclear. Methods Preoperative computed tomography data from 50 patients with idiopathic normal pressure hydrocephalus (January 2018 to September 2024) were retrospectively reviewed. We analyzed the frequency of cerebral sulci beneath Kocher’s point necessitating entry point shifts and the distribution of alternative sites. Shunt malposition rates were compared between navigation-guided puncture on the basis of preoperative simulation and a conventional cohort using surface anatomical landmarks. Results Radiological evaluation of 100 bilateral Kocher’s points predicted minor puncture site adjustments in 20% of patients and major modifications, such as burr hole enlargement or relocation, were predicted in 17% of patients. In the conventional technique, the incidence of hemorrhage along the catheter tract was 7.4%, and the rate of suboptimal catheter tip placement was 33%. Introduction of a navigation system allowed preoperative identification of entry point shifts and trajectory planning. Consequently, no catheter tract hemorrhages occurred, and the rate of suboptimal placement was reduced to 13.0%. Conclusion Unanticipated cerebral sulci at conventional entry points are negative confounding factors for successful ventricular puncture. Preoperative identification of appropriate entry points and trajectories is important for surgical success. Recognizing such anatomical variations through preoperative review of standard radiological images is essential for improving accuracy and safety, even when technological aids are limited. Furthermore, the implementation of a navigation system provides critical support in achieving these objectives and reducing malposition rates.