Comparison of Shunt Obstruction Rates and Failure Rates Depending on Burr Hole Location in Adult Patients With Normal Pressure Hydrocephalus

Introduction: While shunt surgery for normal pressure hydrocephalus (NPH) yields clinical improvement in over 80% of patients, complications, including shunt failure, account for significant morbidity postoperatively. This study compares cases in which frontal versus parietal burr holes were performed regarding shunt complications.

Methods: The Mayo Clinic database was queried for patients who underwent shunt placement for NPH between 2013-2023. Patients were divided into two groups: (1) Frontal burr holes; (2) Parietal burr holes, and baseline characteristics and perioperative outcomes were analyzed.

Results: Total 621 patients were identified, of whom frontal burr holes were performed in 333 patients (53.6%), while parietal burr holes were performed in 288 patients (46.4%, p=0.2). Most patients had right-sided shunts placed in both the frontal (97%) and parietal groups (94.8%, p=0.2). Antibiotic-impregnated shunt catheters were used in 27.6% of patients in the frontal group and 56.9% of patients in the parietal group (p < 0.01). Shunt infection was observed in 12 patients (3.6%) in the frontal group and 16 patients (5.6%) in the parietal group (p=0.2), while obstruction was encountered in 4 patients (1.2%) in the frontal group and 11 patients (3.8%) in the parietal group (p=0.01). Shunt failure was noted in 15 patients (4.5%) in the frontal group and 30 patients (10.4%) in the parietal group (p < 0.01). Shunt revisions were required in 36 patients (10.8%) in the frontal group, and 59 patients (20.5%) in the parietal group (p < 0.01). On multivariable logistic regression, patients in whom frontal burr holes were performed were significantly less likely to develop shunt failure compared to patients in whom parietal burr holes were performed (OR: 0.58, 95%CI: 0.35-0.96, p=0.03).

Conclusion : In our institution, patients with NPH who underwent shunt surgery, and in whom frontal burr holes were performed had significantly lower shunt obstruction rates and failure rates, and required fewer revisions compared to patients in whom parietal burr holes were performed. Our analysis highlights the benefits of frontal burr holes with respect to minimizing shunt-related complications in these patients.