1014 Predictors of Shunt Revision in Idiopathic Normal Pressure Hydrocephalus

INTRODUCTION: While ventriculoperitoneal shunt (VPS) placement is increasingly considered standard of care for idiopathic normal pressure hydrocephalus (iNPH), many patients may require revision. This study aimed to identify independent predictors of shunt revision following VPS for iNPH. METHODS: All patient treated with shunting iNPH at a tertiary care center between January 2000 and January 2023 were retrospectively reviewed, and independent predictors of shunt revision were identified utilizing multivariable logistic regression. RESULTS: Of 574 total patients, 88 (15.3%) underwent revision (). Comparison between revised and non-revised patients disclosed associations of revision with age (73.2 ± 6.4 vs 75.0 ± 6.2 years; p = 0.02), prior shunt placement (2.3% vs 0.0%; p = 0.02), shunt type (ventriculoperitoneal: 94.3% vs 98.8%; ventriculoatrial: 5.7% vs 1.2%; p = 0.02), valve type (fixed: 63.6% vs 37.2%; programmable: 36.4% vs 62.8%; p < 0.01), distal catheter placement technique (open surgery: 71.1% vs 50.8%; laparoscopy: 28.9% vs 49.2%; p < 0.01), and proximal catheter placement approach (frontal: 61.4% vs 41.8%; occipital approach: 38.6% vs 58.2%, p < 0.01). Multivariable logistic regression showed that shunt revision was associated with younger age (OR=1.04/yr; p=0.02), ventriculopleural/ventriculoatrial placement (OR=4.48 [vs VPS]; p=0.02), fixed setting valve (OR=2.85 [versus adjustable]; p<0.01), open approach for distal catheter placement (OR=2.33 [versus laparoscopic]; p<0.01), frontal proximal catheter (OR=2.16 [versus parietal]; p<0.01), and ). Similar results were noted when analyzing predictors of revision amongst only patients who required surgical revision for reasons other than infection. CONCLUSIONS: Shunt revision amongst iNPH patients is associated with factors relating to surgical technique. Shunt revision rates appear lower amongst patients with VPS using an occipital proximal catheter with an adjustable valve and laparoscopic distal catheter placement.