1132. Is Biopsy Result Predictive of Endoscopic Third Ventriculostomy Success? An Analysis of Normal Pressure Hydrocephalus Patients

Authors: Hal Starnes; Satish Krishnamurthy, MD; Jennifer Nath; Michael Tichenor, MD; Brianna Schmidt, MD; Y Mohan, MD (Syracuse, NY)

Introduction: Normal pressure hydrocephalus (“NPH”) has conventionally been treated via ventriculoatrial or ventriculoperitoneal shunt, but it can also be treated via endoscopic third ventriculostomy (“ETV”), a less invasive technique. There is a paucity of evidence on the characteristics of NPH patients who are most likely to benefit from ETV. This study seeks to identify factors that may identify patients as ideal (or poor) candidates for ETV. Methods: This study included 39 NPH patients who underwent ETV at Henry Ford Hospital or Upstate University Hospital between July 2007 and December 2014. Patients were pre-surgically assessed for various risk factors. A cortical biopsy sample was obtained and assessed for plaques consistent with dementia. Post-procedure, patients were tracked over follow-up appointments and were assessed for gait improvement, headache, memory problems, incontinence and dementia symptoms. The average follow-up period for patients with positive biopsies was 4.2 months, versus 8.7 months for patients with negative biopsies. Results: In this study, 67% of patients with negative biopsies showed gait improvement by the last follow-up appointment (suggesting ETV success) versus only 33% of patients with positive biopsies. However, Chi-squared test analysis demonstrated that this relationship was not statistically significant (p=0.188). Younger age was directly correlated with successful ETV (p=.003). The mean age of patients with successful ETVs was 65.8 ± 6.0, versus 74.5 ± 7.0 for failed ETVs. Memory disturbance and incontinence after surgery were both associated with lack of gait improvement by the last follow-up appointment (p=.006 and p=.0003, respectively). Conclusion: Biopsy was not a statistically significant predictor of ETV success as measured by gait improvement. Additional studies are required to determine if a statistically significant relationship between cortical biopsy findings and ETV success does exist in the larger population. Caution should be exercised in recommending older patients for ETV, due to lower success rates.