Ventriculoatrial versus ventriculoperitoneal shunt complications in idiopathic normal pressure hydrocephalus.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a devastating condition that affects the elderly population. Although ventriculoatrial (VA) shunts can be used to manage iNPH, concerns for associated cardiopulmonary and renal complications have decreased their use. However, the rate of these complications is not well understood within this population of patients. PATIENTS AND METHODS: A retrospective review of the electronic medical records of patients diagnosed with iNPH by the senior author between 1993 and 2015 was performed. Demographic information and baseline symptoms were assessed. Complications including infection, shunt obstruction, overdrainage, cardiopulmonary events, renal dysfunction, and shunt revision were recorded. Complication rates were compared between VA and VP shunted patients. Statistical analysis using Chi-square test, Fisher's exact test, logistic regression, Wald t-test, Poisson regression, ANOVA, and ANCOVA was performed. RESULTS: 496 Patients, including 150 receiving VA shunts and 346 receiving VP shunts, were included in the study. The median age was 74 and 73 for VA and VP shunted patients, respectively, with slight male predominance in both (58.0% and 58.4% for VA and VP groups, respectively). A total of 36.0% of VA shunted patients and 42.5% of VP shunted patients experienced at least one post-operative complication. Overdrainage was the most commonly experienced complication in both VA (27.4%) and VP patients (19.9%). Infection occurred in only 2.0% of patients, and renal complications occurred in 1.3%. No patients had cardiopulmonary complications. VA shunted patients were significantly less likely to experience shunt obstruction and require shunt revision compared to VP shunted patients (p=0.008 and <0.001, respectively). Only dizziness and gait disturbance at baseline were correlated with a shorter time to revision in VA shunted patients (p=0.002 for both). CONCLUSION: Although cardiopulmonary and renal complications are serious concerns associated with VA shunt placement, they were uncommon in patients with iNPH. VA shunted patients were less likely to experience shunt obstruction and require shunt revision compared to VP shunted patients. Therefore, VA shunts should be considered as an alternative primary treatment option in the iNPH population.