Comparison of Outcomes Between Patients with Idiopathic Normal Pressure Hydrocephalus Who Received a Primary versus a Salvage Shunt

Introduction: Placement of a ventriculoperitoneal (VP) shunt is the treatment of choice for communicating hydrocephalus; however, the extent to which VP shunting is able to relieve symptoms in patients who had previously been treated with cerebrospinal fluid diverting therapy at an outside institution remains unclear.

Objective: This study aims to verify if VP shunting is able to relieve symptoms in patients who had previously been treated with cerebrospinal fluid diverting therapy.

Methods: A retrospective review of patients with idiopathic normal pressure hydrocephalus treated with VP shunts at a single institution between 1993 and 2013 was conducted. Patients were classified as having received a primary VP shunt if they had not been previously treated with a VP shunt, ventriculoatrial shunt, lumboperitoneal shunt, or endoscopic third ventriculostomy. Patients were classified as having received a salvage VP shunt if they had been previously treated by one of these four modalities at an outside institution prior to their presentation to our institution.

Results: There were 357 patients who received a primary shunt and 33 patients who received a salvage shunt. Patients who had a salvage shunt placed had significantly higher odds of requiring a future revision (54% versus 41%; odds ratio = 2.85; 95% confidence interval [CI]: 1.24–6.57; p = 0.014). Patients who received a salvage shunt had statistically significantly lower rates of gait improvement at 6 months in comparison to patients who received a primary shunt (relative risk = 0.35; 95% CI: 0.14–0.87; p = 0.025).

Conclusions: Despite these findings, there was no significant difference at last follow-up in improvement in gait, continence, and cognition, indicating that outcomes for patients requiring a salvage shunt were comparable to patients receiving a primary shunt.

No conflict of interest has been declared by the author(s).