Title: Anti-Siphon Devices Reduce Symptomatic Complications of Ventriculoperitoneal Shunt in Normal Pressure Hydrocephalus Patients

Author: Yashaar Hafizka

Area of Concentration (Petal): Basic, Clinical, and Translational Research

Specialty (if any): Neurosurgery

Keywords: Normal Pressure Hydrocephalus, Ventriculoperitoneal Shunt

Background: Ventriculoperitoneal shunt (VPS) is the mainstay surgical treatment for patients with Normal Pressure Hydrocephalus (NPH). However, complications of VPS, typically relating to overdrainage, can lead to poor outcomes. New VPS devices utilize anti-siphon valves (ASVs) aimed at reducing complications of VPS associated with overdrainage while still maintaining positive shunt responsiveness.

Objective: We aimed to retrospectively analyze patients with NPH who underwent VPS surgery with and without ASVs to determine whether ASVs decrease complications associated with VPS while still maintaining response from VPS surgery.

Methods: We retrospectively reviewed 121 patients with suspected NPH who underwent a lumbar drain trial prior to VPS at a single academic institution. Patient demographics, post-surgical complications, and VPS response were recorded. Full responders were defined as receiving benefits to the level experienced during the lumbar drain trial by 3 months post-operation. Non-responders included both those who experienced some or no benefit.

Results: Of the 82 patients who underwent VPS surgery, 33 had shunts with ASVs (median follow-up 16 months) and 49 has standard shunt placement (median follow-up 8 months). Patients with ASVs had similar NPH symptom improvement when compared to patients without ASVs (p=0.11). ASVs were associated with a significant reduction in patients with any complication with morbidity grouped together (Odds Ratio: 9.1, 95% CI: 1.2 to 410, p=0.02), but no significant change individually for falls with ED workup (p=0.10), SDHe (p=0.23), or surgical intervention (p=0.63). ASVs were not associated with any significant change in pooled overdrainage symptoms (p=0.70) or individually with overdrainage headaches (p=0.68), SDHe (p=0.23), and SDHy (p=1.0).

Conclusions: ASVs are associated with similar symptomatic improvement and overall decreased complications with morbidity when compared to shunts without ASVs for patients with NPH. However, rates of post-surgical complications including SDHe, SDHy, overdrainage headaches, complications requiring surgical intervention, and falls requiring ED workup were similar.