Revision rates of flow- versus pressure-regulated ventricular shunt valves for the treatment of hydrocephalus in neonates following germinal matrix haemorrhage-a retrospective review

Purpose Neonates with ventricular shunts inserted for hydrocephalus following germinal matrix haemorrhage (GMH) have high rates of shunt revision. The shunt valve plays a key role in regulating the function of the shunt. In this study, we aim to determine if the choice of flow-regulated or pressure-regulated valve used in the initial implantation of a shunt affects the rate of shunt revision. Methods A retrospective cohort comparison study was performed on 34 neonates with hydrocephalus following GMH who underwent placement of a ventricular shunt at the Queensland Children's Hospital from November 2014 to June 2020. The primary outcome examined was the need for revision or replacement of the ventricular shunt after successful initial placement within 2 years of implantation. The secondary outcome examined was the survival time of the shunt. Results 16 patients had placement of a flow-regulated valve, and 18 patients had placement of a pressure-regulated valve. 14 (87.5%) patients with flow-regulated valves required replacement during the follow-up period. 2 (18.18%) patients with a fixed pressure regulated underwent revision, while 2 (28.57%) programmable pressure-regulated shunts required revision. Patients that had a flow-regulated valve had a statistically significant higher rate of revision compared to those who had a pressure-regulated valve, (87.5% flow vs 22.22% pressure) with a P-value of < 0.001. Valve obstruction was also more common in patients with flow-regulated valves than pressure-regulated valves (4 vs 0) with a P-value of 0.010. Overall mean median survival time was 22.06 months, shunts with flow-regulated valves had a shorter median survival time of 3.19 months compared with over 24 months for pressure-regulated valves with a P-value of < 0.001. Conclusion Our study suggests that the initial implantation of flow-regulated valves may carry an increased total rate of shunt revision and valve obstruction within the first 2 years following implantation compared to pressure-regulated valves in patients with hydrocephalus following GMH.