A comparison between flow-regulated and adjustable valves used in hydrocephalus during infancy.

Introduction: Ventriculoperitoneal shunt insertion during the neonatal period and early infancy is associated with a high rate of shunt failure when compared to the adult population. Furthermore, the function of flow-regulated valves and differential pressure valves may be different in neonatal hydrocephalus.

Methods: A retrospective case series of all primary shunt procedures carried out during or immediately following the neonatal period, from August 2011 to February 2018 at Sheffield Children's Hospital. The total sample size was 55. This included 34 patients with adjustable valves (Miethke ProGav) and 21 with flow-regulated valves (Orbis-Sigma); however, only 53 had adequate follow-up.

Results: The overall 1 year shunt survival was 34% (18/53), and there was no significant difference depending on which shunt valve was implanted. The primary shunt infection rate was 11% (6/53) with S. aureus being the most common causative organism. During the first year of life, clinical signs of shunt overdrainage were seen more frequently in patients with adjustable valves than in those with flow-regulated valves (59% [19/32] versus 24% [5/21], p = 0.02). Furthermore, 2 patients in the adjustable valve group developed sagittal craniosynostosis secondary to shunt overdrainage.

Conclusion: Shunt failure is high when inserted during or immediately following the neonatal period. Overdrainage may be less common in patients with flow-regulated valves. However, if overdrainage is observed, adjusting the setting of a differential pressure valve can effectively treat the overdrainage without the need for invasive shunt revision surgery.