Lumboperitoneal shunts for the treatment of normal pressure hydrocephalus

Abstract

Ventriculoperitoneal shunt placement is the standard of care for idiopathic normal pressure hydrocephalus (iNPH). Studies have reported shunt complication rates up to 38%, with subdural hemorrhage rates as high as 10%. Lumboperitoneal (LP) shunts with horizontal-vertical valves (HVV) are an alternative for cerebrospinal fluid (CSF) diversion that avoids direct cerebral injury and may reduce the risk of overdrainage. Here we reviewed our experience with LP-HVV shunt placement for iNPH. We retrospectively reviewed our 33 patients with LP-HVV shunts inserted for the treatment of iNPH from 1998 to 2009. Patients were evaluated for improvements in gait, urinary function, and dementia after shunt placement. All patients had evidence of ventriculomegaly and a positive response to pre-operative lumbar puncture or extended lumbar drainage. All 33 (100%) patients had pre-operative gait dysfunction, 28 (85%) had incontinence, and 20 (61%) had memory deficits. Mean follow-up time was 19 months. Following shunt placement, 33/33 (100%) patients demonstrated improved gait, 13/28 (46%) had improvement in incontinence, and 11/20 (55%) had improvement in memory. Shunt failures requiring revision occurred in nine patients (27%), with an average time to failure of 11 months. Infections occurred in two patients (6%). There were no neurologic complications, including no hemorrhages. Thus, LP-HVV shunt placement is a safe and effective alternative to ventriculoperitoneal shunting for iNPH, resulting in significant symptomatic improvement with a low risk of overdrainage. It should be considered as an option for the treatment of patients with iNPH who demonstrate clinical improvement following lumbar drainage.