Lumboperitoneal shunts for the treatment of idiopathic normal pressure hydrocephalus

The standard of care for idiopathic normal pressure hydrocephalus (iNPH) is placement of a ventriculoperitoneal (VP) shunt. However, VP shunts require intracranial intervention and are associated with notable postoperative complications, with some groups reporting complication rates for VP shunts ranging from 17 to 33%, along with failure rates up to 17.7%. Lumboperitoneal (LP) shunts are an alternative for cerebrospinal fluid diversion that do not require intracranial surgery, thus providing utility in patients where intracranial surgery is not possible or preferred. Here we retrospectively reviewed our 25 patients with LP horizontal-vertical (LP-HV) shunts placement for initial treatment for iNPH from 2014 to 2019. All patients had preoperative gait dysfunction, 16 (64%) had urinary incontinence, and 21 (84%) exhibited cognitive insufficiency. Two weeks post-shunt placement, 23/25 (92%) patients demonstrated improvement in gait, 11/16 (68%) had improvement in incontinence, and 14/21 (66%) had improvement cognitive insufficiency. At six months or greater follow up 13/20 (65%) had improvement in gait, 7/15 (47%) showed improvement in incontinence, and 11/15 (73%) demonstrated improvement in cognitive function. Six patients (24%) required at least one revision of the LP shunt. Shunt malfunctions resulted from CSF leak in one patient, shunt catheter migration in two patients, peritoneal catheter pain in one patient, and clinical symptoms for overdrainage in two patients. Thus, we demonstrate that LP-HV shunt placement is safe and efficacious alternative to VP shunting for iNPH, resulting in notable symptomatic improvement and low risk of overdrainage, and may be considered for patients where cranial approaches should be avoided.