Gravity-assisted valve (GAV) systems to prevent low-pressure headaches in patients with lumboperitoneal shunts.
OBJECTIVE
Low-pressure symptoms after lumboperitoneal (LP) shunting for idiopathic intracranial hypertension (IIH) remain a significant problem. Gravity-assisted valves (GAV) operate at a higher pressure in a vertical position and therefore aim to reduce postural over-drainage. We audited patients with GAV valves inserted in their shunt system to assess their efficacy in reducing low-pressure symptoms and ascertain whether the additional cost of such device can be justified.


METHODS
Using a standard proforma, we reviewed patient medical notes and recorded indications and post-operative outcomes in symptom control.


RESULTS
In total, 24 patients had the GAV system inserted, 12 had low-pressure symptoms after LP and had LP shunts inserted with GAV valves and 11 in developed low-pressure symptoms after insertion of plane LP shunts and had GAV valves added as secondary procedures. One patient was excluded from the study because the indication for the GAV system was secondary to the presence of low lying cerebellar tonsils (secondary Chiari) rather than headache in a patient with IIH who had undergone previous LP shunt insertion. The GAV system was introduced to prevent further tonsillar decent.Out of 23 patients, 17 patients who had the system inserted to prevent or improve low-pressure symptoms reported improvement in their symptoms.


CONCLUSIONS
GAV inserted into LP shunts were effective in reducing low-pressure headaches induced by changes in posture whilst still sufficiently lowering ICP to ameliorate high-pressure symptoms.
a The James Cook University Hospital , Middlesbrough , UK.
Mohammed Akbar
MA
Hussain
a The James Cook University Hospital , Middlesbrough , UK.
Roger David
RD
Strachan
D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects* / Q000191:economics; D003362:Cost-Benefit Analysis; D020773:Headache Disorders / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D019585:Intracranial Hypotension / Q000150:complications; D019635:Neurosurgical Procedures / Q000009:adverse effects; D011183:Postoperative Complications / Q000517:prevention & control*; D016896:Treatment Outcome
CSF dynamics; CSF shunt; CSF shunt complication; idiopathic intracranial hypertension; shunt complications