3 Shuunt Failure Most neurosurgeons manage shunt malfunction by: shunt revision orreplacement,temporary EVD followed by VPS
4 Case (1)17-year-old female patient diagnosed to have congenital hydrocephalus, treated by VPS in early infancy. She underwent 9 revisions.She presented with persistent headache, repeated vomiting and diplopia secondary to distal shunt obstruction.She underwent ETV, removal of the shunt, and insertion of EVD with Codman ICP monitor.ICP recording ranged between 20 and 35 mmHg, and on the 2nd postoperative day she had severe headache and recurrent vomiting that responded to intermittent opening of the EVD to drain CSF.Thereafter, the need to drain CSF has become less frequent, and she tolerated an ICP around 20 mmHg. EVD was removed at the 7th postoperative day. She remained asymptomatic and 6 months follow up CT showed marginal improvement of the ventricular dilatation.
12 Case (2)2 years-old girl had VPS at the age 6 weeks for congenital hydrocephalus. She underwent 4 revisions, 3 of them at the distal end.Her mother has seen the tip of the peritoneal catheter coming out through the anus. She was ill- looking with tachycardia and fever. CSF analysis from the shunt reservoir grew Gram negative bacilli.The shunt was removed and replaced by an EVD for one week till CSF was clear of infection.
13 Case (2)ETV was then performed and an EVD was left. The ICP recording was high (20 mmHg) in the first postoperative 3 days, and she developed bad headache and vomiting that improved with intermittent opening of the EVD to drain about 280 cc of CSF in 3 days, before removal of the EVD at the 5th day when ICP improved and she became asymptomatic. Ventricles remained dilated and ventriculogram confirmed patency of the ETV stoma
21 Case (4)20-year-old man diagnosed to have periaqueductal midbrain lesion causing occlusive hydrocephalus.He had a VPS at the age of 12 years, and later on revised when developed subdural collection.At the age of 20 years he presented with features of shunt obstruction.He underwent ETV, insertion of EVD and ICP. ICP reading was within normal for 24 hours, then removed successfully.Follow up showed reduction in the ventricular size and persistence of the midbrain lesion
25 Case (5)One year old boy who had post-meningitic multiloculated hydrocephalus soon after birth ended by having two shunts.He presented with fever, irritability, vomiting and abdominal distension, and examination of shunt CSF grew G+ve cocci.He underwent Endoscopic fenestration of intraventricular cysts through frontal burr holes, and ETV
26 Case (5)An EVD containing ICP sensor was left in the ventricle. His ICP was slowly rising, with irritablity, and vomiting, and ICP reaching 35 mmHg. Symptoms improve by temporary drainage of CSF.EVD was utilized for installation of antibiotics and a CT ventriculogram.He did not tolerate closure of the EVD and a permanent VPS was inserted.
37 Table no. AGE Sex Shunt Type Duration of H/C No. Of Revisions Shunt FailureEndoscopyICPMVPS117FVA17 Y9ObstructionETV, EVD, ICPM7 dNo2VP2 Y4Infection6 d3M6 mETV, CPC, EVD, ICPM1 d208 YETV,EVD, ICPM5VP, CP4 Y5 dYes6242 m2 d789 Y
38 DiscussionThe use of postoperative ICP measurement after ETV has been suggested as a valid monitoring method, mostly in the early postoperative period.Neurosurgeons observed the existence of different ICP patterns following ETV.
39 DiscussionMonitoring of ICP after ETV has a major advantage. It immediately identifies elevations in ICP. It also provides an early warning of complications, such as failure of ETV, due to narrow or occluded stoma by a second membrane, and formation of hydrocephalus, that will lead to rise in the ICP.ICP Monitors are usually left in place until the ICP has been normalized for at least 24 hours. The CSF resorption pathways may reopen even several days after the procedure.
40 ConclusionWhen ETV is required to treat patients with shunt malfunction or infection, the most benign procedure may be that involving removal of the failed or infected shunt, and insertion of ICP monitor and EVD in the same procedure.It can be used to intermittently drain CSF when patient is symptomatic of raised ICP, to inject intrventricular antibiotics, and to perform ventriculogrm.