CSF Shunt Failure with Stable Normal Ventricular Size

Ahn

et al. 2017

J Korean Neurosurg Soc

ObjectiveThe diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients.MethodsWe retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage.ResultsThe mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was −3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction.ConclusionUnder-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

Section: Discussionmentioning

confidence: 99%

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions

Ahn

et al. 2017

J Korean Neurosurg Soc

“…Ideally these studies, along with a thorough history and physical examination, are sufficient to diagnose many patients in shunt failure, but it is also important to note that ventricular enlargement is not a sine qua nonindicator of shunt failure. [518] Therefore, in these cases, the diagnosis of a patient in shunt failure requires further investigation.…”

Section: Discussionmentioning

confidence: 99%

“…Although not always utilized, this minimally invasive technique has the ability to measure an opening intracranial pressure and assess proximal and distal catheter function. [1315] Traditionally, a ventricular shunt tap is considered a simple, effective, and relatively benign method of sampling CSF and identifying obstruction. The tap itself can be performed by placing a sterile needle directly through the scalp and into the reservoir of the shunt system.…”

Section: Discussionmentioning

confidence: 99%

“…However, these studies can occasionally be inconclusive, as ventricular size does not always change in patients with malfunctioning shunts. [518] Another diagnostic modality that is typically utilized for measuring opening pressure and assessing proximal and distal catheter integrity is a ventricular shunt tap. [1213] In the setting of acute shunt failure, a shunt tap can also be used as a therapeutic temporizing measure to allow for function of a distally occluded shunt.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sonographic localization of a nonpalpable shunt: Ultrasound-assisted ventricular shunt tap

Vega

Buscher²,

Gonzalez³

et al. 2013

Surg Neurol Int

Background:Patients frequently present to the emergency department (ED) for evaluation of cerebrospinal fluid (CSF) shunt malfunction, often requiring urgent management. A typical evaluation in the emergency room setting includes a thorough history and physical examination, noncontrasted head computed tomography (CT), shunt series, and occasionally a ventricular shunt tap.Case Description:We present the case of a 53-year-old male who initially presented to the ED in acute status epilepticus. His history was notable for seizures and multiple craniectomies and cranioplasties with subsequent placement of a ventriculoperitoneal shunt secondary to traumatic brain injury. Imaging in the ED suggested possible shunt failure. No previous imaging was available for comparison, and therefore a ventricular shunt tap was attempted. Initially, the tap could not be performed, as the shunt was not palpable secondary to the thickness of his scalp and location of the reservoir near his complex cranial reconstruction site. We report, for the first time, the utility of emergency ultrasound (EUS) to aid in such an encounter.Conclusion:EUS revealed the exact location of his shunt reservoir, and therefore enabled the shunt tap, which ultimately led to the discovery of the patient's proximal shunt failure in a setting that may have otherwise been missed. The patient underwent urgent shunt revision with a good outcome.

“…The diagnosis is usually suspected after a phase of clinical improvement by the recurrence of symptoms of NPH or ventriculomegaly, despite valve-opening pressure adjustments. While normal ventricular size is not enough to rule out shunt obstruction in the presence of clinical features consistent with NPH, 23 alternatively the shunt might work correctly despite ventriculomegaly 13,14 or poor clinical outcome, since a neurodegenerative disease might progress in parallel. It follows that shunt functionality calls for complementary explorations beyond clinical and CT scan data.…”

mentioning

confidence: 99%

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

Sakka

Chomicki²,

Gabrillargues

et al. 2016

JNS

V entriculoperitoneal shunting remains the firstline treatment for normal pressure hydrocephalus (NPH), despite a high rate of malfunctions that reaches 31% within the 2 years following surgery. 9,12 Its detection is challenging since neuroimaging does not systematically correlate with clinical outcome. Notably, CT scanning often discloses the persistent distension of the cerebral ventricles in clinically improved patients. 13,14 In addition, the cerebrospinal fluid (CSF) dynamic tests recommended by specialized neurosurgical teams 6,17,21 OBJectiVe Ventriculoperitoneal shunting is the first-line treatment for normal pressure hydrocephalus. Noninvasive auditory tests based on recorded otoacoustic emissions were assessed, as currently used for universal neonatal hearing screenings, for the diagnosis of cerebrospinal fluid shunt malfunction. The test was designed based on previous works, which demonstrated that an intracranial pressure change induces a proportional, characteristic, otoacoustic-emission phase shift. methOdS Forty-four patients with normal pressure hydrocephalus (23 idiopathic and 21 secondary cases) were included in this prospective observational study. The male:female sex ratio was 1.44, the age range was 21-87 years (mean age 64.3 years), and the range of the follow-up period was 1-3 years (mean 20 months). Patients were implanted with a Sophy SU8 adjustable-pressure valve as the ventriculoperitoneal shunt. The phase shifts of otoacoustic emissions in response to body tilt were measured preoperatively, immediately postoperatively, and at 3-6 months, 7-15 months, 16-24 months, and more than 24 months postoperatively. Three groups were enrolled: Group 1, 19 patients who required no valve opening-pressure adjustment; Group 2, 18 patients who required valve opening-pressure adjustments; and Group 3, 7 patients who required valve replacement. reSultS In Group 1, phase shift, which was positive before surgery, became steadily negative after surgery and during the follow-up. In Group 2, phase shift, which was positive before surgery, became negative immediately after surgery and increasingly negative after a decrease in the valve-opening pressure. In Group 3, phase shift was positive in 6 cases and slightly negative in 1 case before revision, but after revision phase shift became significantly negative in all cases. cONcluSiONS Otoacoustic emissions noninvasively reflect cerebrospinal fluid shunt function and are impacted by valve-opening pressure adjustments. Otoacoustic emissions consistently diagnosed shunt malfunction and predicted the need for surgical revision. The authors' diagnostic test, which can be repeated without risk or discomfort by an unskilled operator, may address the crucial need of detecting valve dysfunction in patients with poor clinical outcome after shunt surgery.