Neurosurgery Blog

Neurosurgery 67:588-593, 2010 DOI: 10.1227/01.NEU.0000373199.79462.21

Endoscopic third ventriculostomy (ETV) has preferentially been offered to patients with more favorable prognostic features compared with shunt.

OBJECTIVE: To use advanced statistical methods to adjust for treatment selection bias to determine whether ETV survival is superior to shunt survival once the bias of patientrelated prognostic factors is removed.

METHODS: An international cohort of children (≤ 19 years of age) with newly diagnosed hydrocephalus treated with ETV (n = 489) or shunt (n = 720) was analyzed. We used propensity score adjustment techniques to account for 2 important patient prognostic factors: age and cause of hydrocephalus. Cox regression survival analysis was performed to compare time-to-treatment failure in an unadjusted model and 3 propensity score—adjusted models, each of which would adjust for the imbalance in prognostic factors.

RESULTS: In the unadjusted Cox model, the ETV failure rate was lower than the shunt failure rate from the immediate postoperative phase and became even more favorable with longer duration from surgery. Once patient prognostic factors were corrected for in the 3 adjusted models, however, the early failure rate for ETV was higher than that for shunt. It was only after about 3 months after surgery did the ETV failure rate become lower than the shunt failure rate.

CONCLUSIONS: The relative risk of ETV failure is initially higher than that for shunt, but after about 3 months, the relative risk becomes progressively lower for ETV. Therefore, after the early high-risk period of ETV failure, a patient could experience a long-term treatment survival advantage compared with shunt. It might take several years, however, to realize this benefit.

Neurosurgery 67:295-301, 2010 DOI: 10.1227/01.NEU.0000371972.74630.EC

Shunt surgery has been established as the only durable and effective treatment for idiopathic normal pressure hydrocephalus.

OBJECTIVE:We evaluated the “extended” long-term follow-up (> 5 years) in a prospective study cohort who underwent shunting between 1990 and 1995. A secondary objective was to determine the cause of death in these patients.

METHODS: Fifty-one patients were included after confirmation of the diagnosis by extensive clinical and diagnostic investigations. Surgery included ventriculoatrial or ventriculoperitoneal shunting with differential pressure valves in the majority of patients. For each of the cardinal symptoms, postoperative outcome was assessed separately with the Krauss Improvement Index, yielding a value between 0 (no benefit) and 1 (optimal benefit) for the overall outcome.

RESULTS: Mean age at surgery was 70.2 years (range, 50-87 years). Thirty patients were women, and 21 were men. Short-term (18.8 ± 16.6 months) follow-up was available for 50 patients. The Krauss Improvement Index was 0.66 ± 0.28. Long-term (80.9 ± 51.6 months) follow-up was available for 34 patients. The Krauss Improvement Index was 0.64 ±0.33. Twenty-nine patients died during the long-term follow-up at a mean age of 75.8 years (range, 55-95 years). The major causes of death were cardiovascular disorders: cardiac failure (n = 7) and cerebral ischemia (n = 12). Other causes were pneumonia (n = 2), acute respiratory distress syndrome (n = 1), pulmonary embolism (n = 1), cancer (n = 2), renal failure (n = 1), and unknown (n = 3). There was no shunt-related mortality.

CONCLUSION: Idiopathic normal pressure hydrocephalus patients may benefit from shunting over the long term when rigorous selection criteria are applied. Shunt-related mortality is negligible. The main cause of death is vascular comorbidity.

J Neurosurg 113:74–78, 2010. (DOI: 10.3171/2009.9.JNS09171)

In this paper, the authors’ goal was to compare the artifact induced by implanted (in vivo) adjustable shunt valves in spin echo, diffusion weighted (DW), and gradient echo MR imaging pulse sequences.

Methods. The MR images obtained in 8 patients with proGAV and 6 patients with Strata II adjustable shunt valves were assessed for artifact areas in different planes as well as the total volume for different pulse sequences.

Results. Artifacts induced by the Strata II valve were significantly larger than those induced by proGAV valve in spin echo MR imaging pulse sequence (29,761 vs 2450 mm3 on T2-weighted fast spin echo, p = 0.003) and DW images (100,138 vs 38,955 mm3, p = 0.025). Artifacts were more marked on DW MR images than on spin echo pulse sequencse for both valve types.

Conclusions. Adjustable valve–induced artifacts can conceal brain pathology on MR images. This should influence the choice of valve implantation site and the type of valve used. The effect of artifacts on DW images should be highlighted pending the development of less MR imaging artifact–inducing adjustable shunt valves.

J Neurosurg 113:64–73, 2010. DOI: 10.3171/2010.1.JNS091296

The ability to predict outcome after shunt placement in patients with idiopathic normal-pressure hydrocephalus (NPH) represents a challenge. To date, no single diagnostic tool or combination of tools has proved capable of reliably predicting whether the condition of a patient with suspected NPH will improve after a shunting procedure. In this paper, the authors report their experience with 120 patients with the goal of identifying CSF hydrodynamics criteria capable of selecting patients with idiopathic NPH. Specifically, they focused on the comparison between CSF-outflow resistance (R-out) and intracranial elastance (IE).

Methods. Between January 1977 and December 2005, 120 patients in whom idiopathic NPH had been diagnosed (on the basis of clinical findings and imaging) underwent CSF hydrodynamics evaluation based on an intraventricular infusion test. Ninety-six patients underwent CSF shunt placement: 32 between 1977 and 1989 (Group I) on the basis of purely clinical and radiological criteria; 44 between 1990 and 2002 (Group II) on the basis of the same criteria as Group I and because they had an IE slope > 0.25; and 20 between 2003 and 2005 (Group III) on the basis of the same criteria as Group II but with an IE slope ≥ 0.30. Outcomes were evaluated by means of both Stein-Langfitt and Larsson scores. Patients’ conditions were considered improved when there was a stable decrease (at 6- and 12-month follow-up) of at least 1 point in the Stein-Langfitt score and 2 points in the Larsson score.

Results. Group I: while no statistically significant difference in mean R-out value between improved and unimproved cases was observed, a clear-cut IE slope value of 0.25 differentiated very sharply between unimproved and improved cases. Group II: R-out values in the 2 unimproved cases were 20 and 47 mm Hg/ml/min, respectively. The mean IE slope in the improved cases was 0.56 (range 0.30–1.4), while the IE slopes in the 2 unimproved cases were 0.26 and 0.27. Group III: the mean IE slope was 0.51 (range 0.31–0.7). The conditions of all patients improved after shunting. A significant reduction of the Evans ratio was observed in 34 (40.5%) of the 84 improved cases and in none of the unimproved cases.

Conclusions. Our strategy based on the analysis of CSF pulse pressure parameters seems to have a great accuracy in predicting surgical outcome in clinical practice.

Neurosurgery 67:187-191, 2010 DOI: 10.1227/01.NEU.0000370247.11479.B6

Ventriculostomy infections create significant morbidity. To reduce infection rates, a standardized evidence-based catheter insertion protocol was implemented. A prospective observational study analyzed the effects of this protocol alone and with antibiotic-impregnated ventriculostomy catheters.

OBJECTIVE: To compare infection rates after implementing a standardized protocol for ventriculostomy catheter insertion with and without the use of antibiotic-impregnated catheters.

METHODS: Between 2003 and 2008, 1961 ventriculostomies and infections were documented. A ventriculostomy infection was defined as 2 positive CSF cultures from ventriculostomy catheters with a concurrent increase in cerebrospinal fluid white blood cell count. A baseline (preprotocol) infection rate was established (period 1). Infection rates were monitored after adoption of the standardized protocol (period 2), institution of antibioticimpregnated catheter A (period 3), discontinuation of antibiotic-impregnated catheter A (period 4), and institution of antibiotic-impregnated catheter B (period 5).

RESULTS: The baseline infection rate (period 1) was 6.7% (22/327 devices). Standardized protocol (period 2) implementation did not change the infection rate (8.2%; 23/281 devices). Introduction of catheter A (period 3) reduced infections to 1.0% (2/195 devices, P = .0005). Because of technical difficulties, this catheter was discontinued (period 4), resulting in an increase in infection rate (7.6%; 12/157 devices). Catheter B (period 5) significantly decreased infections to 0.9% (9 of 1001 devices, P = .0001). The Staphylococcus infection rate for periods 1, 2, and 4 was 6.1% (47/765) compared with 0.2% (1/577) during use of antibioticimpregnated catheters (periods 3 and 5).

CONCLUSION: The use of antibiotic-impregnated catheters resulted in a significant reduction of ventriculostomy infections and is recommended in the adult neurosurgical population.

Neurosurgery 67:110-117, 2010 DOI: 10.1227/01.NEU.0000370920.44359.91

The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus.

OBJECTIVE: To assess whether intraventricular tissue plasminogen activator (tPA) results in less vasospasm, fewer angioplasties, or fewer cerebrospinal fluid shunting procedures.

METHODS: 41 patients (tPA group, Hunt and Hess 3, 4, 5) from 2007 to 2008 received intraventricular tPA and lumbar drainage for a minimum of 5 days (range 5-7 days) and were compared to a matched group of 35 patients from 2006 to 2007 (Control, HH 3, 4, 5). Statistical comparison was done by t test analysis or Fisher exact tests and data are expressed as average ± standard error of the mean.

RESULTS: There were no significant differences in demographic data, although the tPA group had a trend toward more surgical patients. The tPA group of patients had a significantly higher modified Fisher grade than controls (P < .001) and had a significantly better Hunt and Hess grade than controls (P < .03). The angioplasty rate was significantly lower among the tPA patients (15.0% ± 5.6) than controls (40.0% ± 8.5, P = .019). The number of days spent in severe vasospasm normalized over the 14-day monitoring period by transcranial Doppler was significantly lower in the tPA group (0.09 ± 0.02) than controls (0.17 ± 0.03). The shunt rate was significantly lower among tPA patients (17.5% ± 6.0) than controls (42.8% ± 8.6). There were 2 clinically silent tract hemorrhages in the tPA group (4.8%).

CONCLUSION: Intraventricular tPA is a safe and effective treatment for reducing both angioplasty and shunting rates in patients with SAH H&H Grades 3 to 5. A randomized trial is indicated.

Neurosurgery 67:94-99, 2010 DOI: 10.1227/01.NEU.0000370939.30003.D1

A precise definition of ventricular enlargement is important in the diagnosis of hydrocephalus as well as in assessing central atrophy. The Evans index (EI), a linear ratio between the maximal frontal horn width and the cranium diameter, has been extensively used as an indirect marker of ventricular volume (VV). With modern imaging techniques, brain volume can be directly measured.

OBJECTIVE: To determine reference values of intracranial volumes in healthy elderly individuals and to correlate volumes with the EI.

METHODS:Magnetic resonance imaging (3 T) was performed in 46 healthy white elderly subjects (mean age ± standard deviation, 71 ± 6 years) and in 20 patients (74 ± 7 years) with large ventricles according to visual inspection. VV, relative VV (RVV), and EI were assessed. Ventricular dilation was defined using VV and EI by a value above the 95th percentile range for healthy elderly individuals.

RESULTS: In healthy elderly subjects, we found VV = 37 ± 18 mL, RVV = 2.47 ± 1.17%, and EI = 0.281 ± 0.027. Including the patients, there was a strong correlation between EI and VV (R = 0.94) as well as between EI and RVV (R = 0.95). However, because of a wide 95% prediction interval (VV: ±45 mL; RVV: ± 2.54%), EI did not give a sufficiently good estimate of VV and RVV.

CONCLUSION: VV (or RVV) and the EI reflect different properties. The exclusive use of EI in clinical studies as a marker of enlarged ventricles should be questioned. We suggest that the definition of dilated ventricles in white elderly individuals be defined as VV >77 mL or RVV >4.96 %. Future studies should compare intracranial volumes with clinical characteristics and prognosis.

Acta Neurochir (2010) 152:989–995. DOI 10.1007/s00701-010-0605-x

Purpose: In patients with idiopathic normal pressure hydrocephalus (iNPH) and ventriculomegaly, examine whether there is a gradient in pulsatile intracranial pressure (ICP) from within the cerebrospinal fluid (CSF) of cerebral ventricles (ICPIV) to the subdural (ICPSD) compartment. We hypothesized that pulsatile ICP is higher within the ventricular CSF.

Methods The material includes 10 consecutive iNPH patients undergoing diagnostic ICP monitoring as part of pre-operative work-up. Eight patients had simultaneous ICPIV and ICPSD signals, and two patients had simultaneous signals from the lateral ventricle (ICPIV) and the brain parenchyma (ICPPAR). Intracranial pulsatility was characterized by the wave amplitude, rise time, and rise time coefficient; static ICP was characterized by mean ICP.

Results None of the patients demonstrated gradients in pulsatile ICP, that is, we found no evidence of higher pulsatile ICP within the CSF of the cerebral ventricles (ICPIV), as compared to either the subdural (ICPSD) compartment or within the brain parenchyma (ICPPAR). During ventricular infusion testing in one patient, the ventricular ICP (ICPIV) was artificially increased, but this increase in ICPIV produced no gradient in pulsatile ICP from the ventricular CSF (ICPIV) to the parenchyma (ICPPAR).

Conclusions: In this cohort of iNPH patients, we found no evidence of transmantle gradient in pulsatile ICP. The data gave no support to the hypothesis that pulsatile ICP is higher within the CSF of the cerebral ventricles (ICPIV) than within the subdural (ICPSD) compartment or the brain parenchyma (ICPPAR) in iNPH patients.

Childs Nerv Syst (2010) 26:791–796. DOI 10.1007/s00381-009-1061-x

The reported rate is up to 10% of shunt disconnection or fracture, either ventriculoperitoneal or subduroperitoneal. However, not all of shunt discontinuity is associated with shunt malfunction. We analyzed the discontinuity of the shunt system and related factors and tried to present a follow-up policy.

Methods This is a retrospective study involving 22 patients who presented with shunt disconnection because of malfunction or other reasons between January 2003 and October 2008. To evaluate shunt function, we performed a shuntogram, temporary ligation, or intraoperative exploration.

Results Nine (40.9%) of 22 patients had nonfunctioning shunts. The shunt system was removed in eight cases, and one patient refused surgical management. Of these 22 patients with disconnected shunts, 17 shunts placed in the occipital area were discontinued. The discontinuations were mostly fractured at neck (52%), not disconnected at connection site.

Conclusion Shunt disconnection has not been always represented a shunt malfunction. We thought many patients with disconnected shunt may be independent from shunt system, and it can be a good chance for patient to remove the shunt system

Journal of Neurosurgery, June 2010. DOI: 10.3171/2010.4.JNS10132

Neurosurgery 66:917-924, 2010 DOI: 10.1227/01.NEU.0000367801.35654.EC

Diffusion tensor imaging (DTI) parameters were investigated in patients with chronic idiopathic hydrocephalus to evaluate microstructural changes of brain tissue caused by chronic ventricular dilatation.

METHODS: Eleven patients fulfilling the criteria for possible or probable idiopathic normal pressure hydrocephalus and 10 healthy control subjects underwent MRI at 3 Tesla, including DTI with 12 gradient directions. Patients were scanned before lumbar cerebrospinal fluid (CSF) withdrawal tests. Differences in fractional anisotropy (FA) and mean diffusivity (MD) between patients and controls were assessed using 2 different methods: manual definition of regions of interest and a fully automated method, TBSS (Tract-Based Spatial Statistics). DTI parameters were correlated with clinical findings.

RESULTS: Compared with the control group, patients with chronic idiopathic hydrocephalus had significantly higher MD values in both the periventricular corticospinal tract (CST) and the corpus callosum (CC), whereas FA values were significantly higher in the CST but lower in the CC. DTI parameters of the CST correlated with the severity of gait disturbances.

CONCLUSION:Microstructural changes in periventricular functionally relevant white matter structures (CSF, CC) in chronic idiopathic hydrocephalus can be visualized using DTI. Further studies should investigate the change of DTI parameters after CSF shunting and its relation to neurologic outcome.

Neurosurgery 66:904-909, 2010 DOI: 10.1227/01.NEU.0000368385.74625.96

This study investigated the outcome of early shunt placement in patients with poor-grade subarachnoid hemorrhage and the effect of intraventricular hemorrhage (IVH) and high proteinaceous cerebrospinal fluid (CSF) on subsequent shunt performance. METHODS:This study included 33 consecutive patients with initial Fisher grade (3/4) subarachnoid hemorrhage who had undergone conversion from external ventricular drainage (EVD) to a ventriculoperitoneal (VP) shunt and whose computed tomography scan showed IVH at the time of shunt placement. Early weaning from an EVD and conversion to a VP shunt was performed irrespective of IVH or high protein content in the CSF. RESULTS: The mean interval from EVD to VP shunt placement was 6.4 days. The mean volume of IVH was 9.44 mL, and the mean value of IVH/whole ventricle volume ratio (ie, percentage of blood suspension in the CSF) was 9.81%. The mean perioperative protein level in the CSF was 149 mg/dL. During the follow-up period, 2 patients (6.1%) required VP shunt placement, and no patients experienced complications of ventriculitis or shunt-related infection. CONCLUSION: Based on our data, earlier EVD weaning and shunt placement can effectively treat subarachnoid hemorrhage–induced hydrocephalus in patients with severe subarachnoid hemorrhage. This procedure resulted in no shunt-related infections and a 6.1% revision rate. There were fewer adverse effects of IVH and protein on shunt performance. Therefore, weaning from an EVD and conversion to a permanent VP shunt need not be delayed because of IVH or proteinaceous CSF.

J Neurosurg 112:832–839, 2010. (DOI: 10.3171/2009.7.JNS09550)

Ventriculomegaly is a common imaging finding in many types of conditions. It is difficult to determine whether it is related to true hydrocephalus or to an atrophic process by using only imaging procedures such as MR imaging after traumatic injury, stroke, or infectious disease. Diffusion tensor (DT) imaging can distinguish the compression characteristics of white matter, indicating that increased diffusion anisotropy may be related to white matter compression. In this preliminary study, the authors compared the DT imaging findings of ventriculomegaly with those of chronic hydrocephalus or atrophy to clarify the potential of diffusion anisotropy in the identification of hydrocephalus. Methods. Ten patients with chronic hydrocephalus, 8 patients with atrophy (defined by conventional devices and surgical outcome), and 14 healthy volunteers underwent DT imaging. Images were acquired before and after shunting or once in cases without shunting. The fractional anisotropy (FA) values at many points around the lateral ventricle were evaluated. Results. The FA patterns around the lateral ventricle in the chronic hydrocephalus and atrophy groups were different. Especially in the caudate nucleus, FA was increased in the chronic hydrocephalus group compared with the atrophy group. Furthermore, the FA values returned to normal levels after shunt placement. Conclusions. Assessment of the FA value of the caudate nucleus may be an important, less invasive method for distinguishing true hydrocephalus from ventriculomegaly. Further research in a large number of patients is needed to verify the diagnostic ability of this method.

Neurosurgery 66:465-474, 2010 DOI: 10.1227/01.NEU.0000365272.77634.6B

OBJECTIVE: To evaluate the reliability of the gravitation-assisted adjustable proGAV shunt system with a prospective multicenter study conducted in 10 German hospitals.

METHODS: Enrollment for this observational study began in April 2005 and concluded in February 2006. The protocol required re-examinations 3 and 6 months postoperatively and fixed the endpoint of follow-up at 12 months after implantation. Patients with different types of adult, juvenile, and pediatric hydrocephalus were included and 165 patients were enrolled; 9 died and 12 had incomplete follow-up.

RESULTS: Of the assessable 144 patients, 130 completed the protocol after 12 months, whereas 14 failed because of the need to explant the device, mainly because of infection. In 12 patients, components of the shunt, not the valve, were revised. In 65 of the 144 patients, there were 102 readjustments of the valve in 67 incidences because of underdrainage and in 35 because of overdrainage. In 1 case, readjustment was not possible. Determination of pressure level with the verification instrument was safe and corresponded to the required x-ray controls after adjustments. No unintended readjustments were noted.

CONCLUSION: The proGAV is a safe and reliable device.

Journal of Neurosurgery: Pediatrics. (DOI: 10.3171/2009.9.PEDS09196)

In Uganda, childhood hydrocephalus is common and difficult to treat. In some children, endoscopic third ventriculostomy (ETV) can be successful and avoid dependence on a shunt. This can be especially beneficial in Uganda, because of the high risk of infection and long-term failure associated with shunting. Therefore, the authors developed and validated a model to predict the chances of ETV success, taking into account the unique characteristics of a large sub-Saharan African population.

Methods. All children presenting with hydrocephalus at CURE Children’s Hospital of Uganda (CCHU) between 2001 and 2007 were offered ETV as first-line treatment and were prospectively followed up. A multivariable logistic regression model was built using ETV success at 6 months as the outcome. The model was derived on 70% of the sample (training set) and validated on the remaining 30% (validation set).

Results. Endoscopic third ventriculostomy was attempted in 1406 patients. Of these, 427 were lost to followup prior to 6 months. In the remaining 979 patients, the ETV was aborted in 281 due to poor anatomy/visibility and in 310 the ETV failed during the first 6 months. Therefore, a total of 388 of 979 (39.6% and [55.6% of completed ETVs]) procedures were successful at 6 months. The mean age at ETV was 12.6 months, and 57.8% of cases were postinfectious in origin. The authors’ logistic regression model contained the following significant variables: patient age at ETV, cause of hydrocephalus, and whether choroid plexus cauterization was performed. In the training set (676 patients) and validation set (303 patients), the model was able to accurately predict the probability of successful ETV (Hosmer-Lemeshow p value > 0.60 and C statistic > 0.70). The authors developed the simplified CCHU ETV Success Score that can be used in the field to predict the probability of ETV success.

Conclusions. The authors’ model will allow clinicians to accurately identify children with a good chance of successful outcome with ETV, taking into account the unique characteristics and circumstances of the Ugandan population.

J Neurosurg 112: 399–409, 2010. (DOI: 10.3171/2009.4.JNS081664)

Object. The test-retest method is commonly used in the management of patients with normal-pressure hydrocephalus (NPH). One of the most widely used techniques in the diagnosis of this condition is evaluation of the
patient’s response to CSF evacuation by lumbar puncture (a so-called tap test or spinal tap). However, interpretation of improved results in subsequent evaluations is controversial because higher scores could reflect a real change in specific abilities or could be simply the result of a learning effect.
Methods. To determine the effect of testing-retesting in patients with NPH, the authors analyzed changes documented on 5 neuropsychological tests (the Toulouse-Pieron, Trail Making Test A, Grooved Pegboard, Word Fluency, and Bingley Memory tests) and several motor ability scales (motor performance test, length of step, and walking speed tests) in a series of 32 patients with NPH who underwent the same battery on 4 consecutive days. The same tests were also applied in 30 healthy volunteers. In both groups, the authors used the generalized least-squares regression method with random effects to test for learning effects. To evaluate possible differences in response depending on the degree of cognitive impairment at baseline, the results were adjusted by using the Mini-Mental State Examination scores of patients and controls when these scores were significant in the model.
Results. In patients with NPH there were no statistically significant differences in any of the neuropsychological
or motor tests performed over the 4 consecutive days, except in the results of the Toulouse-Pieron test, which
were significantly improved on Day 3. In contrast, healthy volunteers had statistically significant improvement in the results of the Toulouse-Pieron test, Trail Making Test A, and Grooved Pegboard test but not in the remaining neuropsychological tests. Patients in the healthy volunteer group also exhibited statistically significant improvement in the motor performance test but not in step length or walking speed.
Conclusions. No learning effect was found in patients with NPH on any of the neuropsychological or motor tests. Clinical improvement after retesting in these patients reflects real changes, and this strategy can therefore be used in both the diagnosis and evaluation of surgical outcomes.

Neurosurgery 66:284-289, 2010 DOI: 10.1227/01.NEU.0000363405.12584.4D

BACKGROUND:The average hospital cost for shunt infection treatment is $50 000, making it the most financially costly implant-related infection in the United States. We set out to determine whether introduction of antibiotic-impregnated shunts (AISs) in our practice has decreased the incidence of shunt infection or decreased infection-related hospital costs at our institution.

METHODS: Clinical and hospital billing records of pediatric patients undergoing cerebrospinal fluid (CSF) shunt insertion at a single institution from April 2001 to December 2006 were retrospectively reviewed. Eighteen months before October 2002, all CSF shunts included standard, non-AIS catheters. During the 4 years after October 2002, all CSF shunts included AIS catheters. Patients were followed at least 18 months after surgery.

RESULTS: A total of 406 pediatric patients underwent 608 shunt placement procedures (400 AISs, 208 non-AISs). Of patients with non-AIS catheters, 25 (12%) experienced shunt infection, whereas only 13 patients (3.2%) with AIS catheters experienced shunt infection during follow-up (P < .001). The total hospital cost to treat 25 non-AIS shunt infections over the first 18 months was $1,234,928. The total hospital cost to treat 13 AIS shunt infections over the past 4 years was $606,328. The mean hospital cost per shunt infection was similar for infected AIS and non-AIS catheters ($46 640 vs. $49 397). However, the infection- related hospital cost per 100 patients shunted was markedly lower in the AIS cohort than in the non-AIS cohort ($151 582 vs. $593 715).

DISCUSSION: The introduction of AIS catheters in our institutional practice reduced the incidence of shunt infection and resulted in significant hospital cost savings. AIS systems are efficient and cost-effective instruments to prevent perioperative colonization of CSF shunt components.

Childs Nerv Syst (2010) 26:75–79.DOI 10.1007/s00381-009-0983-7

In the current literature, there are essentially no comparisons of quality of life (QOL) outcome after endoscopic third ventriculostomy (ETV) and shunt in childhood hydrocephalus. Our objective was to compare QOL in children with obstructive hydrocephalus, treated with either ETVor shunt. Methods A cross-sectional survey was conducted at SickKids, Toronto of children between ages five and 18 years, with obstructive hydrocephalus due to aqueductal obstruction and no other brain abnormalities. Measures of QOL were the Hydrocephalus Outcome Questionnaire and the Health Utilities Index Mark 3. A subset of patients was given the Wechsler Intelligence Scales for Children (WISC-IV). Results A total of 47 of 59 (80%) eligible patients participated (24 had ETV as primary treatment, 23 had shunt as primary treatment), with a mean age of 12.1 years (standard deviation 3.9) at assessment. The ETV group was older at initial surgery (p<0.001) and had larger ventricle size at last follow-up (p= 0.047). In all QOL measures, there were no significant differences between the ETV group and shunt group (all p≥ 0.09). Treatment failure, hydrocephalus complications, and the presence of a functioning ETV at assessment were not associated with QOL differences. Among the 11 children (six ETV, five shunt) who were given the WISC-IV, there were no significant differences between the scores of the ETV group and shunt group (all p≥0.11). Conclusions This is the first study to provide a meaningful comparison of QOL after ETV and shunt in children. These preliminary results suggest that there is no obvious difference in QOL after ETVand shunt.

J Neurosurg Pediatrics 5:4–16, 2010.(DOI: 10.3171/2008.7.17690)

This 25-year follow-up study was performed on 120 children with hypertensive hydrocephalus to evalu- ate the influence of the early prophylactic implantation of the Integra antisiphon device (ASD, Integra Neurosciences Ltd.) on the rate of proximal shunt obstructions and the frequency of symptomatic slit ventricle syndrome (SVS). The adaptability of the ASD to growth, proper positioning of the ASD as a necessity for its successful performance, and the 3 phases of SVS development are discussed.

Method. Since 1978, the ASD has consistently been implanted either at the time of primary shunt insertion (66 neonates, mean follow-up 11 years) or during revisions of preexisting shunts (54 children, mean follow-up 11.8 years). The complication rate among the 54 children before ASD implantation (mean follow-up 8.3 years) was com- pared with that among all 120 patients once an ASD had been inserted. Shunt complications were documented as ventricular catheter, distal catheter, and infectious complications.

Results. The study revealed a significant long-term reduction in ventricular catheter obstructions and hospitaliza- tions due to intermittent intracranial hypertension symptoms (symptomatic SVS) after both primary and secondary ASD implantation. Data in the study suggest that the high rate of ventricular catheter obstruction in pediatric shunt therapy is caused by hydrostatic suction induced by differential-pressure valve shunts during mobilization of the patient and that the development of a SVS can be traced back to this constant suction, which causes chronic CSF overdrainage and ventricular noncompliance. Recurrent ventricular catheter obstruction and SVS can be prevented by prophylactic supplementation of every shunt system with an ASD.

Conclusions. To inhibit chronic hydrostatic suction, to prevent overdrainage and proximal shunt obstruction, and to avoid SVS and thus improve the patient’s quality of life, the prophylactic implantation of an ASD in every pediatric hydrocephalus shunt is recommended.

Neurosurgery 66:80-91, 2010 DOI: 10.1227/01.NEU.0000363408.69856.B8

OBJECTIVE: To review our experience of managing idiopathic normal pressure hydrocephalus (iNPH) during the 6-year period from 2002 to 2007, when intracranial pressure (ICP) monitoring was part of the diagnostic workup.

METHODS: The review includes all iNPH patients undergoing diagnostic ICP monitoring during the years 2002 to 2007. Clinical grading was done prospectively using a normal pressure hydrocephalus (NPH) grading scale (scores from 3 to 15). The selection of patients for surgery was based on clinical symptoms, enlarged cerebral ventricles, and findings on ICP monitoring. The median follow-up time was 2 years (range, 0.3-6 years). Both static ICP and pulsatile ICP were analyzed.

RESULTS: A total of 214 patients underwent the diagnostic workup, of whom 131 went on to surgery. Although 1 patient died shortly after treatment, 103 of the 130 patients (79%) improved clinically. This improvement lasted throughout the observation period. The static ICP observed during ICP monitoring was a poor predictor of the response to surgery. In contrast, among 109 of 130 patients with increased ICP pulsatility (ie, ICP wave amplitude >4 mm Hg on average and >5 mm Hg in >10% of recording time), 101 (93%) were responders (ie, increase in the NPH score of >2). Correspondingly, only 2 of 21 (10%) without increased ICP pulsatility were responders. Superficial wound infection was the only complication of ICP monitoring and occurred in 4 (2%) patients.

CONCLUSION: Surgical results in iNPH were good with almost 80% of patients improving after treatment. The data indicate that improvement after surgery can be anticipated in 9 of 10 iNPH patients with abnormal ICP pulsatility, but in only 1 of 10 with normal ICP pulsatility. Diagnostic ICP monitoring had a low complication rate