Postshunt lateral ventricular volume, white matter integrity, and intellectual outcomes in spina bifida and hydrocephalus.

Williams VJ, Juranek J, Stuebing KK, Cirino PT, Dennis M, Bowman RM, Blaser S, Kramer LA, Fletcher JM. (2015) Postshunt lateral ventricular volume, white matter integrity, and intellectual outcomes in spina bifida and hydrocephalus.

J Neurosurg Pediatr. 2015 Apr;15(4):410-9. doi: 10.3171/2014.10.PEDS13644

Abstract

OBJECT No previous reports exist that have evaluated the relationships of white matter (WM) integrity with the number of shunt revisions, ventricular volume after shunting, and cognition in medically stable children who have spina bifida and hydrocephalus (SBH). The authors hypothesized that enlarged ventricles and a greater number of shunt revisions decrease WM integrity in children. METHODS In total, 80 children (mean age 13.7 years) who had SBH underwent MRI and IQ testing. Probabilistic diffusion tractography was performed to determine mean diffusion tensor imaging (DTI) metrics along the frontal and parietal tectocortical pathways. The DTI metrics were evaluated for significant correlation with a composite IQ measure and with the total number of shunt revisions and the total lateral ventricular volume obtained through semiautomated parcellation of T1-weighted MRI scans. RESULTS An enlargement in total lateral ventricle volume and an increase in the number of shunt revisions were both associated with higher fractional anisotropy (FA) and with lower radial diffusivity (RD) along both frontal and parietal tectocortical pathways. Children who had not undergone a shunt revision had on average a greater lateral ventricle volume and higher FA and lower RD along frontal and parietal pathways than those who had undergone multiple shunt revisions. The mean DTI metrics along parietal pathways predicted IQ scores, but intellectual ability was not significantly correlated with ventricular volume or with the number of lifetime shunt revisions. CONCLUSIONS Significant changes in DTI metrics were observed as a function of ventricular volume. An increased lateral ventricle volume was associated with elevated FA and decreased RD. Given that the participants were medically stable at the time of the MRI examination, the results suggested that those who have enlarged ventricles show a DTI pattern consistent with axonal compression due to increased intracranial pressure (ICP) in attenuated hydrocephalus. Although limited by a cross-sectional design, the study's findings suggest that DTI metrics may serve as sensitive indicators for chronic, mild hydrocephalus in the absence of overt clinical symptoms due to increased ICP. Having enlarged ventricles and undergoing multiple shunt revisions did not affect intellectual ability in children with SBH.

Early outcome of combined endoscopic third ventriculostomy and choroid plexus cauterization in childhood hydrocephalus.

Bankole OB, Ojo OA, Nnadi MN, Kanu OO, Olatosi JO. (2015) Early outcome of combined endoscopic third ventriculostomy and choroid plexus cauterization in childhood hydrocephalus.

J Neurosurg Pediatr. 2015 May;15(5):524-8. doi: 10.3171/2014.10.PEDS14228

Abstract

OBJECT Although shunts have been the mainstay in treating hydrocephalus over the past 5 decades, the use of endoscopic techniques in addressing this disorder in children offers both the neurosurgeon and the patient a unique opportunity to avoid shunting and its attendant complications. The combination of endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) remains uncommon in most centers despite its potential promise. The authors sought to investigate the efficacy of combining ETV and CPC (ETV+CPC) in treating childhood hydrocephalus in Nigeria. Infection and spina bifida contribute a high percentage of the cases of hydrocephalus in Nigeria. METHODS Over a 2-year period, all children 0-18 years of age who had endoscopic treatment for hydrocephalus were prospectively evaluated to determine the need for subsequent treatment. Children who had the combination of ETV+CPC were identified as a subcategory and form the basis of this retrospective study. RESULTS Twenty-two of 38 endoscopically treated children had undergone the combination of ETV+CPC for hydrocephalus of varied etiology. There was a male preponderance (2.5:1), and 90% of the patients were infants. The overall success rate was 75%, with the best outcome in children with spina bifida. One child required a repeat ETV. CONCLUSIONS The combination of ETV+CPC is useful in treating children with hydrocephalus of varied etiology. The complication profile is acceptable, and the overall success rate is comparable to that associated with shunt insertion.

Intraabdominal complications secondary to ventriculoperitoneal shunts: CT findings and review of the literature.

Chung JJ, Yu JS, Kim JH, Nam SJ, Kim MJ. (2009) Intraabdominal complications secondary to ventriculoperitoneal shunts: CT findings and review of the literature.
AJR American Journal of Roentgenology. 2009 Nov;193(5):1311-7. Review.

OBJECTIVE: The purpose of our study was to evaluate the abdominopelvic CT findings of various intraabdominal complications secondary to ventriculoperitoneal shunts for hydrocephalus and to review the literature.

MATERIALS AND METHODS: The CT images of 70 patients (33 men and 37 women; mean age, 48.5 years) who underwent ventriculoperitoneal shunt placement and abdominopelvic CT because of shunt-related abdominal symptoms were reviewed retrospectively. CT images were analyzed with regard to the location of the shunting catheter tip; site, size, wall, and septa of localized fluid collection; peritoneal thickening; omentomesentery infiltration; abscess; bowel perforation; abdominal wall infiltration; and thickening of the catheter track wall.

RESULTS: The mean period between the last ventriculoperitoneal shunting operation and CT was 11 months (range, 1 week to 115 months), and the mean number of ventriculoperitoneal shunting operations undergone was 1.4 (range, 1-6). A total of 76 ventriculoperitoneal shunting catheters were introduced in 70 patients: 64 patients had a unilateral catheter inserted and six patients had bilateral catheters inserted. Sixteen patients (22.9%) were pathologically diagnosed with ventriculoperitoneal shunt-related complications: 11 cases (15.7%) of shunt infection, six cases (8.6%) of CSF pseudocyst, four cases (5.7%) of abdominal abscess, three cases (4.3%) of infected fluid collection, and one case (1.4%) of bowel perforation. Microorganisms were cultured from the tip of the shunting catheter or peritoneal fluid in 11 patients (15.7%).

CONCLUSION: On abdominopelvic CT, various intraabdominal complications secondary to ventriculoperitoneal shunt were shown, of which, shunt infection was the most common, followed by CSF pseudocyst, abscess, and infected fluid collection.

PMID: 19843747

Slitlike ventricle syndrome: a life-threatening presentation.

da Silva PS, Suriano IC, Neto HM. (2009) Slitlike ventricle syndrome: a life-threatening presentation. Pediatric Emergency Care. 2009 Oct;25(10):674-6.

From the *Pediatric Intensive Care Unit, Department of Pediatrics, and daggerDepartment of Neurosurgery, Hospital do Servidor Público Municipal, São Paulo, Brazil.

Severely increased intracranial pressure can be life-threatening in shunted children who do not experience ventricular enlargement. This condition is termed normal ventricular hydrocephalus and represents the most severe form of slit ventricle syndrome. CASE REPORT:: A 7-year-old girl with a repaired lumbosacral myelomeningocele and shunted at birth who presented with headache, vomiting, seizure, and deterioration of level of consciousness was admitted to the pediatric intensive care unit. Because her ventricles were small to slitlike on cranial computed tomographic (CT) scan, the shunt was presumed to be working. Although the cerebrospinal fluid analysis was normal, she received initial empirical treatment of viral encephalitis. Twenty-four hours after admission, she evolved with apnea and bradycardia, requiring ventilatory support. Repeated CT scans were unchanged from one study to the next. After 48 hours, her condition worsened, and cerebrospinal pressure during lumbar puncture reached more than 30 mm Hg despite the serial CT scan disclosing no ventricular enlargement. She underwent a shunt revision that showed that the catheter was occluded and had adhered to the ventricular wall. The shunt was replaced, resulting in dramatic neurological improvement. This report highlights a life-threatening condition involving chronically shunted children who present severe intracranial hypertension without ventriculomegaly and may often be neglected or unrecognized by emergency physicians or general neurosurgeons.


PMID: 19834417

Shunt complications in children with myelomeningocele: effect of timing of shunt placement. Clinical article.

Radmanesh F, Nejat F, El Khashab M, Ghodsi SM, Ardebili HE. (2009) Shunt complications in children with myelomeningocele: effect of timing of shunt placement. Clinical article. Journal of Neurosurgery: Pediatrics. 2009 Jun;3(6):516-20.

Department of Neurosurgery, Children's Hospital Medical Center, and Department of Biostatistics, Tehran University of Medical Sciences, Tehran, Iran.

OBJECT There has been controversy over whether CSF shunt insertion simultaneously with repair of myelomeningocele (MMC) might increase shunt-related complications. The purpose of this study was to evaluate shunt complication rates in patients who underwent concurrent MMC surgery and shunt placement and compare them to the rates in patients treated with shunt placement in a separate procedure.

METHODS The authors retrospectively reviewed the outcome of shunt placement in 127 patients with MMC who were followed up for >or=1 year after shunt surgery. In 65 patients shunt surgery was performed in a second operation after MMC repair and in 46 the 2 procedures were performed concurrently. In 7 patients shunt placement was the initial surgery, and in 9 it was the only procedure performed. The patients were evaluated for shunt complications.

RESULTS There was no statistically significant between-groups difference in age at which patients underwent shunt placement. The overall rates of shunt infection and shunt malfunction were 16.5 and 39.4%, respectively. There was a high rate of shunt infection and mortality in those patients treated with CSF shunting only. There was no statistically significant difference between complication rates in patients in whom the 2 procedures were performed concurrently and those who underwent separate operations.

CONCLUSIONS The order in which myelomeningocele repair and shunt placement were carried out did not have a significant effect on the rate of shunt complications. Thus, when indicated these procedures can be performed concurrently with a level of risk comparable to that associated with delayed shunt placement.

PMID: 19485738

Early shunt complications in 46 children with hydrocephalus.

Braga MH, Carvalho GT, Brandão RA, Lima FB, Costa BS. (2009) Early shunt complications in 46 children with hydrocephalus. Arquivos de neuro-psiquiatria. 2009 Jun;67(2A):273-7.

Department of Neurosurgery, Santa Casa de Belo Horizonte, MG, Brazil.

OBJECTIVE: To determine the causes of early shunt complications in 46 children with hydrocephalus. METHOD: A retrospective study was conducted on 46 children submitted to ventriculoperitoneal shunt surgery between February 2005 and February 2007. RESULTS: Thirteen (28%) patients presented complications, which were due to infection in 9 (69%) and to malfunction of the shunt system in 4 (31%).The mean number of surgical procedures performed on patients who presented complications was 2.8 per patient, with a total of 46 surgeries in this group. All patients with infectious complications were identified during their hospital stay. CONCLUSIONS: Infection was the most common complication. The infection rate was proportional to the length of hospital stay. All patients with hydrocephalus due to tumors or myelomeningocele presented complications. A higher incidence of infections was observed in children older than 2 years.

PMID: 19547822

First experiences with an adjustable gravitational valve in childhood hydrocephalus

Rohde V, Haberl EJ, Ludwig H, Thomale UW. First experiences with an adjustable gravitational valve in childhood hydrocephalus. Journal of Neurosurgery: Pediatrics. 2009 Feb;3(2):90-3.

Department of Neurosurgery, Georg-August University, Goettingen; and.

Object The goal of this report was to describe the authors' initial experiences with an adjustable gravity-assisted valve (GAV) called the ProGAV in treating childhood hydrocephalus. Methods The ProGAV was implanted in 53 children (29 boys and 24 girls, median age 7.3 years) with hydrocephalus of various origins. The ProGAV consists of a differential-pressure unit with adjustable opening pressures and a gravitational unit with a fixed opening pressure. Results The mean follow-up period was 15.2 months (range 6-44 months). The authors did not observe any valve-related complications. Four infections (7.5%) occurred, warranting the removal of the shunt. In 19 children, the opening pressure was changed at least once during the follow-up period, for underdrainage in 10, overdrainage in 8, and shunt weaning in 1, with substantial clinical improvement in 18 children. Overall, good clinical results were obtained in 47 (88.7%) of the 53 valve placements. Conclusions With an overall success rate of 88.7%, the first experiences with the ProGAV in childhood hydrocephalus are promising and justify its further use in the pediatric population.

PMID: 19278305

Shunt-related headaches: the slit ventricle syndromes

Rekate HL. Shunt-related headaches: the slit ventricle syndromes.
Child's Nervous System. 2008 Apr;24(4):423-430.

PURPOSE: The purpose of this work is to review the pathophysiology and treatment of severe headache disorders in patients having a shunt for hydrocephalus.

MATERIALS AND METHODS: The literature on the management of the slit ventricle syndrome is reviewed as well as an assessment of personal experiences over a 30-year period in the management of severe headache disorders in shunted patients. RESULTS: If the slit ventricle syndrome is defined as severe, life-modifying headaches in patients with shunts and normal or smaller than normal ventricles with ventricular shunts for the treatment of hydrocephalus, there are five different pathophysiologies that are involved in the process. These pathologies are defined by intracranial pressure measurement as severe intracranial hypotension analogous to spinal headaches, intermittent obstruction of the ventricular catheter, intracranial hypertension with small ventricles and a failed shunt (normal volume hydrocephalus), intracranial hypertension with a working shunt (cephalocranial hypertension), and shunt-related migraine. The treatment of these conditions and identifying patients with each condition are facilitated by attempting to remove the shunt.

CONCLUSIONS: Following the analysis of attempts to remove shunts, there are three possible outcomes. In about a quarter of patients, the shunt can be removed without having to be replaced. This is most common in patients treated in infancy for post-hemorrhagic hydrocephalus or patients shunted early after or before brain tumor surgery. Another half of patients have increased intracranial pressure and enlarged ventricles. In these patients, there is an 80% success rate for endoscopic third ventriculostomy. Finally, the most severe form of the slit ventricle syndrome involves intracranial hypertension without ventriculomegaly, which is managed optimally by shunt strategies that emphasize drainage of the cortical subarachnoid space such as lumbo-peritoneal shunts or shunts that include cisterna magna catheters.

PMID: 18259760

The role of lumbar shunts in the management of slit ventricles: does the slit-ventricle syndrome exist?

Sood S, Barrett RJ, Powell T, Ham SD. The role of lumbar shunts in the management of slit ventricles: does the slit-ventricle syndrome exist? Journal of Neurosurgery. 2005 Aug;103(2 Suppl):119-23.

OBJECT: Slit-ventricle syndrome (SVS) is a confusing description of presentations in patients with chronic shunt-treated hydrocephalus. These patients are prone to acute deterioration with recurrent malfunction. The authors describe the clinical profile and management outcome of using lumboperitoneal (LP) shunts in this population of patients.

METHODS: Thirty-three patients with slit ventricles and recurrent malfunctions were converted to LP shunts (mean age 12 years). The initial ventricular shunt was placed at a mean age of 16.5 months. Ten patients had failed endoscopic third ventriculostomies prior to placement of their LP shunt. At a previous presentation, in 11 patients suspected to have SVS following revision of the shunt, intracranial pressure normalized after insertion of a contralateral shunt, suggesting that their ventricles were isolated. The rate of infection and malfunction was compared before and after conversion to an LP shunt. Twenty-seven patients were successfully converted to LP shunts. Four of the 11 patients with isolated ventricles required ventricular shunts in addition to the LP shunt. During a mean follow-up period of 16.7 months, the malfunction rate per patient decreased from 4.81 for ventriculoperitoneal shunts, prior to conversion to 1.48 after conversion to LP shunts, a statistically significant reduction (p < 0.000). No significant difference was found in the rate of shunt infections (7.1% for VP shunts and 9.6% for LP shunts, p = 0.44). No patient presented with acute symptoms following malfunction of an LP shunt or suffered from a Chiari I malformation.

CONCLUSIONS: Conversion to an LP shunt is a safe and effective procedure in patients prone to rapid decompensation and recurrent shunt malfunctions from small, slitlike ventricles. The term SVS is confusing. The condition is a manifestation of an unrecognized slitlike isolated ventricle and should be abandoned.

PMID: 16370276

Ventriculo-peritoneal shunt performance under hyperbaric conditions

Huang ET, Hardy KR, Stubbs JM, Lowe RA, Thom SR. Ventriculo-peritoneal shunt performance under hyperbaric conditions. Undersea & hyperbaric medicine. 2000 Winter;27(4):191-4.

A novice scuba diver with an implanted ventriculo-peritoneal (VP) shunt inquired about the performance characteristics of his shunt while diving. A literature search revealed no information regarding shunt performance under hyperbaric conditions. The manufacturer could not certify that the shunt would function under pressure. Therefore, four VP shunts were tested according to the manufacturer's testing protocol at 1 and 4 atm abs in a multiplace hyperbaric chamber. The pressure (in mm of H2O) required to establish flow through the shunts was recorded. Trials at 1 atm abs (n = 12) and 4 atm abs (n = 12) show that all shunts performed within the pressure range specified by the manufacturer.

PMID: 11419359

Hydrocephalus in children born in 1999-2002: epidemiology, outcome and ophthalmological findings

Persson EK, Anderson S, Wiklund LM, Uvebrant P. Hydrocephalus in children born in 1999-2002: epidemiology, outcome and ophthalmological findings. Child's Nervous System. 2007 Oct;23(10):1111-8. Epub 2007 Apr 12.

OBJECTIVE: The purpose of this study was to monitor incidence and outcome in children with hydrocephalus.

MATERIALS AND METHODS: This is a population-based prospective study of all the children with hydrocephalus born in western Sweden in 1999-2002. Etiological and clinical information was collected from records, neuroimaging and ophthalmological examinations. Comparisons with 208 children born in 1989-1998 were made.

RESULTS: The incidence was 0.66 per 1,000 live births, 0.48 for infantile hydrocephalus and 0.18 for hydrocephalus associated with myelomeningocele. The corresponding rates for 1989-1998 were 0.82, 0.49 and 0.33. Ventriculo-peritoneal shunt treatment was used in 42 of the 54 children and endoscopic third ventriculostomy in 12. Revisions were performed in 33 (61%). Neurological impairments were present in 63%, and they were more common in children born preterm than in those born at term. The radiological extent of parenchymal lesions correlated significantly with outcome. Ophthalmological abnormalities were found in 80%, including visual impairment in one third.

CONCLUSION: The incidence of post-haemorrhagic hydrocephalus in children born extremely preterm increased; a group running a high risk of neurological sequelae. Ophthalmological abnormalities were frequent and need to be assessed in all children with hydrocephalus. The high rate of morbidity and complications necessitates the further development of preventive and treatment methods.

PMID: 17429657

Regional brain tissue composition in children with hydrocephalus. Relationships with cognitive development

Fletcher JM, McCauley SR, Brandt ME, Bohan TP, Kramer LA, Francis DJ, Thorstad K, Brookshire BL. Regional brain tissue composition in children with hydrocephalus. Relationships with cognitive development. Archives of Neurology. 1996 Jun;53(6):549-57.

OBJECTIVE: To determine whether children with shunted hydrocephalus show variations in regional brain tissue composition that relate to cognitive functions.

DESIGN: Nonequivalent control group.

PATIENTS AND METHODS: Magnetic resonance imaging (MRI) and cognitive skills assessments were obtained on 28 children, 6 to 9 years of age, with shunted hydrocephalus and 13 normal control subjects comparable in age, gender, ethnicity, and socioeconomic status. Three consecutive MRI slices below the vertex were segmented using a fuzzy clustering algorithm to separate pixels into gray matter, white matter, and cerebrospinal fluid (CSF) in quadrants representing left and right anterior and posterior brain regions. The cognitive skills assessments included the Wechsler Intelligence Scale for Children-Revised verbal and performance IQ scores, neuropsychological composites of language and visuospatial skills, a measure of visuomotor dexterity, and 2 measures of problem-solving abilities. The MRI data were analyzed in a group x tissue x hemisphere x region analysis of variance. Spearman rho correlations were computed within the hydrocephalus group between the MRI and cognitive measures.

RESULTS: Children with hydrocephalus showed reductions in overall gray matter percentages and corresponding increased CSF percentages that were more pronounced in posterior than anterior regions of both hemispheres. White matter percentages were reduced in children with hydrocephalus only in the left posterior quadrant. Correlations of posterior, but not anterior, CSF and gray matter percentages were significant with verbal and performance IQ scores and language, visuospatial, and visuomotor dexterity skills, but not with problem-solving abilities. Children with hydrocephalus who had proportionately greater posterior than anterior CSF percentages had significantly poorer visuomotor dexterity and visuospatial skills than did hydrocephalic children with proportionate CSF percentages.

CONCLUSION: Regional variations in brain tissue composition in children with shunted hydrocephalus correlate with a variety of cognitive and visuomotor functions.

PMID: 8660158

Craniofacial asymmetries in shunt-treated hydrocephalic children

Pirttiniemi PM, Huggare JA, Kantomaa TJ, Serlo WS. Craniofacial asymmetries in shunt-treated hydrocephalic children. The Cleft Palate-Craniofacial Journal. 1991 Oct;28(4):369-72.

The degree and direction of craniofacial asymmetry in the frontal plane was studied in a sample of 26 shunt-treated hydrocephalic children aged 5 to 18 years. Thirteen of the children had the regulating shunt fixed on the right side of the head and 13 on the left. The shunt had usually been inserted during the first years of life. An age- and sex-matched group of healthy school children and students served as controls for cephalometric assessment by means of linear and angular measurements. Considerable craniofacial asymmetry was found in the shunt-treated hydrocephalic children, the direction of asymmetry being related to the laterality of the regulating shunt device. The most marked asymmetric changes were recorded in the maxillary and mandibular regions, probably due to the adaptive nature of these regions.

PMID: 1742305

Dental maturation in children with shunt-treated hydrocephalus

Pirttiniemi P, Poikela A, Huggare J, Lopponen T. Dental maturation in children with shunt-treated hydrocephalus. The Cleft Palate-Craniofacial Journal. 2004 Nov;41(6):651-4.

OBJECTIVE: The aim of this study was to examine the relationship between dental maturation and somatic development and to discover their possible deviations in children with shunt-treated hydrocephalus.

DESIGN: Radiographs (orthopantomogram and hand-wrist radiograph) from children with shunt-treated hydrocephalus were analyzed with respect to the dental maturation and compared with values of an age- and sex-matched control group and population standards.

PATIENTS: Forty-one children with shunt-treated hydrocephalus (27 boys and 14 girls) aged from 5 to 16 years (median age 11.0 years).

RESULTS: The mean deviation of dental age from chronological age was significantly greater in the hydrocephalic group than in the control group. The mean value of dental age deviation was advanced in early pubertal stages but reduced in later pubertal stages.

CONCLUSIONS: These findings can be explained by changes in the endocrinological conditions, which are due to disturbed pituitary secretion. The present results could also partly reflect an adaptable developmental pathway in an otherwise strictly genetically determined process.

PMID: 15516170
Full Text Online

Pituitary function in children with hydrocephalus before and after the first shunting operation

Lopponen T, Saukkonen AL, Serlo W, Tapanainen P, Ruokonen A, Lanning P, Knip M. Pituitary function in children with hydrocephalus before and after the first shunting operation. European Journal of Endocrinology. 1998 Feb;138(2):170-5.

OBJECTIVE: Children with shunted hydrocephalus experience slow linear growth in prepuberty, accelerated pubertal maturation and a reduced final height. A substantial proportion of these patients have a poor growth hormone (GH) response to stimulation and reduced pituitary volume. The basic mechanisms behind these phenomena are still unknown, but one can hypothesize that an unphysiological intracranial pressure (ICP) may be involved. This study was undertaken to investigate the effect of increased ICP on pituitary function.

DESIGN: Twenty-one children (nine males) aged 4 months to 15 years were evaluated for pituitary function before and after their first shunting operation.

METHODS: A clinical examination was performed, bone age was determined and a combined pituitary stimulation test was performed to evaluate GH, luteinizing hormone, follicle-stimulating hormone, cortisol, thyrotropin and prolactin secretion.

RESULTS: GH concentrations were significantly higher 10 and 15 min before the operation (P=0.04 and P=0.03 respectively) than after it. The basal levels of insulin-like growth factor-I (IGF-I) tended to be higher before the operation than afterwards and those of its binding protein-3 (IGFBP-3) were significantly so (P<0.01).

CONCLUSIONS: The higher GH response to GH releasing hormone and circulating IGFBP-3 levels in children with hydrocephalus before compared with after their first shunting operation raise the possibility that the reduced GH secretion and retarded linear growth observed in children with shunted hydrocephalus may be a consequence of decreased ICP and/or the lack of physiological pressure variations.

PMID: 9506861
Full Text Online

In-hospital mortality rates after ventriculoperitoneal shunt procedures in the United States, 1998 to 2000: relation to hospital and surgeon volume of

Smith ER, Butler WE, Barker FG 2nd. In-hospital mortality rates after ventriculoperitoneal shunt procedures in the United States, 1998 to 2000: relation to hospital and surgeon volume of care. Journal of Neurosurgery. 2004 Feb;100(2 Suppl Pediatrics):90-7.

OBJECT: Death after ventriculoperitoneal (VP) shunt surgery is uncommon, and therefore it has been difficult to study. The authors used a population-based national hospital discharge database to examine the relationship between annual hospital and surgeon volume of VP shunt surgery in pediatric patients and in-hospital mortality rates.

METHODS: All children in the Nationwide Inpatient Sample (1998-2000, age 90 days-18 years) who underwent VP shunt placement or shunt revision as the principal procedure were included. Main outcome measures were in-hospital mortality rates, length of stay (LOS), and total hospital charges. Overall, 5955 admissions were analyzed (253 hospitals, 411 surgeons). Mortality rates were lower at high-volume centers and for high-volume surgeons. In terms of hospital volume, the mortality rate was 0.8% at lowest-quartile-volume centers (< 28 admissions/year) and 0.3% at highest-quartile-volume centers (> 121 admissions/year). In terms of surgeon volume, the mortality rate was 0.8% for lowest-quartile-volume providers (< nine admissions/year) and 0.1% for highest-quartile-volume providers (> 65 admissions/year). After multivariate adjustment for demographic variables, emergency admission and presence of infection, hospital volume of care remained a significant predictor of death (odds ratio [OR] for a 10-fold increase in caseload 0.38; 95% confidence interval [CI] 0.18-0.81). Surgeon volume of care was statistically significant in a similar multivariate model (OR for a 10-fold increase in caseload 0.3; 95% CI 0.13-0.69). Length of stay was slightly shorter and total hospital charges were slightly higher at higher-volume centers, but the differences were not statistically significant.

CONCLUSIONS: Pediatric shunt procedures performed at high-volume hospitals or by high-volume surgeons were associated with lower in-hospital mortality rates, with no significant difference in LOS or hospital charges.

PMID: 14758935

Referred shoulder pain from ventriculoperitoneal shunts. Report of three cases.

Tubbs RS, Wellons JC 3rd, Blount JP, Grabb PA, Oakes WJ. Referred shoulder pain from ventriculoperitoneal shunts. Report of three cases. Journal of Neurosurgery. 2005 Mar;102(2 Suppl):218-20.

The authors report on three pediatric patients with ventriculoperitoneal (VP) shunts who presented with chronic right shoulder pain. Imaging revealed that the distal peritoneal catheter was positioned between the right hemidiaphragm and liver. Following surgical repositioning of the distal tubing, all patients experienced resolution of their shoulder pain, which has not recurred. Although seemingly rare, referred shoulder pain from a VP shunt should be added to the list of complications seen with this method of cerebrospinal fluid diversion. The clinician who cares for patients with VP shunts may wish to evaluate cases of shoulder pain without obvious neural or musculoskeletal cause by performing imaging of the distal shunt tubing.

PMID: 16156233

What we don't (but should) know about hydrocephalus.

Bergsneider M, Egnor MR, Johnston M, Kranz D, Madsen JR, McAllister JP, Stewart C, Walker ML, Williams MA. What we don't (but should) know about hydrocephalus.
Journal of Neurosurgery. 2006 Mar;104(3 Suppl):157-9.

In an effort to identify critical gaps in the prevailing knowledge of hydrocephalus, the authors formulated 10 key questions. 1) How do we define hydrocephalus? 2) How is cerebrosinal fluid (CSF) absorbed normally and what are the causes of CSF malabsorption in hydrocephalus? 3) Why do the ventricles dilate in communicating hydrocephalus? 4) What happens to the structure and function of the brain when it is compressed and stretched by the expanding ventricles? 5) What is the role of cerebrovenous pressure in hydrocephalus? 6) What causes normal-pressure hydrocephalus? 7) What causes low-pressure hydrocephalus? 8) What is the pathophysiology of slit ventricle syndrome? 9) What is the pathophysiological basis for neurological impairment in hydrocephalus, and to what extent is it reversible? 10) How is the brain of a child with hydrocephalus different from that of a young or elderly adult? Rigorous answers to these questions should lead to more effective and reliable treatments for this disorder.

PMID: 16572631

Proof of the patent subcutaneous fibrous tract in children with V-P shunt malfunction.

Kazan S, Açikbaş C, Rahat O, Tuncer R. Proof of the patent subcutaneous fibrous tract in children with V-P shunt malfunction. Child's Nervous System. 2000 Jun;16(6):351-6.

A connective tissue sheath that forms around the peritoneal catheter of silicone ventriculo-peritoneal (V-P) shunt tubing is quite often observed in children with V-P shunts. However, proof of the passage of cerebrospinal fluid (CSF) through these sheaths has been reported in only one published study to date. We present four cases associated with chronic malfunction of the V-P shunt peritoneal catheter. In these cases, CSF passage through the subcutaneous fibrous tract, which had a pericatheter connective tissue sheath, was demonstrated around the V-P shunt peritoneal catheter. In the first case the patient suffered intermittent headache attacks over a long period of time; abdominal migration of the peritoneal catheter was detected. The second patient, who had been asymptomatic in the follow-up period with an outgrown peritoneal catheter, was admitted with acute hydrocephalus symptoms. A peritoneal catheter disconnection was detected in another patient, who had had multiple shunt revisions previously. In the last case, an obstruction of the peritoneal catheter was detected. The existence of the subcutaneous fibrous tract and its function were demonstrated by radio-opaque shuntogram in two cases and radionuclide shuntogram in the other two cases. In all four cases V-P shunt revision was performed. Within this study, the possible passage of CSF through a fibrous tract in cases of migration, outgrowth, disconnection or obstruction of the peritoneal shunt catheter was demonstrated. In conclusion, patients with shunt malfunction with a well-grown pericatheter fibrous sheath who are either asymptomatic or minimally symptomatic and show no evidence of active ventricular dilatation on their cranial CT scan should not be regarded as having arrested hydrocephalus until radio-opaque or radionuclide shuntogram studies have been done.

PMID: 10933230

Evidence for a patent fibrous tract in fractured, outgrown, or disconnected ventriculoperitoneal shunts.

Clyde BL, Albright AL. Evidence for a patent fibrous tract in fractured, outgrown, or disconnected ventriculoperitoneal shunts. Pediatric Neurosurgery. 1995;23(1):20-5.

As cerebrospinal fluid (CSF) shunts function for several years, outgrowth and disconnection of the distal catheter are seen more frequently. Though a shunt revision is clearly indicated if patients are symptomatic, asymptomatic patients with a disconnection or who have outgrown the distal catheter may no longer require CSF diversion. This follows an assumption that the shunt is no longer functioning and, in an asymptomatic patient, no longer required. However, patent fibrous tracts have been postulated which may allow passage of CSF through disconnected or outgrown distal catheters. We have recently treated 2 patients with ventriculoperitoneal (VP) shunts with evidence of a persistent fibrous tract. A 13-year-old boy was asymptomatic for 2 years after radiographs revealed an outgrown distal VP shunt catheter, after which the acutely deteriorated and died from massive hydrocephalus, although the entire shunt was patent. Another 14-year-old boy who was profoundly retarded presented with subtle changes in his daily activity. Shunt radiographs revealed two disconnections and a broken valve, but a shunt tap revealed a normal opening pressure (OP). A radionuclide shuntogram revealed rapid passage of isotope through fibrous sheaths at the disconnections, and into the peritoneum. A shunt revision was performed and the patient returned to his previous level of health. Patients with outgrown or disconnected distal catheters may be asymptomatic and/or have normal OP, and must not be assumed to have arrested hydrocephalus. A ventricular pressure measurement and radionuclide shuntogram should be performed to rule out a patent persistent fibrous tract.

PMID: 7495662