The baric probe: a novel long-term implantable intracranial pressure monitor with ultrasound-based interrogation

Limbrick DD Jr, Lake S, Talcott M, Alexander B, Wight S, Willie JT, Richard WD, Genin GM, Leuthardt EC. (2012)  The baric probe: a novel long-term implantable intracranial pressure monitor with ultrasound-based interrogation.  Journal of Neurosurgery: Pediatrics. 2012 Dec;10(6):518-24.

OBJECT:

Prompt diagnosis of shunt malfunction is critical in preventing neurological morbidity and death in individuals with hydrocephalus; however, diagnostic methods for this condition remain limited. For several decades, investigators have sought a long-term, implantable intracranial pressure (ICP) monitor to assist in the diagnosis of shunt malfunction, but efforts have been impeded by device complexity, marked measurement drift, and limited instrumentation lifespan. In the current report, the authors introduce an entirely novel, simple, compressible gas design that addresses each of these problems.

METHODS:

The device described herein, termed the "baric probe," consists of a subdural fluid bladder and multichannel indicator that monitors the position of an air-fluid interface (AFI). A handheld ultrasound probe is used to interrogate the baric probe in vivo, permitting noninvasive ICP determination. To assess the function of device prototypes, ex vivo experiments were conducted using a water column, and short- and long-term in vivo experiments were performed using a porcine model with concurrent measurements of ICP via a fiberoptic monitor.

RESULTS:

Following a toe region of approximately 2 cm H(2)O, the baric probe's AFI demonstrated a predictable linear relationship to ICP in both ex vivo and in vivo models. After a 2-week implantation of the device, this linear relationship remained robust and reproducible. Further, changes in ICP were observed with the baric probe, on average, 3 seconds in advance of the fiberoptic ICP monitor reading.

CONCLUSIONS:

The authors demonstrate "proof-of-concept" and feasibility for the baric probe, a long-term implantable ICP monitor designed to facilitate the prompt and accurate diagnosis of shunt malfunction. The baric probe showed a consistent linear relationship between ICP and the device's AFI in ex vivo and short- and long-term in vivo models. With a low per-unit cost, a reduced need for radiography or CT, and an indicator that can be read with a handheld ultrasound probe that interfaces with any smart phone, the baric probe promises to simplify the care of patients with shunt-treated hydrocephalus throughout both the developed and the developing world.

doi: 10.3171/2012.8.PEDS11565

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

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

Endoscopic third ventriculostomy: an outcome analysis of primary cases and procedures performed after ventriculoperitoneal shunt malfunction.

O'Brien DF, Javadpour M, Collins DR, Spennato P, Mallucci CL. (2005) Endoscopic third ventriculostomy: an outcome analysis of primary cases and procedures performed after ventriculoperitoneal shunt malfunction. Journal of Neurosurgery. 2005 Nov;103(5 Suppl):393-400.

Department of Neurosurgery, Royal Liverpool Children's Hospital NHS Trust, Liverpool, United Kingdom.

OBJECT: The authors analyzed the role of endoscopic third ventriculostomy (ETV) as a primary treatment for hydrocephalus and also as an alternative to shunt revision for malfunctioning and infected ventriculoperitoneal (VP) shunts.

METHODS: A retrospective analysis of clinical notes, operation records, and magnetic resonance imaging procedures before and after ventriculostomy was performed to determine the success or failure of ETVs in 170 patients who underwent a primary ETV and in 63 patients who underwent an ETV for shunt malfunction (secondary ETV). The patients' data were derived from an endoscopy database inaugurated in 1998. Of the 63 patients with shunt malfunctions, 49 patients (78%) had mechanical malfunction only and 14 patients (22%) had both infection and malfunction. Seventy-four percent (126 of 170) of patients in the primary ETV group and 70% (44 of 63) of patients in the secondary ETV had a successful outcome at the time of analysis. The success rate for ETVs in cases involving a mechanical shunt malfunction alone was 67% (33 of 49) compared with 79% (11 of 14) in those cases involving an infected shunt. The origin of the hydrocephalus in the primary and shunt malfunction groups was evaluated as a factor contributing to the success of the ETV. In the primary group, patients with a history of intraventricular hemorrhage (IVH) and meningitis as a cause for hydrocephalus had a poor rate of success after the ETV--27% (four of 15) and 0% (none of two), respectively. This pattern was not seen in the series involving shunt malfunction after the ETV, with 71% (five of seven) and 75% (three of four) of cases having a hydrocephalus origin of IVH and meningitis, respectively, in which a successful outcome was attained. A two-way mixed-model analysis of variance yielded a significant effect for origin (p = 0.011), a significant interaction between group and origin (p = 0.028), and a marginally nonsignificant effect of group (p = 0.0686). More than 95% of failures were evident within 1 month of the ETV in both groups. Complications were minimal in both groups, and there were no procedure-related deaths.

CONCLUSIONS: An ETV is a safe procedure with few complications and a high success rate in both primary and secondary groups. An ETV to address shunt malfunction, unlike a primary ETV, is not particularly origin specific. A bonus is its success in dealing with infected shunts. Most failures will be evident early, but long-term follow up is vital.

PMID: 16302610

Complications of endoscopic third ventriculostomy in previously shunted patients.

Hader WJ, Walker RL, Myles ST, Hamilton M. (2008) Complications of endoscopic third ventriculostomy in previously shunted patients. Neurosurgery. 2008 Jul;63(1 Suppl 1):ONS168-74; discussion ONS174-5.

Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.

OBJECTIVE: Endoscopic third ventriculostomy (ETV) is considered to be a safe and effective treatment in selected patients as an initial treatment for obstructive hydrocephalus and at the time of shunt malfunction in previously shunted patients. We compared the outcome and complications of ETV between patients with newly diagnosed hydrocephalus and those with previous shunting procedures.

METHODS: A retrospective review of patients undergoing ETV from 1996 to 2004 at Alberta's Childrens Hospital and Foothills Medical Centre was completed. Patient data included symptoms at clinical presentation, cause of hydrocephalus, age at initial shunt, number of previous shunt revisions, age at ETV, complications, and subsequent shunting procedures performed.

RESULTS: A total of 131 patients were identified with a minimum follow-up duration of 1 year; 71 (82.5%) of 86 patients who underwent ETV as a primary procedure and 36 (80%) of 45 patients who had ETV at the time of shunt malfunction were shunt-free at the last follow-up evaluation. Patients younger than 1 year old who underwent ETV were more likely to require an additional procedure for control of their hydrocephalus (P < 0.01). Serious complications after ETV occurred more frequently in patients who presented at the time of shunt malfunction (14 of 45 patients, 31%) compared with patients who underwent primary ETV (seven of 86 patients, 8%) (P = 0.02). Previously shunted patients with a history of two or more revisions (P = 0.03) and who experienced a serious complication at the time of ETV (P = 0.01) were more likely to require shunt replacement.

CONCLUSION: ETV is an effective treatment both in selected patients with newly diagnosed hydrocephalus and in patients with a previous shunting procedure who are presenting with malfunction. Complications of ETV occur more frequently in previously shunted patients than in patients treated for newly diagnosed hydrocephalus, and care must be taken in the selection and treatment of these patients.

PMID: 18728596

Tethered cord release: a long-term study in 114 patients.

Bowman RM, Mohan A, Ito J, Seibly JM, McLone DG. (2009) Tethered cord release: a long-term study in 114 patients. Journal of Neurosurgery Pediatrics. 2009 Mar;3(3):181-7.

Division of Pediatric Neurosurgery, Children's Memorial Hospital, Chicago, USA. rbowman@childrensmemorial.org

OBJECT: All children born with a myelomeningocele at the authors' institution undergo aggressive treatment to maintain or improve functional outcome. Consequently, when any neurological, orthopedic, and/or urological changes are noted, a search for the cause is initiated. The most common cause of decline in a child born with a myelomeningocele is shunt malfunction. The second most common cause is tethering of the distal spinal cord at the site of the original back closure. In this report, the authors review the indicators of symptomatic spinal cord tethering and discuss the surgical interventions and outcomes in the children with myelomeningocele who underwent treatment at Children's Memorial Hospital from 1975 to 2008.

METHODS: Among the 502 children who underwent original closure at Children's Memorial Hospital, a symptomatic tethered spinal cord developed in 114 (23%). Eighty-one patients (71%) have undergone 1 untethering procedure, and 33 patients (29%) have undergone multiple untetherings, for a total of 163 total surgeries. The indicators of symptomatic spinal cord tethering include scoliosis, decline in lower-extremity (LE) motor strength, LE contractures, LE spasticity, gait change, urinary changes, and pain.

RESULTS: Pain has shown the best response to surgical untethering, with 100% of children experiencing postoperative improvement. The results of long-term follow-up (average 12 years, range 1 month-23.3 years) in this cohort demonstrated scoliosis progression after surgical untethering in 52% of patients, with 28% requiring spinal fusion. On the 3-month postoperative manual muscle test, 70% of patients showed improved LE muscle strength compared to preoperatively. Gait was also similarly improved after untethering as evaluated by an orthopedic surgeon. Spasticity improved in two-thirds of the cohort, and as expected, LE contractures were stable (78%) postoperatively, as assessed by orthopedic and rehabilitation medicine specialists. Urologically, 64% of patients showed improvements on postoperative bladder evaluation.

CONCLUSIONS: Although this is a clinical outcome study with no control group, the authors' experience has been that tethered cord release is beneficial in maintaining neurological, urological, and orthopedic functioning in children born with a myelomeningocele.

PMID: 19338463

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

Complications with shunts in adults with spina bifida

Tomlinson P, Sugarman ID. Complications with shunts in adults with spina bifida. British Medical Journal 1995 Jul 29;311(7000):286-7.

OBJECTIVE--To assess the incidence of malfunction of shunts in adults with spina bifida who have shunts to control hydrocephalus.

DESIGN--A retrospective review of the medical notes and contact by questionnaire of adults with spina bifida to assess symptoms, function of shunts, frequency of operative procedures, and follow-up.

SUBJECTS--110 patients with shunts who attended Lord Mayor Treloar College for the physically disabled between 1978 and 1993.

RESULTS--The average (range) number of revisions of shunts per person was 3.6 (0-28). Although 37 patients underwent an emergency operation for revision in their first year of life, there was a continuing low incidence, increasing in the early teenage years, which persisted into the third decade. Intervals between emergency revisions varied: 202/320 occurred within one year of the last shunt operation, 56 occurred after five years, 24 after 10 years, and 15 after 15 or more years. Fifteen patients had chronic intermittent headaches, of whom four died and three suffered severe morbidity. Thirteen died; three had raised intracranial pressure, and four died suddenly; these deaths were presumed to be related to their shunts. Up to the age of 16 there was 100% hospital follow up, but after that only 40% of young adults underwent review, including review of their shunt function.

CONCLUSION--Shunts to control hydrocephalus may fail after many years without symptoms. This is difficult to diagnose and if missed may lead to chronic morbidity and death. As hospital follow up of this group is falling, both general practitioners and hospital doctors must be aware that a shunt may malfunction after prolonged quiescent periods.

PMID: 7633231

Severe constipation: an under-appreciated cause of VP shunt malfunction: a case-based update

Martinez-Lage JF, Martos-Tello JM, Ros-de-San Pedro J, Almagro MJ. Severe constipation: an under-appreciated cause of VP shunt malfunction: a case-based update. Child's Nervous System. 2007 Oct 10;

BACKGROUND: Increased intra-abdominal pressure has been reported to result in raised intracranial pressure in a variety of conditions such as obesity and pregnancy, and it also constitutes an infrequent cause of ventriculoperitoneal (VP) shunt malfunction. Patients with neurological deficits, as those with myelomeningocele or cerebral palsy, are prone to developing a neurogenic bowel and to suffer chronic constipation. Although previously recognized, VP shunt failure attributed to constipation has only recently been described. We briefly review the etiopathogenesis, diagnosis and management of severe constipation leading to VP shunt malfunction. Our aim is to draw the attention of pediatric neurosurgeons towards severe constipation as a possible cause of VP shunt failure thus avoiding unnecessary surgical valve revisions, to which children with hydrocephalus are often submitted to.

ILLUSTRATIVE CASES: We report two children that developed transient VP shunt failure because of intense constipation that caused exacerbation of previously shunted hydrocephalus. One of the patients constitutes the first description of this complication associated with an anteriorly placed anus and the other with intestinal paresis after ileostomy. Conservative treatment aimed at alleviating the increased intra-abdominal pressure resulted in complete resolution of the children's manifestations of VP shunt failure, without having to resort to surgical revision of the VP shunt.

PMID: 17926043

Death in shunted hydrocephalic children: a follow-up study

Acakpo-Satchivi L, Shannon CN, Tubbs RS, Wellons JC 3rd, Blount JP, Iskandar BJ, Oakes WJ. Death in shunted hydrocephalic children: a follow-up study. Child's Nervous System. 2007 Jun 27; [Epub ahead of print]

INTRODUCTION: The authors previously conducted a retrospective study regarding deaths from CSF shunt failure to identify circumstances surrounding shunt malfunction-related deaths in children in the modern era.

MATERIALS AND METHODS: Using the same methodology, we conducted a follow-up study to determine whether recent policy and procedural changes instituted since the time of the first study had effected a change in the mortality rate of our shunted patient population.

RESULTS: Thirty-nine original patient records (of patients seen at Children's Hospital who died with the diagnosis of hydrocephalus between 1998 and 2004) were identified and reviewed for inclusion into the study. Only four (10.3%) were found to have died directly as a result of shunt malfunction.

CONCLUSIONS: Our rate of shunt malfunction death has decreased over time. It is reasonable to attribute part of this decline to continued improvements in diagnostic and therapeutic techniques and to the use of surveillance scans to identify asymptomatic patients with shunt failure. However, we believe the majority of this decline is due to two additional factors: (1) increased nursing staff and (2) effective patient/family education.

PMID: 17594102

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

Transient ventriculoperitoneal shunt dysfunction in children with myelodysplasia and urinary bladder infection. Report of three cases.

Tubbs RS, Wellons JC 3rd, Blount JP, Oakes WJ. Transient ventriculoperitoneal shunt dysfunction in children with myelodysplasia and urinary bladder infection. Report of three cases. Journal of Neurosurgery. 2005 Mar;102(2 Suppl):221-3.

The authors present three children born with myelomeningocele and hydrocephalus. Each presented with symptoms/signs of ventriculoperitoneal shunt malfunction. All patients at the time of presentation exhibited significant urinary bladder infections and were appropriately treated for their infection. No patient was found to have an underlying shunt infection. All patients without medically threatening symptoms were carefully observed and noted to have resolution of their shunt dysfunction symptoms/signs following treatment of their urinary bladder infections and thus did not undergo a shunt operation. Based on the courses of these patients, we believe that significant urinary bladder infection in patients with myelodysplasia in whom a shunt has been placed may often be enough to bring a subclinical shunt malfunction to clinical attention or even to be the cause of temporary distal peritoneal shunt malabsorption. Although the exact mechanism for this dysfunction is unclear, treatment of the bladder infection may address the symptomatic shunt dysfunction in some patients so as to avoid operative intervention. We emphasize, however, that careful observation of these patients should be performed during hospitalization because they often rely on adequate cerebrospinal fluid diversion. Only patients with mild symptomatology should be observed first as the initial line of treatment.

PMID: 16156234

Periventricular rigidity in long-term shunt-treated hydrocephalus.

Sood S, Lokuketagoda J, Ham SD. Periventricular rigidity in long-term shunt-treated hydrocephalus. Journal of Neurosurgery. 2005 Mar;102(2 Suppl):146-9.

OBJECT: The failure of ventricles to enlarge after acute shunt malfunction in long-term shunt-dependent patients is generally attributed to the presence of periventricular rigidity resulting from gliosis. The aim of this study was to test the hypothesis that periventricular rigidity is present in these patients.

METHODS: Fifteen pediatric patients who presented with acute shunt malfunction were studied; slit ventricles were detected in all of these patients. Pressure measurements were recorded simultaneously in both the ventricle and the brain parenchyma during shunt revision and then repeated after bolus infusion of fluid into the ventricle. The mean intraventricular pressure (IVP) at presentation was 24.1 mm Hg (standard deviation 10 mm Hg). The mean baseline IVP after drainage of cerebrospinal fluid but prior to the infusion was 7.5 +/- 4.3 mm Hg. There was no significant difference in the increase in the IVP and the intraparenchymal pressure (IPP) after bolus infusion into the ventricle (3.6 +/- 2.4 mm Hg and 3.3 +/- 2.1 mm Hg, respectively; p = 0.39). The mean pressure volume index was 24.1 ml (standard error of the mean 4.6 ml).

CONCLUSIONS: The profile of the changes in IVP and IPP indicates that the periventricular wall does not restrict ventricular enlargement following shunt malfunction in long-term shunt-dependent patients.

PMID: 16156222

Long-term outcome of hydrocephalus management in myelomeningoceles.

Tuli S, Drake J, Lamberti-Pasculli M. Long-term outcome of hydrocephalus management in myelomeningoceles. Child's Nervous System. 2003 Jun;19(5-6):286-91. Epub 2003 May 23.

BACKGROUND: The cerebrospinal fluid (CSF) shunt remains an important ongoing management problem in myelomeningocele (MMC) patients. We reviewed the long-term shunt treatment outcome in a prospectively followed group of MMC patients from a single institution.

METHOD: Patients prospectively entered into a hydrocephalus database with a diagnosis of MMC from the years 1987 to 1996 were selected. All data was verified from the medical records and additional details about the shunt surgery were collected. The outcome of shunt failure was categorized as shunt obstruction, shunt infection, presence of loculated ventricles, overdrainage, and other. All deaths were recorded and causation identified. Univariate analysis for shunt failure risk factors was accomplished using Log rank statistics. Multivariable analysis was performed for each repeated failure level using a conditional Cox regression model.

RESULTS: One hundred and twenty (64%) out of 189 MMC patients experienced a first shunt failure with a median time of 303 days; 29 (24%) of the failures were due to shunt infection (the procedure infection rate being 15%). Sixty-one patients experienced a second shunt failure, 38 a third and 36 had four or more. Multivariable analysis of risk factors failed to demonstrate any clear risk factors for either first or subsequent shunt failure. Fifteen patients died, 13 from either shunt or Chiari 1 complications.

CONCLUSION: Shunt complications remain an important cause of morbidity and mortality in MMC patients, particularly shunt infection.

PMID: 12764629

Death in shunted hydrocephalic children in the 1990s.

Iskandar BJ, Tubbs S, Mapstone TB, Grabb PA, Bartolucci AA, Oakes WJ. Death in shunted hydrocephalic children in the 1990s. Pediatric Neurosurgery. 1998 Apr;28(4):173-6.

Using a combined search of the Children's Hospital (Birmingham, Ala., USA) medical records and the Jefferson County Health Department death records, we reviewed all shunt-related deaths that occurred between January 1990 and July 1996. Of these, we excluded patients who died of nonhydrocephalus-related reasons, such as bronchopulmonary dysplasia, as well as patients who had other serious neurological illnesses such as brain tumor and hydranencephaly. Twenty-eight patients died of shunt-related causes in the 6.5-year period. A survival analysis showed that 96% survived 32 months after first shunting. Of 28 patients, 23 were beyond help prior to medical evaluation. However, at least 10 of these patients had symptoms suggestive of shunt failure at least 24 h and as long as 2 weeks prior to their demise. We conclude that hydrocephalic children still die of shunt failure despite the modern technology of the 1990s. Some of these causes may be avoidable through early detection of symptoms. Guidelines to patients, families, and primary caregivers should be emphasized.

PMID: 9732242

Death in shunted hydrocephalic children: a follow-up study.

Acakpo-Satchivi L, Shannon CN, Tubbs RS, Wellons JC 3rd, Blount JP, Iskandar BJ, Oakes WJ. Death in shunted hydrocephalic children: a follow-up study. Child's Nervous System. 2007 Jun 27;

INTRODUCTION: The authors previously conducted a retrospective study regarding deaths from CSF shunt failure to identify circumstances surrounding shunt malfunction-related deaths in children in the modern era.

MATERIALS AND METHODS: Using the same methodology, we conducted a follow-up study to determine whether recent policy and procedural changes instituted since the time of the first study had effected a change in the mortality rate of our shunted patient population. RESULTS: Thirty-nine original patient records (of patients seen at Children's Hospital who died with the diagnosis of hydrocephalus between 1998 and 2004) were identified and reviewed for inclusion into the study. Only four (10.3%) were found to have died directly as a result of shunt malfunction.

CONCLUSIONS: Our rate of shunt malfunction death has decreased over time. It is reasonable to attribute part of this decline to continued improvements in diagnostic and therapeutic techniques and to the use of surveillance scans to identify asymptomatic patients with shunt failure. However, we believe the majority of this decline is due to two additional factors: (1) increased nursing staff and (2) effective patient/family education.

PMID: 17594102

Early programmable valve malfunctions in pediatric hydrocephalus.

Mangano FT, Menendez JA, Habrock T, Narayan P, Leonard JR, Park TS, Smyth MD. Early programmable valve malfunctions in pediatric hydrocephalus. Journal of Neurosurgery. 2005 Dec;103(6 Suppl):501-7.

OBJECT: The use of adjustable differential pressure valves has been recommended to improve ventriculoperitoneal (VP) shunt performance in selected patients; however, published data are scarce regarding their clinical reliability. Recently, the identification of a number of malfunctioning programmable valves during shunt revision surgery in children prompted a retrospective review of valve performance in this patient cohort.

METHODS: The authors performed a retrospective chart analysis of 100 patients with programmable valve shunts and 89 patients with nonprogrammable valve shunts implanted at the St. Louis Children's Hospital between April 2002 and June 2004. They noted the cause of hydrocephalus, the type of shunt malfunction, and cerebrospinal fluid (CSF) protein levels. Regular clinical follow up ranged from 1 to 26 months, with a mean follow-up time of 9.75 months for patients with programmable valves and 10.4 months for patients with nonprogrammable valves. Patient ages ranged from 2 weeks to 18 years. One hundred patients had 117 programmable valves implanted, and 35 of these patients (35%) underwent shunt revision because of malfunction. The programmable valve itself malfunctioned in nine patients who had undergone shunt revision (11.1%/year of follow up). The nonprogrammable valve group had no valve malfunctions. The overall VP shunt revision rate in the nonprogrammable valve group was 20.2%. No significant differences were identified when CSF protein levels and specific malfunction types were compared within the programmable valve and nonprogrammable valve groups.

CONCLUSIONS: In this study the authors demonstrated an annualized intrinsic programmable valve malfunction rate of 11.1%, whereas during the same period no intrinsic valve malfunctions were noted with nonprogrammable valve systems for similar causes of hydrocephalus. The CSF protein levels did not correlate with observed valve malfunction rates. Further evaluation in a prospective, randomized fashion will elucidate specific indications for programmable valve systems and better determine the reliability of these valves in the pediatric population.

PMID: 16383248

Transient ventriculoperitoneal shunt malfunction after chronic constipation: case report and review of literature.

Muzumdar D, Ventureyra EC. Transient ventriculoperitoneal shunt malfunction after chronic constipation: case report and review of literature. Child's Nervous System. 2007 Apr;23(4):455-8. Epub 2006 Aug 29.

BACKGROUND: Significant constipation in patients with shunt-dependent hydrocephalus may often be enough to bring a subclinical shunt malfunction to clinical attention or even to be the cause of temporary distal peritoneal shunt malfunction. The treatment of the constipation may address the symptomatic shunt dysfunction so as to avoid operative intervention. The pathogenesis of distal shunt malfunction and its management in such a situation are discussed, and the relevant literature is briefly reviewed.

CASE REPORT: A 16-year-old young boy had shunt-dependent hydrocephalus secondary to prematurity and intraventricular hemorrhage at birth. He was chronic flaccid paraplegic and had a neurogenic bladder and bowel involvement. He presented with acute dull aching intermittent headaches, nausea, and constipation of short duration. There was no underlying shunt infection. CT brain showed dilated lateral ventricles. Shunt survey revealed a convoluted course and kink in the distal peritoneal catheter. After administration of a bowel enema, the headaches and nausea resolved over the next few hours, and the posttreatment CT showed significant decrease in ventricular size.

CONCLUSION: Chronic constipation is an important predisposing factor for distal malfunction in shunt-dependent hydrocephalus and should be ascertained in evaluation of a ventriculoperitoneal shunt malfunction. Appropriate treatment of significant constipation can relieve shunt malfunction and reestablish cerebrospinal fluid circulation. A shunt exploration can be avoided in such a situation. A close neurological monitoring of the patient is essential during the course of treatment. An interdisciplinary approach between concerned medical specialties and enhanced awareness is mandatory to ensure appropriate bowel management.

PMID: 17009006

Constipation as a reversible cause of ventriculoperitoneal shunt failure. Report of two cases.

Powers CJ, George T, Fuchs HE. Constipation as a reversible cause of ventriculoperitoneal shunt failure. Report of two cases. Journal of Neurosurgery. 2006 Sep;105(3 Suppl):227-30.

Ventriculoperitoneal (VP) shunt failure is a common problem encountered by pediatric neurosurgeons. The majority of such failures are due to obstruction of the device. Conditions in which intraabdominal pressure is chronically elevated, such as pregnancy, have been associated with shunt failure. Chronic constipation may also result in abnormally elevated intraabdominal pressure and may be an underrecognized cause of distal VP shunt failure. The authors describe the cases of two children who presented with clinical and imaging evidence of VP shunt failure and who were also severely constipated. Treatment of their constipation resulted in both clinical and imaging-documented resolution of their shunt failure.

PMID: 16970237

Long-term outcomes in patients with treated childhood hydrocephalus.

Gupta N, Park J, Solomon C, Kranz DA, Wrensch M, Wu YW. Long-term outcomes in patients with treated childhood hydrocephalus. Journal of Neurosurgery. 2007 May;106(5 Suppl):334-9.

OBJECT: The goal in this study was to determine the long-term effects of childhood hydrocephalus.

METHODS: A patient-reported survey completed by 1953 participants was used to collect data in a subgroup of 1459 individuals who had been treated for hydrocephalus in childhood. Data on shunt complications, including total shunt revisions and infections, were examined in those whose hydrocephalus had been diagnosed at least 10 years earlier (718 patients). Social and functional outcomes were examined in patients who were 20 years of age or older at the time of survey completion (403 individuals). Specific questions addressed the presence of depression, the patient's marital status, independent living arrangements, and the educational level attained. Shunt complications were common; 54% of patients had four or more shunt revisions, and 9% had three or more shunt infections. Depression requiring treatment occurred in 45% of participants. Other measures of social functioning all reflected a major impact of childhood hydrocephalus. In general, a worse outcome was found in patients whose hydrocephalus was diagnosed before 18 months of age.

CONCLUSIONS: The lifelong morbidity associated with shunt placement to treat childhood hydrocephalus is substantial, and it includes shunt-related complications and comorbidities that adversely affect social functioning.

PMID: 17566197