A comparison between ventriculo-peritoneal and ventriculo-atrial cerebrospinal fluid shunts in relation to rate of revision and durability

Results of 884 first-time shunts inserted in the time period from 1958 to 1989 are retrospectively evaluated, 1) to perform a durability analysis of a shunt based on Kaplan-Meyer method, 2) to compare the rate of revision for ventriculo-atrial (VA) and ventriculo-peritoneal (VP) shunts, 3) to compare the durability of a VA shunt with a VP shunt and 4) to do a stratified durability analysis comparing the VA and VP shunts in relation to the following background variables: shunt type, time period and age of the patient. Furthermore the specific complications related to VA and VP shunts are identified based on findings in the literature. Overall one-year shunt durability is 57% and five-year shunt durability is 37%. The median shunt durability is 1.68 years. Revision rate is 51% for VA shunts and 38.5% for VP (p < 0.05). Shunt durability is longer for VP shunts though the difference is not significant (p < 0.1). By use of stratified analysis of shunt durability no differences however are found between the two shunting methods. Hence the apparent difference in revision rate between VA and VP shunts seems secondary to variations in follow-up time and variations in background variables. To supplement our statistical analysis we have performed a literature study to look at the specific complications associated with VA and VP shunts. It seems as if the specific complications in relation to the VA shunting method are more severe than in relation to the VP shunting method.     

Immunohistochemical and electrophysiological evidence for omega-conotoxin-sensitive calcium channels in unmyelinated C-fibres of biopsied human sural nerve

Two cases of glomerulonephritis associated with colonization of cerebrospinal fluid shunts inserted for the treatment of hydrocephalus (shunt nephritis) are described and additional 113 cases reported in world literature, are reviewed. Both of our patients were affected by two episodes of shunt nephritis. Complete clinical remission of renal disease followed antibiotic treatment in one patient, and shunt replacement combined with antibiotic therapy in the other. In the 115 cases of shunt nephritis reported to date, the causative organisms, clinical features, pathogenesis, renal histology, treatment, and outcome are discussed in detail. The importance of regular observation for early recognition of this reversible form of glomerulonephritis, is emphasized.     

Police and mental health professionals. Collaborative responses to the impact of violence on children and families

Most pediatric patients with hydrocephalus are treated with ventriculoperitoneal (VP) shunt placement. However, shunt malfunction is common and is usually caused by mechanical failure. Shunt obstructions may be confirmed with radioisotope examination or with fluoroscopically guided injection of iodinated contrast material into the shunt reservoir. Disconnections or breaks are more readily detected at radiography in cases in which barium-impregnated shunt tubing was used. Migration and leakage may also occur. Cerebrospinal pseudocysts may be demonstrated with plain radiography and further evaluated with computed tomography (CT) and sonography. In increasing hydrocephalus, plain radiography may reveal sutural diastasis and increased cranial cavity size, and CT can be used to evaluate ventricle size. In cases of enlarging intracranial cysts, injection of iodinated contrast material followed by CT can help document a connection between the cyst and the ventricles. Ventriculitis and meningitis can be visualized at CT and magnetic resonance imaging as enhancement of the ventricular ependymal lining or cerebral cortical sulci. Other complications associated with VP shunts include surgery-related complications, shunt overdrainage and slit-ventricle syndrome, neoplastic metastasis, pleural effusion, and complications related to shunt variants. Imaging analysis is an essential adjunct to the clinical evaluation of patients with suspected VP shunt malfunctions or complications. Radiologists should be familiar with these potential problems and the diagnostic utility of various imaging modalities.     

A survey of the first complication of newly implanted CSF shunt devices for the treatment of nontumoral hydrocephalus. Cooperative survey of the 1991-1992 Education Committee of the ISPN

The results of an international multicenter study concerning the first complication of newly implanted cerebrospinal fluid shunts in nontumoral hydrocephalus are the subject of the present report. The authors have collected information on 773 cases from four continents. In particular, the following data were evaluated in relation to the general incidence of complications recorded in the first follow-up year: the patient's age at the operation, the etiology of hydrocephalus, the type of CSF shunt device used, and the modality of the surgical procedures. The overall complication rate in the series was 29%. Age and etiology of hydrocephalus appear to play a major role in influencing the complication rate; on the other hand, the choice of a specific CSF shunt device seems to be less important in this respect.     

The role of endoscopic third ventriculostomy in the management of shunt malfunction

OBJECTIVE: To evaluate the effectiveness of third ventriculostomy as an alternative to shunt revision in the management of shunt malfunction and infection in obstructive hydrocephalus. METHODS: All of the clinical notes of 30 patients treated with third ventriculostomy for malfunctioning or infected shunts between January 1, 1974, and December 31, 1996, were retrospectively reviewed. Third ventriculostomy was performed under fluoroscopic control in the first seven patients and endoscopically in the remainder. A successful outcome was achieved if further shunt revision surgery was avoided. The median follow-up duration was 8.7 years RESULTS: Twenty-three patients (76.7%) experienced successful outcomes, resulting in shunt independence. Of the seven failures, three were technical failures at the time of surgery and the remaining four were manifest within a median of 10 days, resulting in shunt revision. There have been no delayed failures. CONCLUSION: Third ventriculostomy is a valuable alternative to shunt revision in patients affected by obstructive hydrocephalus presenting with shunt malfunction or infection. It should be considered in all suitable cases as the first-line treatment for obstructive hydrocephalus of all causes. Because all failures were manifest within a short time, it is likely that these successes will be durable.     

Experience with use of extended length peritoneal shunt catheters

The placement of a ventriculoperitoneal (VP) shunt is the current treatment of choice for diversion of cerebrospinal fluid associated with hydrocephalus. Although there are a host of reported potential abdominal complications related to the procedure, they are notably uncommon. The authors report their experience with the primary insertion of an extended length open-ended peritoneal tubing (120 cm) undertaken expressly to avoid the need for a lengthening procedure because of growth of the patient. In a review of new insertions of VP shunts using the extended length tubing over a 14-year period at Childrens Hospital of Los Angeles, a total 998 shunts were placed in 952 patients, with a mean follow-up period of 6.7 years. The patients experienced a total of 52 distal shunt revisions for a variety of malfunction etiologies. In patients ranging in age from premature neonate to 20 years, there was no increase in the distal complication rate, and specifically no complications were experienced that were directly related to the use of the extended length tubing. The authors conclude that the use of an extended length peritoneal shunt catheter is not associated with an increase in complications and eliminates the need to lengthen the peritoneal catheter for growth of the patient.     

Epilepsy in children with shunted hydrocephalus

OBJECT: The incidence of epilepsy among children with hydrocephalus and its relation to shunts and their complications, raised intracranial pressure (ICP), and developmental outcome are explored in a retrospective study. METHODS: The authors studied a series of 802 children with hydrocephalus due to varying causes, who were treated by ventriculoperitoneal shunt placement between 1980 and 1990, with a mean follow-up period of 8 years. Patients who had tumoral hydrocephalus and those whose files lacked significant data were excluded. Data extracted from medical records, including history of the hydrocephalus and history of seizures, if any, were analyzed. Thirty-two percent of the children had epilepsy, the onset of which frequently occurred at approximately the same time that the diagnosis of hydrocephalus was made. The majority of the affected children had severe uncontrolled epilepsy. The incidence of epilepsy was significantly affected by the original cause of the hydrocephalus. The presence of radiological abnormalities was also found to be a significant predictor of epilepsy. Similarly, shunt complications predisposed to epilepsy. Episodes of raised ICP related to hydrocephalus or in association with shunt malfunction may also predispose to epileptic seizures. Furthermore, the presence of a shunt by itself seems able to promote an epileptogenic focus. Finally, epilepsy appears to be an important predictor of poor intellectual outcome in hydrocephalic children with shunts. CONCLUSIONS: A prospective study is needed to identify clearly and confirm avoidable factors predisposing to seizures in these children so that we can strive to reduce the incidence of these seizures and, subsequently, improve these children's quality of life.     

Comparative nutritive value of winged bean (Psophocarpus tetragonolobus (L) DC) and other legumes grown in Tanzania

BACKGROUND: In order to assess the efficiency of flow-controlled shunts in reducing shunt failure in the treatment of adult hydrocephalus (with a special focus on overdrainage complications), a series of 289 patients was analyzed through a retrospective and comparative study performed in three neurosurgical departments. METHODS: A group of 142 adult patients suffering from hydrocephalus were operated on using a conventional differential pressure (DP) shunt and compared with a group of 147 adult patients operated on using flow-controlled (FC) system (Orbis-Sigma, Cordis). Only the first complication, which required a surgical revision within the first 2 years after shunt implantation, was taken into account for each patient and analyzed using life-table methods. RESULTS: The actuarial risk of shunt infection in the two groups is respectively 8.3% and 10.9% at 1 year (nonsignificant difference). The actuarial risk of mechanical complications at 1 year is 38% for the DP patients and 10% for the FC patients (p = 0.0001); this difference is largely due to a decrease of complications related to overdrainage phenomenon (14/142 subdural collections were observed in the DP group versus 1/147 in the FC group) (p = 0.0001). CONCLUSION: The conclusion of this cooperative and retrospective study is that the use of a flow-controlled system decreases the risk of mechanical complications related to the hydrodynamic properties of the shunts used in the treatment of adult hydrocephalus, especially those related to overdrainage.     

Silicone elastomer cerebrospinal fluid shunt systems. Council on Scientific Affairs, American Medical Association

A 1995 resolution of the American Medical Association House of Delegates, introduced by the American Academy of Neurology, the American Association of Neurological Surgeons, and the Congress of Neurological Surgeons, asked the American Medical Association Council on Scientific Affairs to add the use of hardened silicone shunts to its study of the effects of silicone gel used in breast implants. On consideration of the important differences between the two materials, silicone elastomer ("hardened silicone") and silicone gel, the Council on Scientific Affairs elected to address the subject of silicone elastomer shunt systems separately. This report describes the different types of medical-grade silicone used in medical devices, the incidence of hydrocephalus and its causes and treatment, and the use of cerebrospinal fluid shunt systems made of silicone elastomer. Published case reports of possible immunological disease in patients who have had silicone elastomer cerebrospinal fluid shunt systems implanted are reviewed. The Council on Scientific Affairs concluded that the evidence presented does not support the occurrence of immune-mediated systemic reactions to implanted silicone elastomer cerebrospinal fluid shunt systems. The local granulomatous or inflammatory responses observed in some patients with silicone shunt systems have not been shown to be immunologically mediated; similar reactions have been described with other implanted foreign bodies.     

Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus

OBJECTIVE: Forty percent of standard cerebrospinal fluid shunts implanted for the treatment of pediatric hydrocephalus fail within the first year. Two new shunt valves designed to limit excess flow, particularly in upright positions, were studied to compare treatment failure rates with those for standard differential-pressure valves. METHODS: Three hundred-forty-four hydrocephalic children (age, birth to 18 yr) undergoing their first cerebrospinal fluid shunt insertion were randomized at 12 North American or European pediatric neurosurgical centers. Patients received one of three valves, i.e., a standard differential-pressure valve; a Delta valve (Medtronic PS Medical, Goleta, CA), which contains a siphon-control component designed to reduce siphoning in upright positions; or an Orbis-Sigma valve (Cordis, Miami, FL), with a variable-resistance, flow-limiting component. Patients were monitored for a minimum of 1 year. Endpoints were defined as shunt failure resulting from shunt obstruction, overdrainage, loculations of the cerebral ventricles, or infection. Outcome events were assessed by blinded independent case review. RESULTS: One hundred-fifty patients reached an endpoint; shunt obstruction occurred in 108 (31.4%), overdrainage in 12 (3.5%), loculated ventricles in 2 (0.6%), and infection in 28 (8.1%). Sixty-one percent were shunt failure-free at 1 year and 47% at 2 years, with a median shunt failure-free duration of 656 days. There was no difference in shunt failure-free duration among the three valves (P = 0.24). CONCLUSION: Cerebrospinal fluid shunt failure, predominantly from shunt obstruction and infection, remains a persistent problem in pediatric hydrocephalus. Two new valve designs did not significantly affect shunt failure rates.     

Tuberculous meningitis with hydrocephalus. Contribution of PCR assay of CSF before VP shunting

A 10-month-old infant with tuberculous (Tb) meningitis accompanying hydrocephalus was successfully treated with a VP shunt operation soon after a PCR assay of CSF was found to be negative for Mycobacterium tuberculosis. PCR assay of CSF is helpful for determination of the timing for VP shunting in Tb meningitis.     

Expanding ventricular shunts for hydrocephalus in infancy and childhood

Expanding, adult-length catheters to accommodate continuing somatic growth have been implanted in the course of shunts, either to the heart or peritoneum, in 12 hydrocephalic infants and young children. Three of four patients with direct cardiac shunts are doing well 22, 28 and 30 months following primary shunt operations, and five of eight patients with ventriculo-peritoneal shunts are progressing favourably four to 10 months after shunt placement. While no claims can be made for long-term benefits, the preliminary results of these procedures are encouraging.     

Hydrocephalus secondary to intracranial hemorrhage in premature infants

Premature (low birth weight) infants are particularly susceptible to intracranial hemorrhage. This frequently arises from the subependymal area and may dissect into the brain or into the ventricles. If the infant survives, hydrocephalus is a frequent sequela. Because of major improvements in the care of premature infants in recent years and the proliferation of intensive care nurseries, increasing numbers of low birth weight infants are surviving and developing hydrocephalus. Seven cases are described of infants who developed hydrocephalus following intracranial bleeding. Initially, ventricular and lumbar punctures were done to attempt to control head growth but this was unsuccessful. Two were treated with temporary external ventriculostomy which did not permanently control the hydrocephalus. Definitive treatment included ventriculo-atrial shunts using an expandable 'telescopic' cardiac catheter in two and ventriculoperitoneal shunts in five. The pathogenesis and management of the condition are discussed.     

Mixed bacterial meningitis: a complication of ventriculo- and lumboperitoneal shunts

Infectious complications of ventriculo- and lumboperitoneal shunts in two patients are presented. Cerebrospinal fluid infection due to aerobic and anaerobic enteric flora was characteristic of each case. Both infections occurred several months after shunt surgery and were associated with colonic perforation by the distal limb of the peritoneal catheter. These cases emphasize this unusual hazard of peritoneal shunts and demonstrate methods for diagnosis and effective therapy.     

Angiographic characteristics of infarct-related and non-infarct-related stenoses in patients in whom stable angina progressed to acute myocardial infarction

OBJECT: This study was conducted to evaluate the results of shunting procedures for syringomyelia. METHODS: In a follow-up analysis of 42 patients in whom shunts were placed in syringomyelic cavities, the authors have demonstrated that 21 (50%) developed recurrent cyst expansion indicative of shunt failure. Problems were encountered in patients with syringomyelia resulting from hindbrain herniation, spinal trauma, or inflammatory processes. A low-pressure cerebrospinal fluid state occurred in two of 18 patients; infection was also rare (one of 18 patients), but both are potentially devastating complications of shunt procedures. Shunt obstruction, the most common problem, was encountered in 18 patients; spinal cord tethering, seen in three cases, may account for situations in which the patient gradually deteriorated neurologically, despite a functioning shunt. CONCLUSIONS: Placement of all types of shunts (subarachnoid, syringoperitoneal, and syringopleural) may be followed by significant morbidity requiring one or more additional surgical procedures.     

Posture-related overdrainage: comparison of the performance of 10 hydrocephalus shunts in vitro

OBJECTIVE: Approximately 10 to 30% of shunt revisions may be attributed to posture-related overdrainage. The susceptibility of various hydrocephalus shunts to overdrainage of cerebrospinal fluid requires independent laboratory evaluation. METHODS: Shunts were tested in vitro by using precise computer-controlled equipment that was able to evaluate pressure-flow performance curves under various conditions. Hydrodynamic resistance and opening, closing, and operational pressures were evaluated for at least 28 days with normal (atmospheric) and decreased (-23 mm Hg, based on the International Standard Organization/Draft International Standard 7197 standard, which simulates conditions in upright body positions) outlet pressures. RESULTS: Ten different models of valves have been tested to date (Medtronic PS Medical Delta valve, flow-control valve, and lumboperitoneal shunt, Heyer-Schulte in-line, low-profile, and Pudenz flushing valves, Codman-Medos programmable and nonprogrammable valves, Sophy programmable valve, and Cordis Orbis-Sigma valve). The majority of these valves produced significantly negative (less than -10 mm Hg) average intracranial pressures in vertical body positions. In conjunction with nonphysiologically low hydrodynamic resistance (with the exception of the Orbis-Sigma valve, Medtronic PS Medical lumboperitoneal shunt, and Heyer-Schulte in-line valve), this may result in overdrainage related to body posture. The clinically reported rate of complications related to overdrainage is probably reduced by the long distal catheter, which increases the resistance of these valves by 100 to 200%. A few shunts (the Delta valve, low-profile valve, and Pudenz flushing valve with anti-siphon devices) offer reasonable resistance to negative outlet pressure, preventing complications related to overdrainage, but all valves with siphon-preventing devices may be blocked by increased subcutaneous pressure. CONCLUSION: Shunts without mechanisms preventing very low intracranial pressure in vertical body positions should be identified and avoided for patients likely to develop complications related to cerebrospinal fluid overdrainage.     

Complications of lumboperitoneal shunts. A retrospective study of a series of 195 patients (214 procedures)

BACKGROUND AND PURPOSE: We report our experience with the lumboperitoneal shunt (LPS) in 195 patients. The aim of this retrospective study was to assess and compare the rate of complications and to discuss 4 indications. MATERIAL AND METHOD: Between January 1983 and July 1994, 195 patients including 14 pediatric cases were treated with a LPS. Sex ratio was 1.24. The mean age at insertion was 59.5 years (from 6 months to 88 years) and the follow-up in this series was from 6 months to 12.5 years. The indications for a LPS were: chronic idiopathic hydrocephalus (115 cases), post-hemorrhagic hydrocephalus (37 cases), cerebrospinal fluid fistula (11 cases), post-traumatic hydrocephalus (9 cases), post-surgical hydrocephalus (8 cases), hydrocephalus of the child (6 cases), post-meningitis hydrocephalus (4 cases), benign intracranial hypertension (4 cases), post-radiotherapy hydrocephalus (1). Forty patients (20.5%) presented with at least one complication. A total of 47 complications were observed: chronic subdural effusion (8 cases), meningitis (10 cases), mechanical failures (28 cases), acquired Chiari abnormality (1 case). Mechanical complications varied with the type of shunt. CONCLUSION: Complications of LPS in adults are less frequent than is usually reported after ventricular atrial or peritoneal shunting. In adults, LPS can be used as the first valuable treatment in case of chronic communicating hydrocephalus. LPS is also valuable in the treatment of benign intracranial hypertension or recurrent CSF fistulae. Conversely, in the pediatric cases general and specific complications are frequent, so an indication for LPS must be strictly discussed.     

Low-pressure hydrocephalic state and viscoelastic alterations in the brain

Most shunt-dependent hydrocephalic patients present with predictable symptoms of headache and mental status changes when their cerebrospinal fluid shunts malfunction. Their intracranial pressure (ICP) is usually high, and they usually respond to routine shunt revision. This report describes 12 shunted patients who were admitted with the full-blown hydrocephalic syndrome but with low to low-normal ICP. All 12 patients had been maintained previously on medium-pressure shunts. Their symptoms included headache, lethargy, obtundation, and cranial neuropathies. At peak symptoms, their ventricular sizes were large (ventricular/biparietal ratio of 0.35 to 0.45) in six and massive (ventricular/biparietal ratio > 0.45) in six and their ICPs ranged from 2.2 to 6.6 mm Hg, with a mean of 4.4 +/- 1.3 mm Hg (+/- standard deviation), i.e., below or well within the pressure range of their shunts. The pressure volume index of three patients at peak symptoms ranged from 39.2 to 48.5 ml, with a mean of 43.9 +/- 4.6 ml, which represents a 190% increase from the predicted normal value. Seven patients failed to improve with multiple shunt revisions, including the use of low-pressure valves. In 11 patients, symptoms and ventriculomegaly were not reversed except with prolonged external ventricular drainage at subzero pressures (mean external ventricular drainage nadir pressure of -5.7 +/- 3.6 mm Hg, for a mean period of 22.2 days). During external ventricular drainage treatment, symptoms correlated only with ventricular size and not with ICP. All 11 were subsequently treated successfully with a new medium- or low-pressure shunt. One patient was treated successfully with prolonged shunt pumping. We postulate that: 1) the development of this low-pressure hydrocephalic state is related to alteration of the viscoelastic modulus of the brain, secondary to expulsion of extracellular water from the brain parenchyma, and to structural changes in brain tissues due to prolonged overstretching; 2) certain patients are susceptible to developing low-pressure hydrocephalic state because of an innate low brain elasticity due to bioatrophic changes; 3) low-pressure hydrocephalic state symptoms are due not to pressure changes but to brain tissue distortion and cortical ischemia secondary to severe ventricular distortion and elevated radial compressive stresses within the brain; and 4) treatment must be directed toward allowing the entry of water into the brain parenchyma and the restoration of baseline brain viscoelasticity.     

Use of carbidopa-levodopa in a patient with hydrocephalus and frozen movement

While movement disorders are frequently encountered after brain injuries, and may create a host of complicated problems for the clinician, only a few cases of Parkinsonism associated with hydrocephalus have ever been described in the literature. Parkinsonism-like syndrome complicating hydrocephalus is a rare disorder, especially when associated with nontumoral aqueductal stenosis. Yet as this case report discusses, hdyrocephalus-induced Parkinsonism may be responsive to levodopa-carbidopa administration. This report describes a perplexing case of persistent akinesis following corrective surgery for aqueductal stenosis and the subsequent response to levodopa-carbidopa administration. We present the case of a 28-year-old male with a history of non-tumoral aqueductal stenosis diagnosed at age 12. As a child, he underwent a ventriculo-peritoneal shunt placement for obstructive hydrocephalus followed by multiple shunt revisions over the next several years. Sixteen years after his initial shunt placement, the patient presented with a decline in mental status. A third ventriculocisternostomy was performed rather than another shunt revision. Following surgery, the patient remained obtunded, and displayed profound hypokinesis, best described as freezing in movement. Upon admission to a rehabilitation unit 2 weeks later, he had made only minimal progress. A SPECT (single-photon emission computed tomography) brain scan revealed decreased basal ganglia perfusion. Levodopa/carbidopa therapy was initiated and within 2 weeks, the patient showed improvement in speed of movement, facial expression and verbal output. Eight weeks later, the patient could independently complete his basic activities of daily living and demonstrated little, if any, disordered movement. This report illustrates how dopaminergic agents may be useful in cases of hypokinesis following corrective surgery for aqueductal stenosis. SPECT may further aid in the diagnosis and management of Parkinsonism-like syndromes in brain injuries.     

Epilepsy in shunt-treated hydrocephalus

Although epilepsy is commonly associated with shunt-treated hydrocephalus, its relation to the shunting procedure and the criteria identifying postoperative epilepsy remain controversial. Of 283 patients shunted at Würzburg University Hospital over a 24-year period (1970 to 1994), 182 were followed up for a minimum of 1 year after shunt insertion and entered the study. The data were analyzed retrospectively in 1995 and 1996. Epilepsy was analyzed in relation to the etiology of hydrocephalus, functional status, time and site of shunt insertion, onset of seizures and seizure type, EEG changes, sex, shunt systems, and shunt revisions. Of the 182 patients studied, 37 (20%) developed epilepsy. The incidence of epilepsy varied according to the etiology of hydrocephalus: posthemorrhagic (5%), postinfectious (4%), connatal/miscellaneous/unknown (3%), myelomeningocele (2%), tumor/arachnoidal cyst/aqueduct stenosis (0%). Early shunting and poor functional status was associated with a higher risk for epilepsy. Epilepsy was not influenced by sex, shunt systems, or number of shunt revisions. Twenty-two (12%) of 182 patients developed epilepsy (generalized N=13, focal N=9) after intracranial shunting. Focal EEG abnormalities (N=16) were located mainly at the anatomical site of the shunt (N=14), but only three patients (2%) presented with focal seizures contralateral and focal EEG abnormalities ipsilateral to the site of the shunt. The presence of epilepsy was determined by the etiology of hydrocephalus rather than by surgical intervention. The incidence of postoperative epilepsy (12%) was low. Onset of epilepsy, clinical presentation of seizures, and EEG changes did not appear to be valid criteria for identifying shunt-related epilepsy. Thus, epilepsy as a complication of intracranial shunting might be overestimated in the literature.