Long-term follow-up data from the Shunt Design Trial

Test characteristics of parent's visual analog scale score in predicting ventriculoperitoneal shunt malfunction in the pediatric emergency department

OBJECTIVES

Many parents of children with ventriculoperitoneal shunts present to the emergency department for evaluation of a possible shunt malfunction. No study to date has evaluated their ability to predict a shunt malfunction. Our study objective was to evaluate parents' accuracy for predicting a shunt malfunction in their child. We hypothesize that parents more experienced with prior shunt malfunctions are better able to predict subsequent malfunctions in their child.

METHODS

We conducted a prospective, descriptive study on children younger than 18 years presenting to our tertiary care pediatric emergency department with a possible ventriculoperitoneal shunt malfunction. Parents rated the likelihood of a shunt malfunction using an unmarked 100-mm visual analog scale marked definitely malfunctioning at the high end. An experienced parent was defined as one who had previously experienced at least 3 shunt malfunctions in their child.

RESULTS

We enrolled 85 parent-child dyads in our study. Twenty-four children were diagnosed with a malfunction. The predictive ability of parents to determine a shunt malfunction was found at a threshold visual analog scale score of 66 (sensitivity, 88.9%, and specificity, 62.2%). At a determined threshold value of 85 or more, experienced parents had a high specificity of 89.2% with a positive likelihood ratio of 5.1. Experienced parents showed an area under the curve of 0.7928 (95% confidence interval, 0.6037-0.9819); and inexperienced parents, 0.5611 (95% confidence interval, 0.3646-0.7576) (P = 0.096).

CONCLUSIONS

Experienced parents are better able to predict a shunt malfunction in their child.

Long-term outcomes in patients with treated childhood hydrocephalus

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.

Pediatric gravitational shunts: initial results from a prospective study

OBJECT

The authors' goal in this paper was to evaluate prospectively the efficacy and safety of a new pediatric gravitational shunt to determine whether it warrants inclusion in a randomized, controlled trial with other shunts.

METHODS

A total of 55 children between the ages of 0 and 6 years (median age 0.5 years, average age 4+/-6 years) underwent primary shunt implantation; all received the Miethke Paedi-GAV. The follow-up period ranged between 12 and 77 months (mean 47+/-21 months). The primary end point of the study was the first shunt failure necessitating revision. The 1- and 2-year shunt survival rates were 75 and 68%, respectively. The average failure-free shunt survival duration was 1423 +/- 641 days. Based on imaging findings, no slitlike ventricles occurred. The complication rate was 33%, and the median time to shunt failure was 45 days. Underdrainage occurred in one child (1.8%) and overdrainage in two children (3.6%).

CONCLUSIONS

These preliminary results prove the Miethke Paedi-GAV to be a safe and effective pediatric shunt worthy of inclusion in a randomized comparison with other shunts in the pediatric population.

Third ventriculostomy vs ventriculoperitoneal shunt in pediatric obstructive hydrocephalus: results from a Swiss series and literature review

INTRODUCTION

Few series compare endoscopic third ventriculostomies (ETV) and ventriculoperitoneal shunts (VPS). To avoid the complications after a shunt insertion, there is an increased tendency to perform a third ventriculostomy. We reviewed all pediatric patients operated in the French-speaking part of Switzerland for a newly diagnosed obstructive hydrocephalus since 1992 and compared the outcome of patients who benefited from ETV to the outcome of patients who benefited from VPS. There were 24 ETV and 31 VPS.

DISCUSSION

At 5 years of follow-up, the failure rate of ETV was 26%, as compared to 42% for the VPS group. This trend is also found in the pediatric series published since 1990 (27 peer-reviewed articles analyzed).

CONCLUSION

In accordance to this trend, although a statistical difference cannot be assessed, we believe that ETV should be the procedure of choice in pediatric obstructive hydrocephalus.

Siphon regulatory devices: their role in the treatment of hydrocephalus

OBJECT

The management of hydrocephalus can be challenging because of the unique cerebrospinal fluid (CSF) dynamics in each patient. Various shunt systems have been developed for the treatment of hydrocephalus. One of the main issues surrounding these systems is overshunting due to siphoning. In this paper the authors discuss the pathophysiology of CSF siphoning as well as the various devices used to treat this problem. The pros and cons of each device are discussed, as are the key differences among them. Future concepts are also introduced with an emphasis on upcoming device designs.

METHODS

The authors performed a literature review of articles addressing CSF dynamics, shunting, and regulatory devices. The literature consisted of original research articles, company literature on each device, and patent information. A number of siphon regulatory devices have been developed over the past two decades. Each device has a distinct design, requiring specific techniques of implantation for optimal function.

CONCLUSIONS

For the past two decades, a variety of siphon regulatory devices have been used to help deal with CSF siphoning. With the increasing mobility of the population, every neurosurgeon will be seeing patients with older and newer devices. Familiarity with the various devices will assist in the evaluation and care of these patients.

Longstanding overt ventriculomegaly in adults: pitfalls in treatment with endoscopic third ventriculostomy

Object

The recently described condition of longstanding overt ventriculomegaly in adults (LOVA) has not been defined in terms of the need for intervention, timing of intervention, and ideal treatment. The purpose of this review was to evaluate the role of endoscopic third ventriculostomy (ETV) in the treatment of LOVA.

Methods

Data collected in six patients with LOVA who had undergone ETV were reviewed retrospectively in terms of the definition of treatment success, rates of success, complications, and outcome. All six patients presented with headache disorders. In all patients, triventricular hydrocephalus had been diagnosed as aqueductal stenosis, and head circumference measurements were above the 98th percentile. All six had undergone successful ETV as documented by the free flow of cerebrospinal fluid into the basal cisterns, which remained open throughout the follow-up period. After the procedure, one patient experienced a mild degree of difficulty with short-term memory. Five patients remained symptomatic or had symptoms requiring further treatment 3 months to 3 years after ETV. Four patients received ventriculoperitoneal shunts, and one underwent venous stenting for high intracranial pressure after successful ETV. In two patients in whom aqueductal stenosis had been diagnosed, the sylvian aqueduct was patent after the procedure.

Conclusions

In LOVA patients who present with headaches, ETV may not lead to improvement in the headaches. Despite the presence of triventricular hydrocephalus, closure of the aqueduct may be a secondary phenomenon, and flow through the aqueduct may be reestablished after ETV. If intracranial hypertension persists after successful ETV, its cause may be increased venous sinus pressure.

Adjustable vs set-pressure valves decrease the risk of proximal shunt obstruction in the treatment of pediatric hydrocephalus

INTRODUCTION

The use of programmable shunt valves has increased dramatically in the practice of pediatric hydrocephalus. Despite theoretical advantages, it remains unclear if the use of programmable vs set-pressure valves affects shunt outcome.

MATERIALS AND METHODS

The clinical and radiological records of all pediatric patients undergoing ventriculoperitoneal (VP), ventriculopleural (VPl), and ventriculoatrial (VA) shunt surgery from 2001 to 2004 at an academic institution were reviewed. The association of programmable vs set-pressure valves with subsequent shunt revision was assessed by Kaplan-Meier shunt survival plots and log-rank analysis.

RESULTS

A total of 279 VP, VPl, and VA shunt surgeries were performed on patients with median (interquartile range) age of 4 (1-14) years (161 male, 118 female; 158 communicating, 122 obstructive hydrocephalus). Programmable valves were used in 76 (27%) cases and set-pressure valves in 203 (73%). At mean+/-SD follow-up of 17 +/- 13 months, programmable vs set-pressure valves were associated with reduced risk of both overall shunt revision [26 (35%) vs 109 (54%); relative risk (RR) (95% CI); 0.61 (0.41-0.91), p = 0.016] and proximal obstruction [9 (12%) vs 58 (28%); RR (95% CI); 0.39 (0.27-0.80), p = 0.006]. There was no difference in distal obstruction [3 (4%) vs 11 (5%) cases], infection [6 (8%) vs 12 (6%) cases], valve obstruction [0 (0%) vs 4 (2%)], or shunt disconnection [2 (3%) vs 1 (1%)] between adjustable and set-pressure valves, respectively.

CONCLUSION

In our experience, the use of programmable vales was associated with a decreased risk of proximal shunt obstruction and shunt revision. Programmable valves may be preferred in patients frequently experiencing proximal shunt failure. A prospective, controlled study is warranted to evaluate the potential value of adjustable vs set-pressure valve systems.

Experience with the Strata valve in the management of shunt overdrainage

OBJECT

The overdrainage of cerebrospinal fluid (CSF) in children with shunt-treated hydrocephalus may cause chronic disabling symptoms and require repeated surgery. Externally adjustable valves offer a noninvasive way of altering the valve opening pressure. The authors report on their experience with using the Strata valve in the management of symptomatic CSF overdrainage.

METHODS

The authors treated 24 patients with symptomatic CSF overdrainage by inserting a Strata valve. The severity of symptoms was graded, and the frequency of hospital visits and shunt operations was recorded before and after insertion of the valve. Additionally, results of brain imaging and intracranial pressure monitoring were reviewed. Nineteen patients (79.2%) had severe symptoms at the time of the insertion; 1 year after Strata valve insertion only one patient (4.17%) still suffered severe symptoms. The number of hospital admissions was 3.38/patient/year before placement and 1.21 for the 1st year, 1 for the 2nd, and 0.4 for the 3rd postoperative year. The number of operations was 3.42/patient/year during the year before placement of the valve, and then 0.71 for the 1st, 0.56 for the 2nd, and 0.25 for the 3rd postoperative years. During the 1st year after placement of the Strata valve, the settings were changed 2.79 times/patient/year, 1.29 for the 2nd, and 1.33 times/patient/year for the 3rd year.

CONCLUSIONS

The Strata valve was effective in improving the symptoms of overdrainage in the majority of patients in this series. The number of hospital admissions and operations for valve malfunction was reduced.

Prophylactic antibiotics in pediatric shunt surgery

INTRODUCTION

The optimal antibiotic prophylaxis for pediatric shunt-related procedures is not clear. There is much inconsistency among different medical centers. This paper summarizes and analyzes the various prophylactic antibiotic regiments used for shunt-related surgeries at different pediatric neurosurgery centers in the world.

MATERIALS AND METHODS

A survey questionnaire was distributed through the Pediatric Neurosurgery list-server (an e-mail-based special interest group in pediatric neurosurgery). Forty-five completed questionnaires were received, one per medical center, primarily from pediatric neurosurgeons with the following geographic breakdown: 25 from North America, 13 from Europe, and 7 from Asia and other countries. All centers routinely administered prophylactic antibiotics for shunt-related procedures. The drugs of choice were first-generation cephalosporins (23), second-generation cephalosporins (10), naficillin/oxacillin (4), vancomycin (3), clindamycin (1), amoxicillin (1), and mixed protocols in three centers. The initial drug administration ("first dose") was: in the department before transfer to operating room (5), upon arrival to operating room (11), at induction of anesthesia (13), and at initial skin incision (16). The duration of antibiotic dosage also varied: single dose (13), 24-h administration (26), 48-h administration (2), and longer than 48 h in four centers.

RESULTS AND DISCUSSION

Two general tendencies were noted, common to the majority of participating centers. There was a general trend to modify antibiotic treatment protocol in "high-risk" populations. The second common theme noted in more than half of responding centers was the use of long-term antibiotic treatment for externalized devices (such as externalized shunts, external ventricular drains or lumbar drains), usually till the device was in place.

Management of shunt infections: a multicenter pilot study

OBJECT

Approximately 10% of cerebrospinal fluid (CSF) shunt operations are associated with infection and require removal or externalization of the shunt, in-hospital treatment with antibiotic agents, and insertion of a new shunt. In a previous survey, the authors identified substantial variation in the duration of antibiotic therapy as well as the duration of hospital stay. The present multicenter pilot study was undertaken to evaluate current strategies in the treatment of shunt infection.

METHODS

Patients were enrolled in the study if they had a successful treatment of a CSF shunt infection proved by culture of a CSF specimen. Details of their care and the incidence of culture-proved reinfection were recorded. Seventy patients from 10 centers were followed up for 1 year after their CSF shunt infection. The initial management of the infection was shunt externalization in 17 patients, shunt removal and external ventricular drain insertion in 50, and antibiotic treatment alone in three. Reinfection occurred in 18 patients (26%). Twelve of the 18 reinfections were caused by the same organism and six were due to new organisms. The treatment time varied from 4 to 47 days, with a mean of 17.4 days for those who later experienced a reinfection compared with 16.2 days for those who did not. The most common organism (Staphylococcus epidermidis, 34 patients) was associated with a reinfection rate of 29% and a mean treatment time of 12.8 days for those who suffered reinfection and 12.5 days for those who did not.

CONCLUSIONS

Reinfection after treatment of a CSF shunt infection is alarmingly common. According to the data available, the incidence of reinfection does not appear to be related to the duration of antibiotic therapy.

Evaluation and management of shunt infections in children with hydrocephalus

Shunt infections constitute one of the main risks of shunt surgery for hydrocephalus, which is the single most common type of surgery performed by pediatric neurosurgeons. Infectious complications are responsible for increased morbidity and mortality, lengthy hospitalizations, and high cost. Most modern series report infection rates approaching 10% of all shunt procedures. Despite the high incidence of this complication, optimal management is still unknown, and research on prevention has been hampered by single-institution series and small numbers. This article will review the history, causes, presentation, management, and outcome from shunt infections in children. Pitfalls in diagnosis and management will be reviewed. Finally, prevention strategies and research questions still remaining in this area will be outlined.

Complications and pitfalls of neuroendoscopic surgery in children

OBJECT

Neuroendoscopic surgery is being used as an alternative to traditional shunt surgery and craniotomy in the management of hydrocephalus and intracranial fluid-filled cavities. In this study, the authors evaluated the incidence and type of complications occurring after neuroendoscopic procedures that were performed in a consecutive series of pediatric patients at a single institution to determine the effectiveness of neuroendoscopy in such patients.

METHODS

Four hundred ninety-five neuroendoscopic procedures were consecutively performed in 450 pediatric patients at one institution over a 10-year period. Charts were retrospectively reviewed. A complication was defined as follows: 1) any postoperative neurological deficit that was not observed before surgery; 2) any event occurring during surgery that resulted in the procedure being aborted; or 3) any adverse event occurring within 7 days postsurgery that resulted in a modification of the normal postoperative care. However, headache, vomiting, and fever without cerebrospinal fluid (CSF) pleocytosis were not considered complications. Complications were observed in 40 (8.1%) of 495 procedures. Two patients had two complications. One patient died of diffuse brain edema following endoscopic biopsy sampling of a basal ganglia tumor (mortality rate 0.2%). Other complications observed were abandonment of the procedure in eight cases, CSF leakage in 11 (with associated wound infection in one), intraventricular hemorrhage in six (with external drainage needed in four), intraparenchymal hemorrhage in three, subdural collection in eight (with subdural-peritoneal shunt placement needed in seven), transient oculomotor palsy in two, and transient hemiparesis in one.

CONCLUSIONS

Many complications can be avoided by determining the correct diagnosis and using suitable techniques and instruments. Most complications can be managed conservatively and do not produce long-term morbidity. Complex procedures in most patients and simple procedures in patients with preoperative risk factors carry the highest hazard. Every attempt should be made to optimize the surgical technique. The most serious and potentially the most lethal complication remains arterial bleeding from injury to the basilar artery complex.

Shunt insertion in the summer: is it safe?

OBJECT

The potential for increased complications related to the arrival of new residents in July each year has not previously been demonstrated in the neurosurgical literature. The authors investigated this phenomenon in children undergoing cerebrospinal fluid shunt surgery.

METHODS

Data were obtained from a multicenter hydrocephalus clinical trials database and from hospital admission records in English-speaking Canada. Data pertaining to patients treated in July and August were compared with those pertaining to patients treated during the remainder of the year. The incidence of shunt failure, shunt infection, neurological deficits, wound infection, technical errors, and death were compared using a chi-square test for categorical outcomes, means for continuous outcomes, and survival analysis for time-dependent outcomes. In the hydrocephalus clinical trials database, 138 of 737 patients were treated in July and August. The median duration of shunt lifespan (hereafter referred to as "shunt survival") was 1.7 years for patients treated during the summer months and 2.4 years for those treated throughout the rest of the year (p = 0.10); for shunt infection the figures were 13.8 and 8.8% (p = 0.08) of the total number of cases, and for wound dehiscence they were 2.9 and 0.7% (p = 0.05), respectively. When all shunt procedures were included, an examination of shunt survival and infection incidence rates recorded in the Canadian Hospital Discharge Database seemed to imply a significant advantage to having surgery between September and June (log-rank statistic = 7.10, p = 0.008).

CONCLUSIONS

The data suggest a "July effect" on some outcomes related to shunt surgery, but the effect was small. Nonetheless, the potential morbidity of shunt failure, infection, and the cost of treatment indicate that continued vigilance and appropriate supervision of new staff by attending surgeons is warranted.

Pediatric Neurology of the Dog and Cat

The neurologic examination in the puppy or kitten can be a challenging experience. Understanding the development of behavior reflexes and movement in puppies and kittens enables us to overcome some of these challenges and to recognize the neurologically abnormal patient. Subsequently,we can identify the neuroanatomic localization and generate a differential diagnosis list. This article first reviews the pediatric neurologic examination and then discusses diseases unique to these individuals.

Failure of cerebrospinal fluid shunts: part II: overdrainage, loculation, and abdominal complications

Complications from cerebrospinal fluid shunts are common and can present with a variety of signs and symptoms. In this second part of a two-part review, shunt overdrainage, loculation of the ventricular system in patients with shunts, and abdominal complications related to ventriculoperitoneal shunts are discussed. Familiarity with these types of shunt failure is essential for neurologists and pediatricians because they are often the first to evaluate and triage these children.

Failure of cerebrospinal fluid shunts: part I: Obstruction and mechanical failure

Ventricular shunts are commonly employed to treat children with hydrocephalus. Complications from shunts are common and can present with a variety of signs and symptoms. This pair of reviews discusses the common findings in patients with shunt malfunction, including physical examination and imaging findings. Part I of the series discusses obstruction and mechanical failure of shunts; Part II discusses overdrainage, loculation, and abdominal complications of shunts. An understanding of the presentation and etiology of shunt dysfunction is critical for neurologists and pediatricians who often are the first to evaluate and triage these children.

Signs and symptoms of cerebrospinal fluid shunt malfunction in the pediatric emergency department

OBJECTIVES

Pediatric patients with cerebrospinal fluid shunts frequently present to the emergency department for evaluation of possible shunt malfunction. Most shunt studies appear in the neurosurgical literature. To our knowledge, none have reviewed presenting signs and symptoms of shunt malfunction in patients who present to the pediatric emergency department. The study objective was to evaluate the medical record of children with cerebrospinal fluid shunts who presented to a pediatric emergency department to determine if any signs and/or symptoms were predictive of shunt malfunction.

METHODS

A retrospective chart review was conducted on 352 pediatric patients aged 0 to 18 years, who presented to the pediatric emergency department between January 1, 1998, and December 31, 2002, with signs and/or symptoms that prompted an evaluation for possible shunt malfunction.

RESULTS

Univariate analysis of all signs and symptoms revealed lethargy (odds ratio, 1.99; 95% confidence interval, 1.15-3.42; P = 0.02) and shunt site swelling (odds ratio, 2.56, 95% confidence interval, 1.08-6.07, P = 0.03) to be significantly predictive of shunt malfunction. Logistic regression analysis continued to show significance for lethargy (odds ratio, 2.20; bias-corrected 95% confidence interval, 1.11-3.63) and shunt site swelling (odds ratio, 3.10; bias-corrected 95% confidence interval, 1.38-9.05), but found no other study variable to be significant. Bootstrap resampling validated the importance of the significant variables identified in the regression analysis.

CONCLUSIONS

In this study, lethargy and shunt site swelling were predictive of shunt malfunction. Other signs and symptoms studied did not reach statistical significance; however, one must maintain a high index of suspicion when evaluating children with an intracranial shunt because the presentation of malfunction is widely varied. A missed diagnosis can result in permanent neurological sequelae or even death.

Hospitalist care of the medically complex child

The nature of inpatient pediatrics is changing. Over the past decade, several factors have converged to influence the kinds of children currently being hospitalized. There has been a shift in the relative proportion of otherwise healthy children with acute illnesses being hospitalized to children with increasing medical complexity. This article focuses on hospitalist care of medically complex children and provides an overview on (1) the challenges in defining this population, (2) the unique issues surrounding their inpatient care (using a family-centered care approach that includes coordinated care, minimizing secondary complications, nutritional needs, functional limitations, transdisciplinary collaboration, and primary care issues), (3) technology devices commonly found, and (4) a proposal for a research agenda regarding medically complex children.

Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension

INTRODUCTION

Cerebrospinal fluid (CSF) shunting effectively reverses symptoms of idiopathic intracranial hypertension (IIH). Lumboperitoneal (LP) shunts have traditionally been used in patients with IIH due to a frequently undersized ventricular system. However, the advent of image-guided stereotaxis has enabled effective ventricular catheter placement in patients with IIH. We describe the first large series of frameless stereotactic ventriculoperitoneal (VP) shunting for patients with slit ventricles and IIH.

METHODS

We describe the frameless stereotactic VP shunting technique for IIH in 32 procedures. Outcomes following shunt placement, time to shunt failure, and etiology of shunt failure are reported.

RESULTS

A total of 21 patients underwent 32 ventricular shunting procedures (20 VP, 10 ventriculoatrial, 2 ventriculopleural). One hundred percent of shunts were successfully placed into slit ventricles, all requiring only one pass of the catheter under stereotactic guidance to achieve the desired location and CSF flow. There were no procedure-related complications and each ventricular catheter showed rapid egress of CSF. All (100%) patients experienced significant improvement of headache immediately after shunting. Ten percent of ventricular shunts failed at 3 months after insertion, 20% failed by 6 months, 50% failed by 12 months, and 60% failed by 24 months. Shunt revision was due to distal obstruction in 67%, overdrainage in 20%, and distal catheter migration or CSF leak in 6.5%. There were no shunt revisions due to proximal catheter obstruction or shunt infection.

CONCLUSIONS

In our experience treating patients with IIH, frameless stereotactic ventricular CSF shunts were extremely effective at treating IIH-associated intractable headache, and continued to provide relief in nearly half of patients 2 years after shunting without many of the shunt-related complications that are seen with LP shunts. Placing ventricular shunts using image-guided stereotaxis in patients with IIH despite the absence of ventriculomegaly is an effective, safe treatment option.

[The cerebrospinal fluid shunt]

The cerebrospinal fluid shunt is one of the most common surgical procedures in pediatric neurosurgery. Nevertheless, an important rate of failure (mechanical, infectious or functional) can occur. These complications can result from the hydrocephalus itself, the surgical technique (type of material and surgeon experience) and infectious problems related to foreign material. Most of the time, the clinical signs of these failures are obvious (intracranial hypertension or signs of meningitis) but can also be insidious.

A multicenter prospective cohort study of the Strata valve for the management of hydrocephalus in pediatric patients

OBJECT

Previous reports suggest that adjustable valves may improve the survival of cerebrospinal fluid shunts or relieve shunt-related symptoms. To evaluate these claims, the authors conducted a prospective multicenter cohort study of children who underwent placement of Strata valves.

METHODS

Patients undergoing initial shunt placement (Group 1) or shunt revision (Group 2) were treated using Strata valve shunt systems. Valves were adjustable to five performance level settings by using an externally applied magnet. The performance levels were checked using an externally applied hand tool and radiography. Patients were followed for 1 year or until they underwent shunt revision surgery. Between March 2000 and February 2002, 315 patients were enrolled in the study. In Group 1 (201 patients) the common causes of hydrocephalus were myelomeningocele (16%), aqueductal stenosis (14%), and hemorrhage (14%). The overall 1-year shunt survival was 67%. Causes of shunt failure were obstruction (17%), overdrainage (1.5%), loculated ventricles (2%), and infection (10.6%). Patients in Group 2 (114 patients) were older and the causes of hydrocephalus were similar. Among patients in Group 2 the 1-year shunt survival was 71%. There were 256 valve adjustments. Symptoms completely resolved (26%) or improved (37%) after 63% of adjustments. When symptoms improved or resolved, they did so within 24 hours in 89% of adjustments. Hand-tool and radiographic readings of valve settings were the same in 234 (98%) of 238 assessments.

CONCLUSIONS

The 1-year shunt survival for the Strata valve shunt system when used in initial shunt insertion procedures or shunt revisions was similar to those demonstrated for other valves. Symptom relief or improvement following adjustment was observed in 63% of patients. Hand-tool assessment of performance level settings reliably predicted radiographic assessments.

Physiological insights into Shechita

The Government recently announced that it intends to reject a recommendation by the Farm Animal Welfare Council that all animals should be stunned before slaughter (see VR, April 10, p 446). In this Viewpoint article, Dr Stuart Rosen discusses physiological aspects of Shechita, the Jewish method of religious animal slaughter. He outlines the religious context and describes the act of Shechita. He discusses the scientific literature on the behavioural responses to Shechita as well as neurophysiological studies relevant to the assessment of pain, and concludes that Shechita is a painless and humane method of animal slaughter.

Cerebrospinal Fluid Diversion Procedures

Cerebrospinal fluid (CSF) diversion procedures remain the principal method of treatment of hydrocephalus and an important option in treating idiopathic intracranial hypertension. Recent advances in CSF shunt hardware offer some promise in reducing the rate of complications. Third ventriculostomy has become an increasingly practiced alternative to conventional shunting in an ever-widening patient population. Long-term follow-up studies have identified complications of lumboperitoneal shunt placement. Advances in surgical navigation suggest that ventriculoperitoneal shunting may be a viable alternative in patients with idiopathic intracranial hypertension.

Hydrocephalus

Hydrocephalus is not an exotic condition in general pediatric practice. A general pediatrician might expect to serve two to five children with CSF shunts. This article reviews posthemorrhagic hydrocephalus in detail.

A single-pass tunneling technique for CSF shunting procedures

Implantation of ventriculoperitoneal shunts in the precoronal position is generally accomplished using a retroauricular incision for subcutaneous tunneling. Retroauricular incisions can be associated with complications, including cerebrospinal fluid leak and shunt infection. We describe a technique for 'single-pass' shunt tunneling from frontal to abdominal incisions and our initial results in a consecutive, prospective series of 15 children (age 2 days to 5 years). Eleven patients presented with congenital hydrocephalus (including 5 with myelomeningocele and 3 with posthemorrhagic hydrocephalus) and 4 with hydrocephalus secondary to central nervous system (CNS) tumors. The average length of clinical follow-up was 6 months (range 1-13 months). There were no perioperative or long-term complications of the single-pass technique. Nine of the 11 patients with congenital hydrocephalus are currently well without any further medical or surgical intervention. Two underwent shunt revision for proximal obstruction, with an intact distal system. Three of the 4 patients with hydrocephalus secondary to CNS tumor suffered secondary shunt complications during periods of severe neutropenia resulting from chemotherapy (6 weeks to 6 months after shunt insertion). For primary ventriculoperitoneal shunt insertion in infants and young children, the single-pass tunneling technique is safe and avoids one source of complications.

Pediatric hydrocephalus: current management

Hydrocephalus is a common problem in pediatric neurology and neurosurgery. The key to the diagnosis of hydrocephalus is the clinical or radiographic progression over time. Most children who have hydrocephalus require ventriculoperitoneal shunts, but the complications of shunting remain distressingly common. Using current endoscopic techniques, a small proportion of patients can be treated without ventriculoperitoneal shunts. The population of pediatric patients who have had hydrocephalic shunts is maturing; these young adults now face issues related to independent living, pregnancy, and long-term care of their hydrocephalus.

Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used

OBJECT

The goal of this study was to evaluate the long-term results of a flow-regulating shunt (Orbis Sigma Valve [OSV] II Smart Valve System; Integra NeuroSciences, Sophia Antipolis, France) in the treatment of hydrocephalus, whether it was a first insertion procedure or surgical revision of another type of shunt, in everyday clinical practice in a multicenter prospective study.

METHODS

Patients of any age who had hydrocephalus underwent implantation of an OSV II system. The primary end point of the study was defined as any shunt-related surgery. The secondary end point was a mechanical complication (shunt obstruction, overdrainage, catheter misplacement, migration, or disconnection) or infection. The overall 5-year shunt survival rates and survival as it applied to different patient subgroups were assessed. Five hundred fifty-seven patients (48% of whom were adults and 52% of whom were children) were selected for OSV II shunt implantation; 196 patients reached the primary end point. Shunt obstruction occurred in 75 patients (13.5%), overdrainage in 10 patients (1.8%), and infection in 46 patients (8.2%). The probability of having experienced a shunt failure-free interval at 1 year was 71% and at 2 years it was 67%; thereafter the probability remained quite stable in following years (62% at the 5-year follow-up examination). No difference in shunt survival was observed between the overall pediatric (< or = 16 years of age) and adult populations. In the pediatric age group, however, there was a significantly lower rate of shunt survival in children younger than 6 months of age (55% at the 5-year follow-up examination).

CONCLUSIONS

In this prospective study the authors demonstrate the effectiveness of flow regulation in the treatment of hydrocephalus both in children and in adults. Flow-regulating shunts limit the incidence of overdrainage and shunt-related complications. The overall 5-year shunt survival rate (62%) compares favorably with rates cited in other recently published series.

Results of endoscopic septal fenestration in the treatment of isolated ventricular hydrocephalus

A surgical series detailing the results and complications of neuroendoscopy for the treatment of isolated lateral ventricular hydrocephalus (ILVH) has yet to be presented. This retrospective case review of 32 patients examines our experience at the Primary Children's Medical Center with endoscopic fenestration of the septum pellucidum (septostomy) for ILVH. The patients who underwent endoscopic septostomy between the years of 1993 and 2001 were identified from our database. Forty-three septostomies were performed, with a mean follow-up of 30.9 months. Fifty-three percent of initial septostomies remained patent. Nine patients had a least one more septostomy performed after failure of their initial septostomy. All but one was successful. Including repeat septostomies, 81% of the patients had relief of their ILVH on the last follow-up. No septostomy failures occurred later than 6 months postoperatively. A history of multiple previous shunt procedures was highly predictive of initial septostomy failure, increasing this risk 4.5 times. Complications involved significant intraventricular hemorrhage, wound breakdown, shunt infection and sterile meningitis in four cases. We conclude that endoscopic septostomy is a reasonable treatment option for ILVH, avoiding additional shunts. Outcome is negatively affected by multiple prior shunt procedures. Favorable results can be achieved with repeat septostomies in patients who have failed prior septostomy. Lasting results are expected for septostomies that remain patent after 6 months.

The influence of surgical operative experience on the duration of first ventriculoperitoneal shunt function and infection

The relationship of surgeon experience, measured by operative volume, to the outcomes of ventricular shunt treatment of hydrocephalus in children is not clear. This paper explores this relationship based on first ventriculoperitoneal shunts (VPS) implanted in English-speaking Canada during the period from April 1989 to March 2001. Three thousand seven hundred and ninety-four first VPS insertions, performed by 254 surgeons, were reviewed. Surgical experience was represented by the number of shunt operations performed during the study period by each surgeon prior to the date of the operation. The 6-month shunt failure risk for less experienced surgeons was 38%, compared to 31% for more experienced surgeons. This difference decreased to 4% at 60 months and 3% at 120 months (p = 0.001). The infection rate for initial shunt insertions was 7% for patients treated by more experienced surgeons and 9.4% for those treated by less experienced surgeons (p = 0.006). A relationship between surgeon experience and shunt outcome that appears to be based on the operative experience that a surgeon brings to a procedure is in keeping with clinical experience. This observation has implications for public policy, service planning and surgical mentorship during the earlier years of a surgeon's career.

Endoscopic third ventriculostomy for shunt dysfunction in occlusive hydrocephalus: long-term follow up and review

OBJECT

Endoscopic third ventriculostomy (ETV) is the treatment of choice for occlusive (noncommunicating) hydrocephalus. Nevertheless, its routine use in patients who have previously undergone shunt placement is still not generally accepted. The authors' aim was to investigate the long-term effects of ETV in a group of prospectively chosen patients.

METHODS

Patients who underwent ETV and had previously undergone shunt placement for occlusive hydrocephalus were followed prospectively for at least 3 years (range 36-103 months, mean 63.6 months). Nine female and eight male patients ranging from 8 to 54 years of age (mean 32 years) had undergone shunt placement 0.7 to 23.5 years (mean 8.1 years) before ETV. Fifteen patients were admitted with underdrainage and two with overdrainage. In six cases, ETV was performed as an emergency operation. The origin of hydrocephalus was aqueductal stenosis in 12 cases and aqueductal compression by a tumor in two cases. Three patients suffered from a fourth ventricle outlet syndrome, and in two patients an additional malresorptive component was suspected. Thirteen patients underwent ETV with shunt removal and insertion of an external drain in one session. The drain served as a safety measure; it could be opened if raised intracranial pressure or ventricular dilation was observed on postoperative imaging studies. In the other four patients the shunt was initially ligated and then removed during a second operation. Fourteen patients (82%) have remained shunt free. The other three patients, including the two with an additional malresorptive component, needed shunt reimplantation 3 days, 2 weeks, or 7 months after ETV.

CONCLUSIONS

Use of ETV is safe and effective for the treatment for shunt dysfunction in patients with obstructive hydrocephalus.

Clinical experience with the use of a shunt with an adjustable valve in children with hydrocephalus

OBJECT

The goal of this study was to assess the value of making adjustments in the opening pressure of a shunt valve and to determine shunt survival in children and young adults in whom an adjustable valve was used to manage cerebrospinal fluid drainage.

METHODS

The authors conducted a single-center retrospective study of 158 children and young adults who had received 199 Codman Hakim programmable valves (noninvasively adjustable to settings in the range of 30-200 mm H2O). The mean age at which the patients underwent shunt implantation was 4.4 years (median 0.4 years, maximum 18 years); 94 patients were younger than 2 years of age, including 14 patients with a gestational age younger than 38 weeks at the time of implantation. In 84 (53.2%) of the 158 patients, valve pressure adjustment was required at least once (mean 1.3 times, maximum 16 times). Among the 202 adjustments made in patients the reason for adjustment was underdrainage in 74 adjustments (36.6%) and overdrainage in 119 (58.9%). The clinical status of the patient improved after 121 (69.1%) of 175 adjustments and after 58 (73.4%) of 79 minor adjustments (less than or equal to +/- 20 mm H2O). The shunt infection rate was 13 (10.9%) of 119 patients. Shunt survival was 60.5% at 1 year, 47.1% at 2 years, and 43.9% at 3 years of follow-up review.

CONCLUSIONS

Adjustment of the valve's opening pressure further improves outcome in pediatric patients.

Lack of benefit of endoscopic ventriculoperitoneal shunt insertion: a multicenter randomized trial

OBJECT

Endoscopically assisted ventricular catheter placement has been reported to reduce shunt failure in uncontrolled series. The authors investigated the efficacy of this procedure in a prospective multicenter randomized trial.

METHODS

Children younger than 18 years old who were scheduled for their first ventriculoperitoneal (VP) shunt placement were randomized to undergo endoscopic or nonendoscopic insertion of a ventricular catheter. Eligibility and primary outcome (shunt failure) were decided in a blinded fashion. An intention-to-treat analysis was performed. The sample size offered 80% power to detect a 10 to 15% absolute reduction in the 1-year shunt failure rate. The authors studied 393 patients from 16 pediatric neurosurgery centers between May 1996 and November 1999. Median patient age at shunt insertion was 89 days. The baseline characteristics of patients within each group were similar: 54% of patients treated with endoscopy were male and 55% of patients treated without endoscopy were male; 30% of patients treated with and 26% of those without endoscopy had myelomeningocele; a differential pressure valve was used in 51% of patients with and 49% of those treated without endoscopy; a Delta valve was inserted in 38% of patients in each group; and a Sigma valve was placed in 9% of patients treated with and 12% of those treated without endoscopy. Median surgical time lasted 40 minutes in the group treated with and 35 minutes in the group treated without endoscopy. Ventricular catheters, which during surgery were thought to be situated away from the choroid plexus, were demonstrated to be in it on postoperative imaging in 67% of patients who had undergone endoscopic insertion and 61% of those who had undergone nonendoscopic shunt placements. The incidence of shunt failure at 1 year was 42% in the endoscopic insertion group and 34% in the nonendoscopic group. The time to first shunt failure was not different between the two groups (log rank = 2.92, p = 0.09).

CONCLUSIONS

Endoscopic insertion of the initial VP shunt in children suffering from hydrocephalus did not reduce the incidence of shunt failure.

Lumboperitoneal shunts in children

OBJECTIVE

To determine the safety and efficacy of lumboperitoneal (LP) shunts in carefully selected children with abnormalities of the absorption of cerebrospinal fluid.

METHODS

Magnetic resonance imaging studies, indications for treatment and pre- and postoperative symptoms of 25 patients (mean age 9.6 years) who had undergone LP shunting in the past 10 years in a single pediatric neurosurgical practice were analyzed retrospectively.

RESULTS

Indications for treatment included postoperative pseudomeningocele, pseudotumor cerebri and a severe form of slit ventricle syndrome. Preoperative symptoms resolved completely in all 25 patients as a result of the shunt, and no patient developed symptomatic or radiographic hindbrain herniation. Twenty-one shunts incorporated valve mechanisms.

CONCLUSION

LP shunts may be used for specific indications without excessive risk of hindbrain herniation.

Outcome analysis of initial neonatal shunts: does the valve make a difference?

OBJECTIVE

Ventriculoperitoneal shunts have one of the highest complication rates of all neurosurgical procedures. The purpose of this study was to identify factors associated with malfunction of shunts placed in infants with neonatal hydrocephalus, with the goal of maximizing long-term shunt survival.

METHODS

We performed a retrospective chart review of 200 consecutive patients less than 1 year old who underwent primary intracranial shunt placement for hydrocephalus by one of two experienced pediatric neurosurgeons at a single institution. A multivariate analysis was conducted to identify variables that were statistically independent predictors of a shunt malfunction or problem.

RESULTS

Adequate data were available for 158 patients, with a mean follow-up of 39.8 months (range 6-99 months). Variables tested for independent prediction of shunt revision included the etiology of the hydrocephalus, gestation period, age at shunt placement, surgeon, ventricular catheter entry site and valve opening pressure. Frontal versus occipital catheter entry site was not associated with a different revision rate. The only significant controllable factor associated with shunt malfunction was the valve opening pressure. The revision rate per year of follow-up was 4 times higher for patients with no valve or a low-pressure valve than for patients with a medium- or high-pressure valve.

CONCLUSIONS

This retrospective review demonstrated that the valve opening pressure is an important component of the shunt complication rate. A prospective multicenter randomized trial is warranted to further evaluate the conclusions of this study.

Duration of antibiotic therapy for the treatment of shunt infection: a surgeon and patient survey

The ideal duration of antibiotic treatment for shunt infection remains a major unanswered question in pediatric neurosurgery. To date, no study has objectively determined the best length of treatment, i.e. that which minimizes both the length of hospital stay and the chance of reinfection. This study was undertaken to determine whether an increase in reinfection risk would be tolerated if the duration of therapy were shortened. Sixty-one members of the American Society of Pediatric Neurosurgeons (44 responding) and 831 patients or parents of patients with shunts (385 responding) were surveyed using similar questionnaires. Sixty-four percent of neurosurgeons (28/44) and 54% of patients (178/325) responding to the survey would tolerate an increased reinfection risk in order to gain a shorter duration of treatment. These data support the feasibility of a planned randomized study to determine the ideal length of antibiotic treatment for shunt infection.

Cerebrospinal fluid shunt complications after urological procedures in children with myelodysplasia

OBJECTIVE

Invasive urological procedures, commonly performed on patients with myelodysplasia, may contribute to the occurrence of cerebrospinal fluid shunt complications. Shunt complications that occurred after urological procedures in children with myelodysplasia were studied.

METHODS

Shunt complications occurring after urological procedures were examined in 29 patients. Differences between patients with or without complications were studied. Complications were analyzed according to the location of abnormality, the treatment, and the timing after shunt and urological surgery.

RESULTS

The 1-year incidence of shunt complications after a urological procedure had been performed was 31% (overall incidence, 41.4%). Shunt complications were observed only after intraperitoneal urological procedures. Most complications were distal, occurring more than 1 year after the preceding shunt surgery. The patients in the shunt complications group had significantly more intraperitoneal urological procedures (3.2 versus 0.8, P = 0.004) and previous shunt revisions (2.0 versus 0.9, P = 0.015) than had the group without complications. As compared with the group of patients with extraperitoneal complications, the intraperitoneal group experienced significantly more infections (4 of 9 versus 0 of 10, P = 0.014) requiring more complex treatment, and their complications occurred significantly earlier in the follow-up period after the urological procedure had been performed (7.2 versus 27.3 mo, P = 0.006). The patients in the group with extraperitoneal complications experienced significantly more mechanical shunt malfunctions than did the intraperitoneal group (9 of 10 versus 4 of 9, P = 0.016), which required simple shunt revisions.

CONCLUSION

Patients with spina bifida and shunted hydrocephalus may have an increased risk of developing intraperitoneal shunt complications after intraperitoneal urological procedures have been performed. These intraperitoneal shunt complications usually occur a few months after urological surgery and require complex treatment.

The treatment of cerebrospinal fluid shunt infections. Results from a practice survey of the American Society of Pediatric Neurosurgeons

It is our impression that the management strategy for infected cerebrospinal fluid (CSF) shunts varies significantly among pediatric neurosurgeons. The purpose of this paper is to present the results of a practice survey on the treatment of shunt infections which was distributed to all active members of the American Society of Pediatric Neurosurgeons (ASPN). Eighty-four of 129 ASPN members (65%) responded to the survey. Most ASPN members remove the shunt and place an external ventricular drain (EVD) to treat Staphylococcus epidermidis (59.5%), S. aureus (64.3%) and gram-negative rod infections (67.9%). The second most common method of treatment was externalization of the shunt (33.3, 29.8 and 25%, respectively). The duration of antibiotic treatment was extremely variable. When the shunt was removed and an EVD inserted, the duration of antibiotic treatment for S. epidermidis and S. aureus ranged from 5 to 21 total days (2-21 days of sterile cultures). For gram-negative rod infections treated with shunt removal and an EVD, the total duration of antibiotic therapy ranged from 5 to 24 days (2-37 days of sterile cultures). The majority of ASPN members remove the infected CSF shunt and place an EVD for the management of shunt infections. Significant variation exists in the duration of antibiotic therapy. Determining the most effective duration of antibiotic therapy in an effort to shorten hospitalization and minimize complications without sacrificing efficacy will require further study.