Cerebrospinal Fluid Diversion Procedures Research Articles

Lumboperitoneal shunt for idiopathic intracranial hypertension: patients’ selection and outcome

Surgical treatment of idiopathic intracranial hypertension (IIH) includes cerebrospinal fluid (CSF) diversion procedures most commonly lumboperitoneal (LP) shunt. LP shunt addresses the cause of both headache and papilledema more directly by effecting a global reduction of intracranial pressure. Twenty-two cases were included in the study. All patients underwent clinical, imaging, and CSF manometry evaluations. All patients showed failure or noncompliance to medical treatment and necessitated placement of an LP shunt. Analysis of data was conducted and evaluation of outcome was assessed. Among 22 patients who underwent LP shunt placement for IIH, 16 (72.8%) patients had severe and fulminant opening CSF pressures with values of more than 400mmH(2)O. Among this group, 19 (86.4%) patients reported recovery of their headache and 16 (72.7%) patients showed complete resolution of papilledema. Shunt complications included two (9%) cases of shunt infection that required shunt extraction and antibiotic therapy, and six (27%) cases of shunt obstruction that required shunt revision. Manometric predictors for surgical treatment of IIH may include severe and fulminant opening CSF pressures as well as poor manometric response to repeated lumbar taps. Lumboperitoneal shunt is easy and effective for treating intractable headaches and visual impairment associated with IIH. Its usefulness can be optimized by meticulous technical placement of the shunt guided by rigorous protocols for shunt procedures.

Update on Idiopathic Intracranial Hypertension

To provide an update on various features of idiopathic intracranial hypertension. Perspective. Selected articles on the epidemiology, clinical and imaging features, natural history, pathophysiology, and treatment of idiopathic intracranial hypertension were reviewed and interpreted in the context of the authors' clinical and research experience. Idiopathic intracranial hypertension primarily is a disease of obese women of childbearing age, but it can affect patients of any weight, sex, and age. Although a relatively rare disorder, idiopathic intracranial hypertension's associated costs in the United States entail hundreds of millions of dollars. Even after treatment, headaches frequently are persistent and may require the continued involvement of a neurologist. Quality-of-life reductions and depression are common among idiopathic intracranial hypertension patients. However, visual dysfunction, especially visual field abnormalities, represents the major morbidity of this disorder, and serial automated perimetry remains the primary method of patient monitoring. Patients who are men, black, very obese, or anemic are at higher risk of visual loss. Vitamin A metabolism, adipose tissue as an actively secreting endocrine tissue, and cerebral venous abnormalities are areas of active study regarding the pathophysiology of idiopathic intracranial hypertension. Treatment studies show that lumbar puncture is a valuable treatment (in addition to its crucial diagnostic role), and that weight management is critical. However, open questions remain regarding the efficacy of acetazolamide, cerebrospinal fluid diversion procedures, and cerebral venous stenting. Many questions remain unanswered about idiopathic intracranial hypertension. Ongoing studies, especially an ongoing National Institutes of Health-funded clinical trial of acetazolamide, should provide more insight into this important, yet poorly understood, syndrome of isolated intracranial hypertension.

Fourth ventricular neurocystercercosis presenting with acute hydrocephalus

Neurocysticercosis is an infection caused by the larvae of the pork tapeworm Taenia solium. Parenchymal lesions commonly present with seizure activity and intraventricular lesions can cause hydrocephalus. A 33-year-old female patient presented in a comatose state with acute hydrocephalus and a fourth ventricle lesion. She underwent placement of an external ventricular drain. Resection of the fourth ventricle lesion through a suboccipital approach allowed for restoration of normal cerebrospinal fluid (CSF) flow and relief of midbrain compression. The lesion was resected intact and the patient returned to normal neurological function. No CSF diversion procedure was necessary. The patient was discharged on cysticidal and steroid therapy. We concluded that surgical resection of lesions in the fourth ventricle attributed to neurocysticercosis is appropriate when brainstem compression is prominent. Resection may also avoid the need for permanent CSF diversion. We also reviewed the evidence-based management strategies described in the literature.

Efficacy of simultaneous single-trajectory endoscopic tumor biopsy and endoscopic cerebrospinal fluid diversion procedures in intra- and paraventricular tumors

Intraventricular and paraventricular tumors resulting in hydrocephalus commonly require a CSF diversion procedure. A tumor biopsy can often be performed concurrently. Although the tissue samples obtained during endoscopic biopsy procedures are small, a diagnosis can be made in most cases. In the present study the authors analyzed the efficacy of concurrent endoscopic biopsy and CSF diversion procedures using a single bur hole and trajectory. Eighty-seven patients with intraventricular and paraventricular tumors were treated with endoscopic biopsy and CSF diversion procedures using a rigid rod-lens endoscope or a rigid fiberscope during a 10-year period. All patients underwent a tumor biopsy and an endoscopic third ventriculostomy (ETV), aqueductal stenting (AS), or ventriculoperitoneal (VP) shunting, depending on the tumor location and site of obstruction. A single bur hole for both procedures was used in all patients. Among the 87 patients, the biopsy was diagnostic in 72 (83%) and merely suggestive in 7 (8%); in 8 patients (9%) the sample was nondiagnostic. Among the 22 patients who underwent an initial endoscopic biopsy and subsequent procedures, the specimen obtained at the second surgery was concordant with the initial endoscopic biopsy sample in 13 patients; it was somewhat similar in 4 patients. In the other 5 patients, either a microsurgical or stereotactic approach was used to correctly diagnose the pathology. Fifty-five patients were considered for endoscopic CSF diversion procedures; an ETV was performed in 52 patients and AS in 2. An ETV could not be performed in 3 patients for technical reasons. A VP shunt was inserted in 32 patients, with 25 undergoing shunt placement at the same time as the ETV and 7 at a later date. Significant bleeding was encountered in 3 patients during the tumor biopsy and in 1 patient during the ETV. The ETV failed in 1 patient during the follow-up, and a repeat ETV was required. Endoscopic biopsy sampling and a concurrent CSF diversion procedure through a single bur hole and trajectory can be considered for intraventricular tumors. The overall success rates of 83% for the biopsy procedure and 86% for the ETV indicate that the procedures are beneficial in the majority of cases. A concordance rate of 75% was found in patients who underwent an initial biopsy procedure and a subsequent microsurgical approach for tumor excision.

The syndrome of pseudotumour cerebri and idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a condition in which raised intracranial pressure is associated with a high body mass index, and in those societies in which the prevalence of obesity is increasing the disorder is of increasing importance. It is one cause of the syndrome of pseudotumour cerebri but the cause and the link with a rise in body weight are not understood. Furthermore the treatment of the more severe, sight-threatening cases is controversial. A major theme in recent years has been an attempt to identify the underlying mechanism of IIH. Some theories - such as the dural sinus stenosis theory - seem to ignore the relationship with weight gain; others have proposed a direct link between obesity and raised intracranial pressure through a specific fat distribution in the body; others through the production of lipokines; and yet others have suggested a converse causation with raised intracranial pressure giving rise to obesity. Uncontrolled case series continue to demonstrate the success of interventions such as cerebrospinal fluid diversion procedures, venous sinus stenting and bariatric surgery but there are no level 1 clinical trials. Interest in IIH is increasing and currently generating numerous studies but there is no consensus view on either cause or management.

Malignant Ascites after Subduroperitoneal Shunt in a Patient with Leptomeningeal Metastasis

Leptomeningeal metastasis is a devastating complication of advanced stage cancer. It is frequently accompanied by hydrocephalus and intracranial hypertension that must be treated by ventriculoperitoneal shunts. However, there are actual risks of peritoneal seeding or accumulation of malignant ascites after the cerebrospinal fluid diversion procedure, though it has not been reported. Here, we present the case of a patient with non-small cell lung cancer with leptomeningeal metastasis in whom malignant ascites developed after a subduroperitoneal shunt.

Tension pneumoventricle after excision of third ventricular tumor in sitting position

Occurrence of tension pneumoventricle (symptomatic intraventricular air) can result in rapid clinical deterioration in an otherwise stable patient. It is a rare clinical entity, mentioned in relation to cerebrospinal fluid (CSF) diversion procedures, during the late postoperative period. We present a patient with posterior third ventricular tumor who underwent excision by midline suboccipital craniotomy in sitting position. Neurological status of the patient deteriorated rapidly in the immediate postoperative period owing to development of tension pneumoventricle. The condition improved after twist-drill burr-hole evacuation of air under water-seal. Pre-existing gross hydrocephalus, exploration of third ventricle in sitting position, and residual tumor in third ventricle were possibly the factors responsible for this complication.

Surgical Activity of First-Year Canadian Neurosurgical Residents

Surgical activity is probably the most important component of surgical training. During the first year of surgical residency, there is an early opportunity for the development of surgical skills, before disparities between the skill sets of residents increase in future years. It is likely that surgical skill is related to operative volumes. There are no published guidelines that quantify the number of surgical cases required to achieve surgical competency. The aim of this study was to describe the current trends in surgical activity in a recent cohort of first-year Canadian neurosurgical trainees. This study utilized retrospective database review and survey methodology to describe the current state of surgical training for first-year neurosurgical trainees. A committee of five residents designed this survey in an effort to capture factors that may influence the operative activity of trainees. Nine out of a cohort of 20 first-year Canadian neurosurgical trainees that began training in July of 2008 participated in the study. The median number of cases completed by a resident during the initial three month neurosurgical rotation was 66, within which the trainee was identified as the primary surgeon in 12 cases. Intracranial hemorrhage and cerebrospinal fluid diversion procedures were the most common operations to have the trainee as primary surgeon. Based on this pilot study, it appears that the operative activity of Canadian first-year residents is at least equivalent to the residents of other studied training systems with respect to volume and diversity of surgical activity.

Protective effect of rifampicin and clindamycin impregnated devices against Staphylococcusspp. infection after cerebrospinal fluid diversion procedures

BackgroundInfection is a major complication of cerebrospinal fluid shunting procedures. The present report assesses the efficacy of such catheters in both shunts and external ventricular drains (EVDs) against infection and particularly against Staphylococcus spp. infection.MethodsAll shunt and EVD procedures performed by means of antibiotic-impregnated catheters (AICs) and non-AICs during the period of study were registered. In cases of shunt procedures, a minimal follow-up of 90 days was considered, as well as de novo insertion and catheter revisions. Single valve revisions were not included. In cases of EVD procedures, those catheters removed before the fifth post-insertion day were not included. A total of 119 cerebrospinal fluid shunting procedures performed with AICs were studied in comparison with 112 procedures performed by means of non-AICs.ResultsAntibiotic-impregnated catheters were associated with a significant decrease in both overall and staphylococcal infection (p = 0.030 and p = 0.045, respectively). The number needed to treat for AICs was 8 to prevent one infection and 14 to prevent one staphylococcal infection. When comparing with shunts, the use of EVDs was associated with a 37-fold increased likelihood of infection.ConclusionsAntibiotic-impregnated catheters are a safe and helpful tool to reduce CSF shunting device-related infections.

Intraoperative ventriculo-stomographic evaluation of endoscopic cerebrospinal fluid diversion and flow restoration procedures

Purpose. This prospective study was designed for intra-operative demonstration of cerebrospinal fluid (CSF) flow in ventricles and cisternal spaces before and after neuroendoscopic procedure. The aim of this study was to evaluate site of obstruction of CSF flow and subsequent stomal or aqueductal patency after endoscopic third ventriculostomy (ETV) or aqueductoplasty in patients with hydrocephalus of diverse aetiology.Method. Seventeen patients with hydrocephalus due to diverse aetiology underwent ETV (n = 15) and aqueductoplasty (n = 2) or cysto-ventrticulostomy (n = 1) or transaqueductal removal of neurocysticercus cyst (NCC) (n = 1). Intra-operatively, radio-opaque contrast agent (iohexol) instillation into the third ventricle was used for qualitative evaluation of obstruction and post-procedure CSF flow across the stoma into cisternal spaces.Result: 11 male and 6 female patients ranging from 3 to 50 years of age were included in the study. Post-procedure intra-operative ventriculo-stomography (IOVSG) showed free flow of dye across the endoscopic stoma (n = 13) or aqueduct (n = 2) into cisternal spaces. Diagnosis of fourth ventricular NCC was made in one patient with panventriculomegaly. In two patients of tuberculous meningitis hydrocephalus, poor flow of contrast in the prepontine area and basal cisterns was seen on IOVSG. They were subjected to ventriculoperitoneal shunt insertion in the same sitting. Cine MRI confirmed the patency of stoma or aqueduct in follow-up period in all patients with successful endoscopic procedure.Conclusion. IOVSG is a simple and safe technique that helps in confirming the adequacy of endoscopic procedure during surgery and thereby facilitates intra-operative decision about further management.

Cranioplasty After Postinjury Decompressive Craniectomy: Is Timing of the Essence?

The appropriate timing of cranioplasty after decompressive craniectomy for trauma is unknown. Potential benefits of delayed intervention (>6 weeks) for reducing the risk of infection must be balanced by persistent altered cerebrospinal fluid dynamics leading to hydrocephalus. We reviewed our recent 5-year experience in an effort to improve patient throughput and develop a rational decision making plan. A 5-year query (2003-2007) of our level I neurotrauma database. From 2,400 head injuries, we performed a total of 350 craniotomies. Of the 350 patients who underwent craniotomy for trauma, 70 patients (20%) underwent decompressive craniectomy requiring cranioplasty. Timing of cranioplasty, cranioplasty material, postoperative infections, and incidence of hydrocephalus were evaluated with logistic regression to study potential associations between complications and timing, adjusted for risk factors. No specific time frame was predictive of hydrocephalus or infection, and logistic regression failed to identify significant predictors among the collected variables. In our experience, the prior practice of delayed cranioplasty (3-6 months postdecompressive craniectomy), requiring repeat hospital admission, does not seem to lower postcranioplasty infection rates nor the need for cerebrospinal fluid diversion procedures. Our current practice emphasizes cranioplasty during the initial hospital admission, as soon as there is resolution on computed tomography scan of brain swelling outside of the cranial vault with concurrent clinical examination. This occurs as early as 2 weeks postcraniectomy and should lower the overall cost of care by eliminating the need for additional hospital admissions.

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a condition which affects predominantly overweight women and is characterized by raised intracranial pressure without any identifiable pathology in the brain and with normal cerebrospinal fluid (CSF) composition. The cause of IIH is unclear and as such it remains a diagnosis of exclusion. Although the pathophysiology of IIH remains elusive, some observations have recently been added to our understanding of this, including the presence of transverse sinus stenosis on many patients and the possible role of leptin and inflammation in the disease pathogenesis. Headache is the most common symptom and papilloedema is the major clinical finding. Choices of medical treatment are limited to the use of diuretics particularly acetazolamide and encouragement of weight loss. Surgical therapies such as CSF diversion procedures and fenestration of the optic nerve may be necessary in some cases with persistent symptoms or progressive visual deterioration. While not life-threatening, IIH has a significant morbidity with up to 25% of patients developing visual impairment from optic atrophy. Visual surveillance is therefore vital. Long-term follow-up is recommended as the disease may worsen after an initial period of stability.

Transventricular neuroendoscopic excision of giant racemose subarachnoid cysticercosis

Subarachnoid cysticercosis, an uncommon form of neurocysticercosis, can occasionally grow to giant size causing mass effect and obstructive hydrocephalus. These often require surgical excision to relieve the mass effect and re-establish the cerebrospinal fluid (CSF) pathways. The authors report a rare case of giant anterior interhemispheric racemose cysticercosis with extension to the region of septum pellucidum causing obstructive hydrocephalus. Due to the proximity of the cysts to the dilated ventricular system, a frontal transventricular endoscopic approach was preferred over a conventional microsurgical or endoscopic-assisted microsurgical approach. Most of the cysts could be successfully resected from the region of septum pellucidum and the anterior interhemisphere. The patient did not require a CSF diversion procedure in the postoperative period. Depending on the location and nature of the lesion, a transfrontal transventricular endoscopic approach can be successfully utilized to approach lesions in the anterior interhemispheric region.

Shunting in tuberculous meningitis: a neurosurgeon’s nightmare

I read with interest the original paper by Sil et al. entitled “Shunting in tuberculous meningitis: a neurosurgeon’s nightmare” [Childs Nerv Syst (2008) 24:1029–1032]. I am delighted and congratulate the authors on presenting their valuable work on shunting in tuberculous meningitis, which is indeed a difficult decision-making process and associated with a variable outcome. They conclude that early shunting is the best option to prevent long-term neurological sequelae. Tuberculous meningitis still continues to be a grave problem in Indian population at large, especially in children. It frequently forms an important differential diagnosis for childhood chronic meningitis. The sequelae can be devastating and contributes significantly to the economic burden of the family as well as the nation. The CSF diversion procedure is largely based on the Palur’s grading system for tubercular meningitis. In the era prior to effective antitubercular medication, there was a little choice for the clinician apart from a shunt procedure for hydrocephalus. The potential ill effects of shunt infection and a relatively high incidence of repeated shunt blockade have always been worrisome and precluded easy decision making for shunt insertion. Following an effective antitubercular medication and steroids for tubercular meningitis, aggressive neurosurgical intervention was largely avoided and a wait and watch policy was adopted. However, in absence of an objective criterion, the uniformity for cerebrospinal fluid (CSF) diversion procedure is still questionable among neurosurgical fraternity and ranges from close neurological observation to a delayed time interval for CSF diversion procedure. An intellectual indifference and a false sense of security could occur on the part of the clinician which could result in delay for intervention, especially since the symptomatology of meningitis secondary to vasculitis and arachnoiditis versus raised intracranial pressure tend to overlap and/or coexist. There is little controversy about the role of shunt in noncommunicating hydrocephalus in tuberculous meningitis which is confirmed readily on serial imaging. The decision for shunt insertion in communicating hydrocephalus could be difficult and needs to be appropriately measured. The neurosurgeon’s role in tuberculous meningitis is largely restricted to the cerebrospinal fluid diversion procedures as mentioned by the authors. The selection of the patient for cerebrospinal fluid diversion is important for optimal outcome [1, 2]. The outcome of CSF diversion procedure is more gratifying if the timing of intervention is appropriate. The decision to perform a CSF diversion procedure is a sum product of the clinical profile of the patient and radiological imaging. It is a function of time. It requires to be stressed that the clinical history of the patient is paramount. This is reflected by the author’s results in which Palur grade II patients had a better outcome. The moderate hydrocephalus in Palur grades I and II should be closely monitored clinically for the need of possible early intervention to maximize the neurological outcome and prevent potential irreversible morbidity. Nature and homeostatic mechanisms allow a certain time frame for optimal outcome. The neurosurgeon should be Childs Nerv Syst (2008) 24:1383–1384 DOI 10.1007/s00381-008-0741-2

Magnetic resonance angiography in the evaluation of infants with hydrocephalus: a new standard?

As part of the Dutch Hydrocephalus and Ischemia Research project, Leliefeld and colleagues have conducted a prospective study in which they attempted to use quantitative MR angiography to measure cerebral blood flow (CBF) in infants with progressive hydrocephalus. Furthermore, they aimed to explore the relationship between CBF and intracranial pressure (ICP) before and after cerebrospinal fluid (CSF) diversion. As the authors point out, clinical signs alone may be inadequate for defining the optimal time point for intervention in infants with hydrocephalus. Moreover, with suture closure in infants, ICP does not always correlate with ventricular size or with clinical signs or symptoms. Hence, an overall goal of this study was to determine whether CBF, as determined by quantitative MR angiography, could provide additional objective data that may guide the treatment of infants with hydrocephalus. Fifteen patients with progressive hydrocephalus (age range 1 day–7 months) were included. All patients underwent intracranial pressure monitoring with either anterior fontanel pressure (AFP) measurement or intraventricular measurement, quantitative MR angiography, and mean arterial blood pressure measurement before and after CSF diversion procedures. To correct for age-dependent increases in CBF, brain volume was also determined using MR imaging. Although mean arterial blood pressure did not change before and after CSF diversion procedures, ICP decreased significantly (from a mean of 19.1 to 6.7 cm H2O), and CBF increased significantly (from a mean of 25.7 to 50.1 ml/100 cm3 brain/min) following CSF diversion (a shunt in 12 patients and a third ventriculostomy in 3 patients). Several aspects of this study merit further discussion. First, the method for measurement of ICP requires clarification. Intracranial pressure was measured by assessing the AFP by using the Rotterdam Teletransducer (and subsequently applying an established correction factor as AFP values are typically slightly higher than ICP values). This technique has been previously validated and demonstrates excellent correlation with intraventricular pressure. If the fontanel was closed or too small for measurement, ICP was measured directly from the ventricle. All measurements were obtained with patients asleep without sedation except for 4 patients who underwent intraventricular ICP measurement while in a state of general anesthesia on the day of the postoperative MR imaging. There were no significant differences noted between these pressure measurements. One concern regarding the way in which these measurements were obtained is whether anesthesia or failure to control for CO2 levels influenced the results. However, consecutive measurements were obtained under similar conditions and, as mentioned, measurements obtained after induction of general anesthesia were compared with those obtained while the child was asleep without sedation. Taken together, the methods used appear reasonable and the authors have, at least in part, attempted to minimize the influence of these variables. It is worth noting that 8 of the 15 patients in the authors’ series had ICP values of 15 cm H2O or less, a number that is often considered normal, whereas 3 of these patients had ICP values of 10 cm H2O. Despite these potentially normal ICP values, when treated with shunts the patients in question exhibited significant decreases in ICP, with concomitant increases in CBF. This could perhaps signify that while the ICP values appeared to be within normal limits, they may have actually been suboptimal for those particular patients. Although there was a wide range of preoperative ICP values, shunt treatment had a profound effect across all starting points, and resulted in changes after CSF diversion that are striking and believable. A second critical aspect of this study that warrants discussion concerns the methods used for assessing CBF. Is phase-contrast MR angiography an appropriate tool for measurement of CBF in this context? The authors clearly outline the technique used for the study in the text of the manuscript. Furthermore, they provide an extensive bibliography of prior work validating this method for measuring CBF and they correct for the physiological increase in CBF with increasing age. It appears that this method is indeed appropriate for measuring CBF in this context. Similar to their findings regarding ICP values, the marked improvement in CBF following CSF diversion is plausible. The authors state that CBF improves to normal levels following CSF diversion. Historical control data are used to support this assertion. The technique used for establishing normal baseline CBF, however, is important for historical control data to be appropriate for inclusion. The authors provide references where CBF is measured using various techniques including the 15O steady-state inhalation technique,3 SPECT using 133Xe,2 and most importantly using a

Hemorrhagic complications associated with stent-assisted coil embolization

There is little doubt that the development and implementation of intracranial stents such as the Neuroform (Boston Scientific) and more recently the Enterprise stent (Cordis Neurovascular) in the US has enabled the successful endovascular treatment of intracranial aneurysms previously not amenable to endovascular techniques. Stent-assisted coil embolization is an important technique in the armamentarium of most neurointerventionalists, although the proportion of cases in which it is used varies considerably among practitioners. Like any other technique, stent-assisted coil embolization is associated with risks and limitations, some of which have been incompletely defined. In this report, the highly experienced group from Emory University raises concerns about hemorrhagic complications associated with stent-assisted coil embolization and dual antiplatelet therapy in patients who also require periprocedural cerebrospinal fluid (CSF) diversion procedures.

Tension pneumoventricle following exposure of shunt chamber

Pneumocephalus is the presence of air within the intracranial vault. Intraventricular pneumocephalus, also known as pneumoventricle is relatively rare and commonly occurs following cerebrospinal fluid diversion procedures. This may occur immediately or be delayed. Although a small amount of pneumoventriculus is asymptomatic and may not require any treatment, when present under tension it needs to be evacuated. We present a case of tension pneumoventricle following exposure of the shunt chamber, which resulted in deterioration of the patients' neurological condition and required evacuation.

Patients with autosomal-recessive osteopetrosis presenting with hydrocephalus and hindbrain posterior fossa crowding

Osteopetrosis is a heterogeneous group of disorders characterized by abnormal bone sclerosis. As a result, patients often require input regarding various neurological complications. Although autosomal-recessive osteopetrosis has been associated with hydrocephalus, it has not been linked to hindbrain abnormalities. The authors present 3 cases of auto-somal-recessive osteopetrosis in patients who presented with hydrocephalus. In each of these patients, cerebrospinal fluid diversion procedures were required and hindbrain compression developed. To date, only 1 patient has needed craniocervical decompression due to symptomatic brainstem compression.

Visual outcomes comparing surgical techniques for management of severe idiopathic intracranial hypertension

The object of this study was to compare surgical techniques for management of visual loss in idiopathic intracranial hypertension (IIH) unresponsive to medical treatment. The published literature was reviewed using electronic and manual search techniques. Articles were categorized based upon the surgical procedure performed, including optic nerve sheath decompression (ONSD), also called optic nerve sheath fenestration; intracranial venous sinus stent placement; ventriculoperitoneal (VP) shunt placement; and lumboperitoneal (LP) shunt placement. Demographic data and visual outcome of the cumulative experience were compiled and compared for each type of surgical intervention. Seventeen patients treated by stent placement, 31 by VP shunt placement, 44 by LP shunt placement, and 252 patients by ONSD were identified in the literature; average follow-up ranged from 11.8 months for patients treated with stents to 57.2 months for those treated with LP shunts. Improved or resolved vision deficit was noted in 38.7% of patients after VP shunt placement, 47% of patients after stent placement, 44.6% of patients after LP shunt placement, and 80% of eyes after ONSD. Visual worsening was rare for all procedures evaluated. There is a paucity of information regarding visual outcomes from intracranial venous stent placement and cerebrospinal fluid diversion procedures. Visual outcomes from ONSD are better documented and appear to be superior to other surgical techniques for management of IIH. Further studies with improved data collection regarding visual outcomes are needed for surgical procedures other than ONSD in order to assess their possible value as treatments for visual loss in IIH.

The impact of antibiotic-impregnated catheters on shunt infection in children and neonates

Infection remains a significant problem with cerebrospinal fluid (CSF) diversion procedures. Antibiotic-impregnated shunt catheters (AIS) have been introduced to prevent infection, mainly in the early post-operative period when most infections occur. We evaluate the impact on infection rates in children following the introduction of catheters impregnated with rifampicin and clindamycin. The study was a retrospective analysis of all paediatric shunt procedures undertaken after the introduction of AIS systems in 2003. All procedures where a complete AIS system was implanted were included. For the purpose of analysis, shunt procedures were classified as de novo (group 1), clean revision (group 2) and following external ventricular drainage with either sterile CSF (group 3) or infected CSF (group 4). Results were compared to a historical cohort of shunt procedures undertaken before the introduction of AIS catheters. A total of 214 AIS were implanted in 150 children between October 2003 and December 2006. There were 4 infections in group 1 (8.5%), 6 infections in group 2 (5.3%) and 11 infections in groups 3 and 4 (20%). The historical control group comprised 77 shunts in 65 children. The infection rate in neonatal de novo shunts reduced from 27 to 10.4% following the introduction of AIS catheters. AIS catheters can reduce the number of shunt infections seen in clinical practice in certain subgroups. This has had a significant impact on the neonatal hydrocephalic population. The high risk of shunt infection after a period of external ventricular drainage raises the issue of emergence of bacterial resistance.