Slit Ventricle Syndrome Research Articles

The therapeutic strategies for the slit ventricle syndrome after cyst-peritoneal shunting for the temporal arachnoid cyst in children:six cases report and literatures review

Objective To investigate early diagnosis evidences, optimal therapeutic strategies and the prophylactic methods of the slit - ventricle syndrome（SVS） in the temporal lobe arachnoid cysts patients who received the cyst - peritoneal（CP） shunting.Method Six cases of SVS in the temporal lobe arachnoid cysts patients who received the CP shunting were treated by the senior author from Jan 2005 to Jan 2009.The radiological data, treatment process and therapeutic results were reviewed retrospectively.Results There were 4 male and 2 female patients.The mean age of presentation was 57.5 months.The final treatment was to change the original shunt with the programmable valve or combined with the ventricular - peritoneal（VP）shunting.All the symptoms of the patients disappeared totally, and the mean follow - up duration was 30mouths.Conclusions To use programmable shunts to substitute for the original shunt or combined with inserting a VP shunt is an optimal therapeutic method for SVS.The use of low - pressure shunts to treat the ararchoid systs should be abandoned unless dictated by specific indications. Key words: Slit ventricle syndrome; Ventriculoperitoneal shunt; Arachnoid cysts; Cystperitoneal shunting; Headache

Analysis of therapeutic choices for slit ventricle syndrome after cyst-peritoneal shunting for temporal arachnoid cysts in children

The goal in this study was to investigate early diagnostic evidence, optimal therapeutic strategies, and prophylactic methods for slit ventricle syndrome (SVS) in patients with temporal lobe arachnoid cysts who received cyst-peritoneal (CP) shunts. Six cases of SVS in patients with temporal lobe arachnoid cysts who received CP shunts were treated by the senior authors in 2 institutions between January 2005 and January 2009. The radiological data, treatment process, and therapeutic results were reviewed retrospectively. There were 4 boys and 2 girls, whose mean age at presentation was 4 years and 1 month. The main clinical symptoms were severe headache, nausea, vomiting, and decreasing eyesight. Radiological studies showed normal or slightly smaller than normal ventricles, and arachnoid cysts that had shrunk dramatically. The most effective treatment for SVS was to replace the original shunts with devices that had a programmable valve, or if this was unsuccessful, to replace the original shunts with ventriculoperitoneal (VP) shunts. All symptoms in these patients disappeared, and the mean follow-up duration was 24 months. The SVS presents more often in patients with hydrocephalus who undergo VP shunting. However, it is also a serious complication in patients with arachnoid cysts who receive a CP shunt. The SVS is not a single condition; rather, different pathophysiological conditions can underlie this complicated syndrome. Because there are no striking morphological changes on radiological studies of the SVS in the patients with CP shunts, it is not easy for this syndrome to be diagnosed in time and treated rationally. Misdiagnosis and delayed treatment usually occur. The use of programmable shunts or VP shunts to replace the original shunt is an optimal therapeutic choice. The use of low-pressure shunts to treat arachnoid cysts should be abandoned unless dictated by specific indications.

Modified bilateral subtemporal decompression for resistant slit ventricle syndrome

Slit ventricle syndrome (SVS) remains a major problem for early shunted children. Several conservative and surgical treatment paradigms have been suggested; however, there is no consensus on the optimal surgical treatment. We present our experience using bilateral subtemporal decompressions with dura and arachnoid opening for the treatment of a subgroup of children with severe and resistant SVS. Fifteen children with severe and resistant SVS underwent a modified bilateral subtemporal craniectomy, with dura and arachnoid opening. Their clinical and radiological data were retrospectively reviewed. Seven (46.6%) patients had a complete recovery from their symptoms with a follow-up of 5.9 ± 2.6years.The remaining eight (53.3%), underwent additional surgeries. Four (26.6%), had a single proximal shunt revision after dilatation of their ventricles. Following these procedures these four children are well and stable with a follow-up of 1.8 ± 2years. The other four had further cranial vault expansion, one of which was followed by a proximal shunt revision. Thus, 11 of these 15 patients (73.4%) had a very good outcome, attributable to this technique, with a mean follow-up of 4.5 ± 3years. Modified bilateral subtemporal decompression with dura and arachnoid opening yields a high cure rate for severe and resistant slit ventricle syndrome. Proximal shunt revision may be safely performed in a subset of patients that dilate their ventricles following the procedure. Further cranial expansion may be reserved for children with recurrent SVS symptoms who do not respond to STD and remain with very small ventricles.

Hydrocephalus shunt practice of experienced pediatric neurosurgeons

The objective of this study is to evaluate the ways experienced pediatric neurosurgeons insert ventriculo-peritoneal shunts and manage the shunted children afterward. Seven pediatric neurosurgeons with extensive experience in hydrocephalus were surveyed about their choice of shunts, methods of shunt insertion, shunt follow-ups, management of incidental ventriculomegaly, and prevention of slit-ventricle syndrome. The author completed the survey also. No particular shunt was used by a majority of respondents, although differential pressure valves were used most often. Adjuncts to insert the ventricular catheter were used by half. Shunt catheters were inserted frontally in half and posteriorly in half. No one obtained annual follow-up scans after 5 years of age, and no one operated on asymptomatic children with ventriculomegaly except perhaps in spina bifida cases. No techniques were identified to prevent slit-ventricle syndrome, but respondents emphasized the need for reticence in initial shunt insertions and in shunt revisions. There are substantial variations among extremely experienced pediatric neurosurgeons in their choice of shunts and their techniques of shunt insertion but reasonable uniformity in their frequency of follow-up, in not-obtaining routine scans after age five, and in rarely revising asymptomatic children. Methods to accurately position ventricular catheters and to prevent slit-ventricle syndrome need to be evaluated in multicenter studies.

Lumbar peritoneal shunt

A lumbar peritoneal (LP) shunt is a technique of cerebrospinal fluid (CSF) diversion from the lumbar thecal sac to the peritoneal cavity. It is indicated under a large number of conditions such as communicating hydrocephalus, idiopathic intracranial hypertension, normal pressure hydrocephalus, spinal and cranial CSF leaks, pseudomeningoceles, slit ventricle syndrome, growing skull fractures which are difficult to treat by conventional methods (when dural defect extends deep in the cranial base or across venous sinuses and in recurrent cases after conventional surgery), raised intracranial pressure following chronic meningitis, persistent bulging of craniotomy site after operations for intracranial tumors or head trauma, syringomyelia and failed endoscopic third ventriculostomy with a patent stoma. In spite of the large number of indications of this shunt and being reasonably good, safe, and effective, very few reports about the LP shunt exist in the literature. This procedure did not get its due importance due to some initial negative reports. This review article is based on search on Google and PubMed. This article is aimed to review indications, complications, results, and comparison of the LP shunt with the commonly practiced ventriculoperitoneal (VP) shunt. Shunt blocks, infections, CSF leaks, overdrainage and acquired Chiari malformation (ACM) are some of the complications of the LP shunt. Early diagnosis of overdrainage complications and ACM as well as timely appropriate treatment especially by programmable shunts could decrease morbidity. Majority of recent reports suggest that a LP shunt is a better alternative to the VP shunt in communicating hydrocephalus. It has an advantage over the VP shunt of being completely extracranial and can be used under conditions other than hydrocephalus when the ventricles are normal sized or chinked. More publications are required to establish its usefulness in the treatment of wide variety of indications.

Prevention of ventricular catheter obstruction and slit ventricle syndrome by the prophylactic use of the Integra antisiphon device in shunt therapy for pediatric hypertensive hydrocephalus: a 25-year follow-up study

This 25-year follow-up study was performed on 120 children with hypertensive hydrocephalus to evaluate the influence of the early prophylactic implantation of the Integra antisiphon device (ASD, Integra Neurosciences Ltd.) on the rate of proximal shunt obstructions and the frequency of symptomatic slit ventricle syndrome (SVS). The adaptability of the ASD to growth, proper positioning of the ASD as a necessity for its successful performance, and the 3 phases of SVS development are discussed. Since 1978, the ASD has consistently been implanted either at the time of primary shunt insertion (66 neonates, mean follow-up 11 years) or during revisions of preexisting shunts (54 children, mean follow-up 11.8 years). The complication rate among the 54 children before ASD implantation (mean follow-up 8.3 years) was compared with that among all 120 patients once an ASD had been inserted. Shunt complications were documented as ventricular catheter, distal catheter, and infectious complications. The study revealed a significant long-term reduction in ventricular catheter obstructions and hospitalizations due to intermittent intracranial hypertension symptoms (symptomatic SVS) after both primary and secondary ASD implantation. Data in the study suggest that the high rate of ventricular catheter obstruction in pediatric shunt therapy is caused by hydrostatic suction induced by differential-pressure valve shunts during mobilization of the patient and that the development of a SVS can be traced back to this constant suction, which causes chronic CSF overdrainage and ventricular noncompliance. Recurrent ventricular catheter obstruction and SVS can be prevented by prophylactic supplementation of every shunt system with an ASD. To inhibit chronic hydrostatic suction, to prevent overdrainage and proximal shunt obstruction, and to avoid SVS and thus improve the patient's quality of life, the prophylactic implantation of an ASD in every pediatric hydrocephalus shunt is recommended.

Clinical Experience of Ventriculoperitoneal Shunt Dysfunction in a Patient with Hydrocephalus after Brain Injury: A casereport

We report a case of an adult patient with post-traumatic hydrocephalus who was treated using a ventriculoperitoneal (VP) shunt with a fixed pressure setting valve. Slit ventricle syndrome was found two months later and an antisiphon device (ASD) was added. A fixed pressure valve with ASD was found not to be optimal in terms of improving his neurological symptoms and a programmable valve system was therefore implanted with a pressure setting of 140 mmH2O in the beginning. The valve then was gradually programmed to reduce down to 70 mmH2O over two months. This case demonstrates that selection of a shunting device is difficult, and even after deliberate selection and use of an antisiphon device, slit ventricle syndrome could not be avoided. In addition, the patient in this case had increased episodes of seizure that were associated with acute intracranial hypertension; these were caused by obstruction. Good clinical monitoring of such patients is needed because of the intermittent nature of the high intracranial pressure symptoms. Notwithstanding this, minor complications involving shunt dysfunction may be neglected once the initial treatment has been completed in the neurosurgical ward and the patient has been transferred to a rehabilitation ward. It should be noted that this patient was very sensitive to over-drainage and siphoning was required in order to generate an effective transmantle pressure gradient. Thus, the highest valve setting available was used at the beginning of treatment and this was followed by a methodically lowering of the opening pressure based on the clinical response and computed tomography findings. Overall, the programmable valve shunt system would seem to be more effective when there is a need to deal with shunt dysfunction non-invasively.

Reply to the comments by Dr. Udayakumaran on our article “A late complication of CSF shunting: acquired Chiari I malformation”

Dear Editor: We are grateful to Dr. Udayakumaran for his interest in our paper [1] on secondary Chiari I malformation developing in patients shunted for congenital hydrocephalus or cyst. As described in the article, we interpreted this anomaly (“acquired” because in no case it was present at the time of the initial diagnosis and treatment) as the result of CSF venting from the intracranial, mainly supratentorial, space with secondary reduction of the intracranial volume and consequent “bidirectional” herniation of the cerebellum, downward into the cervical canal and upward into the tentorial notch. CSF shunt function was described as “satisfactory” with reference to the correction of the ventricular dilation, obviously not with reference to the tonsil herniation. In our opinion, disproportion between the exceeding cranial volume and the reduced intracranial content is sufficient to explain the novel appearance of this condition, without the necessity to take into consideration the slit ventricle syndrome. Everyone experiences cases of slit-like ventricles, with or without clinical manifestation; anyway, tonsillar herniation is quite exceptional in these cases. Although the adopted surgical strategy was, for some regards, identical to that traditionally adopted for the treatment of the slit ventricle syndrome, this does not imply that the anomaly described is comparable to that. Coming to the case proposed for discussion and comparative analysis, we have some difficulties in considering that tonsillar herniation observed by the author similar to our own cases. In his case, the radiological picture suggests a poorly functioning CSF shunt with secondary tonsillar herniation, rather than a satisfactorily working shunt (as described in our cases). Certainly this topic remains matter of debate and further contributions are appreciated to highlight this intriguing condition in shunted chronic hydrocephalic subjects

Post CSF shunting Chiari I malformation—sequel or complication? Hypertension or hypotension?

Dear Editor: We read with great interest the article by Caldarelli et al. [1]. It is an excellent thought-provoking and truly intriguing “late complication” of CSF shunt surgery. However, we would like to take issue on few pertinent points. The authors have tried to explain this “developmental” anomaly as the result of modifications of skull growth induced by shunt, and consider this finding as a “variant” of slit ventricle syndrome. Here, we illustrate a preterm infant shunted at fourth month of infancy for posthaemorrhagic hydrocephalus, with MRI at 11 months of age showing an acquired postshunt Chiari I malformation (Fig. 1). Is “posterior fossa disproportion” enough to explain tonsillar herniation of such an early onset? The authors have not explored the possibility of intracranial hypotension secondary to shunting, primarily causing Chiari I malformation. Chiari I malformation and syringomyelia [3–5] have been described in association with cerebral hypotension, probably secondary to the sagging induced by the lack of buoyant action of intracranial CSF (one patient in the authors’ series had syringomyelia). Relief of hydrocephalus alleviating tonsillar herniation [2, 6] and contrary of shunt failure causing disappearance of tonsillar herniation [personal communication, Swift. D, March 27, 2009] have been well documented. In addition to tonsillar herniation, the authors describe thickening of the skull vault and base, increase in paranasal sinuses volume, and reduced ventricular volume, as effects of “satisfactorily working CSF shunt”. It is therefore not surprising that in this series, there is a lack of correlation of the radiological findings to the symptomatology (some patients had severe Chiari I but were asymptomatic) and the patient’s response to surgery. Out of six patients who underwent surgical treatment, only one patient underwent suboccipital craniectomy and still developed syringomyelia. Additionally, five patients underwent cranial vault enlargement, implying the posterior fossa disproportion has never been addressed or implicated directly in the authors’ series. Fig. 1 Sagittal MR of a shunted premature infant with posthaemorrhagic hydrocephalus with evidence of acquired Chiari I malformation

The use of noninvasive electromagnetic neuronavigation for slit ventricle syndrome and complex hydrocephalus in a pediatric population

The aim of this study was to prospectively evaluate the use of noninvasive electromagnetic neuronavigation in children, in particular its use in complex hydrocephalus and slit ventricle syndrome. Prospective data was collected from all pediatric patients undergoing insertion of ventriculoperitoneal shunts using electromagnetic frameless neuronavigation from January 2006 to November 2007. Twenty-three patients fulfilled the study criteria. All ventricles were cannulated on the first pass. There were no immediate or early postprocedural complications. All but 1 patient had resolution of symptoms (mainly chronic headache) on follow-up (median 7 months, range 1-17 months). The proximal revision rate was 9% (2 of 23 patients). One patient required distal catheter revision. Infection occurred in 1 patient. Electromagnetic neuronavigation using a frameless and pinless system is especially suited for pediatric patients. The authors hypothesize that successful placement of ventricular catheters will reduce morbidity and improve shunt longevity.

Cranial Vault Expansion in the Management of Postshunt Craniosynostosis and Slit Ventricle Syndrome

Slit ventricle syndrome and postshunt craniosynostosis are uncommon complications after shunting procedures for congenital hydrocephalus. Slit ventricle syndrome occurs as a complication in 1 to 5 percent of patients after shunting procedures for hydrocephalus during infancy. These patients usually have had a shunt in place for years, with overdrainage of cerebrospinal fluid resulting in very small ventricles. Excessive intracranial decompression may result in ventricular collapse with the formation of slit-like ventricles and cranial vault collapse with secondary craniosynostosis. A retrospective review of 12 patients who had undergone cranial vault expansion for management of postshunt craniosynostosis and slit ventricle syndrome refractory to other treatment modalities was performed. All patients had initially been shunted for congenital hydrocephalus and subsequently underwent a mean of 4.9 shunt revisions before cranial vault expansion. All 12 patients demonstrated decreased ventricular volume, with noncompliant slit-like ventricles in nine of these patients. Five patients demonstrated pancraniosynostosis, three patients demonstrated multiple sutural fusion, and isolated sagittal synostosis occurred in two patients. Two patients appeared to have "functional" synostoses with narrowed, overlapping sutures that were not actually fused. Eleven patients underwent bilateral fronto-orbital advancement with frontotemporoparietal expansion; one patient underwent only posterior vault expansion. Seven of the 12 patients required a mean of 2.3 shunt revisions after cranial vault expansion; five patients did not require subsequent revisions. Improvement in cranial vault shape was achieved in all 12 patients, as was improvement of neurologic symptoms in nine of the 12 patients. Cranial vault expansion is a useful approach in the management of the restricted cranium associated with slit ventricle syndrome and postshunt craniosynostosis. This approach resulted in a decreased need for shunt revisions and improvement of neurologic symptoms and cranial vault shape.

Slit Ventricle Syndrome and Headache

The management of slit ventricle syndrome and shunt-related headache is reviewed by researchers at the Barrow Neurological Institute, St Joseph's Hospital, Phoenix, AZ.

Shunt-related headaches: the slit ventricle syndromes

The purpose of this work is to review the pathophysiology and treatment of severe headache disorders in patients having a shunt for hydrocephalus. The literature on the management of the slit ventricle syndrome is reviewed as well as an assessment of personal experiences over a 30-year period in the management of severe headache disorders in shunted patients. If the slit ventricle syndrome is defined as severe, life-modifying headaches in patients with shunts and normal or smaller than normal ventricles with ventricular shunts for the treatment of hydrocephalus, there are five different pathophysiologies that are involved in the process. These pathologies are defined by intracranial pressure measurement as severe intracranial hypotension analogous to spinal headaches, intermittent obstruction of the ventricular catheter, intracranial hypertension with small ventricles and a failed shunt (normal volume hydrocephalus), intracranial hypertension with a working shunt (cephalocranial hypertension), and shunt-related migraine. The treatment of these conditions and identifying patients with each condition are facilitated by attempting to remove the shunt. Following the analysis of attempts to remove shunts, there are three possible outcomes. In about a quarter of patients, the shunt can be removed without having to be replaced. This is most common in patients treated in infancy for post-hemorrhagic hydrocephalus or patients shunted early after or before brain tumor surgery. Another half of patients have increased intracranial pressure and enlarged ventricles. In these patients, there is an 80% success rate for endoscopic third ventriculostomy. Finally, the most severe form of the slit ventricle syndrome involves intracranial hypertension without ventriculomegaly, which is managed optimally by shunt strategies that emphasize drainage of the cortical subarachnoid space such as lumbo-peritoneal shunts or shunts that include cisterna magna catheters.

SURGICAL MANAGEMENT OF ADULT HYDROCEPHALUS

The management of adult hydrocephalus spans a broad range of disorders and ages. Modern management strategies include endoscopic and adjustable cerebrospinal fluid shunt diversionary techniques. The assessment and management of the following clinical conditions are discussed: 1) the adult patient with congenital or childhood-onset hydrocephalus, 2) adult slit ventricle syndrome, 3) multicompartmental hydrocephalus, 4) noncommunicating hydrocephalus, 5) communicating hydrocephalus, 6) normal pressure hydrocephalus, and 7) the shunted patient with headaches. The hydrodynamics of cerebrospinal fluid shunt diversion are discussed in relation to mechanisms of under- and overdrainage conditions. A rationale for the routine implementation of adjustable valves for adult patients with hydrocephalus is provided based on objective clinical and experimental data. For the condition of normal pressure hydrocephalus, recommendations are offered regarding the evaluation, surgical treatment, and postoperative management of this disorder.

Endoscopic stent placement for treatment of secondary bilateral occlusion of the Monro foramina following endoscopic third ventriculostomy in a patient with aqueductal stenosis

Nontumoral bilateral occlusion of the Monro foramina is a rare clinical condition. Treatment includes shunt placement, endoscopic procedures, or both. The authors describe the case of a 22-year-old woman who had previously undergone placement of a ventriculoperitoneal shunt via a right frontal approach for management of triventricular dilation due to aqueductal stenosis. Six years postoperatively she presented with right-sided slit-ventricle syndrome and stenosis of the right Monro foramen, which was treated with an endoscopic third ventriculostomy and fenestration of the septum pellucidum. Two years later she presented with bilateral lateral ventricular dilation. Inspection of the right lateral ventricle with a fiberscope revealed occlusion of the septum pellucidum fenestration; on observation, the right Monro foramen was covered by thick, tough granulation tissue and the left was occluded by thin membranous tissue. Repeated fenestration of the septum pellucidum and left Monro foraminoplasty were therefore performed by perforating this thin tissue. A stent was then introduced into the third ventricle via the right lateral ventricle, the fenestration in the septum pellucidum, and the left Monro foramen. The authors note that fiberscopes are in general more maneuverable than rigid endoscopes and conclude that they are particularly useful for the treatment of this type of hydrocephalus.

Predicting slitlike ventricles in children on the basis of baseline characteristics at the time of shunt insertion

Slit ventricle syndrome (SVS) is a delayed complication of shunt insertion and occurs only in children with slitlike ventricles after shunt placement. Although SVS appears to be related to early shunt placement, its predisposing factors are largely unknown. Baseline data in 737 children who had received shunts were obtained from the databases of two previous clinical trials. Ventricular size before shunt placement and at the last routine follow up was measured using the frontooccipital horn ratio (FOHR). Ventricles with an FOHR less than or equal to 0.2 at follow up were classified as slitlike ventricles. A univariate analysis was performed on data obtained in children with more than 1 year of clinical and radiographic follow up to identify risk factors for developing slitlike ventricles. These results were entered into a multivariate analysis to identify independent predictors of slitlike ventricles. Two hundred forty-four children had more than 1 year of clinical and radiographic follow-up data. The 23 patients (9.4%) who developed slitlike ventricles had shunts inserted at a younger age (42 compared with 134 days, p = 0.09) and were more likely to have developed hydrocephalus secondary to infection (37.5%), head injury (25.0%), or aqueductal stenosis (22.2%). Slitlike ventricles were seen in 10.8% of patients with differential-pressure valves, 10.5% of patients with Delta valves, and 3.6% of patients with Orbis-Sigma valves (p = 0.007). Regression analysis supported the role of the valve type in developing slitlike ventricles. Age at shunt insertion and valve type appear to be the modifiable risk factors for developing slitlike ventricles. If the authors of subsequent studies can further validate these conclusions, slow-draining valves and delayed shunt insertion might be used to decrease the incidence of slitlike ventricles and SVS.

ADJUSTABLE SHUNT VALVE REPROGRAMMING AT HOME

Abstract OBJECTIVE Shunt valve resistance changes using a specialized magnetic programming device permit noninvasive changes to cerebrospinal fluid drainage. In selected cases between 2001 and 2005, patients and families used shunt valve programming devices at home. This study examines the safety and efficacy of this practice. METHODS We conducted a retrospective review of the medical records of patients who had been given a shunt valve-programming device for home use. A survey was mailed to patients or family members requesting information regarding their experiences with the shunt valve programming device. Patient and family responses were tabulated and a statistical analysis was performed. RESULTS Twenty patients or families returned the survey. The median patient age was 19.6 years (range, 6–48 yr); 25% were male. Seventeen patients had pseudotumor cerebri, one had an arachnoid cyst, and two had slit ventricle syndrome. Fifteen patients had lumboperitoneal shunts, one had a ventriculoperitoneal shunt, three had cisterna magna shunts, and one had an arachnoid cyst-to-peritoneal shunt. No adverse events were attributable to the use of the home shunt valve programmer. Thirty-five percent of respondents used the programmer at least once every week, 40% used the programmer between once a week and once a month, and 25% used the programmer less frequently than once per month. Overall, 85% of respondents reported that they benefited “very much” from the use of a home shunt valve programmer and 15% of respondents benefited “somewhat.” CONCLUSION Providing shunt valve programming devices to selected patients for home use is a safe practice associated with high patient satisfaction. However, the selection of appropriate patients, comprehensive patient education, and close patient-physician communication are crucial to the success of this practice.

Shunts vs endoscopic third ventriculostomy in infants: are there different types and/or rates of complications?

The decision-making process when we compare endoscopic third ventriculostomy (ETV) with shunts as surgical options for the treatment of hydrocephalus in infants is conditioned by the incidence of specific and shared complications of the two surgical procedures. Our literature review shows that the advantages of ETV in terms of complications are almost all related to two factors: (a) the avoidance of a foreign body implantation and (b) the establishment of a 'physiological' cerebrospinal fluid (CSF) circulation. Both these kinds of achievements are particularly important in infants because of the relative high rate of some intraoperative (i.e. abdominal) and late (secondary craniosynostosis, slit-ventricle syndrome) shunt complications in this specific subset of patients. On the other side, the main factor which is claimed against ETV is the relatively high risk of immediate mortality and neurological complications. Clinical manifestations of neurological structure damage seem to be more frequent in infants, probably due to the more relevant effect of parenchymal and vascular damage in this age group; however, both the immediate mortality and neurological damage risk of ETV procedures should be weighted against the long-term mortality and the late neurological damage which is not infrequently described as a consequence of shunt malfunction and proximal shunt revision procedures. Infections are possible in both ETV and extrathecal CSF procedures, especially in infants. However, the incidence of infective complications is significantly lower in case of ETV (1-5% vs 1-20%). Moreover, different from shunting procedures, infections in children with third ventriculostomy have a more benign course, being generally controlled by antibiotic treatment alone.

Severe intracranial hypertension in slit ventricle syndrome managed using a cisterna magna–ventricle–peritoneum shunt

Severely increased intracranial pressure (ICP) can be life threatening in patients who had previously undergone shunt treatment but who do not experience ventricular enlargement. The authors analyzed the utility of placing shunts into the cisterna magna concurrently with ventricular shunts in patients who were not candidates for lumboperitoneal (LP) shunt placement. Ten patients treated with cisterna magna-ventricle-peritoneum (CMVP) shunts for complex problems of shunt function were reviewed retrospectively. All patients had documented increases in ICP and ventricles that did not expand despite life-threatening increases (> 80 mm Hg in one case) in ICP. Between 1995 and 2003, 10 patients (four males and six females, age range 4-32 years) were identified as having life-threatening increases in ICP despite small or slit-like ventricles on imaging studies. Each episode was documented with intraparenchymal pressure monitoring. All patients had documented ventricular catheter failures at the time of the intervention, and all had undergone at least one previous attempt to treat the condition with a valve upgrade and replacement of the ventricular catheter. Three patients had achondroplasia, four had spina bifida, and three had a preexisting Chiari malformation Type I. All patients improved after the procedure, and none suffered permanent complications. For at least 48 hours after surgery, all patients underwent intraparenchymal monitoring of ICP (an intraparenchymal monitor was used that documented normal ICP). The CMVP shunts are an excellent option for patients who are not candidates for LP shunts but who have high ICP and ventricles that do not enlarge at shunt failure. The ability to access the spinal fluid in the cortical subarachnoid space presumably accounts for this success.

Shunt-related craniocerebral disproportion: treatment with cranial vault expanding procedures

Two patients with intracranial arachnoid cysts, one with myelomeningocele-hydrocephalus and the other with a subdural fluid collection, were given a cerebrospinal (CSF) extracranial shunt. All four patients developed features of CSF overdrainage following shunting and were treated by cranial vault expanding procedures. Before undergoing decompressive craniotomy, the patients were treated by a variety of procedures, including changing of obstructed ventricular catheters (n=4), insertion or upgrading of programmable valves (n=3), and foramen magnum decompression (n=1). Clinical manifestations of these four patients were attributed to craniocerebral disproportion caused by chronic and progressive skull changes due to dampening of the CSF pulse pressure, which is necessary for maintaining normal cranial growth. On the basis of our previous experience with expanding craniotomies in cases of minimal forms of craniosynostosis, we treated these patients with bilateral parietal craniotomies, with satisfactory results. In conclusion, biparietal decompressive craniotomy constitutes a useful and safe procedure for relieving the clinical manifestations of some CSF overdrainage syndromes, especially in cases with slit-ventricle syndrome and craniocerebral disproportion that prove to be refractory to simpler management procedures.