Seven years of clinical experience with the programmable Codman Hakim valve: a retrospective study of 583 patients

OBJECT: The goal of this study was to assess the value of the Codman Hakim programmable valve to settings in the range of 30 to 200 mm H2O. This valve can be adjusted noninvasively for cerebrospinal fluid (CSF) drainage. METHODS: The authors conducted a single-center retrospective study of 583 patients (421 adults and 162 children) suffering from hydrocephalus of various causes (379 patients), normal-pressure hydrocephalus (174 patients), arachnoid cyst (14 patients), and pseudotumor cerebri (16 patients). In all cases a Codman Hakim programmable valve was implanted; in 82.8% of cases it was included during the patient's first shunt implantation. In 42.4% of the cases valve pressure adjustment was required at least once (mean number of adjustments 1.2, maximum 23). The patients' clinical status improved after 64.6% of pressure adjustments. Accidental resetting of opening pressure, other than that caused by magnetic resonance (MR) imaging, was uncommon. Because MR imaging caused resetting in 26.8% of cases in which it was used, it was deemed mandatory to obtain an x-ray film after MR imaging. Valve malfunction, blockage, or adjustment difficulties occurred in 2% of valves implanted, and nontraumatic subdural fluid collections were demonstrated in 5.1% of patients (13 of whom were treated by valve pressure adjustment alone). Five-year shunt survival was 53.1% for first-time shunt implantations. The shunt infection rate was 8.5% of valve implantations. Catheter-related complications and shunt-related infections were the main reasons for surgical revision and the major cause of shunt failure. At follow-up review, 97% of children and 90% of adults had improved. CONCLUSIONS: Because one cannot know in advance which case will turn out to be complicated, the authors' preference is to use the Codman Hakim programmable valve for all conditions in which CSF should be drained.     

Laboratory Testing of Hydrocephalus Shunts – Conclusion of the U.K. Shunt Evaluation Programme

Summary.  16 models of valves, currently in use in the U.K., have been tested long-term in the U.K. Shunt Evaluation Laboratory according to the protocol based on the new ISO 7197 standard. Valves tested were:  Medtronic PS Medical: Delta Valve, Flow Control and Lumbo-Peritoneal Shunt  Heyer-Schulte Nero-Care: In-line, Low Profile and Pudenz Flushing Valve  Codman: Codman-Hakim Programmable, Hakim Precision, Accu-Flo, Holter, Uni-Shunt, and siphon-preventing device – SiphonGuard  NMT: Orbis-Sigma Valve, Omni-Shunt and Hakim Valve  Sophysa: Sophy Programmable Valve  Radionics: Contour-Flex Valve.  The majority of the valves had a non-physiologically low hydrodynamic resistance (with the exception of Orbis-Sigma, PS Lumbo-Peritoneal and Heyer-Schulte In-Line). This may result in overdrainage both related to posture and during nocturnal cerebral vasogenic waves. A long distal catheter increases the resistance of these valves by 100–200%. Drainage through valves without siphon-preventing mechanism is very sensitive to body posture. This may produce grossly negative intracranial pressure after implantation. A few shunts (Delta, Low Profile and Pudenz-Flushing with Anti-Siphon Devices) offer a reasonable resistance to negative outlet pressure, and hence potentially might prevent complications related to overdrainage. On the other hand, valves with siphon-preventing devices may be blocked by raised subcutaneous pressure (exception: SiphonGuard, but this device may block the drainage because of its faulty design). In most of the silicone-diaphragm valves, closing pressure varied and reached values lower than that specified by the manufacturer (exception: Heyer-Schulte Pudenz Flushing Valve). All programmable valves are susceptible to overdrainage in the upright body position. Programmed settings may be changed by external magnetic fields. Most shunts are very sensitive to the presence of small particles in the drained fluid.  The behavior of a valve revealed during such testing is of immediate relevance to the surgeon and may not be adequately described in the manufacturer's product information. These results are also relevant to the assessment of shunt function in-vivo using an infusion test. Published online June 20, 2002     

Diamox® Challenge Test to Decide Indications for Cerebrospinal Fluid Shunting in Normal Pressure Hydrocephalus

Summary ? Objective. The indications for cerebrospinal fluid (CSF) shunting in patients with normal pressure hydrocephalus (NPH) have not been established. Establishment of clear-cut indications for this procedure is essential to ensure cost-effective, and safe treatment. We report the usefulness of the Diamox^? challenge test in evaluating indications for CSF shunting in patients with NPH.  Methods. Pre- and post-operative responses in cerebral blood flow (CBF) and intracranial pressure (ICP) to intravenous administration of Diamox^? 1000mg (Diamox^? administration) were analysed in 41 patients with NPH who were treated by ventriculoperitoneal (VP) shunt with a programmable valve and an on-off valve.  Results. The preoperative response of ICP to Diamox^? administration was more than 10 mmHg in most patients in whom the shunt was effective (shunt effective group), however, it was less than 10 mmHg in most patients in whom the shunt was ineffective (shunt non-effective group). Furthermore, the postoperative response of ICP to Diamox^? administration decreased to less than 10 mmHg in most patients in the shunt effective group. The increases in CBF in response to Diamox^? administration were similar in the two groups both before and after placement of the VP shunt.  Conclusion. Patients in whom ICP increased by more than 10 mmHg in response to Diamox^? administration were regarded to have poor CSF circulation and to thus be candidates for CSF shunting. The Diamox^? challenge test is a simple, safe procedure, useful in evaluating the response to treatment.     

Efficacy of Lumbo-Peritoneal Versus Ventriculo-Peritoneal Shunting for Management of Chronic Hydrocephalus Following Aneurysmal Subarachnoid Haemorrhage

Summary ? Background. The clinical usefulness of lumboperitoneal (LP) shunts in selecting patients with communicating hydrocephalus after aneurysmal subarachnoid haemorrhage (SAH) was compared with that of ventriculoperitoneal (VP) shunts.  Method. Chronic hydrocephalus was defined as clinically and radiographically demonstrated hydrocephalus which lasted 3 weeks or longer after the original haemorrhage and which required shunting. Indications for a CSF shunt were assessed on the basis of neurological symptoms and signs, CT findings, and isotope cisternogram findings. The patients were treated with either LP or VP shunts. A significant response to shunting was defined as an improvement of function to a higher grade. The functioning of the shunt was evaluated by the location of the catheter on x-ray studies, CT features, and isotope cisternograms. The operation groups were checked for comparability of demographic and clinical variables including age, Fisher grade, hypertension, vasospasm, shunt interval, preshunt functional grade, and CT findings. A comparative analysis of the outcome was carried out between the two operation groups.  Findings. Fifty-six patients underwent shunt placements (LP shunts: 22, VP shunts with medium pressure valve: 2, VP shunts with high pressure valve: 32). There was no statistically significant difference in patient demographics and clinical characteristics between the patients with LP shunts and those with VP shunts. A follow-up time of 3 months to 8 years revealed clinical improvement in 11 cases (50.0%) of patients with LP shunts and 31 cases (91.1%) in VP shunts was seen (Fisher's exact test, P<0.005).  Interpretation. These findings suggest that VP shunts are a better choice of treatment than LP shunts in treating chronic hydrocephalus after aneurysmal SAH.     

A clinical audit of the Hakim programmable valve in patients with complex hydrocephalus

The objective of the investigation was to determine the pattern of use of the Hakim (Medos) programmable valve implanted in patients with complex hydrocephalus and their clinical outcome. A prospective audit of patients with complex hydrocephalus undergoing Hakim programmable valve implantation between 1989 and 1994 in the United Kingdom and Ireland, was followed-up for a minimum of 5 years. Surgical practice and complications were audited together with clinical outcome. One-hundred-and-thirty-nine patients (80 male, 59 female; mean age 43.4 years; median 47 years; range 1 month-84 years) with complex hydrocephalus due to a wide range of aetiologies were implanted with the Hakim programmable valve. Eighty-eight (63%) had large or massive ventricles prior to implantation; seven (5%) were slit. Fifty-five (40%) had previously been shunted with a fixed pressure system. One-hundred-and-thirty-one (94%) of the Hakim programmable shunts were ventriculoperitoneal; four (3%) ventriculoatrial; two (1.4%) cystoperitoneal; and two (1.5%) lumboperitoneal. The initial opening pressure selected ranged from 50 to 200 mmH2O (median 120). Valves were reprogrammed on average 1.7 times with 143 reprogrammings in the first year after implantation; 67 in the second; 19 in the third; three in the fourth; two in the fifth. Forty-nine (36%) valves were never reprogrammed after implantation. During the 5 years audit period, there were 70 (50%) shunt revisions, 40 of which were performed within 1 year of implantation. Thirty-six (27%) shunts were removed. There were 24 (18%) shunt infections. Subdural collections were identified in 37(27%) patients after Hakim programmable valve implantation; 10 (27%) required surgical drainage. Five (3.7%) patients developed symptomatic slit ventricles after Hakim programmable valve implantation. Headache was improved following reprogramming in 27(71%) of the 38 patients with refractory headache. After Hakim programmable valve implantation, patients underwent an average of 4.6 CT scans (range 1-25); 0.3 MRI (range 1-5) and 1.8 skull radiographs (range 1-20). The mean hospital stay per patient over 5 years was 26 days (range 1-110 days). Five years after implantation, the Glasgow Outcome scale was favourable in 64% of patients. The Hakim programmable valve is useful in the management of patients with complex hydrocephalus and may reduce the need for shunt revision for headache. Non-haemorrhagic, post-shunting, subdural collections identified on routine postoperative CT may be treated by reprogramming.     

Non-obstructive hydrocephalus associated with intracranial schwannomas: hyperproteinorrhachia as an etiopathological factor?

Summary.  Background: This series illustrates the association of communicating hydrocephalus with intracranial non-obstructive schwannomas. This association has commonly been observed, however it has only been reported once previously. Moreover, in all the patients we present, hyperproteinorrhachia was a common denominator. This finding may therefore be the underlying mechanism for hydrocephalus.  Method and findings: Seven patients presenting with intracranial schwannomas along with non-obstructive hydrocephalus and hyperproteinorrhachia are reported. Six had a vestibular schwannoma and presented with a unilateral deafness and various degrees of gait disturbance, urinary incontinence and neuropsychological impairment. Due to their advanced ages, these patients underwent a ventriculo-peritoneal shunt, and their symptoms related to hydrocephalus resolved.  One patient that suffered from hemifacial dysesthesia and memory deficits presented with a non-obstructive trigeminal schwannoma. In this case the tumour was removed and the hydrocephalus was consequently reversed, and the CSF protein content normalized.  Interpretation: The constant finding of hyperproteinorrhachia in all these patients suggests that a high CSF protein content may be the underlying cause of hydrocephalus through a speculative mechanism of decreased CSF resorption. Published online January 14, 2003  Correspondence: Jocelyne Bloch, Service de Neurochirurgie, BH-13, 1011 Lausanne CHUV, Switzerland.     

Serum- and CSF-concentrations of brain specific proteins in hydrocephalus

Summary.  Object: Hydrocephalus is characterised by elevated intracranial pressure (ICP) and gives rise to brain damage. The aim of this study was to investigate the significance of brain specific proteins as markers in the evaluation of brain damage in hydrocephalus. Therefore we determined the levels of four brain specific proteins in cerebrospinal fluid (CSF) and serum of symptomatic hydrocephalic patients.  Methods: During 41 CSF shunt-operations (both primarily placed shunts and shunt-revisions) CSF and blood samples were obtained and analysed for neuron-specific enolase (NSE), S-100b, glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP). The results were compared with an age-matched control group. Patients with varying clinical symptoms, denoting different levels of increased intracranial pressure prior to surgery, were included in this study.  Results: We observed significantly increased CSF-levels of S-100b and GFAP in the hydrocephalic patients, whereas NSE and MBP were markedly increased only in patients with very severe symptoms. Serum levels of all proteins were only minimally increased and did not correlate with CSF-levels. The slightly elevated levels of CSF-NSE in most of the patients suggest only subtle neuronal damage, which is not related to permanent neurological symptoms. The elevated levels of S-100b and GFAP are indicative of a reactive astrogliosis, which has also been demonstrated in histopathological studies. No demyelination seems to occur, according to the normal levels of MBP observed in this study.  Conclusions: Although CSF levels of brain specific proteins are elevated in hydrocephalic patients, indicating brain damage due to hydrocephalus, neither CSF- nor serum-concentrations of brain specific proteins seem to be valuable tools in the clinical evaluation of the severity of hydrocephalus. Published online January 14, 2003  Correspondence: T. Beems, M.D., Department of Neurosurgery, UMC Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.     

Mounting device for external cerebrospinal fluid drainage: the Freiburg Stativ

Background  External drainage of cerebrospinal fluid (CSF) is one of the most common neurosurgical procedures. It is important to maintain a stable drainage rate, but with the commonly available mountings for CSF drainage this can be difficult to achieve. The drainage rate is dependent on the height-difference between the CSF space and the drip chamber of the device. Most mountings for open CSF drainage cannot be satisfactorily fixed at the bed of the patient; especially if the head of the bed is moved, there is a risk of over- or underdrainage. Materials and methods  We have therefore constructed a mounting for open CSF drainage which allows appropriate adjustment of the rate of CSF outflow, even if the patient’s head part of the bed is moved. Findings  The device was easily mountable or exchangeable at any hospital bed and served equally well for ventricular or for lumbar drainage. Conclusion  We think that this device can help to reduce serious complication of over- or underdrainage in external CSF drainage.     

Technical Note: External Cerebrospinal Fluid (CSF) Drainage by Percutaneous Needle Punction in Newborn Children

Summary  External drainage of CSF in children is indicated in acute hydrocephalus e.g. after intraventricular bleeding or infection. In these cases the drainage has to remain in place until physiological CSF circulation is restored or an internal shunt can be inserted. External drainage is mostly performed using a silicon catheter connected to a plastic bag. An external CSF drainage left for several days in situ bears an increasing risk of bacterial infection. In these cases a metal needle minimizes the risk of ventriculitis.  For prevention of accompanying infection we implanted a Cytocan^R port needle with a 20 G diameter in 7 infants. The needle is easily inserted with low risk of complications. By its plastic top angulated at 90° to the needle the system can be fixed to the skin very safely by suture or tape.  With this system neither an implantation related intracerebral haemorrhage nor an accompanying ventriculitis was encountered. In two cases a pre-existing ventriculitis was cured by this needle drainage and antibiotic treatment. In five cases an acute hydrocephalus after intraventricular haemorrhage was drained by the port needle system.     

Experience with a programmable valve shunt system.

OBJECT: The goal of this study was to clarify the efficacy of the Codman Hakim programmable valve. Clinical data obtained in 179 patients with hydrocephalus or other intracranial fluid-accumulating diseases were analyzed. METHODS: Shunt placement operations were effective in 168 patients, approximately one half (50.6%) of whose devices required reprogramming of opening pressure postoperatively. This was a significantly larger number of shunts than the authors had thought would need reprogramming. Extremely narrowed ventricles observed on computerized tomography scans, as well as clinical symptoms related to inadequate or excessive cerebrospinal fluid drainage, improved in patients after shunt reprogramming. Shunt reprogramming frequently was necessary in patients with posthemorrhagic acute hydrocephalus; the programmable valve proved particularly beneficial for such patients. Subdural effusion and arachnoid cyst also proved to be good indications for use of the valve. Twelve patients (7%) suffered complications postoperatively. The most common complication was valve obstruction, which occurred in five patients, most of whom had brain tumors. CONCLUSIONS: The programmable valve was beneficial for the treatment of hydrocephalus and other intracranial fluid-accumulating diseases. It is important to be careful in selecting patients for treatment with the programmable valve, because complications involving the valve seem more likely in brain tumor cases. The valve proved to be poorly resistant to magnetic fields; therefore, it is essential to confirm opening pressure after every magnetic resonance imaging examination. The authors recommend that an identification system for patients be developed so that medical personnel will be aware of the presence of the valve and the previous setting of opening pressure.     

Obstruction of Magendie's and Luschka's Foramina. Cine-MRI, Ætiology and Pathogenesis

Summary  Background. Obstruction of the foramina of Magendie and Luschka represents one possible aetiology for a progressive tetra-ventricular hydrocephalus.  Method. Our case report is a 58-year-old woman initially presenting with a pseudo-vertebrobasilar insufficiency clinical syndrome. A ventriculo-cisternostomy of the third ventricle was performed by an endoscopic procedure with a clinical and radiological success (three year follow-up).  Findings. Comparative studies of cerebrospinal fluid (CSF) flow measurements by cine magnetic resonance imaging (cine-MRI) showed that Magendie's and Luschka's foramina permeabilities were restored after the ventriculo-cisternostomy.  Interpretation. This case shows that endoscopic ventriculo-cisternostomy of the third ventricle can provide an effective treatment for specific tetra-ventricular hydrocephalus. Cine-MRI findings open the discussion on possible aetiologies and pathophysiologies.     

Endoscopic third ventriculostomy for hydrocephalus: early and late efficacy in relation to aetiology

Summary.  Objectives: The aim of the study was to analyse the effectiveness and usefulness of treatment of hydrocephalus by Endoscopic Third Ventriculostomy (ETV). We sought to relate rates of failure to the cause of hydrocephalus, distinguishing between early and late outcome.  Patients and methods: Between September 1999 and April 2001, 30 patients underwent ETV. In 23 patients hydrocephalus was caused by an expansive mass (tumour). Three groups of patients were distinguished, according to the different aims of ETV. Thus in group T – ETV was carried out to eliminate hydrocephalus prior to the main surgery (53%), in C – ETV was the definite treatment of choice (30%), and in group P – ETV was a palliative treatment (17%). The results were assessed in the early postoperative period and in long term follow-up using clinical relief of symptoms, and radiological criteria (pre- and postoperative computed tomography and/or magnetic resonance scans).  Results: In the early postoperative period ETV was rated to be effective by clinical criteria in 29 patients, and by radiological criteria in 27. According to late assessment the method was successful in 25 patients using clinical criteria, and in 21 using radiological criteria. There was no peri-operative mortality. A transient complication (wound CSF leak) occurred in two patients.  Conclusions: ETV is effective in well chosen patients in relieving symptoms of hydrocephalus. It is valuable before a definitive major operation to remove the cause of hydrocephalus, as a palliative treatment, and in itself as a method of definitive management when indications are correct. Published online March 3, 2003 Acknowledgments  The authors wish to thank professor B. L. Bauer from the Department of Neurosurgery in Hannover for his help in the training and also the team from the Department of Paediatric Neurosurgery in Warsaw led by professor Marcin Roszkowski for their help in the practical use of the neuroendoscopic method at our department.  Correspondence: Stanisław J. Kwiek MD, Ph.D., Department of Neurosurgery, Medical University of Silesia, ul. Medyków 14, 40-752 Katowice, Poland.     

Intracranial cerebrospinal fluid distribution and its postoperative changes in normal pressure hydrocephalus

Summary  Background. This study was conducted to investigate the usefulness of intracranial cerebrospinal fluid (CSF) volume measurement using MR-based methods in the management of patients with normal pressure hydrocephalus (NPH).  Methods. The study group comprised 19 patients with NPH who showed a favorable outcome after ventricular shunting, 15 normal volunteers (NV), and 15 patients with cerebrovascular disease (CVD). A 3D-fast asymmetric spin echo MR imaging sequence and the region-growing method were used to extract the CSF space from MR images. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured and the VV/ICV ratio was calculated in each case. In NPH patients, the CSF volume was measured again after shunting.  Findings. The mean VV and VV/ICV ratio in the NPH group (91.1 mL and 45.2%, respectively) were significantly (p<0.01) higher than those in the NV group (26.5 mL and 13.7%) and in the CVD group (44.5 mL and 17.8%). On the other hand, mean ICV values were not significantly different among the three groups. The VV was markedly decreased postoperatively (mean −40.7%), whereas the ICV was unchanged, resulting in a marked reduction in the VV/ICV ratio (mean −39.3%).  Interpretation. These results suggest that patients with NPH have a unique intracranial CSF distribution, with an enlarged VV and a slightly increased ICV, resulting in a high VV/ICV ratio. Shunting led to dramatic improvement in our patients. It is likely that CSF measurement can provide valuable information in the management of patients with NPH.     

Ventriculoperitoneal shunts with the use of pressure-adjustable valve in the management of hydrocephalus

Sixteen patients with hydrocephalus of varied etiology who underwent ventriculo-peritoneal shunts utilizing pressure-adjustable valves were reviewed, and the usefulness of the pressure-adjustable valve in the management of hydrocephalus was evaluated. Before shunting all patients had CT evidence of hydrocephalus with Evans' Index greater than 30%. High-, medium- and low-pressure settings were chosen in 3, 11 and 2 patients respectively, according to the CSF pressure as measured during lumber puncture or ventricular drainage. Following the shunting procedures with programmable pressure valves, hydrocephalus was alleviated with Evans' Index being 27% on the average, as evaluated by CT scans. Such clinical symptoms as disturbed consciousness, dementia and increased intracranial pressure all subsided. There were no mortality, infection or revision during the follow-up period of 5 to 16 months. Of particular note was that, among these 16 cases, there were three illustrative cases in which programmable pressure valves were found useful in coping with newly developed subdural effusion and low-intracranial-pressure syndrome, by manually adjusting the valves to higher pressure settings.     

Programmable shunt valves: in vitro assessment of safety of the magnetic field generated by a portable game machine

Cerebrospinal fluid (CSF) shunts are frequently used to treat hydrocephalus. The use of a programmable shunt valve allows physicians to easily change the opening pressure. Since patients with adjustable CSF shunt valves may use portable game machines, the permanent magnets in these machines may alter the shunt valve programmed settings or permanently damage the device. This study investigated the risk of unintentional valve adjustment associated with the use of game machines in patients with programmable CSF shunt valves. Four adjustable valves from 4 different manufacturers, Sophysa Polaris model SPV (Polaris valve), Miethke proGAV (proGAV), Codman Hakim programmable valve (CHPV), and Strata II small valve (Strata valve), were evaluated. Magnetic field interactions were determined using the portable game machine, Nintendo DS Lite (DS). The maximum distance between the valve and the DS that affected the valve pressure setting was measured by x-ray cinematography. The Polaris valve and proGAV were immune to unintentional reprogramming by the DS. However, the settings of the CHPV and Strata valves were randomly altered by the DS. Patients with an implanted shunt valve should be made aware of the risks posed by the magnetic fields associated with portable game machines and commonly used home electronics.     

The Frankfurt horizontal plane as a reference for the implantation of gravitational units: a series of 376 adult patients

Background

The in-line combination of adjustable differential pressure valves with fixed gravitational units is increasingly recommended in the literature. The spatial positioning of the gravitational unit is thereby decisive for the valve opening pressure. We aimed at providing data on factors contributing to primary overdrainage and underdrainage of cerebrospinal fluid (CSF), with special attention paid to the implantation angle of the gravitational unit.

Methods

Weretrospectively analyzed the postoperative course of 376 consecutive patients who received a ventriculoperitoneal shunt with a proGAV valve. The incidence of both primary CSF overdrainage and underdrainage was correlated with the implantation angle of the gravitational unit in regard to the Frankfurt horizontal plane and the patients’ general parameters.

Results

Primary overdrainage was found in 41 (10.9 %) patients. Primary underdrainage was found in 113 (30.1 %) patients. A mean deviation of 10° (±7.8) for the gravitational unit in regard to the vertical line to the Frankfurt horizontal plane was found. In 95 % of the cases the deviation was less than 25°. No significant correlation between the implantation angle and the incidence of overdrainage or underdrainage of CSF was found. The patients’ age and having single hydrocephalus entities were identified as factors significantly predisposing patients to overdrainage or underdrainage.

Conclusion

The implantation of the gravitational unit of the proGAV valve within a range of at least 10° in regard to the vertical line to the Frankfurt horizontal plane does not seem to predispose patients to primary overdrainage or underdrainage in ventriculoperitoneal shunting. The plane may serve as a useful reference for the surgeon’s orientation.     

MRimaging Findings after Ventricular Puncture in Patients with SAH

Summary  Object. Using magnetic resonance (MR) imaging, we studied brain injury from ventricular puncture performed during craniotomy in the acute stage of subarachnoid hemorrhage (SAH).  Methods. 80 patients underwent craniotomy for aneurysm obliteration within 48 hr after SAH, ventricular puncture for drainage of cerebrospinal fluid (CSF) was perfomed to reduce intracranial pressure. MR imaging was performed within 3 days following surgery to measure the size of the lesion, and was repeated on postoperative days 14 and 30.  Conclusions. Of the 80 patients with ventricular puncture preceding craniotomy, 65 (81%) showed MR evidence of brain injury from the puncture. Overall, 149 lesions were detected. According to coronal images, cortical injuries (54 cases), penetrating injury to tracts along the ventricular tube (55 cases), caudate injury (25 cases), and corpus callosum injury (15 cases). Brain injuries from ventricular puncture did not correlate significantly to patient outcome. While ventricular puncture and drainage of CSF can readily be performed to decrease brain volume at the time of craniotomy in acute-stage SAH, neurosurgeons should be aware of a surprisingly high incidence of brain injury complicating puncture.     

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.     

Long-standing overt ventriculomegaly in adults (LOVA) needing ventriculo-peritoneal shunt with double programmable pressure valves

A 44-year-old man presented with symptomatic hydrocephalus due to aqueductal stenosis. Endoscopic third ventriculostomy was performed but proved ineffective, so ventriculo-peritoneal shunt using a programmable pressure valve (PPV) was carried out. Subdural hematoma appeared 5 weeks postoperatively and subsequently increased though the pressure setting was maximum. One more valve was implanted in the right chest wall and drainage of the hematoma was performed 2 months after the shunt operation. Adjustment of pressure was repeated. Findings of overdrainage and underdrainage were seen once each afterwards. We followed up the patient with the first valve set at 200 mm H?O and the second valve set at 60 mm H?O. Disturbance of memorization improved. The patient was in a stable condition 10 months after the final pressure settings. Flow volume changes were examined under conditions of various pressures in tandemly connected double programmable valves in vitro. When total pressure increased, flow showed a linear decrease that was not associated with the order of the pressure settings. This method of adding one more PPV was effective, and appears to be a useful choice for treating overdrainage.     

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.