Multimodal radionuclide shuntography for device patency: New procedural tips for anuncommon historical technique.

Cerebrospinal fluid (CSF) shunting is an established long-term treatment option for hydrocephalus, and is one of the most commonly performed neurosurgical procedures in western countries.Despite advances in CSF shunt design and management, its failure rates remain high and is most commonly due to obstruction and infection.Cerebrospinal fluidshunt failure diagnosis should be prompt and accurate in establishing timely if its revision is appropriate. Radionuclide shuntography with technetium-99m-diethylenetriaminepetaacetic acid (99mTc-DTPA) is a useful technique for evaluation CSF shunts and management of patients presenting with shunt-related problems, in particular it can avoid unnecessary replacement interventions. Although its execution and interpretation require specific skills, we suggest its execution for the evaluation of device's patency. We here describe the radionuclide shuntography performed with recent hybrid multimodal technologies, with a procedure customized to a complicated patient with hydrocefalus and neoplastic disease. We suggest considering radionuclide shuntography in association with conventional imaging and strongly recommend the additional performance of single photon emission computed tomography/computed tomography (SPECT/CT) because it also provides valuable information to complete the interpretation of planar images.

In vitro performance of combinations of anti-siphon devices with differential pressure valves in relation to the spatial position.

BACKGROUND: Programmable differential pressure (DP) valves combined with an anti-siphon device (ASD) represent the current standard of care in preemtping overdrainage associated with ventriculoperitoneal shunting for hydrocephalus. OBJECTIVE: We aimed to provide comparative data of four combinations of two ASDs of different working principles in combination with two DP valves in an in vitro model in order to achieve a better understanding of the flow characteristics and potential clinical application. METHODS: We analyzed the flow performance of four possible combinations of two DP valves (CHPV [HM]; proGAV 2.0[PG]) in combination with either a gravity-regulated (Shuntassistant [SA]) or a flow-regulated (SiphonGuard [SG]) ASD in an in vitro setup. A DP between 4 and 60 cmH2O was generated, and the specific flow characteristics were measured. In addition, the two combinations with gravity-regulated ASDs were measured in defined spatial positions. RESULTS: Flow characteristics of the SA combinations corresponded to the DP in linear fashion and to the spatial position. Flow characteristics of the SG combinations were dependent upon the DP in a non-linear fashion and independent of the spatial position. Highest mean flow rate of the PG-SG- (HM-SG-) combination was 1.41 ± 0.24 ml/min (1.16 ± 0.06 ml/min). The mean flow rates sharply decreased with increasing inflow pressure and subsequently increased slowly up to 0.82 ± 0.26 ml/min (0.77 ± 0.08 ml/min). CONCLUSION: All tested device combinations were able to control hydrostatic effect and prevent consecutive excessive flow, to varying degrees. However, significant differences in flow characteristics can be seen, which might be relevant for their clinical application.

Persistent shunt dependency in children treated with CSF diversion for idiopathic intracranial hypertension (IIH).

Long-term shunt dependency rates in children treated for IIH with CSF diversion have not been established. We therefore present our experience with 4 children shunted for Idiopathic Intracranial Hypertension (IIH) during the years 1988-2000 with very long-time follow-up. Two out of these patients have experienced late or very late episodes of severe shunt failure during the second or third decade after initial shunt treatment. They were all boys and may not be representative for IIH patients as a whole. Two of them appear, however, to be permanently shunt dependent, indicating that long-term shunt dependency in children treated for IIH with CSF diversion may be more common than previously expected.

An [18F]-Positron Emitting Fluorophore Allows Safe Evaluation of Small Molecule Distribution in the CSF, CSF Fistulas, and CNS Device Placement.

The small molecule fluorescein is commonly used to guide the repair of cerebral spinal fluid leaks (CSFLs) in the clinic. We modified fluorescein so that it is also visible by positron emission tomography (PET). This probe was used to quantitatively track the fast distribution of small molecules in the CSF of rats. We tested this probe in models relevant to the clinical diagnosis and treatment of central nervous system (CNS) diseases that affect CSF flow. In this study, fluorescein was radiolabeled with fluorine-18 to produce Fc-AMBF3. [18/19F]-Fc-AMBF3 was introduced at trace quantities (13.2 nmols, 100 µCi) intrathecally (between L5 and L6) in rats to observe the dynamic distribution and clearance of small molecules in the CSF by both [18F]-PET and fluorescence (FL) imaging. Murine models were used to demonstrate the following utilities of Fc-AMBF3: (1) utility in monitoring the spontaneous CSFL repair of a compression fracture of the cribriform plate and (2) utility in quantifying CSF flow velocity during neurosurgical lumboperitoneal shunt placement. Fc-AMBF3 clearly delineated CSF-containing volumes based on noninvasive PET imaging and in ex vivo FL histology. In vivo morbidity (n = 16 rats, <2.7 mg/kg, 77 times the PET dose) was not observed. The clearance of the contrast agent from the CNS was rapid and quantitative (t1/2 = 33.8 ± 0.6 min by FL and t1/2 = 26.0 ± 0.5 min by PET). Fc-AMBF3 was cleared from the CSF through the vasculature and/or lymphatic system that supplies the cribriform plate and the temporal bone. Fc-AMBF3 can be used to diagnose CSFLs, image CSFL repair, and determine the CSF flow velocity in the CNS or through lumboperitoneal shunts by PET/FL imaging. In conclusion, Fc-AMBF3 PET imaging has been demonstrated to safely and dynamically quantitate CSF flow, diagnose fistulas associated with the CSF space, and approximate the clearance of small molecules in the CSF.

Port-a-cath and ventriculoatrial shunt at the same atrium: technical note.

Hydrocephalus is a rare complication of brain involving acute lymphoblastic leukemia (ALL). The standard treatment is ventriculoperitoneal (VP) shunting, while ventriculoatrial (VA) shunting is the second option in a case of VP shunt failure in young children. But the presence of port catheter at the right atrium restricts and makes a VA shunt difficult to place in the same atrium. We presented a 4-year-old boy who had the diagnoses of ALL and underwent chemotherapy through a port-a-cath. He also had hydrocephalus due to the brain invasion of the ALL. He firstly underwent VP shunting for the treatment of hydrocephalus, but it failed due to an intraabdominal cyst. Then, he underwent VA shunting through the left internal jugular vein. This is the first case in the literature showing both catheters in the right atrium.

Next generation of ventricular catheters for hydrocephalus based on parametric designs.

BACKGROUND: The flow pattern of the cerebrospinal fluid is probably the most important factor related to obstruction of ventricular catheters during the normal treatment of hydrocephalus. To better comprehend the flow pattern, we have carried out a parametric study via numerical models of ventricular catheters. In previous studies, the flow was studied under steady and, recently, in pulsatile boundary conditions by means of computational fluid dynamics (CFD) in three-dimensional catheter models. OBJECTIVE: This study aimed to bring in prototype models of catheter CFD flow solutions as well to introduce the theory behind parametric development of ventricular catheters. METHODS: A preceding study allowed deriving basic principles which lead to designs with improved flow patterns of ventricular catheters. The parameters chosen were the number of drainage segments, the distances between them, the number and diameter of the holes on each segment, as well as their relative angular position. RESULTS: CFD results of previously unreleased models of ventricular catheter flow solutions are presented in this study. Parametric development guided new designs with better flow distribution while lowering the shear stress of the catheters holes. High-resolution 3D printed catheter solutions of three models and basic benchmark testing are introduced as well. CONCLUSIONS: The next generation of catheter with homogeneous flow patterns based on parametric designs may represent a step forward for the treatment of hydrocephalus, by possibly broadening their lifespan.

Modalities and accuracy of diagnosis of external ventricular drainage-related infections: a prospective multicentre observational cohort study.

BACKGROUND: Device infection is a major complication of placement external ventricular drains (EVD). Diagnostic features are often masked by underlying disease or cerebrospinal fluid (CSF) contamination by blood. We aim to assess which diagnostic modalities are applied for EVD-related infection (ERI) diagnosis and evaluate their accuracy. METHODS: This observational prospective study included 187 adult patients with an EVD. Modalities of clinical diagnosis of ERI diagnosed by treating physicians on clinical grounds and blood and CSF analysis (clinically diagnosed ERI (CD-ERI)) were assessed prospectively. Additionally, the diagnostic accuracy of clinical and laboratory parameters for the diagnosis of culture proven ERI (CP-ERI) was evaluated, using data of the study patients and including a retrospective cohort of 39 patients with CP-ERI. RESULTS: Thirty-one CD-ERIs were diagnosed in the prospective cohort. Most physicians used CSF analysis to establish the diagnosis. ROC analysis revealed an AUC of 0.575 (p = 0.0047) for the number of positive SIRS criteria and AUC of 0.5420 (p = 0.11) for the number of pathological neurological signs for diagnosis of CP-ERI. Diagnostic accuracy of laboratory values was AUC 0.596 (p = 0.0006) for serum white blood cell count (WBCC), AUC 0.550 (p = 0.2489) for serum C-reactive protein, AUC 0.644 (p < 0.0001) for CSF WBCC and AUC 0.690 for CSF WBC/red blood cell count ratio (both p < 0.0001). Neither a temporal trend in potential predictors of CP-ERI nor a correlation between clinical diagnosis and proven CSF infection was found. CONCLUSIONS: Clinicians base their diagnosis of ERI mostly on CSF analysis and occurrence of fever, leading to over-diagnosis. The accuracy of the clinical diagnosis is low. Commonly used clinical and laboratory diagnostic criteria have a low sensitivity and specificity for ERI.

Differential Pressure Shunt for Simultaneous Diversion of Ventricular Fluid and Extracerebral Fluid.

BACKGROUND/AIMS: The management of extracerebral collections of fluid in patients with hydrocephalus can be problematic for either their simultaneous separate management or sequential management, each of which may require multiple surgeries and the management of external drains. The object of this report is to review the experience with a shunt configuration that simultaneously diverts ventricular fluid and extracerebral fluid, whether subdural or subarachnoid in location, through different outflow resistances. METHODS: The medical records, including neuroimaging of patients with hydrocephalus and clinically significant extracerebral collections of low density who were managed by implanting a differential pressure type shunt, were retrospectively reviewed. RESULTS: Four patients, 3 children and 1 adult, met inclusion criteria. Three had the entire differential pressure shunt implanted under 1 anesthetic, and 1 had a catheter inserted into the subdural space and connected into an existing ventriculoperitoneal shunt system. The extracerebral fluid collections cleared in all 4 patients, and the CSF shunt continued to function normally. CONCLUSION: A single surgical procedure to implant a differential pressure shunt can simultaneously drain and obliterate an extracerebral fluid collection while managing the hydrocephalus. Compared to routines that include external drainage, differential pressure shunting requires fewer surgeries, shorter hospitalization, with expected less expense.

Conversion of external ventricular drainage to ventriculo-peritoneal shunt: to change or not to change the proximal catheter?

PURPOSE: In this study, we investigate the occurrence rate of early shunt infection and malfunction in pediatric patients after converting an external ventricular drainage (EVD) to a ventriculo-peritoneal shunt (VPS) without replacing the ventricular catheter. METHODS: Data was retrospectively reviewed for 17 pediatric patients (11 male (64.7%), mean age 7.5 years, range 0.25-15 years) who underwent 18 consecutive direct conversions of tunneled EVD to VPS without replacing the ventricular catheter between 2008 and 2017. In each case, the EVD was inserted in sterile fashion within the operating room and tunneled subcutaneously 5-7 cm away from the insertion site. Primary outcome measure was the occurrence of early (within 30 days) VPS infection or malfunction. The mean follow-up time was 56.8 months (±35.7 months). RESULTS: The mean period of EVD before VPS placement was 9.0 days (±3.6 days, range 2-18 days). Five patients had shunt infections/malfunctions. One patient (5.6%) had an early shunt infection after 30 days. One patient had a late shunt infection after 9 months. One patient had an early shunt malfunction after 9 days. Two patients (11.1%) had late shunt malfunctions after 6.5 months and 9 years. There were no other incidents of shunt-related complications or shunt-related mortality. CONCLUSION: In the pediatric population, the conversion of a tunneled EVD to a VPS without replacing the ventricular catheter can be safely done. Cranial entry is spared, while the rates of shunt infection and malfunction do not increase significantly.

Comparison of anti-siphon devices-how do they affect CSF dynamics in supine and upright posture?

BACKGROUND: Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in upright posture best without leading to CSF accumulation. METHODS: Three shunts each of the types Codman Hakim with SiphonGuard (flow-regulated), Miethke miniNAV with proSA (gravitational), and Medtronic Delta (membrane controlled) were tested. The shunts were compared on a novel in vitro setup that actively emulates the physiology of a shunted patient. This testing method allows determining the CSF drainage rates, resulting CSF volume, and intracranial pressure in the supine, sitting, and standing posture. RESULTS: The flow-regulated ASDs avoided increased drainage by closing their primary flow path when drainage exceeded 1.39 ± 0.42 mL/min. However, with intraperitoneal pressure increased in standing posture, we observed reopening of the ASD in 3 out of 18 experiment repetitions. The adjustable gravitational ASDs allow independent opening pressures in horizontal and vertical orientation, but they did not provide constant drainage in upright posture (0.37 ± 0.03 mL/min and 0.26 ± 0.03 mL/min in sitting and standing posture, respectively). Consequently, adaptation to the individual patient is critical. The membrane-controlled ASDs stopped drainage in upright posture. This eliminates the risk of overdrainage, but leads to CSF accumulation up to the volume observed without shunting when the patient is upright. CONCLUSIONS: While all tested ASDs reduced overdrainage, their actual performance will depend on a patient's specific needs because of the large variation in the way the ASDs influence CSF dynamics: while the flow-regulated shunts provide continuous drainage in upright posture, the gravitational ASDs allow and require additional adaptation, and the membrane-controlled ASDs show robust siphon prevention by a total stop of drainage.

I can hear my shunt-audible noises associated with CSF shunts in hydrocephalic patients.

BACKGROUND: Cerebrospinal fluid (CSF) shunts are life-long implants, and patients have reported anecdotally on noises associated with their shunts. There is, however, a marked lack of information regarding acoustic phenomena related to CSF shunts. METHODS: We identified all patients who had been treated or followed in our neurosurgical department within a 15-year period from January 2000 up to the end of 2014. After approval of the local ethics committee all patients who were cognitively intact were explored by a questionnaire and by personal interview about acoustic phenomena related to their shunts. RESULTS: Three hundred forty-seven patients were eligible for the survey, and 260 patients completed the questionnaire. Twenty-nine patients (11.2%) reported on noises raised by their shunts. All of them experienced short-lasting noises while changing body posture, mainly from a horizontal to an upright position, or while reclining the head. Most of the patients reported on soft sounds, but loud and even very loud noises occurred in some patients. Seventy-six percent of the patients were not bothered by these noises as they considered it as a normal part of the therapy or as proof that the shunt device was functioning. Modern valves with gravitational units are prone to produce noises in young adults, but nearly all valve types can evoke noises. CONCLUSIONS: Noises caused by a shunt do occur in a considerable number of patients with shunts. One should be aware of this phenomenon, and these patients must be taken seriously.

Shunt Devices for Neurointensivists: Complications and Management.

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

Cerebrospinal Fluid Shunting Complications in Children.

Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity.

Timing of Permanent Ventricular Shunt Placement Following External Ventricular Drain Placement in Primary Intracerebral Hemorrhage.

BACKGROUND: Intraventricular hemorrhage requiring ventriculostomy placement is a frequent complication of spontaneous intracerebral hemorrhage. Although a subset of patients will require permanent ventricular shunt placement, little is known about contemporary practices regarding the timing of ventriculostomy and ventricular shunt placement after intracerebral hemorrhage. METHODS: Using the 2010-2012 National Inpatient Sample, we identified patients with International Classification of Diseases, Ninth Revision codes for intracerebral hemorrhage, excluded secondary causes, and examined procedure dates. RESULTS: Of 35,899 patients with primary intracerebral hemorrhage, 2443 (6.8%) received ventriculostomy, 93% within the first 3 days of admission and 66% within the first day. Permanent shunt placement occurred in 173 (7.1%) patients following ventriculostomy at a median interval of 15 days (interquartile range: 11-20). Among those remaining alive and in hospital at 14, 21, and 28 days, 5%, 11%, and 15%, respectively, underwent shunt placement following ventriculostomy, and 24% of those with multiple ventriculostomy insertions required permanent shunt by 4 weeks of hospitalization. Multiple ventriculostomies, tracheostomy, and black race were associated with longer time to permanent shunt. CONCLUSIONS: A wide variation in delay to permanent shunt placement is present, with substantial and increasing prevalence with time in hospital. Better understanding of the risk factors associated with persistent hydrocephalus will help optimize patient selection and timing of treatment.

Comparison of the use of ventricular access devices and ventriculosubgaleal shunts in posthaemorrhagic hydrocephalus: systematic review and meta-analysis.

INTRODUCTION: Ventricular access devices (VAD) and ventriculosubgaleal shunts (VSGS) are currently both used as temporising devices to affect CSF drainage in neonatal posthaemorrhagic hydrocephalus (PHH), without clear evidence of superiority of either procedure. In this systematic review and meta-analysis, we compared the VSGS and VAD regarding complication rates, ventriculoperitoneal shunt conversion and infection rates, and mortality and long-term disability. METHODS: The review was registered with the PROSPERO international prospective register of systematic reviews (registration number CRD42015019750) and was conducted in accordance with PRISMA guidelines. RESULTS AND CONCLUSIONS: The literature search of five databases identified 338 publications, of which 5 met the inclusion criteria. All were retrospective cohort studies (evidence class 3b and 4). A significantly lower proportion of patients with a VSGS required CSF tapping compared to patients with a VAD (log OR -4.43, 95% CI -6.14 to -2.72). No other significant differences between the VAD and VSGS were identified in their rates of infection (log OR 0.03, 95% CI -0.77 to 0.84), obstruction (log OR 1.25, 95% CI -0.21 to 2.71), ventriculoperitoneal shunt dependence (log OR -0.06, 95% CI -0.93 to 0.82), subsequent shunt infection (log OR 0.23, 95% CI -0.61 to 1.06), mortality (log OR 0.37, 95% CI -0.95 to 1.70) or long-term disability (p = 0.9). In all studies, there was a lack of standardised criteria, variations between surgeons in heterogeneous cohorts of limited sample size and a lack of neurodevelopmental follow-up. This affirms the importance of an ongoing multicentre, prospective pilot study comparing these two temporising procedures to enable a more robust comparison.

Who Needs a Revision? 20 Years of Cambridge Shunt Lab.

Shunt testing independent of manufacturers provides knowledge that can significantly improve the management of patients with hydrocephalus. The Cambridge Shunt Evaluation Laboratory was created 20 years ago. Thanks to financial support from the Department of Health (1993-1998), all shunts in use in the UK were systematically evaluated, with "blue reports" being published. Later new devices were tested as they appeared in public domain.Twenty-six models have been evaluated. The majority of the valves had a non-physiologically low hydrodynamic resistance that may result in over-drainage, 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 a siphon-preventing mechanism is very sensitive to body posture. Shunts with siphon-preventing accessories offer a reasonable resistance to negative outlet pressure. Bench parameters were used to test shunt performance in vivo using infusion tests. A criterion for correctly performing a shunt procedure was established. Pressure measured in the shunt prechamber during the plateau phase of infusion should not remain more than 5 mmHg above the le shunt's operating pressure plus hydrodynamic resistance of the valve multiplied by the infusion rate. "Critical levels" for every shunt and every performance level have been used in the shunt testing wizard of ICM+ software.

Shunt Testing In Vivo: Observational Study of Problems with Ventricular Catheter.

Most shunt obstructions happen at the inlet of the ventricular catheter. Three hundred six infusion studies from 2007 to 2011 were classified as having a typical pattern of either proximal occlusion or patency. We describe different patterns of shunt ventricular obstruction.Solid block: Cerebrospinal fluid (CSF) aspiration was impossible. Baseline pressure was without pulse waveform (respiratory waveform may be visible). A quick increase of pressure to a level compatible with the shunt's setting was recorded in response to infusion. Distal occlusion of the shunt via transcutaneous compression resulted in a rapid increase in pressure to levels above 50 mmHg. This pattern was attributed to a solid ventricular block.Slit ventricles: At baseline, a pattern similar to that of the solid block was observed. After compression, the pressure increases, the pulse waveform appears, and the intracranial pressure is often stabilized at 25-40 mmHg. It is probable that previously slit ventricles were opened during the test.Partial block: In a partial block of the ventricular catheter by an in-growing choroid plexus, the pulse waveform at baseline was observed and CSF aspiration was possible. During infusion, the pressure increased, but the pulse amplitude disappeared. During the increase in the pressure in the shunt prechamber, the connection with the ventricles is disturbed by repositioning of the plexus.Infusion study via the shunt prechamber is able to visualize ventricular obstruction of the hydrocephalus shunt.

In vitro performance of the fixed and adjustable gravity-assisted unit with and without motion-evidence of motion-induced flow.

BACKGROUND: Anti-siphon devices and gravitational-assisted valves have been introduced to counteract the effects of overdrainage after implantation of a shunt system. The study examined the flow performance of two gravitational-assisted valves (shunt assistant - SA and programmable shunt assistant - proSA, Miethke & Co. KG, Potsdam, Germany) in an in vitro shunt laboratory with and without motion. METHODS: An in vitro laboratory setup was used to model the cerebrospinal fluid (CSF) drainage conditions similar to a ventriculo-peritoneal shunt and to test the SA (resistance of +20 cmH2O in 90°) and proSA (adjustable resistance of 0 to +40 cmH2O in 90°). The differential pressure (DP) through the simulated shunt and tested valve was adjusted between 0 and 60 cmH2O by combinations of different inflow pressures (40, 30, 20, 10, and 0 cmH2O) and the hydrostatic negative outflow pressure (0, -20, and -40 cmH2O) in several differing device positions (0°, 30°, 60°, and 90°). In addition, the two devices were tested under vertical motion with movement frequencies of 2, 3, and 4 Hz. RESULTS: Both gravity-assisted units effectively counteract the hydrostatic effect in relation to the chosen differential pressure. The setting the proSA resulted in flow reductions in the 90° position according to the chosen resistance of the device. Angulation-related flow changes were similar in the two devices in 30-90° position, however, in the 0-30° position, a higher flow is seen in the proSA. Repeated vertical movement significantly increased flow through both devices. While with the proSA a 2-Hz motion was not able to induce additional flow (0.006 ± 0.05 ml/min), 3- and 4-Hz motion significantly induced higher flow values (3 Hz: +0.56 ± 0.12 ml/min, 4 Hz: +0.54 ± 0.04 ml/min). The flow through the SA was not induced by vertical movements at a low DP of 10 cmH2O at all frequencies, but at DPs of 30 cmH2O and higher, all frequencies significantly induced higher flow values (2 Hz: +0.36 ± 0.14 ml/min, 3 Hz: +0.32 ± 0.08 ml/min, 4 Hz: +0.28 ± 0.09 ml/min). CONCLUSIONS: In a static setup, both tested valves effectively counteracted the hydrostatic effect according to their adjusted or predefined resistance in vertical position. Motion-induced increased flow was demonstrated for both devices with different patterns of flow depending on applied DP and setting of the respective valve. The documented increased drainage should be considered when selecting appropriate valves and settings in very active patients.

Cross-sectional imaging of thoracic and abdominal complications of cerebrospinal fluid shunt catheters.

This study aims to review the imaging findings of distal (thoracic and abdominal) complications related to ventriculo-peritoneal (VP), ventriculo-pleural (VPL), and ventriculo-atrial (VA) cerebrospinal fluid (CSF) shunt catheter placement. Institution review board-approved single-center study of patients with thoracic and abdominal CSF catheter-related complications on cross-sectional imaging examinations over a 14-year period was performed. Clinical presentation, patient demographics, prior medical history, and subsequent surgical treatment were recorded. The presence or absence of CSF catheter-related infection and/or acute hydrocephalus on cross-sectional imaging was also recorded. There were 81 distal CSF catheter-related complications identified on 47 thoracic or abdominal imaging examinations in 30 patients (age 5-80 years, mean 39.3 years), most often on CT (CT = 42, MRI = 1, US = 4). Complications included 38 intraperitoneal and 11 extraperitoneal fluid collections. Extraperitoneal collections included nine abdominal wall subcutaneous (SC) pseudocysts associated with shunt migration and obesity, an intrapleural pseudocyst, and a breast pseudocyst. There were also two large VPL-related pleural effusions, a fractured catheter in the SC tissues, and a large VA shunt thrombus within the right atrium. Ten patients (33.3 %) had culture-positive infection from CSF or shunt catheter samples. Ten patients (33.3 %) had features of temporally related acute or worsening hydrocephalus on neuroimaging. In four of these patients, the detection of thoracic and abdominal complications on CT preceded and predicted the findings of acute hydrocephalus on cranial imaging. Thoracic and abdominal complications of CSF shunts, as can be identified on CT, include shunt infection and/or obstruction, may be both multiple and recurrent, and may be predictive of concurrent acute intracranial problems.

Ommaya reservoir infection rate: a 6-year retrospective cohort study of Ommaya reservoir in pediatrics.

OBJECTIVES: In this study, we investigated Ommaya reservoir among pediatric patients, its infection rate, and the predisposing factors. We also investigated its role in the reduction of CSF protein. Finally, we explored other factors that would influence the decision to insert an Ommaya in comparison to external ventricular drainage. METHODS: This is a 6-year retrospective cohort study from a tertiary hospital in Saudi Arabia. RESULTS: In our study, females were 48.9% (n = 22) while males were 51.1% (n = 23). The mean age at insertion was 2.9 days, SD of 1.67 day. The mean weight at insertion was 0.98 kg, SD of 0.57 kg. The total duration of Ommaya days was 2523 days. The median duration of the reservoir was 21 days. The Ommaya reservoir infection rate was 6.6%. We found an association between organisms cultured from urinary tract and the organisms cultured from the CSF. We also found that CSF protein level is lower in non-infected reservoirs in comparison to those with infection. The number of Ommaya days and the number of days of infection could not explain the mean CSF protein. CONCLUSIONS: Ommaya reservoir has a low infection rate. Although CSF protein increased by infection, we failed to prove that Ommaya tapping provides a reduction in the CSF protein and, hence, reduction of shunt malfunctions thereafter. We conclude with expert opinions that take into account the psychological factors in addition to the clinical sense in choosing between Ommaya reservoir and external ventricular drainage (EVD).