Safety and function of programmable ventriculo-peritoneal shunt valves: An in vitro 7 Tesla magnetic resonance imaging study.

OBJECTIVE: The quantity of ultra-high field MRI neuroimaging studies has rapidly increased. This study tests function, safety, and image artifacts of two frequently implanted programmable ventriculo-peritoneal (VP) shunt valves in a 7T MRI system. METHODS: All tests were performed using a whole-body 7T MRI system. Three proGAV 2.0 and 3 CODMAN CERTAS® Plus programmable VP-shunt valves were tested in three steps. 1) Deflection angle tests close to the bore opening at the location of a static magnetic field gradient of 3-5 T/m. 2) Valves were fixed on a spherical phantom in 3 positions (a. lateral, b. cranial, c. cranial with 22.5° tilt anteriorly) and assessed for keeping the programmed pressure setting and reprogrammability. 3) Valves were fixed on the phantom and positioned lateral in a radiofrequency head coil. MRI scans were performed for both models, including MPRAGE, GRE and SE sequences. RESULTS: Deflection angles were moderate (13°, 14°, 13°) for the proGAV valves and close to critical (43°, 43°, 41°) for the CODMAN valves at the test location. Taking a scaling factor of 2-3 for the maximum spatial magnetic field gradient accessible to a patient within the magnet bore into account renders both valves MR unsafe regarding ferromagnetic attraction. The proGAV valves kept the pressure settings in all positions and were reprogrammable in positions a. and b. In position c., reprogrammability was lost. The CODMAN valves changed their pressure setting and reprogrammability was lost in all positions. MR image signal homogeneity was unaltered in the phantom center, artifacts limit the assessability of structures in close vicinity to the valves. CONCLUSION: Both tested programmable VP-shunt valves are MR unsafe for 7T systems. Novel programming mechanisms using permanent magnets with sufficient magnetic coercivity or magnet-free mechanisms may allow the development of programmable VP-shunt valves that are conditional for 7T MR systems.

Ventriculoperitoneal shunt malfunction diagnosis based on substance dilution.

OBJECTIVE: Current methods for the diagnosis of ventriculoperitoneal (VP) shunt malfunction lack specific standards; therefore, it may be missed or misdiagnosed. Hence, providing a reliable diagnostic method will help improve the accuracy of preoperative decision-making. Therefore, the aim of the study was to provide a new method for the diagnosis of VP shunt malfunction. METHODS: After in vitro testing, we enrolled a total of 12 patients with VP shunt malfunction. Before revision surgery, 0.1 mL of a 5% sodium valproate (SV) solution was injected into the reservoir; 0.1 mL of the cerebrospinal fluid (CSF) was withdrawn 20 minutes later from the reservoir to measure the SV concentration. The process was repeated on the seventh day after surgery and compared with the preoperative results. RESULTS: The mean ±â€Šstandard deviation preoperative SV concentration in the cerebrospinal fluid was greater than the postoperative concentration (5967.8 ±â€Š1281.3 vs 391.1 ±â€Š184.6 µg/mL, P = .001). CONCLUSION: The proposed method is a reliable, safe, and relatively simple alternative for the diagnosis of VP shunt malfunction and further provides a reference for treatment.

Development of an In Vitro Hemorrhagic Hydrocephalus Model for Functional Evaluation of Magnetic Microactuators Against Shunt Obstructions.

OBJECTIVE: Occlusion of ventriculoperitoneal shunts placed after intraventricular hemorrhage occurs frequently. The objective of this study was to develop a hemorrhagic hydrocephalus model to assess the ability of an oscillating microactuator within the ventricular catheter (VC) to prevent shunt obstruction. METHODS: An in vitro hydrocephalus model with extreme risk of shunt obstruction was created. Phosphate-buffered saline, blood, and thrombin were driven through ventriculoperitoneal shunts for 8 hours. Five VCs were fitted with a microactuator and compared with 5 control VCs. The microactuator was actuated by an external magnetic field for 30 minutes. Pressure within the imitation lateral ventricle was measured. RESULTS: In the 5 control shunts, 6 obstructions developed (3 VC, 3 valve-distal catheter) compared with 1 obstruction (VC) in the 5 microactuator shunts. In the control and microactuator groups, the median volume exiting the shunts in 8 hours was 30 mL versus 256 mL. Median time to reach an intraventricular pressure of 40 mm Hg (13.8 minutes vs. >8 hours), median total time >40 mm Hg (6.2 hours vs. 0.0 hours), and median maximum pressure (192 mm Hg vs. 36 mm Hg) were significantly improved in the microactuator group (P < 0.01). CONCLUSIONS: In addition to protecting the VC, the microactuator appeared to prevent hematoma obstructing the valve or distal catheter, resulting in a much longer duration of low intraventricular pressures. A microactuator activated by placing the patient's head in an external magnetic field could reduce shunt obstructions in hemorrhagic hydrocephalus.

The Sensor Reservoir-does it change management?

BACKGROUND: The Miethke Sensor Reservoir sits within a ventriculoperitoneal shunt system to give a reading of the pressure within the shunt. This information can guide the management of hydrocephalus patients who present frequently with headaches. METHODS: We reviewed a cohort of 12 patients who underwent implantation of a Sensor Reservoir to assess how the management of their symptoms changed over a 4-year period. RESULTS: When comparing the group before the Sensor Reservoir and after the Sensor Reservoir insertion, there was a 75% reduction in number of CT head scans (P<0.05), 100% reduction in episodes of ICP monitoring (P<0.05), 55% reduction in number of X-ray shunt series, and a 50% reduction in acute presentation to hospital with shunt-related symptoms. The number of clinic attendances increased by 44%. In addition, cost analysis showed a saving of £6952 per patients over the 2-year period following Sensor Reservoir insertion as a result of reduced admissions and investigations. Complications were seen in 3 patients-two patients developed shunt-related infections, and 1 patient underwent shunt revision due to a proximal shunt obstruction. Seventy-five percent of patients showed an improvement in their symptoms at the end of the 4-year period. CONCLUSION: Implantation of a Sensor Reservoir in shunt patients with chronic headaches can reduce the number of investigations and hospital admissions and guide management resulting in a clinical improvement.

Free-hand stereotactic ventricular catheter insertion technique based on radio-anatomical landmarks. How I do it.

BACKGROUND: Accurate ventricular catheter (VC) placement plays an important role in reducing the risk of ventriculoperitoneal shunt failure. Free-hand VC insertion is associated with a significant misplacement rate. Consequently, several expensive alternative methods that are unfortunately not available worldwide have been used. To overcome these limitations, we developed a simple surgical technique based on radio-anatomical landmarks aimed at reducing VC's misplacements. METHOD: We reproduce the preoperative imaging on the patient's head using common anatomical landmarks. This allows defining stereotactic VC coordinates to be followed during the surgical procedure. CONCLUSION: This simple and cost-effective method improves VC insertion accuracy.

In vitro performance of six combinations of adjustable differential pressure valves and fixed anti-siphon devices with and without vertical motion.

OBJECTIVE: Adjustable differential pressure (DP) valves in combination with fixed anti-siphon devices are currently a popular combination in counteracting the effects of cerebrospinal fluid overdrainage following implantation of a ventriculoperitoneal shunt system. The study examined the flow performance of three DP valves in successive combination with an anti-siphon device in an in vitro shunt laboratory with and without vertical motion. METHODS: We analyzed three DP valves (Codman Hakim Medos programmable valve [HM], Codman CertasPlus [CP], and Miethke proGAV [PG], in combination with either Codman SiphonGuard [SG] or Miethke ShuntAssistant [SA]), resulting in the evaluation of six different valve combinations. Defined DP conditions between 4 and 40 cm H2O within a simulated shunt system were generated and the specific flow characteristics were measured. In addition, combinations with SA, which is a gravity-dependent valve, were measured in defined spatial positions (90°, 60°). All device combinations were tested during vertical motion with movement frequencies of 2, 3, and 4 Hz. RESULTS: All valve combinations effectively counteracted the siphon effect in relation to the chosen DP. Angulation-related flow changes were similar in the three combinations of DP valve and SA in the 60° and 90° position. In CP-SA and PG-SA, repeated vertical movement at 2, 3, and 4 Hz led to significant increase in flow, whereas in HM-SA, constant increase was seen at 4 Hz only (flow change at 4Hz, DP 40 cm H2O: PG (opening pressure 4 cm H2O) 90°: 0.95 ml/min, 60°: 0.71 ml/min; HM (opening pressure 4 cm H2O) 90°: 0.66 ml/min, 60°: 0.41 ml/min; CP (PL 2) 90°: 0.94 ml/min, 60°: 0.79 ml/min; p < 0.01); however, HM-SA showed relevant motion-induced flow already at low DPs (0.85 ml/min, DP 4 cm H2O). In combinations of DP valve with SG, increase of flow was far less pronounced and even led to significant reduction of flow in certain constellations. Maximum overall flow increase was 0.46 ± 0.04 ml/min with a HM (opening pressure 12 cm H2O) at 2 Hz and a DP of 10 cm H2O, whereas maximum flow decrease was 1.12 ± 0.08 with a PG (opening pressure 4 cm H2O) at 3 Hz and a DP of 10 cmH2O. CONCLUSION: In an experimental setup, all valve combinations effectively counteracted the siphon effect in the vertical position according to their added resistance. Motion-induced increased flow was consistently demonstrated in combinations of DP valve and SA. The combination of HM and SA especially showed relevant motion-induced flow already at low DPs. In combinations of DP and SG, the pattern of the motion induced flow was more inconsistent and motion even led to significant flow reduction, predominantly at DPs of 10 and 20 cmH2O.

Ventriculo-peritoneal shunting devices for hydrocephalus.

BACKGROUND: Hydrocephalus is a common neurological disorder, caused by a progressive accumulation of cerebrospinal fluid (CSF) within the intracranial space that can lead to increased intracranial pressure, enlargement of the ventricles (ventriculomegaly) and, consequently, to brain damage. Ventriculo-peritoneal shunt systems are the mainstay therapy for this condition, however there are different types of shunt systems. OBJECTIVES: To compare the effectiveness and adverse effects of conventional and complex shunt devices for CSF diversion in people with hydrocephalus. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (2020 Issue 2); Ovid MEDLINE (1946 to February 2020); Embase (Elsevier) (1974 to February 2020); Latin American and Caribbean Health Science Information Database (LILACS) (1980 to February 2020); ClinicalTrials.gov; and World Health Organization International Clinical Trials Registry Platform. SELECTION CRITERIA: We selected randomised controlled trials or quasi-randomised trials of different types of ventriculo-peritoneal shunting devices for people with hydrocephalus. Primary outcomes included: treatment failure, adverse events and mortality. DATA COLLECTION AND ANALYSIS: Two review authors screened studies for selection, assessed risk of bias and extracted data. Due to the scarcity of data, we performed a Synthesis Without Meta-analysis (SWiM) incorporating GRADE for the quality of the evidence. MAIN RESULTS: We included six studies with 962 participants assessing the effects of standard valves compared to anti-syphon valves, other types of standard valves, self-adjusting CSF flow-regulating valves and external differential programmable pressure valves. All included studies started in a hospital setting and offered ambulatory follow-up. Most studies were conducted in infants or children with hydrocephalus from diverse causes. The certainty of the evidence for most comparisons was low to very low. 1. Standard valve versus anti-syphon valve Three studies with 296 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with standard valve and anti-syphon valves (very low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and anti-syphon valves (range 0 to 2.9%) (low certainty of the evidence). Mortality may be similar in those with standard valves (0%) and anti-syphon valves (0.9%) (RD 0.01%, 95% CI -0.02% to 0.03%, low certainty of the evidence). Ventricular size and head circumference may be similar in those with standard valves and anti-syphon valves (low certainty of the evidence). None of the included studies reported the quality of life of participants. 2. Comparison between different types of standard valves Two studies with 174 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with different types of standard valves (early postoperative period: RR 0.41, 95% CI 0.13 to 1.27; at 12 months follow-up: RR 1.17, 95% CI 0.72 to 1.92, very low certainty of the evidence). None of the included studies reported adverse events beyond those included under "treatment failure". We are uncertain about the effects of different types of standard valves on mortality (range 2% to 17%, very low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference. 3. Standard valve versus self-adjusting CSF flow-regulating valve One study with 229 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with standard valves (42.98%) and self-adjusting CSF flow-regulating valves (39.13%) (low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and those with self-adjusting CSF flow-regulating valves (range 0 to 7.2%) (low certainty of the evidence). The included study reported no deaths in either group in the postoperative period. Beyond the early postoperative period, the authors stated that nine patients died (no disaggregated data by each type of intervention was available, low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference. 4. External differential programmable pressure valve versus non-programmable valve One study with 377 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with programmable valves (52%) and non-programmable valves (52%)  (RR 1.02, 95% CI 0.84 to 1.24, low certainty of the evidence). The incidence of adverse events may be similar in those with programmable valves (6.19%) and non-programmable valves (6.01%) (RR 0.97, 95% CI 0.44 to 2.15, low certainty of the evidence). The included study did not report the effect of these interventions on mortality, quality of life or head circumference. Ventricular size reduction may be similar in those with programmable valves and non-programmable valves (low certainty of the evidence). AUTHORS' CONCLUSIONS: Standard shunt valves for hydrocephalus compared to anti-syphon or self-adjusting CSF flow-regulating valves may cause little to no difference on the main outcomes of this review, however we are very uncertain due to the low to very low certainty of evidence. Similarly, different types of standard valves and external differential programmable pressure valves versus non-programmable valves may be associated with similar outcomes. Nevertheless, this review did not include valves with the latest technology, for which we need high-quality randomised controlled trials focusing on patient-important outcomes including costs.

Ventriculostomy with subsequent ventriculoperitoneal shunt placement after subarachnoid hemorrhage: the effect of implantation site on postoperative complications-a single-center series.

BACKGROUND: Patients suffering from aneurysmal subarachnoid hemorrhage (SAH) with shunt-dependent hydrocephalus require subsequent placement of a ventriculoperitoneal shunt (VPS) after ventriculostomy. However, in patients with previous ventriculostomy, the site for proximal VPS catheter placement is still controversial. We investigated the effect of catheter placement on postoperative complications by analyzing patients with ventriculostomy and subsequent VPS placement after SAH. METHODS: From January 2004 to December 2018, 164 of 1128 patients suffering from SAH underwent subsequent VPS placement after ventriculostomy in the authors' institution. Patients were divided into two groups according to the position of the ventriculostomy and the site of the proximal VPS catheter ("same site" group versus "contralateral site" group). VPS-related infectious and bleeding complications following VPS placement were assessed and analyzed. RESULTS: Overall, VPS-related infections occurred in 11 of the 164 patients (7%). Furthermore, five of the 164 patients (3%) suffered from VPS-related hemorrhage. However, VPS infection rate was lower 5% (6/115) in the same site compared to 10% (5/49) in the contralateral site group, although without reaching statistical significance (OR = 0.48 (0.14, 1.67) 95% confidence interval, p = 0.3). VPS-related hemorrhage rate did not differ significantly between patients in the same site group (3.5%, 4/115) and the contralateral site group (2.0%, 1/49; OR = 1.73 (0.18, 15.9), p = 1.0). CONCLUSIONS: Our study suggests that the use of the ventriculostomy site for VPS placement does not significantly increase the risk of either VPS-related infections or VPS-related hemorrhages.

Clinical performance of fixed-pressure Sphera Duo® hydrocephalus shunt.

INTRODUCTION: Cerebral hydrodynamics complications in shunted patients are due to the malfunction of the system. The objective of this retrospective, single-center, single-arm cohort study is to confirm the safety and performance of Sphera® Duo when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cysts. METHODS: Data were generated by reviewing 112 adult patient's charts, who were submitted to a ventriculoperitoneal shunt surgery and followed for one year after surgery. RESULTS: The results show us that 76% of patients had their neurological symptoms improved and that the reoperation rate was 15% in the first year following surgery. DISCUSSION: Sphera Duo® shunt system is an applicable shunt option in routine neurosurgical management of hydrocephalus by several causes. It has presented good results while mitigating effects of overdrainage. Overdrainage is especially important in adults with non-hypertensive hydrocephalus and can cause functional shunt failure, which causes subnormal ICP (particularly in the upright position) and is associated with characteristic neurological symptoms, such as postural headache and nausea. CONCLUSION: Sphera Duo® shunt system is safe when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cyst.

Inusual complicación en cirugía laparoscópica de urgencia: sección accidental de catéter de derivación ventriculoperitoneal / An unusual complication in urgent laparoscopic surgery: Accidental transection of a ventriculoperitoneal shunt

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Clinical performance of fixed-pressure Sphera Duo® hydrocephalus shunt / Performance clínica da válvula de pressão fixa Sphera Duo®

Abstract Introduction: Cerebral hydrodynamics complications in shunted patients are due to the malfunction of the system. The objective of this retrospective, single-center, single-arm cohort study is to confirm the safety and performance of Sphera® Duo when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cysts. Methods: Data were generated by reviewing 112 adult patient's charts, who were submitted to a ventriculoperitoneal shunt surgery and followed for one year after surgery. Results: The results show us that 76% of patients had their neurological symptoms improved and that the reoperation rate was 15% in the first year following surgery. Discussion: Sphera Duo® shunt system is an applicable shunt option in routine neurosurgical management of hydrocephalus by several causes. It has presented good results while mitigating effects of overdrainage. Overdrainage is especially important in adults with non-hypertensive hydrocephalus and can cause functional shunt failure, which causes subnormal ICP (particularly in the upright position) and is associated with characteristic neurological symptoms, such as postural headache and nausea. Conclusion: Sphera Duo® shunt system is safe when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cyst.

Resumo Introdução: As complicações da hidrodinâmica cerebral em pacientes com derivação ventriculoperitoneal são frequentemente relacionadas ao malfuncionamento do sistema. O objetivo deste estudo retrospectivo de coorte de centro único é avaliar a segurança e performance clínica do Sistema Sphera® Duo quando utilizado em adultos com hidrocefalia, pseudotumor cerebral ou cistos aracnoides. Métodos: Avaliamos os prontuários de 112 pacientes adultos submetidos a cirurgia de derivação ventriculoperitoneal e acompanhados por 1 ano após a cirurgia. Resultados: O resultado mostra que 76% dos pacientes melhoraram dos sintomas neurológicos e a taxa de reoperação foi de 15% no primeiro ano após a cirurgia. Discussão: O sistema de derivação Sphera Duo® é uma opção de shunt adequada a ser usada no tratamento neurocirúrgico da hidrocefalia por causas diversas. Ele demonstrou bons resultados clínicos enquanto reduziu riscos de hiperdrenagem. A hiperdrenagem é especialmente preocupante e mórbida em pacientes adultos com hidrocefalia não hipertensiva e pode levar a prejuízo clínico e disfunção da válvula, com sintomas de hipotensão craniana, como cefaléia ortostática e náuseas. Conclusão: O sistema de derivação Sphera Duo® é seguro para tratamento da hidrocefalia, pseudotumor cerebri ou cistos aracnóides em adultos.

Neonatal Hydrocephalus Treatment with Ultrasmall Valve Implantation.

OBJECTIVE: Neonatal hydrocephalus remains a difficult condition to manage, due to high failure rates among all management strategies. Neurosurgeons commonly manage hydrocephalus with ventriculoperitoneal shunt (VPS) implantation, and valves of variable sizes and profiles are available for implantation. This study examines primary ventricular shunt valve implantation complication rates based on valve profiles in pediatric patients with hydrocephalus. METHODS: This study retrospectively reviews pediatric patients younger than 1 year of age who underwent ventricular shunt placement at a single institution from January 2001 to January 2017. Patients were classified by valve profile and categorized as either ultrasmall valves or regular-sized valves. Time until complication and type of complication were studied. RESULTS: A total of 156 patients met the inclusion criteria. Forty-eight (31%) patients received an ultrasmall shunt valve, while 108 patients received a regular valve. On average, patients undergoing ultrasmall valve placement were younger (2.1 months) than patients undergoing placement of regular valves (3.1 months) (P = 0.03). The overall complication rate within 2 years of VPS placement was 37.5% in patients with the ultrasmall valve and 41.7% in the regular valve population. There was no difference in 1-year shunt survival rate between the 2 cohorts. CONCLUSION: Our review did not find a significant difference in complication rates between ultrasmall and regular valves in patients under 1 year of age. However, the etiology of shunt malfunction did differ between the groups. This work further supports evidence suggesting a surgeon's preference for shunt hardware alone does not significantly impact outcome.

Laparoscopic repositioning of an obstructed ventriculoperitoneal shunt catheter with laparoscopy-assisted partial omentectomy and omentopexy.

OBJECTIVE: To describe the use of laparoscopy for repositioning of a ventriculoperitoneal shunt (VPS) catheter. STUDY DESIGN: Case report. ANIMAL: One 11-month-old male cairn terrier weighing 5.5 kg. METHODS: The dog had placement of a VPS system for primary hydrocephalus at 4 months of age. Poor functioning of the shunt system was suspected because of deteriorating neurological signs. A contrast study of the VPS system provided evidence of a distal shunt obstruction, and repeated brain computed tomography (CT) was consistent with persistent hydrocephalus. RESULTS: Laparoscopy was used to free the abdominal catheter of the shunt system and perform a partial omentectomy and omentopexy of the remaining omentum. Concurrently, the dog was sterilized. Recovery was routine, and follow-up CT 1 year after repositioning revealed that the hydrocephalus had substantially improved. Results of a contrast study of the VPS system also provided evidence that it was functional. CONCLUSION: Ventriculoperitoneal shunt systems are placed in dogs with primary and secondary hydrocephalus, and complications are quite common, including obstruction, bleeding, infection, and overshunting or undershunting. This is the first published clinical case report in which the repositioning of a VPS catheter with partial omentectomy and omentopexy in a dog are described. CLINICAL SIGNIFICANCE: Future studies may be performed to determine whether laparoscopy can be considered as a treatment to assist with safe placement of VPS systems, avoiding misplacement of the shunt system and iatrogenic damage to the viscera and vessels.

Ventriculoperitoneal shunt in treating of idiopathic normal pressure hydrocephalus-single-center study.

OBJECT: Idiopathic normal pressure hydrocephalus (iNPH) is the only variant of dementia disorders possibly treatable by neurosurgical intervention. iNPH is a neurodegenerative condition clinically characterized by gait ataxia, urinary incontinence, and memory disturbance. We present one of the largest single-center studies, which was designed to prove efficacy of our low-pressure setting of gravitational valve at all three symptoms of iNPH and to find statistically significant cut-off time for best clinical improvement according to the duration of symptoms. METHODS: Sixty-one consecutive patients (mean age 74.9 ± 5.3) with iNPH were prospectively observed from the time of surgery with minimal 6 months follow-up. All patients underwent implantation of the same type of gravitational valve with the same setting-pro GAV with low opening pressure at 5 cm H2O-and were operated by the same team of 2 neurosurgeons. We statistically evaluated gait disturbance, psychological changes, and incontinence preoperatively and at 6 months after surgery and timing of the surgery according to the duration of symptoms and to the age. RESULTS: Paired t test showed a statistically significant increase in MMSE, a statistically significant decrease in 10-m walk test and 360 deg. rotation test (p < 0.0001). The correlation among the change of the MMSE, the walk test, and the rotation test, and the age and time of symptoms' duration was verified by Pearson's correlation coefficient. Pearson's correlation coefficient showed a medium strong correlation between the change of MMSE and the time of symptoms (r = - 0.580; p < 0.0001) and between the change of the number of steps and the time of symptoms (r = 0.517, p < 0.0001). There was a statistically significant weak (poor) correlation between the change of the walk test and the time of symptoms (r = 0.351, p = 0.006). All 3 ROC tests confirmed optimal cut-off for the best improvement of symptoms as 9.5 months of the symptom duration. CONCLUSIONS: We proved statistical significant optimal cut-off for the best improvement of the symptoms as 9.5 months of the symptom duration. This study also confirmed successful treatment of iNPH with VP shunting using low pressure setting of gravitational valve with overall improvement in 75% and low over drainage complications in 5% We proved statistically significant increase in MMSE, decrease in 10 m walk test and number of steps test, p < 0.0001.

Flow-regulated versus differential pressure valves for idiopathic normal pressure hydrocephalus: comparison of overdrainage rates and neurological outcome.

BACKGROUND: To compare flow-regulated (FR) and differential pressure (DP) valves for treatment of patients with idiopathic normal hydrocephalus (iNPH) focusing on overdrainage and neurological outcome. METHODS: This is a retrospective study of patients with iNPH treated with FR and DP valves at a single institution between 2008 and 2018. The neurological status was evaluated retrospectively with the Kiefer scale at baseline, after shunt placement and at the 6-month follow-up. Groups were compared using inverse probability of treatment weighting based on propensity scores. RESULTS: The study cohort consisted of 38 patients treated with FR valves and 49 with DP valves. The mean patient age was 72.0 ± 7.6 years. Based on the Kiefer scale score, neurological improvement at the 6-month follow-up was recorded in 79.6% in the DP group and 89.5% in the FR group (p = 0.252). The overdrainage rates were higher among DP valves (10.2%) than among FR valves (2.6%, adjusted p = 0.002). Valve malfunction occurred in 2.0% in the DP group and 5.3% in the FR group (adjusted p = 0.667). CONCLUSIONS: The current study demonstrates a comparable neurological improvement between DP and FR valves, with potentially lower overdrainage rates among FR valves. Long-term studies will be necessary to draw a definite conclusion on FR valves for treatment of iNPH patients.

Edema of the Floor of the Fourth Ventricle Accompanying Shunt Malfunction and Disappearance of It After Shunt Repair: Case Report and Literature Review.

BACKGROUND The ventriculoperitoneal shunt remains, despite recent advances, the mainstay of treatment for hydrocephalus. Although it is used as a routine practice, and besides its recorded and documented safety, it often malfunctions due to a variety of reasons, most commonly referred to as obstruction, breakage, migration and infection. A usual finding of those children suspected to magnetic resonance imaging is the detection of a rim of hyperintensity in the periventricular white matter (halo). CASE REPORT We describe the case of a 7-year-old male patient, treated 4 years ago for an infratentorial ependymoma, who developed hydrocephalus at the time of clinical presentation. During his previous follow-up, he was disease-free but developed clinically evident acute shunt malfunction, accompanied by imaging findings on magnetic resonance imaging (MRI) consisting of interstitial edema surrounding the supratentorial ventricular system, with additional involvement of the floor of the fourth ventricle. This peculiar and novel imaging finding subsided after successful management of hydrocephalus. CONCLUSIONS At present, contemporary computed tomography and MRI modalities constitute the gold standard in order to assess and follow-up patients with established hydrocephalus. Periventricular interstitial edema is a well-established imaging feature of acute hydrocephalus and, in cases of ventriculoperitoneal shunt, of shunt malfunction. Besides that, a newly described, to the best of our knowledge, imaging feature could be the distinction of that signal alteration at the floor of the fourth ventricle. It seems to have prognostic significance regarding the adequacy of management of hydrocephalus, as it disappeared after its successful treatment.

Intraoperative measurement of intraventricular pressure in dogs with communicating internal hydrocephalus.

Collapse of the lateral cerebral ventricles after ventriculo-peritoneal drainage is a fatal complication in dogs with internal hydrocephalus. It occurs due to excessive outflow of cerebrospinal fluid into the peritoneal cavity (overshunting). In most shunt systems, one-way valves with different pressure settings regulate flow into the distal catheter to avoid overshunting. The rationale for the choice of an appropriate opening pressure is a setting at the upper limit of normal intracranial pressure in dogs. However, physiological intraventricular pressure in normal dogs vary between 5 and 12 mm Hg. Furthermore, we hypothesise that intraventricular pressure in hydrocephalic dogs might differ from pressure in normal dogs and we also consider that normotensive hydrocephalus exists in dogs, as in humans. In order to evaluate intraventricular pressure in hydrocephalic dogs, twenty-three client owned dogs with newly diagnosed communicating internal hydrocephalus were examined before implantation of a ventriculo-peritoneal shunt using a single use piezo-resistive strain-gauge sensor (MicroSensor ICP probe). Ventricular volume and brain volume were measured before surgery, based on magnetic resonance images. Total ventricular volume was calculated and expressed in relation to the total volume of the brain, including the cerebrum, cerebellum, and brainstem (ventricle-brain index). Multiple logistic regression analysis was performed to assess the influence of the covariates "age", "gender", "duration of clinical signs", "body weight", and "ventricle-brain index" on intraventricular pressure. The mean cerebrospinal fluid pressure in the hydrocephalic dogs was 8.8 mm Hg (standard deviation 4.22), ranging from 3-18 mm Hg. The covariates "age", (P = 0.782), "gender" (P = 0.162), "body weight", (P = 0.065), or ventricle-brain index (P = 0.27)" were not correlated with intraventricular pressure. The duration of clinical signs before surgery, however, was correlated with intraventricular pressure (P< 0.0001). Dogs with internal hydrocephalus do not necessarily have increased intraventricular pressure. Normotensive communicating hydrocephalus exists in dogs.