Location-Specific Hematoma Volume Cutoff and Clinical Outcomes in Intracerebral Hemorrhage

BACKGROUND

Major intracerebral hemorrhage (ICH) trials have largely been unable to demonstrate therapeutic benefit in improving functional outcomes. This may be partly due to the heterogeneity of ICH outcomes based on their location, where a small strategic ICH could be debilitating, thus confounding therapeutic effects. We aimed to determine the ideal hematoma volume cutoff for different ICH locations in predicting ICH outcomes.

METHODS

We retrospectively analyzed consecutive ICH patients enrolled in the University of Hong Kong prospective stroke registry from January 2011 to December 2018. Patients with premorbid modified Rankin Scale score >2 or who underwent neurosurgical intervention were excluded. ICH volume cutoff, sensitivity, and specificity in predicting respective 6-month neurological outcomes (good [modified Rankin Scale score 0-2], poor [modified Rankin Scale score 4-6], and mortality) for specific ICH locations were determined using receiver operating characteristic curves. Separate multivariate logistic regression models were also conducted for each location-specific volume cutoff to determine whether these cutoffs were independently associated with respective outcomes.

RESULTS

Among 533 ICHs, the volume cutoff for good outcome according to ICH location was 40.5 mL for lobar, 32.5 mL for putamen/external capsule, 5.5 mL for internal capsule/globus pallidus, 6.5 mL for thalamus, 17 mL for cerebellum, and 3 mL for brainstem. ICH smaller than the cutoff for all supratentorial sites had higher odds of good outcomes (all P<0.05). Volumes exceeding 48 mL for lobar, 41 mL for putamen/external capsule, 6 mL for internal capsule/globus pallidus, 9.5 mL for thalamus, 22 mL for cerebellum, and 7.5 mL for brainstem were at greater risk of poor outcomes (all P<0.05). Mortality risks were significantly higher for volumes that exceeded 89.5 mL for lobar, 42 mL for putamen/external capsule, and 21 mL for internal capsule/globus pallidus (all P<0.001). All receiver operating characteristic models for location-specific cutoffs had good discriminant values (area under the curve >0.8), except in predicting good outcome for cerebellum.

CONCLUSIONS

ICH outcomes differed with location-specific hematoma size. Location-specific volume cutoff should be considered in patient selection for ICH trials.

Pushing the limits of low-cost ultralow-field MRI by dual-acquisition deep learning 3D superresolution

PURPOSE

Recent development of ultralow-field (ULF) MRI presents opportunities for low-power, shielding-free, and portable clinical applications at a fraction of the cost. However, its performance remains limited by poor image quality. Here, a computational approach is formulated to advance ULF MR brain imaging through deep learning of large-scale publicly available 3T brain data.

METHODS

A dual-acquisition 3D superresolution model is developed for ULF brain MRI at 0.055 T. It consists of deep cross-scale feature extraction, attentional fusion of two acquisitions, and reconstruction. Models for T₁ -weighted and T₂ -weighted imaging were trained with 3D ULF image data sets synthesized from the high-resolution 3T brain data from the Human Connectome Project. They were applied to 0.055T brain MRI with two repetitions and isotropic 3-mm acquisition resolution in healthy volunteers, young and old, as well as patients.

RESULTS

The proposed approach significantly enhanced image spatial resolution and suppressed noise/artifacts. It yielded high 3D image quality at 0.055 T for the two most common neuroimaging protocols with isotropic 1.5-mm synthetic resolution and total scan time under 20 min. Fine anatomical details were restored with intrasubject reproducibility, intercontrast consistency, and confirmed by 3T MRI.

CONCLUSION

The proposed dual-acquisition 3D supe-resolution approach advances ULF MRI for quality brain imaging through deep learning of high-field brain data. Such strategy can empower ULF MRI for low-cost brain imaging, especially in point-of-care scenarios or/and in low-income and mid-income countries.

Chemical Exchange Saturation Transfer Magnetic Resonance Imaging for Longitudinal Assessment of Intracerebral Hemorrhage and Deferoxamine Treatment at 3T in a Mouse Model

BACKGROUND

Noninvasive imaging of molecular alterations after intracerebral hemorrhage (ICH) could provide valuable information to guide and monitor treatments. Chemical exchange saturation transfer (CEST) magnetic resonance imaging has demonstrated promises in identifying proliferation, necrosis, and changes in cellularity in brain tumors. Here, we applied CEST magnetic resonance imaging to monitor molecular changes in hematoma without and with treatment noninvasively over 2 weeks at 3T using endogenous contrast.

METHODS

CEST contrast related to proteins at 3.5 ppm (amide proton transfer) and proteins/lipids at -3.5 ppm (relayed nuclear overhauser effect [rNOE]) were examined over 14 days in a collagenase-induced ICH mouse model. Imaging findings were validated with immunohistochemistry based on the ICH neuropathology. We also examined iron-containing phantoms that mimicked iron concentrations in hematoma to ensure the iron will not attenuate the CEST contrast during disease progression. Based on the validity of the CEST contrast of hematoma, we further examined related molecular alterations under iron-chelation treatment with deferoxamine.

RESULTS

We observed the temporal and spatial differences of CEST contrasts between rNOE at -3.5 ppm and amide proton transfer at 3.5 ppm, in which the core and perihematoma could be identified by rNOE on day 3 and day 14, and amide proton transfer on day 1, day 7, and day 14. Moreover, we observed a 25.7% significant reduction (P<0.05) of rNOE contrast after deferoxamine treatment to the ICH mice on day 3, which was not observable in amide proton transfer contrast. Our histology data indicated that rNOE primarily correlated with the myelin pathology, and amide proton transfer could reflect the cellularity increase at hematoma up to day 7.

CONCLUSIONS

Significant rNOE changes correlated well with histologic findings, especially myelin lipids, and regional characteristics in hematoma indicate the uniqueness of CEST magnetic resonance imaging in monitoring molecular changes during ICH and treatment.

Development and Validation of Indicators for Population Injury Surveillance in Hong Kong: Development and Usability Study

BACKGROUND

Injury is an increasingly pressing global health issue. An effective surveillance system is required to monitor the trends and burden of injuries.

OBJECTIVE

This study aimed to identify a set of valid and context-specific injury indicators to facilitate the establishment of an injury surveillance program in Hong Kong.

METHODS

This development of indicators adopted a multiphased modified Delphi research design. A literature search was conducted on academic databases using injury-related search terms in various combinations. A list of potential indicators was sent to a panel of experts from various backgrounds to rate the validity and context-specificity of these indicators. Local hospital data on the selected core indicators were used to examine their applicability in the context of Hong Kong.

RESULTS

We reviewed 142 articles and identified 55 indicators, which were classified into 4 domains. On the basis of the ratings by the expert panel, 13 indicators were selected as core indicators because of their good validity and high relevance to the local context. Among these indicators, 10 were from the construct of health care service use, and 3 were from the construct of postdischarge outcomes. Regression analyses of local hospitalization data showed that the Hong Kong Safe Community certification status had no association with 5 core indicators (admission to intensive care unit, mortality rate, length of intensive care unit stay, need for a rehabilitation facility, and long-term behavioral and emotional outcomes), negative associations with 4 core indicators (operative intervention, infection rate, length of hospitalization, and disability-adjusted life years), and positive associations with the remaining 4 core indicators (attendance to accident and emergency department, discharge rate, suicide rate, and hospitalization rate after attending the accident and emergency department). These results confirmed the validity of the selected core indicators for the quantification of injury burden and evaluation of injury-related services, although some indicators may better measure the consequences of severe injuries.

CONCLUSIONS

This study developed a set of injury outcome indicators that would be useful for monitoring injury trends and burdens in Hong Kong.

Postcooling But Not Precooling Benefits Motor Recovery by Suppressing Cell Death After Surgical Spinal Cord Injury in Rats

BACKGROUND

Surgical spinal cord injury (SSCI) is often inevitable in patients with intramedullary lesions. Although regional hypothermia (RH) has been demonstrated neuroprotective, the value of priming RH in SSCI has never been studied. Herein, the authors investigated the impact of pre- and post-RH on neurologic recovery in a clinically relevant model.

METHODS

An SSCI model was established at T10. RH was conducted by focal 4oC saline perfusion; room temperature (RT) saline was used as controls. Animals were randomized into 6 groups: SHAM-RT/RH, Pre-RT/RH, and Post-RT/RH. Motor and sensory functions were evaluated using the Basso, Beattie, and Bresnahan rating scale and Plantar test 2 weeks after surgery. TUNEL assay and Fluoro-Jade C staining were conducted to examine the cell death, and the alterations of apoptotic markers including total and cleaved casepase 3, Bcl-2, and Bax, as well as the pyroptotic proteins including NLRP3, ASC, and caspase 1, were determined.

RESULTS

RH perfusion successfully created an intramedullary hypothermia approximately at 24oC, while RT controls remained above 30oC. Animals receiving postinjury RH had the least cell death and the best motor performance, while pre-RH showed the most dead cells and worst hind limb movements. Immunoblotting depicted that post-RH suppressed both apoptotic and pyroptotic death as the cleaved/total caspase 3, Bcl-2/Bax ratio, and NLRP3/ASC/caspase 1 signaling were inhibited. Priming cooling, on the contrary, elevated pyroptosis and did not affect apoptosis significantly.

CONCLUSIONS

Priming RH before surgical incision could not be supported as it caused excessive cell death. In contrast, instant introduction of RH is beneficial in rescuing neurologic function.

A low-cost and shielding-free ultra-low-field brain MRI scanner

Magnetic resonance imaging is a key diagnostic tool in modern healthcare, yet it can be cost-prohibitive given the high installation, maintenance and operation costs of the machinery. There are approximately seven scanners per million inhabitants and over 90% are concentrated in high-income countries. We describe an ultra-low-field brain MRI scanner that operates using a standard AC power outlet and is low cost to build. Using a permanent 0.055 Tesla Samarium-cobalt magnet and deep learning for cancellation of electromagnetic interference, it requires neither magnetic nor radiofrequency shielding cages. The scanner is compact, mobile, and acoustically quiet during scanning. We implement four standard clinical neuroimaging protocols (T1- and T2-weighted, fluid-attenuated inversion recovery like, and diffusion-weighted imaging) on this system, and demonstrate preliminary feasibility in diagnosing brain tumor and stroke. Such technology has the potential to meet clinical needs at point of care or in low and middle income countries.

Burnout and well-being in young doctors in Hong Kong: a territory-wide cross-sectional survey

INTRODUCTION

This territory-wide study evaluated the level of burnout and health status among young doctors in Hong Kong.

METHODS

All young doctors in Hong Kong, defined as residents-in-training or doctors within 10 years of their specialist registration, were invited to participate in an online cross-sectional survey. This survey used standardised questionnaires including the Copenhagen Burnout Inventory (CBI) for burnout, Patient Health Questionnaire-9 for depression, and general health questionnaires.

RESULTS

In total, 514 doctors completed the survey; 284 were doctors within 10 years of their specialist registration, while 230 were residents-in-training. There were 277 women (54%); among all respondents, the mean age was 33.7 ± 6.1 years. Using a CBI subscale cut-off score of ≥50 (moderate and higher), 72.6% (n=373) of respondents reported personal burnout; 70.6% (n=363) of respondents reported work-related burnout; and 55.4% (n=285) of respondents reported client-related burnout. Furthermore, 24% (n=125) of respondents were "somewhat dissatisfied" with their present job position; 4% (n=19) of respondents were "very dissatisfied" with their present job position. The prevalence of depression among respondents was 21% (n=110).

CONCLUSIONS

In this territory-wide cross-sectional survey of young doctors in Hong Kong, a high prevalence of burnout was identified among young doctors; respondents exhibited a considerable level of depression and substantial dissatisfaction with their current positions. Strategies to address these problems must be formulated to ensure the future well-being of the medical and dental workforce in Hong Kong.

3D dissimilar-siamese-u-net for hyperdense Middle cerebral artery sign segmentation

The hyperdense middle cerebral artery sign (HMCAS) representing a thromboembolus has been declared as a vital CT finding for intravascular thrombus in the diagnosis of acute ischemia stroke. Early recognition of HMCAS can assist in patient triage and subsequent thrombolysis or thrombectomy treatment. A total of 624 annotated head non-contrast-enhanced CT (NCCT) image scans were retrospectively collected from multiple public hospitals in Hong Kong. In this study, we present a deep Dissimilar-Siamese-U-Net (DSU-Net) that is able to precisely segment the lesions by integrating Siamese and U-Net architectures. The proposed framework consists of twin sub-networks that allow inputs of left and right hemispheres in head NCCT images separately. The proposed Dissimilar block fully explores the feature representation of the differences between the bilateral hemispheres. Ablation studies were carried out to validate the performance of various components of the proposed DSU-Net. Our findings reveal that the proposed DSU-Net provides a novel approach for HMCAS automatic segmentation and it outperforms the baseline U-Net and many state-of-the-art models for clinical practice.

HGG-27. ANTI-CANCER POTENTIAL OF ARGINASE FOR HIGH-GRADE GLIOMA IN VITRO & IN-VIVO

BACKGROUND

High-grade glioma is currently incurable. It was reported that glioma may be auxotrophic to arginine due to the lack of urea cycle genes expressions, suggesting arginase may be a potential agent for high grade glioma. AIM: We investigated the efficacy of pegylated arginase I (pegArg-I) or in combination with other anti-cancer drugs for high-grade glioma in vitro and in vivo.

METHODS

4 high-grade glioma cell lines (U87, U373, U138, D54) were treated with pegArg-I in vitro. The molecular mechanism of pegArg-I-induced cytotoxicity was tested in U87. The ultra-morphological changes of pegArg-I-treated U87 was investigated by both scanning and transmission electron microscopy. Orthotopic glioma xenograft model with luciferase-transfected U87 cell line was tested for anti-cancer efficacy of peg-Arg I in vivo.

RESULTS

We showed that pegArg-I induced significant cell death in all 4 cell lines in vitro. Temozolomide, difluoromethyornithine and chloroquine (CQ) were then tested together with pegArg-I in U87 in vitro. We found that only CQ showed additive effect with pegArg-I against glioma in vitro. Such additive cytotoxic effect may be associated with enhanced autophagy and necrosis as shown in transmission electron microscopy and autophagy markers’ expression by Western blotting. PegArg-I prolonged the survival of glioma mice, suggesting its possible anti-glioma efficacy. However, CQ+pegArg-I didn’t show further significant anti-cancer efficacy in vivo.

CONCLUSION

PegArg-I may be useful in slowing the progression of glioma, but additional drug candidate which works synergistically with pegArg-I remains to be explored.

Automated Hierarchy Evaluation System of Large Vessel Occlusion in Acute Ischemia Stroke

BACKGROUND

The detection of large vessel occlusion (LVO) plays a critical role in the diagnosis and treatment of acute ischemic stroke (AIS). Identifying LVO in the pre-hospital setting or early stage of hospitalization would increase the patients' chance of receiving appropriate reperfusion therapy and thereby improve neurological recovery.

METHODS

To enable rapid identification of LVO, we established an automated evaluation system based on all recorded AIS patients in Hong Kong Hospital Authority's hospitals in 2016. The 300 study samples were randomly selected based on a disproportionate sampling plan within the integrated electronic health record system, and then separated into a group of 200 patients for model training, and another group of 100 patients for model performance evaluation. The evaluation system contained three hierarchical models based on patients' demographic data, clinical data and non-contrast CT (NCCT) scans. The first two levels of modeling utilized structured demographic and clinical data, while the third level involved additional NCCT imaging features obtained from deep learning model. All three levels' modeling adopted multiple machine learning techniques, including logistic regression, random forest, support vector machine (SVM), and eXtreme Gradient Boosting (XGboost). The optimal cut-off for the likelihood of LVO was determined by the maximal Youden index based on 10-fold cross-validation. Comparisons of performance on the testing group were made between these techniques.

RESULTS

Among the 300 patients, there were 160 women and 140 men aged from 27 to 104 years (mean 76.0 with standard deviation 13.4). LVO was present in 130 (43.3%) patients. Together with clinical and imaging features, the XGBoost model at the third level of evaluation achieved the best model performance on testing group. The Youden index, accuracy, sensitivity, specificity, F1 score, and area under the curve (AUC) were 0.638, 0.800, 0.953, 0.684, 0.804, and 0.847, respectively.

CONCLUSION

To the best of our knowledge, this is the first study combining both structured clinical data with non-structured NCCT imaging data for the diagnosis of LVO in the acute setting, with superior performance compared to previously reported approaches. Our system is capable of automatically providing preliminary evaluations at different pre-hospital stages for potential AIS patients.

Burden of large vessel occlusion stroke and the service gap of thrombectomy: A population-based study using a territory-wide public hospital system registry

Background

Ischemic stroke due to large vessel occlusion can be effectively treated with thrombectomy but access to this treatment is limited in many parts of the world. Local incidence of large vessel occlusion is critical in determining the development of thrombectomy service, but reliable data from Asian countries are lacking.

Aims

We performed a population-based study to estimate the burden of large vessel occlusion and the service gap for thrombectomy in Hong Kong.

Methods

All acute ischemic stroke patients admitted in 2016 to the public healthcare system, which provided 90% of the emergency healthcare in the city, was identified from the Hong Kong Hospital Authority’s central electronic database. The diagnosis of large vessel occlusion was retrospectively verified by two independent cerebrovascular specialists in a randomly sampled cohort based on clinical and neuroimaging data. The incidence of large vessel occlusion in the population was estimated through weighting the sample results and compared with the thrombectomy data in the same period.

Results

There were 6859 acute ischemic stroke patients treated in the public health system in 2016. Amongst the 300 patients randomly sampled according to diagnosis coding, 130 suffered from anterior circulation large vessel occlusion. This translated to 918 patients (95% CI 653–1180) and 13.3% of all ischemic stroke patients. The estimated incidence of anterior circulation large vessel occlusion was 12.5 per 100,000 persons per year (95% CI 11.7–13.4). Large vessel occlusion stroke patients were more commonly female than male (67.4% vs. 31.6%, p = 0.003), and were older than non-large vessel occlusion stroke patients (mean of 80.5 years vs. 71.4 years, p = < 0.001). They also had higher 30-day mortality rate (31.1% vs. 4.6%, p = < 0.001), and longer hospital stay (mean 38.6 vs. 21.1 days, p = 0.003) than non-large vessel occlusion stroke. In the same period, 83 thrombectomies for large vessel occlusion were performed, representing 9.1% of the estimated large vessel occlusion incidence.

Conclusion

The estimated incidence of anterior circulation large vessel occlusion in the Hong Kong Chinese population is lower than that in the West. There is however a substantial service gap for endovascular thrombectomy with less than 10% of large vessel occlusion patients receiving thrombectomy.

Emergency endoscopic third ventriculostomy for blocked shunts? Univariate and multivariate analysis of independent predictors for failure

OBJECTIVE

Hydrocephalus with a blocked ventriculoperitoneal (VP) shunt is a life-threatening condition. Emergency endoscopic third ventriculostomy (ETV) is a potential treatment option. The aim of the study was to identify independent risk factors associated with failure of ETV in treating patients with blocked shunts.

METHODS

The authors retrospectively reviewed data from consecutive patients admitted for blocked shunt treated by ETV during the study period from 2000 to 2016. Univariate and multivariate analyses were performed to identify independent factors associated with failed ETV for blocked shunts, such as age, sex, history of CNS infection, number of previous shunt revisions, operations performed as an emergency or elective, number of specialists, and other factors.

RESULTS

In total, 121 patients underwent ETV during the study period. Of these, 31 patients (25.6%) had ETV for treatment of a blocked shunt. In 25 (80.6%) of 31 ETV was performed as an emergency procedure. There was no significant difference in the success rate of ETV depending on whether it was performed as an emergency procedure (64% [16/25]) or an elective procedure (66.7% [4/6]; OR 0.062, 95% CI 0.001-2.708; p = 0.149). Univariate and multivariate analyses identified that history of a CNS infection was an independent risk factor for failure of ETV in treating patients with a blocked shunt (OR 0.030, 95% CI 0.001-0.888; p = 0.043).

CONCLUSIONS

Emergency ETV had a comparable success rate as elective ETV. A history of CNS infection is an independent predictor of ETV failure in treating patients with blocked shunts.

Clinical significance of CRNDE transcript variants in glioblastoma multiforme

The long non-coding RNA CRNDE is an oncogene that promotes tumor growth in glioblastoma multiforme (GBM). At least five CRNDE transcript variants with possibly different functional roles have been described in recent studies. Here, we report our preliminary findings on the differential expressions of CRNDE transcript variants in GBM, and their prognostic significance. Our preliminary data suggest that different transcript variants of CRNDE might have different functions in GBM and should be further studied as potential biomarkers for clinical prognostication.

Endoplasmic reticulum chaperone prolyl 4-hydroxylase, beta polypeptide (P4HB) promotes malignant phenotypes in glioma via MAPK signaling

Endoplasmic reticulum (ER) chaperone Prolyl 4-hydroxylase, beta polypeptide (P4HB) has previously been identified as a novel target for chemoresistance in glioblastoma multiforme (GBM). Yet its functional roles in glioma carcinogenesis remain elusive. In clinical analysis using human glioma specimens and Gene Expression Omnibus (GEO) profiles, we found that aberrant expression of P4HB was correlated with high-grade malignancy and an angiogenic phenotype in glioma. Furthermore, P4HB upregulation conferred malignant characteristics including proliferation, invasion, migration and angiogenesis in vitro, and increased tumor growth in vivo via the mitogen-activated protein kinase (MAPK) signaling pathway. Pathway analysis suggested genetic and pharmacologic inhibition of P4HB suppressed MAPK expression and its downstream targets were involved in angiogenesis and invasion. This is the first study that demonstrates the oncogenic roles of P4HB and its underlying mechanism in glioma. Since tumor invasion and Vascularisation are typical hallmarks in malignant glioma, our findings uncover a promising anti-glioma mechanism through P4HB-mediated retardation of MAPK signal transduction.

Outcome analysis of management of liver trauma: A 10-year experience at a trauma center

AIM: To review the outcomes of liver trauma in patients with hepatic injuries only and in patients with associated injuries outside the liver.

METHODS: Data of liver trauma patients presented to our center from January 2003 to October 2013 were reviewed. The patients were divided into two groups. Group 1 consisted of patients who had hepatic injuries only. Group 2 consisted of patients who also had associated injuries outside the liver.

RESULTS: Seven (30.4%) patients in group 1 and 10 (28.6%) patients in group 2 received non-operative management; the rest underwent operation. Blunt trauma occurred in 82.8% (48/58) of the patients and penetrative trauma in 17.2% (10/58). A higher injury severity score (ISS) was observed in group 2 (median 45 vs 25, P < 0.0001). More patients in group 1 were hemodynamically stable (65.2% vs 37.1%, P = 0.036). Other parameters were comparable between groups. Group 1 had better 30-d survival (91.3% vs 71.4%, P = 0.045). On multivariate analysis using the logistic regression model, ISS was found to be associated with mortality (P = 0.004, hazard ratio = 1.035, 95%CI: 1.011-1.060).

CONCLUSION: Liver trauma patients with multiple injuries are relatively unstable on presentation. Despite a higher ISS in group 2, non-operative management was possible for selected patients. Associated injuries outside the liver usually account for morbidity and mortality.

Separation and quantification of lactate and lipid at 1.3 ppm by diffusion-weighted magnetic resonance spectroscopy

PURPOSE

To separate the spectrally overlapped lactate and lipid signals at 1.3 ppm using diffusion-weighted magnetic resonance spectroscopy (DW-MRS) based on their large diffusivity difference.

METHODS

DW-MRS was applied to the gel phantoms containing lactate and lipid droplets, and to the rat brain tumors. Lactate and lipid signals and their apparent diffusion coefficients were computed from the diffusion-weighted proton spectra. Biexponential fitting and direct spectral subtraction approaches were employed and compared.

RESULTS

DW-MRS could effectively separate lactate and lipid signals both in phantoms and rat brain C6 glioma by biexponential fitting. In phantoms, lactate and lipid signals highly correlated with the known lactate concentration and lipid volume fractions. In C6 glioma, both lactate and lipid signals were detected, and the lipid signal was an order of magnitude higher than lactate signal. The spectral subtraction approach using three diffusion weightings also allowed the separation of lactate and lipid signals, yielding results comparable to those by the biexponential fitting approach.

CONCLUSION

DW-MRS presents a new approach to separate and quantify spectrally overlapped molecules and/or macromolecules, such as lactate and lipid, by using the diffusivity difference associated with their different sizes or mobility within tissue microstructure. Magn Reson Med 77:480-489, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Simultaneous pancreas and kidney transplantation as the standard surgical treatment for diabetes mellitus patients with end-stage renal disease

OBJECTIVES

To review the outcome following simultaneous pancreas and kidney transplantation in patients with type 1 diabetes mellitus and end-stage renal disease, as well as those with type 2 diabetes mellitus, and to discuss the applicability of this treatment in this locality.

METHODS

A systematic literature review was performed by searching the PubMed and Elsevier databases. The search terms used were "simultaneous pancreas and kidney transplantation", "diabetes", "pancreas transplant" and "SPK". Original and major review articles related to simultaneous pancreas and kidney transplantation were reviewed. Papers published in English after 1985 were included. Clinical outcomes following transplantation were extracted for comparison between different treatment methods. Outcomes of simultaneous pancreas and kidney transplant and other transplantation methods were identified and categorised into patient survival, graft survival, diabetic complications, and quality of life. Patient survivals and graft survivals were also compared.

RESULTS

Currently available clinical evidence shows good outcomes for type 1 diabetes mellitus in terms of patient survival, graft survival, diabetic complications, and quality of life. For type 2 diabetes mellitus, the efficacy and application of the procedure remain controversial but the outcomes are possibly comparable with those in type 1 diabetes mellitus.

CONCLUSIONS

Simultaneous pancreas and kidney transplantation is a technically demanding procedure that is associated with significant complications, and it should be regarded as a 'last resort' treatment in patients whose diabetic complications have become life-threatening or severely burdensome despite best efforts in maintaining good diabetic control through lifestyle modifications and medications.

Multitask training promotes automaticity of a fundamental laparoscopic skill without compromising the rate of skill learning

Background

A defining characteristic of expertise is automated performance of skills, which frees attentional capacity to better cope with some common intraoperative stressors. There is a paucity of research on how best to foster automated performance by surgical trainees. This study examined the use of a multitask training approach to promote automated, robust laparoscopic skills.

Methods

Eighty-one medical students completed training of a fundamental laparoscopic task in either a traditional single-task training condition or a novel multitask training condition. Following training, participants’ laparoscopic performance was tested in a retention test, two stress transfer tests (distraction and time pressure) and a secondary task test, which was included to evaluate automaticity of performance. The laparoscopic task was also performed as part of a formal clinical examination (OSCE).

Results

The training groups did not differ in the number of trials required to reach task proficiency (p = .72), retention of skill (ps > .45), or performance in the clinical examination (p = .14); however, the groups did differ with respect to the secondary task (p = .016). The movement efficiency (number of hand movements) of single-task trainees, but not multitask trainees, was negatively affected during the secondary task test. The two stress transfer tests had no discernable impact on the performance of either training group.

Conclusion

Multitask training was not detrimental to the rate of learning of a fundamental laparoscopic skill and added value by providing resilience in the face of a secondary task load, indicative of skill automaticity. Further work is needed to determine the extent of the clinical utility afforded by multitask training.

Oligodendrocyte Precursor Cells in Spinal Cord Injury: A Review and Update

Spinal cord injury (SCI) is a devastating condition to individuals, families, and society. Oligodendrocyte loss and demyelination contribute as major pathological processes of secondary damages after injury. Oligodendrocyte precursor cells (OPCs), a subpopulation that accounts for 5 to 8% of cells within the central nervous system, are potential sources of oligodendrocyte replacement after SCI. OPCs react rapidly to injuries, proliferate at a high rate, and can differentiate into myelinating oligodendrocytes. However, posttraumatic endogenous remyelination is rarely complete, and a better understanding of OPCs' characteristics and their manipulations is critical to the development of novel therapies. In this review, we summarize known characteristics of OPCs and relevant regulative factors in both health and demyelinating disorders including SCI. More importantly, we highlight current evidence on post-SCI OPCs transplantation as a potential treatment option as well as the impediments against regeneration. Our aim is to shed lights on important knowledge gaps and to provoke thoughts for further researches and the development of therapeutic strategies.

Glioma Association and Balancing Selection of ZFPM2

ZFPM2, encoding a zinc finger protein and abundantly expressed in the brain, uterus and smooth muscles, plays important roles in cardiac and gonadal development. Abnormal expression of ZFPM2 in ovarian tumors and neuroblastoma has been reported but hitherto its genetic association with cancer and effects on gliomas have not been studied. In the present study, the hexamer insertion-deletion polymorphism rs71305152, located within a large haplotype block spanning intron 1 to intron 3 of ZFPM2, was genotyped in Chinese cohorts of glioma (n = 350), non-glioma cancer (n = 354) and healthy control (n = 463) by direct sequencing and length polymorphism in gel electrophoresis, and ZFPM2 expression in glioma tissues (n = 69) of different grades was quantified by real-time RT-PCR. Moreover, potential natural selection pressure acting on the gene was investigated. Disease-association analysis showed that the overall genotype of rs71305152 was significantly associated with gliomas (P = 0.016), and the heterozygous genotype compared to the combined homozygous genotypes was less frequent in gliomas than in controls (P = 0.005) or non-glioma cancers (P = 0.020). ZFPM2 mRNA expression was negatively correlated with the grades of gliomas (P = 0.002), with higher expression levels in the low-grade gliomas. In the astrocytoma subtype, higher ZFPM2 expression was also correlated with the rs71305152 heterozygous genotype (P = 0.028). In addition, summary statistics tests gave highly positive values, demonstrating that the gene is under the influence of balancing selection. These findings suggest that ZFPM2 is a glioma susceptibility gene, its genotype and expression showing associations with incidence and severity, respectively. Moreover, the balancing selection acting on ZFPM2 may be related to the important roles it has to play in multiple organ development or associated disease etiology.

Comparison between self-assembling peptide nanofiber scaffold (SAPNS) and fibrin sealant in neurosurgical hemostasis

RADA16-I is a synthetic type I self-assembling peptide nanofiber scaffold (SAPNS) which may serve as a novel biocompatible hemostatic agent. Its application in neurosurgical hemostasis, however, has not been explored. Although RADA16-I is nontoxic and nonimmunogenic, its intrinsic acidity may potentially provoke inflammation in the surgically injured brain. We conducted an animal study to compare RADA16-I with fibrin sealant, a commonly used agent, with the hypothesis that the former would be a comparable alternative. Using a standardized surgical brain injury model, 30 Sprague-Dawley rats were randomized into three treatment groups: RADA16-I, fibrin sealant or gelatin sponge (control). Animals were sacrificed on day 3 and 42. Astrocytic and microglial infiltrations within the cerebral parenchyma adjacent to the operative site were significantly lower in the RADA16-I and fibrin sealant groups than control. RADA16-I did not cause more cellular inflammatory response despite its acidity when compared with fibrin sealant. Immunohistochemical studies showed infiltration by astrocytes and microglia into the fibrin sealant and RADA16-I grafts, suggesting their potential uses as tissue scaffolds. RADA16-I is a promising candidate for further translational and clinical studies that focus on its applications as a safe and effective hemostat, proregenerative nanofiber scaffold as well as drug and cell carrier.

MicroRNA-210 and Endoplasmic Reticulum Chaperones in the Regulation of Chemoresistance in Glioblastoma

Glioblastoma multiforme (GBM) is the commonest primary brain tumour in adults characterized by relentless recurrence due to resistance towards the standard chemotherapeutic agent temozolomide (TMZ). Prolyl 4-hydroxylase, beta polypeptide (P4HB), an endoplasmic reticulum (ER) chaperone, is known to be upregulated in TMZ-resistant GBM cells. MicroRNAs (miRNAs) are non-protein-coding transcripts that may play important roles in GBM chemoresistance. We surmised that miRNA dysregulations may contribute to P4HB upregulation, hence chemoresistance. We found that miRNA-210 (miR-210) was P4HB-targeting and was highly downregulated in TMZ-resistant GBM cells. Forced overexpression of miR-210 led to P4HB downregulation and a reduction in TMZ-resistance. A reciprocal relationship between their expressions was also verified in clinical glioma specimens. Our study is the first to demonstrate a potential link between miR-210 and ER chaperone in determining chemosensitivity in GBM. The findings have important translational implications in suggesting new directions of future studies.

Use of viscoelastic haemostatic assay in emergency and elective surgery

OBJECTIVES

To review the current evidence for the use of viscoelastic haemostatic assays in different surgical settings including trauma, cardiac surgery, liver transplantation, as well as the monitoring of antiplatelet agents and anticoagulants prior to surgery.

DATA SOURCES

PubMed database.

STUDY SELECTION

Key words for the literature search were "thromboelastography" or "ROTEM" in combination with "trauma", "antiplatelet", "cardiac surgery", "liver transplantation" or "anticoagulants".

DATA EXTRACTION

Original and major review articles related to the use of viscoelastic haemostatic assays.

DATA SYNTHESIS

Haemostatic function is a critical factor determining patient outcomes in emergency or elective surgery. The increasing use of antiplatelet agents and anticoagulants has potentially increased the risks of haemorrhages and the need for transfusion. Conventional coagulation tests have limitations in detecting haemostatic dysfunctions in subgroups of patients and are largely ineffective in diagnosing hyperfibrinolysis. The viscoelastic haemostatic assays are potentially useful point-of-care tools that provide information on clot formation, clot strength, and fibrinolysis, as well as to guide goal-directed transfusion and antifibrinolytic therapy. They may also be used to monitor antiplatelet and anticoagulant therapy. However, standardisation of techniques and reference ranges is required before these tests can be widely used in different clinical settings.

CONCLUSIONS

Viscoelastic haemostatic assays, as compared with conventional coagulation tests, are better for detecting coagulopathy and are the only tests that can provide rapid diagnosis of hyperfibrinolysis. Goal-directed administration of blood products based on the results of viscoelastic haemostatic assays was associated with reduction in allogeneic blood product transfusions in trauma, cardiac surgery, and liver transplantation cases. However, there is currently no evidence to support the routine use of viscoelastic haemostatic assays for monitoring platelet function prior to surgery.

Factors affecting implementation of accreditation programmes and the impact of the accreditation process on quality improvement in hospitals: a SWOT analysis

OBJECTIVES

The objectives of this review were to identify factors that influence implementation of hospital accreditation programmes and to assess the impact of the accreditation process on quality improvement in public hospitals.

DATA SOURCES

Two electronic databases, Medline (OvidSP) and PubMed, were systematically searched.

STUDY SELECTION

"Public hospital", "hospital accreditation", and "quality improvement" were used as the search terms. A total of 348 citations were initially identified. After critical appraisal and study selection, 26 articles were included in the review.

DATA EXTRACTION

The data were extracted and analysed using a SWOT (strengths, weaknesses, opportunities, threats) analysis.

DATA SYNTHESIS

Increased staff engagement and communication, multidisciplinary team building, positive changes in organisational culture, and enhanced leadership and staff awareness of continuous quality improvement were identified as strengths. Weaknesses included organisational resistance to change, increased staff workload, lack of awareness about continuous quality improvement, insufficient staff training and support for continuous quality improvement, lack of applicable accreditation standards for local use, and lack of performance outcome measures. Opportunities included identification of improvement areas, enhanced patient safety, additional funding, public recognition, and market advantage. Threats included opportunistic behaviours, funding cuts, lack of incentives for participation, and a regulatory approach to mandatory participation.

CONCLUSIONS

By relating the findings to the operational issues of accreditation, this review discussed the implications for successful implementation and how accreditation may drive quality improvement. These findings have implications for various stakeholders (government, the public, patients and health care providers), when it comes to embarking on accreditation exercises.

Hyperoxia resensitizes chemoresistant glioblastoma cells to temozolomide through unfolded protein response

BACKGROUND

Intratumoural hypoxia is associated with chemoresistance in glioblastoma multiforme (GBM), a highly malignant brain tumour. Adaptive response to endoplasmic reticulum stress induced by temozolomide is a major obstacle in recurrent GBM. We investigated whether hyperoxia resensitizes temozolomide-resistant GBM cells to temozolomide by abrogating the hypoxia-induced, unfolded protein response (UPR)-related protective mechanisms.

MATERIALS AND METHODS

We examined changes to key UPR modulators in temozolomide-sensitive and -resistant human GBM cells (D54 and U87) treated with/without temozolomide at different oxygen concentrations using western blotting, and cytotoxic benefits of overexpressing key chaperone, P4HB, in GBM cells (U87 and U251) under normoxia and hyperoxia.

RESULTS

Hyperoxia, alone or synergistically with temozolomide, activated the UPR in sensitive and resistant D54 and U87 cell lines. Hyperoxia also reduced survival benefit of U87 and U251 cells with P4HB overexpression through the UPR.

CONCLUSION

Hyperoxia enhanced GBM cell sensitivity to temozolomide, likely through UPR, highlighting an important treatment modality targeting chemosensitive and -resistant GBM.

Effect of clinical context on simulator-based assessment of blood pressure taking - a pilot randomized study

BACKGROUND

Blood pressure measurement is an essential clinical skill that can readily be assessed in objective structured clinical examination (OSCE). While the use of simulators can enhance test validity and reliability, the given clinical context may also affect student performance.

AIMS

To investigate the impact of variations in clinical context on blood pressure measurement in a simulator-based OSCE.

METHOD

We randomized 162 first-year medical students into four groups that received different lead-in statements before measuring blood pressure on a manikin simulator. These statements described hypothetical patients with different likelihoods of having systemic hypertension.

RESULTS

The lead-in that described the highest likelihood of hypertension was associated with significantly higher reported readings and lower accuracy. The lead-in that suggested normality yielded the best performance.

CONCLUSION

Student performance in simulator-based OSCE may be affected by the clinical context provided. However, we argue that construct validity should be viewed in light of the application of a test, in that patients may also present with different cues and likelihoods of having hypertension. Variations in construct design should be further explored to enhance the training and assessment of clinical competence that reflects the unpredictability encountered in daily clinical practice.

Patient Perception of Physician Attire Before and After Disclosure of the Risks of Microbial Contamination

Background: The white coat is traditionally considered to be the appropriate attire for physicians but it may also be contaminated with microbes and act as a potential source of infection. We aimed to study patients’ acceptance of physicians’ attire, their underlying reasons, and their reactions to an educational intervention with regards to the risks of contamination. Methods: We conducted a voluntary ques­tionnaire survey at a university teaching hospital in Hong Kong from February to July 2012. 262 patient-responses from adult inpatients and outpatients across various specialties were analysed. Results: White coats were highly favoured (90.8%) when compared with scrubs (22.1%), smart casual (7.6%) and formal (7.3%) wears. ’Professional image’ and ‘ease of identification’ were the main attributes of the white coat. Most patients (92.2%) would prefer doctors washing their white coats every few days, whilst 80.9% believed that doctors were actually doing so. After patients were informed of the potential risk of microbial contamination, white coats remained as the most favoured attire (66.4%), but with scrubs doubling in popularity (45.8%). Smart casual (9.2%) and formal attire (4.6%) remain the least accepted. Conclusion: Despite cross-infections being a significant concern within the healthcare environments, patients’ predominant acceptance and perceived attributes towards the white coat were maintained after an educational intervention on the risks of microbial contamination.

Refining the continuous tracking paradigm to investigate implicit motor learning

In two experiments we investigated factors that undermine conclusions about implicit motor learning in the continuous tracking paradigm. In Experiment 1, we constructed a practice phase in which all three segments of the waveform pattern were random, in order to examine whether tracking performance decreased as a consequence of time spent on task. Tracking error was lower in the first segment than in the middle segment and lower in the middle segment than in the final segment, indicating that tracking performance decreased as a function of increasing time-on-task. In Experiment 2, the waveform pattern presented in the middle segment was identical in each trial of practice. In a retention test, tracking performance on the repeated segment was superior to tracking performance on the random segments of the waveform. Furthermore, substitution of the repeated pattern with a random pattern (in a transfer test) resulted in a significantly increased tracking error. These findings imply that characteristics of the repeated pattern were learned. Crucially, tests of pattern recognition implied that participants were not explicitly aware of the presence of a recurring segment of waveform. Recommendations for refining the continuous tracking paradigm for implicit learning research are proposed.

Inhibition of prolyl 4-hydroxylase, beta polypeptide (P4HB) attenuates temozolomide resistance in malignant glioma via the endoplasmic reticulum stress response (ERSR) pathways

BACKGROUND

Glioblastoma multiforme (GBM), the most aggressive malignant primary brain tumor of the central nervous system, is characterized by a relentless disease recurrence despite continued advancement in surgery, radiotherapy, and chemotherapy. Resistance to temozolomide (TMZ), a standard chemotherapeutic agent for GBM, remains a major challenge. Understanding the mechanisms behind TMZ resistance can direct the development of novel strategies for the prevention, monitoring, and treatment of tumor relapse.

METHODS AND RESULTS

Our research platform, based on the establishment of 2 pairs of TMZ-sensitive/resistant GBM cells (D54-S and D54-R; U87-S and U87-R), has successfully identified prolyl 4-hydroxylase, beta polypeptide (P4HB) over-expression to be associated with an increased IC50 of TMZ. Elevated P4HB expression was verified using in vivo xenografts developed from U87-R cells. Clinically, we found that P4HB was relatively up-regulated in the recurrent GBM specimens that were initially responsive to TMZ but later developed acquired resistance, when compared with treatment-naive tumors. Functionally, P4HB inhibition by RNAi knockdown and bacitracin inhibition could sensitize D54-R and U87-R cells to TMZ in vitro and in vivo, whereas over-expression of P4HB in vitro conferred resistance to TMZ in both D54-S and U87-S cells. Moreover, targeting P4HB blocked its protective function and sensitized glioma cells to TMZ through the PERK arm of the endoplasmic reticulum stress response.

CONCLUSIONS

Our study identified a novel target together with its functional pathway in the development of TMZ resistance. P4HB inhibition may be used alone or in combination with TMZ for the treatment of TMZ-resistant GBM.

Pipeline embolization device for intracranial aneurysm: a systematic review

INTRODUCTION

The pipeline embolization device (PED) is a new endovascular stent designed for the treatment of challenging intracranial aneurysms (IAs). Its use has been extended to nonruptured and ruptured IAs of a variety of configurations and etiologies in both the anterior and posterior circulations.

METHODS

We conducted a systematic review of ten eligible reports on its clinical efficacy and safety.

RESULTS

There were 414 patients with 448 IAs. The majority of the IAs were large (40.2 %), saccular or blister-like (78.3 %), and were located mostly in the anterior circulation (83.5 %). The regimens of antiplatelet therapy varied greatly between and within studies. The mean number of the PED used was 2.0 per IA. Deployment was successful in around 95 % of procedures. Aneurysm obliteration was achieved in 82.9 % of IAs at 6-month. The overall incidences of periprocedural intracranial vascular complication rate and mortality rate were 6.3 and 1.5 %, respectively.

CONCLUSION

The PED is a safe and effective treatment for nonruptured IAs. Its use in the context of acute subarachnoid hemorrhage (SAH) should be cautioned. Its main limitations include the need for prolonged antiplatelet therapy, as well as the potential risks of IA rupture and non-IA-related intracerebral hemorrhages (ICH). Future studies should aim at identifying factors that predispose to incomplete obliteration, delayed rupture, and thromboembolic complications.

Hyperoxia resensitizes chemoresistant human glioblastoma cells to temozolomide

Temozolomide (TMZ) is standard chemotherapy for glioblastoma multiforme (GBM). Intratumoral hypoxia is common in GBM and may be associated with the development of TMZ resistance. Oxygen therapy has previously been reported to potentiate the effect of chemotherapy in cancer. In this study, we investigated whether hyperoxia can enhance the TMZ-induced cytotoxicity of human GBM cells, and whether and how it would resensitize TMZ-resistant GBM cells to TMZ. TMZ-sensitive human GBM cells (D54-S and U87-S) were treated with TMZ to develop isogenic subclones of TMZ-resistant cells (D54-R and U87-R). All cell lines were then exposed to different oxygen levels (1, 21, 40, or 80 %), with or without concomitant TMZ treatment, before assessment of cell cytotoxicity and morphology. Cell death and survival pathways elicited by TMZ and/or hyperoxia were elucidated by western blotting. Our results showed that TMZ sensitivity of both chemo-sensitive and resistant cells was enhanced significantly under hyperoxia. At the cell line-specific optimum oxygen concentration (D54-R, 80 %; U87-R, 40 %), resistant cells had the same response to TMZ as the parent chemosensitive cells under normoxia via the caspase-dependent pathway. Both TMZ and hyperoxia were associated with increased phosphorylation of ERK p44/42 MAPK (Erk1/2), but to a lesser extent in D54-R cells, suggesting that Erk1/2 activity may be involved in regulation of hyperoxia and TMZ-mediated cell death. Overall, hyperoxia enhanced TMZ toxicity in GBM cells by induction of apoptosis, possibly via MAPK-related pathways. Induced hyperoxia is a potentially promising approach for treatment of TMZ-resistant GBM.

Loss of brain-enriched miR-124 microRNA enhances stem-like traits and invasiveness of glioma cells

miR-124 is a brain-enriched microRNA that plays a crucial role in neural development and has been shown to be down-regulated in glioma and medulloblastoma, suggesting its possible involvement in brain tumor progression. Here, we show that miR-124 is down-regulated in a panel of different grades of glioma tissues and in all of the human glioma cell lines we examined. By integrated bioinformatics analysis and experimental confirmation, we identified SNAI2, which is often up-regulated in glioma, as a direct functional target of miR-124. Because SNAI2 has been shown to regulate stem cell functions, we examined the roles of miR-124 and SNAI2 in glioma cell stem-like traits. The results showed that overexpression of miR-124 and knockdown of SNAI2 reduced neurosphere formation, CD133(+) cell subpopulation, and stem cell marker (BMI1, Nanog, and Nestin) expression, and these effects could be rescued by re-expression of SNAI2. Furthermore, enhanced miR-124 expression significantly inhibited glioma cell invasion in vitro. Finally, stable overexpression of miR-124 and knockdown of SNAI2 inhibited the tumorigenicity and invasion of glioma cells in vivo. These findings reveal, for the first time, that the tumor suppressor activity of miR-124 could be partly due to its inhibitory effects on glioma stem-like traits and invasiveness through SNAI2.

Protein alterations associated with temozolomide resistance in subclones of human glioblastoma cell lines

Temozolomide (TMZ) is the standard chemotherapeutic agent for human malignant glioma, but intrinsic or acquired chemoresistance represents a major obstacle to successful treatment of this highly lethal group of tumours. Obtaining better understanding of the molecular mechanisms underlying TMZ resistance in malignant glioma is important for the development of better treatment strategies. We have successfully established a passage control line (D54-C10) and resistant variants (D54-P5 and D54-P10) from the parental TMZ-sensitive malignant glioma cell line D54-C0. The resistant sub-cell lines showed alterations in cell morphology, enhanced cell adhesion, increased migration capacities, and cell cycle arrests. Proteomic analysis identified a set of proteins that showed gradual changes in expression according to their 50% inhibitory concentration (IC₅₀). Successful validation was provided by transcript profiling in another malignant glioma cell line U87-MG and its resistant counterparts. Moreover, three of the identified proteins (vimentin, cathepsin D and prolyl 4-hydroxylase, beta polypeptide) were confirmed to be upregulated in high-grade glioma. Our data suggest that acquired TMZ resistance in human malignant glioma is associated with promotion of malignant phenotypes, and our reported molecular candidates may serve not only as markers of chemoresistance but also as potential therapeutic targets in the treatment of TMZ-resistant human malignant glioma, providing a platform for future investigations.

Using bevacizumab in the fight against malignant glioma: first results in Asian patients

OBJECTIVES

To investigate the efficacy and safety profile of bevacizumab in combination with irinotecan in Hong Kong Chinese patients with recurrent malignant glioma and to determine whether their response differed from that reported in other populations.

DESIGN

Retrospective study.

SETTING

Two private clinics and a public hospital in Hong Kong.

PATIENTS

Fourteen individuals who presented with recurrent glioma presenting to the hospital between November 2005 and November 2009.

INTERVENTION

Salvage therapy with bevacizumab (10 mg/kg) and irinotecan (125 mg/m(2) [340 mg/m(2) for those taking enzyme-inducing antiepileptic drugs]) on a 14-day schedule.

RESULTS

A radiological response was observed in 12 (86%) of the patients, four (33%) of whom had a complete response. The median progression-free survival was 6 (range, 1-15) months; 71% remained progression-free at 6 months. The median overall survival was 18 (range, 9-61) months. The most common adverse events during the bevacizumab and irinotecan treatment period were haematological; five patients had grade 2/3 adverse events. Pulmonary embolism occurred in two patients, one of whom died. Intracranial haemorrhage was not detected in any of the 14 treated patients.

CONCLUSIONS

Bevacizumab plus irinotecan was at least as effective at treating Chinese patients with recurrent glioma as previously reported in clinical trials in different patient populations.

A Multicenter Multinational Registry for Assessing Ventriculoperitoneal Shunt Infections for Hydrocephalus

BACKGROUND:

Reported infection rates after ventriculoperitoneal shunt surgery vary from 1 to 25%. Antibiotic-impregnated (AI) catheters may reduce shunt infection rates, but this is uncertain.

OBJECTIVE:

To establish a prospective shunt registry to evaluate short-term (3-month) infection rates associated with ventriculoperitoneal shunts and standard or AI catheters during surgical treatment of hydrocephalus.

METHODS:

A prospective, multicenter, noncontrolled, open-label registry investigated patients with de novo catheter implantation or catheter replacement of an existing ventriculoperitoneal shunt. The primary outcome was shunt infection.

RESULTS:

A total of 440 patients were entered into the registry at 10 sites: 3 in North America, 2 in Singapore, 4 in China and 1 in India. Seven patients were excluded. Of the 433 remaining patients, 314 had new shunts and 119 were revisions. Shunt infections occurred in 14 of 433 patients (3.2%) overall and in 2 of 37 infants (5.2%) younger than 1 year. AI catheters were used in 46 of 433 patients at 7 centers. The shunt infection rate was 0 of 46 for shunts with AI catheters and 14 of 387 (3.6%) without AI catheters. Infection rates were similar with AI catheters, adjusting for age and catheter type.

CONCLUSION:

The overall shunt infection rate was lower than in previous multicentered studies. The low infection rate and low rate of AI catheter use precludes any meaningful statement regarding the value of AI catheters in reducing the infection rate. Consideration should be given to performing a well designed, adequately powered, prospective randomized controlled trial to determine whether AI catheters reduce shunt infection rates.