Management of cerebral cavernous malformations in the pediatric population: a literature review and case illustrations

Cavernous malformations (CM) are vascular malformations of the central nervous system that may occur in the brain and spinal cord. They are one of the four major types of vascular malformations that also includes developmental venous anomalies (DVA)s, arteriovenous malformations (AVMs), and capillary telangiectasias. CMs are a common vascular malformation, and 25% of them occur in the pediatric age group. They can present with acute or chronic symptoms including headache, neurologic deficits secondary to hemorrhage, mass effect, or epilepsy. This review will focus on the neurosurgical management of intracranial cavernous malformations in children. Pediatric CMs have special considerations different from CM that occur in the adult population which are highlighted throughout this review. Characteristics specific to pediatric CM epidemiology, genetics, presentation, pathology, location, size, epilepsy, and management will be discussed. Specific considerations must be entertained with the diagnosis of pediatric CM in that management needs to include consideration of the lifetime risk of hemorrhage, as well as the possibility of development of epilepsy. If in an accessible location, most cavernomas should be surgically removed in a timely fashion to provide lifelong cure for pediatric patients. The review closes with the discussion of two interesting cavernous malformation cases occurring in a 12-year old male and a 12-year old female that exhibit many of the important aspects specific to the management of a pediatric patient with CM, highlighting the importance of a multidisciplinary approach to treatment.

Colistimethate sodium powder and tobramycin powder for inhalation for the treatment of chronic Pseudomonas aeruginosa lung infection in cystic fibrosis: systematic review and economic model

BACKGROUND

Cystic fibrosis (CF) is an inherited condition characterised by the abnormal transport of chloride ions across transporting epithelia. This leads to the production of thick sticky mucus in the lungs, pancreas, liver, intestine and reproductive tract, and an increase in the salt content in sweat. Among other problems, people with CF experience recurrent respiratory infections and have difficulties digesting food. CF affects over 9000 individuals in the UK. CF shortens life expectancy and adversely affects quality of life. In 2010, CF was recorded as the cause of 103 deaths in England and Wales.

OBJECTIVE

To evaluate the clinical effectiveness and cost-effectiveness of colistimethate sodium dry powder for inhalation (DPI) (Colobreathe(®), Forest Laboratories) and tobramycin DPI (TOBI Podhaler(®), Novartis Pharmaceuticals) for the treatment of Pseudomonas aeruginosa lung infection in CF.

DATA SOURCES

Electronic databases were searched in February and March 2011 [MEDLINE, MEDLINE In-Process & Other Non-Indexed citations, EMBASE, The Cochrane Library databases, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, Conference Proceedings Citation Index (CPCI) and Bioscience Information Service (BIOSIS) Previews]. Relevant databases were searched for ongoing and unpublished studies, and bibliographies of relevant systematic reviews and the manufacturers' submissions were also hand-searched.

REVIEW METHODS

A systematic review of the clinical effectiveness and cost-effectiveness of colistimethate sodium DPI and tobramycin DPI for the treatment of chronic P. aeruginosa lung infection in CF was conducted. Existing economic evidence within the literature was reviewed and a de novo health economic model was also developed.

RESULTS

Three randomised controlled trials (RCTs) were included in the clinical effectiveness review. Both colistimethate sodium DPI and tobramycin DPI were reported to be non-inferior to nebulised tobramycin for the outcome forced expiratory volume in first second percentage predicted (FEV1%). It was not possible to draw any firm conclusions as to the relative efficacy of colistimethate sodium DPI compared with tobramycin DPI. The economic analysis suggests that colistimethate sodium DPI produces fewer quality-adjusted life-years (QALYs) than nebulised tobramycin. Given the incremental discounted lifetime cost of tobramycin DPI compared with nebulised tobramycin, it highly unlikely that tobramycin DPI has an incremental cost-effectiveness ratio that is better than £30,000 per QALY gained.

LIMITATION

The uncertainty surrounding the short-term evidence base inevitably results in uncertainty surrounding the long-term clinical effectiveness and cost-effectiveness of colistimethate sodium DPI.

CONCLUSIONS

Both DPI formulations have been shown to be non-inferior to nebulised tobramycin as measured by FEV1%. The results of these trials should be interpreted with caution owing to the means by which the results were analysed, the length of follow-up, and concerns about the ability of FEV1% to accurately represent changes in lung health. Although the increase in QALYs is expected to be lower with colistimethate sodium DPI than with nebulised tobramycin, a price for this intervention had not been agreed at the time of the assessment. Depending on the price of colistimethate sodium DPI, this results either in a situation whereby colistimethate sodium DPI is dominated by nebulised tobramycin or in one whereby the incremental cost-effectiveness of nebulised tobramycin compared with colistimethate sodium DPI is in the range of £24,000-277,000 per QALY gained. The economic analysis also suggests that, given its price, it is unlikely that tobramycin DPI has a cost-effectiveness ratio of < £30,000 per QALY gained when compared with nebulised tobramycin. A RCT to assess the longer-term (≥ 12 months) efficacy of colistimethate sodium DPI and tobramycin DPI in comparison with nebulised treatments would be beneficial. Such a study should include the direct assessment of HRQoL using a relevant preference-based instrument. Future studies should ensure that the European Medicines Agency guidelines are adhered to. In addition, high-quality research concerning the relationship between forced expiratory volume in first second % (FEV1%) predicted or other measures of lung function and survival/health-related quality of life (HRQoL) would be useful.

STUDY REGISTRATION

PROSPERO CRD42011001350.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Systematic review, network meta-analysis and exploratory cost-effectiveness model of randomized trials of minimally invasive techniques versus surgery for varicose veins

BACKGROUND

A Health Technology Assessment was conducted to evaluate the relative clinical effectiveness and cost-effectiveness of minimally invasive techniques (foam sclerotherapy (FS), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA)) for managing varicose veins, in comparison with traditional surgery.

METHODS

A systematic review of randomized clinical trials (RCTs) was undertaken to assess the effectiveness of minimally invasive techniques compared with other treatments, principally surgical stripping, in terms of recurrence of varicose veins, Venous Clinical Severity Score (VCSS), pain and quality of life. Network meta-analysis and exploratory cost-effectiveness modelling were performed.

RESULTS

The literature search conducted in July 2011 identified 1453 unique citations: 31 RCTs (51 papers) satisfied the criteria for effectiveness review. Differences between treatments were negligible in terms of clinical outcomes, so the treatment with the lowest cost appears to be most cost-effective. Total FS costs were estimated to be lowest, and FS was marginally more effective than surgery. However, relative effectiveness was sensitive to the model time horizon. Threshold analysis indicated that EVLA and RFA might be considered cost-effective if their costs were similar to those for surgery. These findings are subject to various uncertainties, including the risk of bias present in the evidence base and variation in reported costs.

CONCLUSION

This assessment of currently available evidence suggests there is little to choose between surgery and the minimally invasive techniques in terms of efficacy or safety, so the relative cost of the treatments becomes one of the deciding factors. High-quality RCT evidence is needed to verify and further inform these findings.

Clinical effectiveness and cost-effectiveness of minimally invasive techniques to manage varicose veins: a systematic review and economic evaluation

BACKGROUND

Varicose veins are enlarged, visibly lumpy knotted veins, usually in the legs. Uncomplicated varicose veins can cause major discomfort and some complications. They are part of chronic venous disease (CVD), which is reported to have a substantial negative impact on health-related quality of life (HRQoL). Traditional treatments for varicose veins involve surgical stripping and ligation and liquid sclerotherapy (LS), but can be invasive and painful. New minimally invasive treatments offer an alternative. These treatments typically involve use of laser, radiofrequency or foam sclerosant. They are increasingly widely used and offer potential benefits such as reduced complications, faster recovery, fewer physical limitations and improved quality of life.

OBJECTIVE

The aim of this report is to evaluate the clinical effectiveness, safety and cost-effectiveness of the minimally invasive techniques of foam sclerotherapy (FS), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) in comparison with other techniques, including traditional surgical techniques, LS and conservative management, in the management of varicose veins.

DATA SOURCES

A systematic search was made of 11 bibliographic databases of published and unpublished literature from their inception to July 2011: MEDLINE; EMBASE; Cumulative Index to Nursing and Allied Health Literature; The Cochrane Library; Biological Abstracts; Science Citation Index (SCI); Social Sciences Citation Index; Conference Proceedings Citation Index-Science; UK Clinical Research Network; Current Controlled Trials; and ClinicalTrials.gov.

REVIEW METHODS

A systematic review of randomised controlled trials (RCTs) to assess the clinical effectiveness of minimally invasive techniques compared with other treatments, principally surgical stripping, in terms of recurrence of varicose veins, retreatment and clinical symptoms, as measured by the Venous Clinical Severity Score (VCSS), pain and quality of life. Network meta-analysis and exploratory cost-effectiveness modelling were performed.

RESULTS

The literature search identified 1453 unique citations, of which 34 RCTs (54 papers) satisfied the criteria for the clinical effectiveness review. The minimally invasive techniques reported clinical outcomes similar to surgery. Rates of recurrence were slightly lower for EVLA, RFA and FS, especially for longer follow-up periods; VCSS score was lower for EVLA and FS than for stripping, but slightly higher for RFA; short-term pain was less for FS and RFA but higher for EVLA; higher quality-of-life scores were reported for all evaluated interventions than for stripping. Differences between treatments were therefore negligible in terms of clinical outcomes, so the treatment with the lowest cost appears to be most cost-effective. Our central estimate is that total FS costs were lowest and FS is marginally more effective than stripping. However, this result was sensitive to the model time horizon. Threshold analysis indicated that EVLA and RFA might be considered cost-effective if their costs are equivalent to stripping. These findings are subject to uncertainty on account of the risk of bias present in the evidence base and the variation in costs.

LIMITATIONS

The relative clinical effectiveness and cost-effectiveness of the techniques are principally based on rates of post-operative technical recurrence rather than symptomatic recurrence, as this was the reported outcome in all trials. The true proportion of treated individuals who are likely to present with symptoms of recurrence requiring retreatment is therefore not certain. A figure reflecting the likely proportion of treated individuals who would experience symptomatic recurrence requiring retreatment (with its associated costs), therefore, had to be calculated by the authors based on a small number of studies. The findings of this report also need to be verified by data from future trials with longer follow-up and using more standardised outcome measures.

CONCLUSIONS

This assessment of the currently available evidence suggests there is little to choose between the minimally invasive techniques in terms of efficacy or cost, and each offers a viable, clinically effective alternative to stripping. FS might offer the most cost-effective alternative to stripping, within certain time parameters. High-quality RCT evidence is needed. Future trials should aim to measure and report outcomes in a standardised manner, which would permit more efficient pooling of their results.

STUDY REGISTRATION

PROSPERO number CRD42011001355.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

ICT reuse in socio-economic enterprises

In Europe, socio-economic enterprises such as charities, voluntary organisations and not-for-profit companies are involved in the repair, refurbishment and reuse of various products. This paper characterises and analyses the operations of socio-economic enterprises that are involved in the reuse of Information and Communication Technology (ICT) equipment. Using findings from a survey, the paper specifically analyses the reuse activities of socio-economic enterprises in the U.K. from which Europe-wide conclusions are drawn. The amount of ICT products handled by the reuse organisations is quantified and potential barriers and opportunities to their operations are analysed. By-products from reuse activities are discussed and recommendations to improve reuse activities are provided. The most common ICT products dealt with by socio-economic enterprises are computers and related equipment. In the U.K. in 2010, an estimated 143,750 appliances were reused. However, due to limitations in data, it is difficult to compare this number to the amount of new appliances that entered the U.K. market or the amount of waste electrical and electronic equipment generated in the same period. Difficulties in marketing products and numerous legislative requirements are the most common barriers to reuse operations. Despite various constraints, it is clear that organisations involved in reuse of ICT could contribute significantly to resource efficiency and a circular economy. It is suggested that clustering of their operations into "reuse parks" would enhance both their profile and their products. Reuse parks would also improve consumer confidence in and subsequently sales of the products. Further, it is advocated that industrial networking opportunities for the exchange of by-products resulting from the organisations' activities should be investigated. The findings make two significant contributions to the current literature. One, they provide a detailed insight into the reuse operations of socio-economic enterprises. Previously unavailable data has been presented and analysed. Secondly, new evidence about the by-products/materials resulting from socio-economic enterprises' reuse activities has been obtained. These contributions add substantially to our understanding of the important role of reuse organisations.

Training on motor and visual spatial learning tasks in early adulthood produces large changes in dendritic organization of prefrontal cortex and nucleus accumbens in rats given nicotine prenatally

Experience-dependent plasticity is an ongoing process that can be observed and measured at multiple levels. The first goal of this study was to examine the effects of prenatal nicotine on the performance of rats in three behavioral tasks (elevated plus maze (EPM), Morris water task (MWT), and Whishaw tray reaching). The second goal of this experiment sought to examine changes in dendritic organization following exposure to the behavioral training paradigm and/or low doses of prenatal nicotine. Female Long-Evans rats were administered daily injections of nicotine for the duration of pregnancy and their pups underwent a regimen of behavioral training in early adulthood (EPM, MWT, and Whishaw tray reaching). All offspring exposed to nicotine prenatally exhibited substantial increases in anxiety. Male offspring also showed increased efficiency in the Whishaw tray-reaching task and performed differently than the other groups in the probe trial of the MWT. Using Golgi-Cox staining we examined the dendritic organization of the medial and orbital prefrontal cortex as well as the nucleus accumbens. Participation in the behavioral training paradigm was associated with dramatic reorganization of dendritic morphology and spine density in all brain regions examined. Although both treatments (behavior training and prenatal nicotine exposure) markedly altered dendritic organization, the effects of the behavioral experience were much larger than those of the prenatal drug exposure, and in some cases interacted with the drug effects.

Systematic review, meta-analysis and economic modelling of diagnostic strategies for suspected acute coronary syndrome

BACKGROUND

Current practice for suspected acute coronary syndrome (ACS) involves troponin testing 10-12 hours after symptom onset to diagnose myocardial infarction (MI). Patients with a negative troponin can be investigated further with computed tomographic coronary angiography (CTCA) or exercise electrocardiography (ECG).

OBJECTIVES

We aimed to estimate the diagnostic accuracy of early biomarkers for MI, the prognostic accuracy of biomarkers for major adverse cardiac adverse events (MACEs) in troponin-negative patients, the diagnostic accuracy of CTCA and exercise ECG for coronary artery disease (CAD) and the prognostic accuracy of CTCA and exercise ECG for MACEs in patients with suspected ACS. We then aimed to estimate the cost-effectiveness of using alternative biomarker strategies to diagnose MI, and using biomarkers, CTCA and exercise ECG to risk-stratify troponin-negative patients.

DATA SOURCES

We searched MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations; Cumulative Index of Nursing and Allied Health Literature (CINAHL), EMBASE, Web of Science, Cochrane Central Database of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), NHS Database of Abstracts of Reviews of Effects (DARE) and the Health Technology Assessment database from 1985 (CTCA review) or 1995 (biomarkers review) to November 2010, reviewed citation lists and contacted experts to identify relevant studies.

REVIEW METHODS

Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool and prognostic studies using a framework adapted for the project. Meta-analysis was conducted using bayesian Markov chain Monte Carlo simulation. We developed a decision-analysis model to evaluate the cost-effectiveness of alternative biomarker strategies to diagnose MI, and the cost-effectiveness of biomarkers, CTCA or exercise ECG to risk-stratify patients with a negative troponin. Strategies were applied to a theoretical cohort of patients with suspected ACS. Cost-effectiveness was estimated as the incremental cost per quality-adjusted life-year (QALY) of each strategy compared with the next most effective, taking a health-service perspective and a lifetime horizon.

RESULTS

Sensitivity and specificity (95% predictive interval) were 77% (29-96%) and 93% (46-100%) for troponin I, 80% (33-97%) and 91% (53-99%) for troponin T (99th percentile threshold), 81% (50-95%) and 80% (26-98%) for quantitative heart-type fatty acid-binding protein (H-FABP), 68% (11-97%) and 92% (20-100%) for qualitative H-FABP, 77% (19-98%) and 39% (2-95%) for ischaemia-modified albumin and 62% (35-83%) and 83% (35-98%) for myoglobin. CTCA had 94% (61-99%) sensitivity and 87% (16-100%) specificity for CAD. Positive CTCA and positive-exercise ECG had relative risks of 5.8 (0.6-24.5) and 8.0 (2.3-22.7) for MACEs. In most scenarios in the economic analysis presentation, high-sensitivity troponin measurement was the most effective strategy with an incremental cost-effectiveness ratio (ICER) of less than the £20,000-30,000/QALY threshold (ICER £7487-17,191/QALY). CTCA appeared to be the most cost-effective strategy for patients with a negative troponin, with an ICER of £11,041/QALY. However, when a lower MACE rate was assumed, CTCA had a high ICER (£262,061/QALY) and the no-testing strategy was optimal.

LIMITATIONS

There was substantial variation between the primary studies and heterogeneity in their results. Findings of the economic model were dependent on assumptions regarding the value of detecting and treating positive cases.

CONCLUSIONS

Although presentation troponin has suboptimal sensitivity, measurement of a 10-hour troponin level is unlikely to be cost-effective in most scenarios compared with a high-sensitivity presentation troponin. CTCA may be a cost-effective strategy for troponin-negative patients, but further research is required to estimate the effect of CTCA on event rates and health-care costs.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Protection against L-NAME-induced reduction in cardiac output persists even after cessation of angiotensin-converting enzyme inhibitor treatment

AIM

We have demonstrated that short-term angiotensin-converting enzyme (ACE) inhibition in adult spontaneously hypertensive rats produces cardiac changes that persist following cessation of treatment that result in a reduced inflammatory, proliferative and fibrotic response to the nitric oxide synthase inhibitor N(ω) -Nitro-l-arginine methyl ester (L-NAME). The present study examines whether prior ACE inhibition with enalapril also protects against L-NAME-induced cardiac dysfunction.

METHODS

Rats were treated with enalapril (Enal + L) or tap water (Con, Con + L) for 2 weeks followed by a 2-week washout period. At this point, Con + L and Enal + L rats were treated with L-NAME for 10 days. Hearts were perfused in the working mode, mean arterial pressure (MAP) was assessed via radiotelemetry, and myocardial injury was evaluated in hematoxylin and eosin-stained sections.

RESULTS

L-NAME increased MAP by a similar magnitude in Con + L and Enal + L. L-NAME-induced statistically significant decreases in flow-mediated functional parameters in Con + L rats including cardiac output, stroke volume and coronary flow. This was prevented by prior enalapril treatment. Prior enalapril did not prevent L-NAME-induced myocardial injury, but may have lessened the degree of it. Regardless of treatment, changes in cardiac function did not correlate with myocardial injury.

CONCLUSION

Despite equivalent impact on MAP and incidence of myocardial infarction, prior enalapril treatment resulted in the preservation of cardiac function following L-NAME. Understanding the mechanisms by which transient ACE inhibition protects against reductions in cardiac function in the absence of ongoing treatment may reveal novel targets for heart failure treatment.

Stress during development alters dendritic morphology in the nucleus accumbens and prefrontal cortex

The long-term effects of stress during development have been well characterized. However, the effects of developmental stress on the underlying neurological mechanisms related to the reward system are not well understood. The present report studied the long term effects of stress during development on the structural plasticity in the cortical and subcortical regions. Rats exposed to stress during embryonic development (prenatal stress; PS) or soon after birth (maternal separation; MS) were studied for structural alteration at the neuronal level in the nucleus accumbens (NAc), orbital frontal cortex (OFC), and medial prefrontal cortex (mPFC). The findings show that stress during development increased dendritic branching, length, and spine density in the NAc, and subregions of the PFC. PS experience increased dendritic branching and length in the mPFC apical and basilar dendrites. In contrast, a PS-associated decrease in dendritic branching and length was observed in the basilar branches of the OFC. MS resulted in an increase in dendritic growth and spine density in the subregions of the PFC. The effect of PS on neuroanatomy was more robust than MS despite the shorter duration and intensity. The altered dendritic growth and spine density associated with stress during development could have potential impact on NAc and PFC related behaviors.

Hemiarthroplasty and total hip arthroplasty for treating primary intracapsular fracture of the hip: a systematic review and cost-effectiveness analysis

BACKGROUND

Hip fracture is a common problem in people aged > 60 years. The treatment options for individuals with high pre-fracture mobility, function and independence are hemiarthroplasty (HA) and total hip arthroplasty (THA).

OBJECTIVE

The aim of this report is to assess the clinical effectiveness and cost-effectiveness evidence of THA compared with HA in patients with displaced intracapsular fracture who are cognitively intact with high pre-fracture mobility or function.

DATA SOURCES

A systematic search was made of 11 databases of published and unpublished literature from their inception to december 2010: MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Biological Science Citation Index, Social Science Citation Index, Conference Proceedings Citation Index - Science, UK Clinical Trials Research Network and the National Research Register archive, Current Controlled Trials and ClinicalTrials.gov.

REVIEW METHODS

A systematic review of randomised controlled trials (RCTs) to assess the effectiveness of THA compared with HA in terms of dislocations, revisions, pain and function, and quality of life. Meta-analysis, independent subgroup analyses and exploratory cost-effectiveness modelling were performed.

RESULTS

The literature search identified 532 unique citations, of which eight RCTs with almost 1000 participants satisfied the criteria for the effectiveness review. Meta-analysis found a statistically significant increased risk of dislocation for patients treated with THA compared with HA (p = 0.01), but a reduced risk of revision (p = 0.0003). There were no differences in terms of mortality. In all trials, individuals treated with THA reported better function and mobility and less pain than those treated with HA. Four trials reporting utility data found similar trends. Sensitivity analyses indicated that there were no statistically significant differences in outcomes based on follow-up, study quality, surgical approach taken, type of head or the use of cement. Four papers reported a cost-utility analysis or the cost-effectiveness of THA compared with HA. Exploratory modelling was undertaken that showed that THA is likely to be cost-effective compared with HA even when the limitations of the data and methodology are considered.

LIMITATIONS

The costs and disutilities associated with revisions and dislocations were not included in the economic evaluation.

CONCLUSIONS

THA appears to be more cost-effective than HA. It is likely that THA will be associated with increased costs in the initial 2-year period, but lower longer-term costs, owing to potentially lower revision rates. However, these longer-term costs have not been modelled. The capacity and experience of surgeons to perform THA have not been explored and these would need to be addressed at local level were THA to become recommended for active, elderly patients in whom THA is not contraindicated. Further studies examining the impact of surgeon experience on performing the two procedures may offer more robust evidence on outcomes.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.