Hospital-based health technology assessment of innovative medical devices: insights from a nationwide survey in France.

OBJECTIVES: To better understand the process of hospital acquisition of innovative medical devices (MDs) and the hospital-based health technology assessment (HB-HTA) pathways in France, an in-depth study based on a quantitative approach is needed. The aim of the present study was to assess through a national survey how HB-HTA is currently implemented in French hospitals and to identify its level of formalization. METHODS: A quantitative online survey was conducted among hospitals performing HB-HTA in France, with a focus on the acquisition of innovative MDs for individual use. The survey, conducted between March and June 2022, was developed by a scientific board composed of members of the French-speaking Society for HB-HTA. RESULTS: Sixty-seven out of 131 surveyed hospitals with HB-HTA activities responded, including 29 university hospitals, 24 nonprofit private hospitals, and 14 local hospitals. Sixty-one respondents (91 percent) reported the existence of a process dedicated to evaluating innovative MDs; of these, 16 declared that their hospitals had a formalized unit with HB-HTA activity. These units were more frequently found in larger hospitals with more than 500 inpatient beds (n = 16, p = 0.0160) and in university hospitals (n = 12, p = 0.0158). No hospital reported any collaboration with HAS, the French national HTA agency. CONCLUSION: A diverse range of HB-HTA organizations with different structural levels exist in France for MD procurement linked to the category of hospitals. The study highlights the need for recognition of HB-HTA activity at the regulatory level in France and for direct collaboration between HTA activities performed at local and national levels.

Polarity in immune cells.

Immune cells are responsible for pathogen detection and elimination, as well as for signaling to other cells the presence of potential danger. In order to mount an efficient immune response, they need to move and search for a pathogen, interact with other cells, and diversify the population by asymmetric cell division. All these actions are regulated by cell polarity: cell polarity controls cell motility, which is crucial for scanning peripheral tissues to detect pathogens, and recruiting immune cells to sites of infection; immune cells, in particular lymphocytes, communicate with each other by a direct contact called immunological synapse, which entails a global polarization of the cell and plays a role in activating lymphocyte response; finally, immune cells divide asymmetrically from a precursor, generating a diversity of phenotypes and cell types among daughter cells, such as memory and effector cells. This review aims at providing an overview from both biology and physics perspectives of how cell polarity shapes the main immune cell functions.

Functionalized Lipid Droplets and Microfluidics Approach to Study Immune Cell Polarity In Vitro.

The study of lymphocyte polarization upon antigen encounter typically relies on the random pairing between the cells of interest and a stimulating particle (micro bead) that mimics only some of the properties of the antigen-presenting cells. Here, we show how to build and use a microfluidic chip that allows to multiplex and synchronize the encounter between a lymphocyte and an antigen-presenting object: a functionalized oil-in-water droplet. We also explain how to fabricate and functionalize lipid droplets, an antigen-presenting tool that is, at the same time, deformable, fluid, and spherical.

Phenotyping polarization dynamics of immune cells using a lipid droplet-cell pairing microfluidic platform.

The immune synapse is the tight contact zone between a lymphocyte and a cell presenting its cognate antigen. This structure serves as a signaling platform and entails a polarization of intracellular components necessary to the immunological function of the cell. While the surface properties of the presenting cell are known to control the formation of the synapse, their impact on polarization has not yet been studied. Using functional lipid droplets as tunable artificial presenting cells combined with a microfluidic pairing device, we simultaneously observe synchronized synapses and dynamically quantify polarization patterns of individual B cells. By assessing how ligand concentration, surface fluidity, and substrate rigidity impact lysosome polarization, we show that its onset and kinetics depend on the local antigen concentration at the synapse and on substrate rigidity. Our experimental system enables a fine phenotyping of monoclonal cell populations based on their synaptic readout.

Microtubules restrict F-actin polymerization to the immune synapse via GEF-H1 to maintain polarity in lymphocytes.

Immune synapse formation is a key step for lymphocyte activation. In B lymphocytes, the immune synapse controls the production of high-affinity antibodies, thereby defining the efficiency of humoral immune responses. While the key roles played by both the actin and microtubule cytoskeletons in the formation and function of the immune synapse have become increasingly clear, how the different events involved in synapse formation are coordinated in space and time by actin-microtubule interactions is not understood. Using a microfluidic pairing device, we studied with unprecedented resolution the dynamics of the various events leading to immune synapse formation and maintenance in murine B cells. Our results identify two groups of events, local and global, dominated by actin and microtubules dynamics, respectively. They further highlight an unexpected role for microtubules and the GEF-H1-RhoA axis in restricting F-actin polymerization at the lymphocyte-antigen contact site, thereby allowing the formation and maintenance of a unique competent immune synapse.

Quality of economic evaluations of drug-coated balloons and drug-eluting stents in peripheral artery disease: a systematic review.

OBJECTIVE: We aimed to perform a systematic review of economic evaluations of drug-coated balloons (DCBs) and drug-eluting stents (DESs) in peripheral artery disease (PAD) and to assess the level of evidence of relevant studies. The purpose was not to present economic findings. METHODS: A systematic review was performed using four electronic databases to identify health economic evaluation studies reporting on the use of DCBs and DESs in PAD. The methodological and reporting quality of the studies was assessed using three different tools, the Drummond, Cooper, and CHEERS (Consolidated Health Economic Evaluation Reporting Standards) checklists. RESULTS: Six articles were included in this review of the 1,728 publications identified. Four studies were cost-effectiveness analyses and two cost-utility analyses. According to the Cooper hierarchy scale, the studies used good-quality data sources. The level of evidence used for clinical effect sizes, safety data, baseline clinical data, and costs was of high quality in general. In contrast, an evaluation of the reporting quality suggested that essential information was lacking. CONCLUSION: The present study demonstrates that clinical data used in economic evaluations of DCBs and DESs in PAD are from clinical studies of high quality in general. However, the quality of reporting represents a concern when interpreting the results provided by these economic studies.

Pinching the cortex of live cells reveals thickness instabilities caused by myosin II motors.

The cell cortex is a contractile actin meshwork, which determines cell shape and is essential for cell mechanics, migration, and division. Because its thickness is below optical resolution, there is a tendency to consider the cortex as a thin uniform two-dimensional layer. Using two mutually attracted magnetic beads, one inside the cell and the other in the extracellular medium, we pinch the cortex of dendritic cells and provide an accurate and time-resolved measure of its thickness. Our observations draw a new picture of the cell cortex as a highly dynamic layer, harboring large fluctuations in its third dimension because of actomyosin contractility. We propose that the cortex dynamics might be responsible for the fast shape-changing capacity of highly contractile cells that use amoeboid-like migration.

Traction Force Microscopy to Study B Lymphocyte Activation.

Traction force microscopy (TFM) enables the measurement of forces produced by a cell on a substrate. This technique infers traction force measurements from an experimentally observed displacement field produced by a cell pulling on an elastic substrate. Here, we adapted TFM to investigate the spatial and temporal structure of the force field exerted by B cells when activated by antigen engagement of the B cell receptor. Gel rigidity, bead density, and protein functionalization must be optimized for the study of relatively small cells (~ 6 µm) that interact with, and respond specifically to ligands for cell surface receptors.

Quality of economic evaluations of ventricular assist devices: A systematic review.

OBJECTIVE: Because of a lack of suitable heart donors, alternatives to transplantation are required. These alternatives can have high costs. The aim of this study was to perform a systematic review of cost-effectiveness studies of ventricular assist devices (VADs) and to assess the level of evidence of relevant studies. The purpose was not to present economic findings. METHODS: A systematic review was performed using four electronic databases to identify health economic evaluation studies dealing with VADs. The methodological quality and reporting quality of the studies was assessed using three different tools, the Drummond, Cooper, and CHEERS (Consolidated Health Economic Evaluation Reporting Standards) checklists. RESULTS: Of the 1,258 publications identified, thirteen articles were included in this review. Twelve studies were cost-utility analyses and one was a cost-effectiveness analysis. According to the Cooper hierarchy scale, the quality of the data used was heterogeneous. The level of evidence used for clinical effect sizes, safety data, and baseline clinical data was of poor quality. In contrast, cost data were of high quality in most studies. Quality of reporting varied between studies, with an average score of 17.4 (range 15-19) according to the CHEERS checklist. CONCLUSION: The current study shows that the quality of clinical data used in economic evaluations of VADs is rather poor in general. This is a concern that deserves greater attention in the process of health technology assessment of medical devices.

Evaluation of 3D printing costs in surgery: a systematic review.

OBJECTIVES: The use of three-dimensional (3D) printing in surgery is expanding and there is a focus on comprehensively evaluating the clinical impact of this technology. However, although additional costs are one of the main limitations to its use, little is known about its economic impact. The purpose of this systematic review is to identify the costs associated with its use and highlight the first quantitative data available. METHODS: A systematic literature review was conducted in the PubMed and Embase databases and in the National Health Service Economic Evaluation Database (NHS EED) at the University of York. Studies that reported an assessment of the costs associated with the use of 3D printing for surgical application and published between 2009 and 2019, in English or French, were included. RESULTS: Nine studies were included in our review. Nine types of costs were identified, the three main ones being printing material costs (n = 6), staff costs (n = 3), and operating room costs (n = 3). The printing cost ranged from less than U.S. dollars (USD) 1 to USD 146 (in USD 2019 values) depending on the criteria used to calculate this cost. Three studies evaluated the potential savings generated by the use of 3D printing technology in surgery, based on operating time reduction. CONCLUSION: This literature review highlights the lack of reliable economic data on 3D printing technology. Nevertheless, this review makes it possible to identify expenditures or items that should be considered in order to carry out more robust studies.

Diacylglycerol kinase ζ promotes actin cytoskeleton remodeling and mechanical forces at the B cell immune synapse.

Diacylglycerol kinases (DGKs) limit antigen receptor signaling in immune cells by consuming the second messenger diacylglycerol (DAG) to generate phosphatidic acid (PA). Here, we showed that DGKζ promotes lymphocyte function-associated antigen 1 (LFA-1)-mediated adhesion and F-actin generation at the immune synapse of B cells with antigen-presenting cells (APCs), mostly in a PA-dependent manner. Measurement of single-cell mechanical force generation indicated that DGKζ-deficient B cells exerted lower forces at the immune synapse than did wild-type B cells. Nonmuscle myosin activation and translocation of the microtubule-organizing center (MTOC) to the immune synapse were also impaired in DGKζ-deficient B cells. These functional defects correlated with the decreased ability of B cells to present antigen and activate T cells in vitro. The in vivo germinal center response of DGKζ-deficient B cells was also reduced compared with that of wild-type B cells, indicating that loss of DGKζ in B cells impaired T cell help. Together, our data suggest that DGKζ shapes B cell responses by regulating actin remodeling, force generation, and antigen uptake-related events at the immune synapse. Hence, an appropriate balance in the amounts of DAG and PA is required for optimal B cell function.

The learning curve in transcatheter aortic valve implantation clinical studies: A systematic review.

BACKGROUND: Transcatheter aortic-valve implantation (TAVI) has become an essential alternative to surgical aortic-valve replacement in the treatment of symptomatic severe aortic stenosis, and this procedure requires technical expertise. The aim of this study was to identify prospective studies on TAVI from the past 10 years, and then to analyze the quality of information reported about the learning curve. MATERIALS AND METHODS: A systematic review of articles published between 2007 and 2017 was performed using PubMed and the EMBASE database. Prospective studies regarding TAVI were included. The quality of information reported about the learning curve was evaluated using the following criteria: mention of the learning curve, the description of a roll-in phase, the involvement of a proctor, and the number of patients suggested to maintain skills. RESULTS: A total of sixty-eight studies met the selection criteria and were suitable for analysis. The learning curve was addressed in approximately half of the articles (n = 37, 54 percent). However, the roll-in period was mentioned by only eight studies (12 percent) and with very few details. Furthermore, a proctorship was disclosed in three articles (4 percent) whereas twenty-five studies (37 percent) included authors that were proctors for manufacturers of TAVI. CONCLUSION: Many prospective studies on TAVI over the past 10 years mention learning curves as a core component of successful TAVI procedures. However, the quality of information reported about the learning curve is relatively poor, and uniform guidance on how to properly assess the learning curve is still missing.

Differential nanoscale organisation of LFA-1 modulates T-cell migration.

Effector T-cells rely on integrins to drive adhesion and migration to facilitate their immune function. The heterodimeric transmembrane integrin LFA-1 (αLß2 integrin) regulates adhesion and migration of effector T-cells through linkage of the extracellular matrix with the intracellular actin treadmill machinery. Here, we quantified the velocity and direction of F-actin flow in migrating T-cells alongside single-molecule localisation of transmembrane and intracellular LFA-1. Results showed that actin retrograde flow positively correlated and immobile actin negatively correlated with T-cell velocity. Plasma membrane-localised LFA-1 forms unique nano-clustering patterns in the leading edge, compared to the mid-focal zone, of migrating T-cells. Deleting the cytosolic phosphatase PTPN22, loss-of-function mutations of which have been linked to autoimmune disease, increased T-cell velocity, and leading-edge co-clustering of pY397 FAK, pY416 Src family kinases and LFA-1. These data suggest that differential nanoclustering patterns of LFA-1 in migrating T-cells may instruct intracellular signalling. Our data presents a paradigm where T-cells modulate the nanoscale organisation of adhesion and signalling molecules to fine tune their migration speed, with implications for the regulation of immune and inflammatory responses.This article has an associated First Person interview with the first author of the paper.

Benefits of 3D printing applications in jaw reconstruction: A systematic review and meta-analysis.

BACKGROUND: Three-dimensional (3D) printing has changed surgical practice over the past few years, especially in maxillofacial surgery. However, little is known about its real clinical impact. The objectives of our study were to identify clinical outcomes that have been evaluated in the literature regarding 3D printing applications in jaw reconstruction, and to quantify the impact of this technology on operating times. METHODS: A systematic review was conducted by searching PubMed and EMBASE to collect comparative studies on 3D printing applications in jaw reconstruction. A meta-analysis of operating times was then performed. A Cochran's Q test was used to determine heterogeneity, and the overall effect size was calculated using a random effects model. RESULTS: Fourteen studies were included in our review. Eighteen clinical end-points were identified, of which the most frequently reported were operating time (n = 5; 35.7%) and the final aesthetic result (n = 4; 28.6%). Operating times were significantly lower in the 3D printing groups, with an overall estimated effect of 21.2% (95% CI 10-33%; p < 0.001). CONCLUSION: The use of 3D printing in jaw reconstruction was associated with a significant reduction in operating times. The end-points evaluated differed largely among the studies. More studies with higher levels of evidence are needed to confirm our results.

Actomyosin-driven force patterning controls endocytosis at the immune synapse.

An important channel of cell-to-cell communication is direct contact. The immune synapse is a paradigmatic example of such type of interaction: it forms upon engagement of antigen receptors in lymphocytes by antigen-presenting cells and allows the local exchange of molecules and information. Although mechanics has been shown to play an important role in this process, how forces organize and impact on synapse function is unknown. We find that mechanical forces are spatio-temporally patterned at the immune synapse: global pulsatile myosin II-driven tangential forces are observed at the synapse periphery while localised forces generated by invadosome-like F-actin protrusions are detected at its centre. Noticeably, we observe that these force-producing actin protrusions constitute the main site of antigen extraction and endocytosis and require myosin II contractility to form. The interplay between global and local forces dictated by the organization of the actomyosin cytoskeleton therefore controls endocytosis at the immune synapse.

New European Regulation for Medical Devices: What Is Changing?

INTRODUCTION: The Medical Devices Regulation (MDR) 2017/745/EU will fully apply from May 2020. Interventional radiologists use medical devices on a daily basis and so must be aware of the impact that this new regulation will have on their daily practice. MATERIALS AND METHODS: In this paper, we describe the major transformation that the MDR brings to the medical devices sector, with a focus on clinical evaluations and clinical investigations. RESULTS: This regulation significantly tightens controls to ensure that devices are safe and effective. In addition, equivalence to already existing devices, which allowed an accelerated access to the market, will now be possible only in some cases. Furthermore, post-marketing clinical follow-up is extended under the MDR and is required for all devices. These new requirements will probably lead to a dramatic increase in the number of clinical investigations and also to a delay in the availability of certain devices on the market. CONCLUSIONS: In the coming years, interventional radiologists are likely to be affected by these changes in their daily practice, in terms of medical device availability and/or in terms of increased involvement in clinical investigations.

Actin filaments regulate microtubule growth at the centrosome.

The centrosome is the main microtubule-organizing centre. It also organizes a local network of actin filaments. However, the precise function of the actin network at the centrosome is not well understood. Here, we show that increasing densities of actin filaments at the centrosome of lymphocytes are correlated with reduced amounts of microtubules. Furthermore, lymphocyte activation resulted in disassembly of centrosomal actin and an increase in microtubule number. To further investigate the direct crosstalk between actin and microtubules at the centrosome, we performed in vitro reconstitution assays based on (i) purified centrosomes and (ii) on the co-micropatterning of microtubule seeds and actin filaments. These two assays demonstrated that actin filaments constitute a physical barrier blocking elongation of nascent microtubules. Finally, we showed that cell adhesion and cell spreading lead to lower densities of centrosomal actin, thus resulting in higher microtubule growth. We therefore propose a novel mechanism, by which the number of centrosomal microtubules is regulated by cell adhesion and actin-network architecture.

Level of Evidence in Economic Evaluations of Left Atrial Appendage Closure Devices: A Systematic Review.

OBJECTIVES: The objective of the present work was to assess the level of evidence in economic evaluations of percutaneous left atrial appendage closure devices, and to test the complementarity of three different tools for assessing the quality of economic evaluations. METHODS: We conducted a systematic review of articles in English or French listed in MEDLINE, Embase, Cochrane, the Cost-Effectiveness Analysis registry and the National Health Service Economic Evaluation Database. We included only economic evaluations concerning left atrial appendage closure devices. Data were extracted from articles by two authors working independently and using three analysis grids to measure the quality of economic evaluations [the British Medical Journal (BMJ) checklist, the hierarchy scale developed by Cooper et al. (J Health Serv Res Policy 10:245-50, 2005) and the Quality of Health Economic Studies (QHES) instrument]. RESULTS: Seven economic evaluations met our inclusion criteria. All were published between 2013 and 2016. All were cost-utility analyses, and fully complied with the BMJ checklist. According to the hierarchy scale developed by Cooper et al., the quality of data used was heterogeneous. Finally, the mean score for the seven economic studies was 90/100 with the QHES instrument. CONCLUSIONS: Despite the recent development of left atrial appendage closure devices, most economic evaluations conducted here were well-designed studies. Furthermore, different tools used to assess the quality of these studies were complementary, but none gave a global vision of the quality of economic studies.

Single-use flexible bronchoscopes compared with reusable bronchoscopes: Positive organizational impact but a costly solution.

RATIONALE, AIMS, AND OBJECTIVES: There is at present no standard methodology to analyse the organizational impacts (OIs) of medical devices (MDs), and the field is still in its infancy. The aim of the present study was to assess, at a hospital level, the organizational and economic impacts of the introduction of a new MD, specifically the single-use flexible bronchoscope (FB). METHODS: Both the organizational and economic impacts of the single-use FB were evaluated in comparison with the reusable FB currently used as standard practice in our institution. First, process maps were created for both devices (reusable and single use). Based on the 12 types of OI defined by Roussel et al, interviews were conducted with all stakeholders, and the positive and negative aspects of the reusable and single-use processes were analysed. In a second step, microcosting analysis was conducted to determine the most economical balance in use of the 2 technologies. RESULTS: Process maps highlighted the complexity of the reusable device process when compared with the single-use device process. Among the 12 types of OI, the single-use FB process scored better than the reusable FB process in 75% of cases. With the "fleet" of 15 reusable FBs available in our institution, using single-use FBs would represent an extra cost of €154 per procedure. Single-use and reusable devices would have the same cost (€232 per procedure) with a theoretical annual activity of 328 bronchoscopies, which is much lower than our current activity (1644 procedures per year). CONCLUSIONS: Organizational impact should be considered when assessing MDs. We show in this study that from an organizational viewpoint, there are many advantages to using single-use bronchoscopes. However, in economic impact, it is more cost-effective for our institution, with more than 1500 bronchoscopies performed annually, to use reusable devices.

Existing reporting guidelines for clinical trials are not completely relevant for implantable medical devices: a systematic review.

OBJECTIVES: The aim of this study was to determine relevant items for reporting clinical trials on implantable medical devices (IMDs) and to identify reporting guidelines which include these items. STUDY DESIGN AND SETTING: A panel of experts identified the most relevant items for evaluating IMDs from an initial list based on reference papers. We then conducted a systematic review of articles indexed in MEDLINE. We retrieved reporting guidelines from the EQUATOR network's library for health research reporting. Finally, we screened these reporting guidelines to find those using our set of reporting items. RESULTS: Seven relevant reporting items were selected that related to four topics: randomization, learning curve, surgical setting, and device information. A total of 348 reporting guidelines were identified, among which 26 met our inclusion criteria. However, none of the 26 reporting guidelines presented all seven items together. The most frequently reported item was timing of randomization (65%). On the contrary, device information and learning curve effects were poorly specified. CONCLUSION: To our knowledge, this study is the first to identify specific items related to IMDs in reporting guidelines for clinical trials. We have shown that no existing reporting guideline is totally suitable for these devices.