Air tightness is a challenging task for 3D-printed components, especially for fused filament fabrication (FFF), due to inherent issues, related to the layer-by-layer fabrication method. On the other hand, the capability of 3D print airtight cavities with complex shapes is very attractive for several emerging research fields, such as soft robotics. The present paper proposes a repeatable methodology to 3D print airtight soft actuators with embedded air connectors. The FFF process has been optimized to manufacture monolithic bending PneuNets (MBPs), an emerging class of soft robots. FFF has several advantages in soft robot fabrication: (i) it is a fully automated process which does not require manual tasks as for molding, (ii) it is one of the most ubiquitous and inexpensive (FFF 3D printers costs < $200) 3D-printing technologies, and (iii) more materials can be used in the same printing cycle which allows embedding of several elements in the soft robot body. Using commercial soft filaments and a dual-extruder 3D printer, at first, a novel air connector which can be easily embedded in each soft robot, made via FFF technology with a single printing cycle, has been fabricated and tested. This new embedded air connector (EAC) prevents air leaks at the interface between pneumatic pipe and soft robot and replaces the commercial air connections, often origin of leakages in soft robots. A subsequent experimental study using four different shapes of MBPs, each equipped with EAC, showed the way in which different design configurations can affect bending performance. By focusing on the best performing shape, among the tested ones, the authors studied the relationship between bending performance and air tightness, proving how the Design for Additive Manufacturing approach is essential for advanced applications involving FFF. In particular, the relationship between chamber wall thickness and printing parameters has been analyzed, the thickness of the walls has been studied from 1.6 to 1 mm while maintaining air tightness and improving the bending angle by 76.7% under a pressure of 4 bar. It emerged that the main printing parameter affecting chamber wall air tightness is the line width that, in conjunction with the wall thickness, can ensure air tightness of the soft actuator body. Soft robotics is an emerging scientific field conceptually conflicting with traditional hard robotics, the latter is typically characterized by (i) rigid interconnected links that can move in predetermined environments, (ii) robots that are typically heavy and expensive, and (iii) a high level of control due to expansive electronics. In contrast, soft robotics (i) typically employs continuum bodies which can function in a wide range of unknown environments, (ii) have low weight and cost, and (iii) have a low level of control .4 to 109 MPa, hence all materials with a Young modulus in that range could be defined as soft materials [Soft materials are key to manufacturing soft robots. This material class provides several benefits such as the possibility to passively adapt the robot body to the surrounding environment, a high impact resistance, and the possibility to design robots with very complex geometries and shapes . Biologiaterials . An impooctopus vulgaris and following the octopus’ muscular hydrostat principle [Animals and biological organisms can perform complex movements with soft structures and can adapt to several environments, which is why they often serve as a source of inspiration for researchers who try to apply biological concepts to the field of soft robotics . A milesrinciple . The octrinciple  consistsrinciple ,9,10; inrinciple ,12. In arinciple , it is principle ,15,16. Arinciple ,18 and rrinciple , additivrinciple ,22,23,24rinciple ,26, polyrinciple , and sterinciple  are usedIn this paper, the feasibility of manufacturing a monolithic bending PneuNet (MBP) actuator with FFF technology by replacing the classic manufacturing process based on the elastomeric rubber molding with the melting extrusion of flexible filaments made by thermoplastic polyurethane has been investigated. The advantages offered by FFF technologies in soft robotics are: (i) reduction of assembly tasks and (ii) increase of automation degree during the manufacturing process. This is achieved by designing a 3D-printed embedded air connector (EAC) to be embedded into the soft robots produced by FFF. This novel and innovative EAC is completely air tight and embeds the male air connector, assuring compatibility with standard female air connectors. Indeed, the EAC is manufactured in the same printing cycle of the soft robot and does not require any assembly. Several design and process parameters have been tested to find the optimal printing orientation that ensures complete air tightness.Four different monolithic bending PneuNet (MBP) shapes have been experimentally studied to find the one exhibiting the best bending angles and flexibility and identify the design parameters that affect bending performance. Finally, a way to improve bending performance (the bending angle was improved by 78.7%), working on the best MBP shape, has been found by examining the relationship between printing parameters and constitutive design elements and proving how the Design for Additive Manufacturing (DfAM) approach is useful in applications like these. In summary, the workflow of this research can be outlined as follows: (i) manufacturing of a leakage-free air connector, (ii) identifying the most performing actuator shape with embedded air connector, and (iii) improving the performances of the best actuator shape in terms of flexibility.The dual-extruder 3D printer Ultimaker 3 , which enables the usage of two different filaments in the same printing cycle, has been used to manufacture the monolithic bending PneuNet (MBP). The two commercial filaments chosen were: (i) polyurethane thermoplastic produced by Ultimaker with a shore A hardness of 95 (TPU 95A), a tensile modulus of 26 MPa, and an elongation at break of 580% and (ii) a low-friction polyurethane thermoplastic developed by BASF  and on the market since 2019 with a shore A hardness of 80 (TPU 80A LF) and a tensile strength ranging from 17 to 22 MPa depending on the printing direction of the sample. All technical data were from filament’s datasheets. TPU 95 A was used to create the male embedded air connector and to fabricate the inextensible portion of the actuator, whereas TPU 80 A LF was chosen to manufacture the extensible segment of the MBP.The ideal material to manufacture the air connector was rigid and does neither break nor twist under high pressure (up to 7 bar). At the same time, boundary interface problems between the two materials with very different hardness values must be taken into account during the dual-extruder printing process.As demonstrated by Lopes et al. , the tenA common problem with pneumatic soft-robots typically occurs at the interface between the soft robot and the pneumatic system that supplies the compressed air, where recurrent air leaks may not only reduce the soft robot performance but may also pose a potential danger for the surrounding environment once high pressures are reached. This problem is often addressed through solutions that are rather complex from an assembling point of view ,30.1 to D4 in Here, an innovative 3D-printed male embedded air connector (EAC) which can be easily embed in every soft robot made with FFF technology requiring only one printing cycle has been developed. The proposed EAC ensures the total absence of any air leaks at the interface between the soft robot and the pneumatic system. Its general purpose is to mimic the commercial male air connectors (often made of steel), quickly engraftable into the female connector attached to pneumatic pipe . Since 3Ultimaker Cura 4.4 software  was used to set the printing parameters and communicate with the 3D printer. This printing orientation also guarantees the complete absence of air leaks.The printed EAC was inserted into the pneumatic pipe and several tests were performed to evaluate its air tightness. For each test, the EAC was submerged in a beaker filled with water to facilitate the detection of air leaks. To work safely, EAC was anchored to the beaker trough a custom-made support. Each EAC underwent the following 3 tests: (i) the pressure was increased in steps of 1 bar from 0 to 7 bar (uphill phase) and then reduced again in the same manner to reach 0 bar (downhill phase), with 1 min between pressure changes. This test was repeated 10 times for each specimen; (ii) here, the pressure abruptly alternated between 0 and 7 bar, remaining for 5 s at each level and repeating these cycles 50 times; and (iii) here, the specimens were exposed to a pressure of 7 bar for a time of 15 min.During each of the above tests, no water bubble was detected into the beaker full of water, thus demonstrating the absence of any air leaks.The innovativeness of the EAC consists in a single-step printing cycle to embed connectors potentially in every soft robot made by FFF, reducing the use of commercial solutions, often unsuitable for pneumatic soft robots.In this section, one alternative printing orientation has been examined : with thRegarding the cylindricity, it has been decided to investigate the staircase effect on EAC air tightness. Layer heights considered in this study were 0.15 mm (the same used in the first printing orientation) and 0.05 mm, the minimum layer height allowed by the Ultimaker 3 3D printer.2 factorial experiment has been performed to understand the influence of these factors on air tightness and if a combination of factors that ensures the absence of air leaks exists. The response variable was the leakage (L/min) measured with the following method: The EAC is connected to the pneumatic pipe of the compressor and a pressure The air supply is stopped and the amount of pressure reduction (indicative of an air leak) is measured, resulting in the time Compressed air is resupplied and the time to reach Using the support material and layer height as factors and assigning two levels to each factor, a full 2The amount of air leakage . The cost, as estimated by the slicing software, for the four combinations Several conclusions can be drawn from the data analysis :No combiIn conclusion, if the EAC is printed with its longitudinal axis perpendicular to the build plate, it results in complete air tightness. If the EAC is printed with its longitudinal axis parallel to build plate, some air leakage occurs, which can be minimized to a mean value of 0.157 L/min, however, by using tailored strategies .In this section, four different monolithic bending PneuNet (MBP) shapes to find the best shape in terms of flexibility have been analyzed. First of all, a manner to fabricate MBPs to ensure air tightness has been presented. Afterwards, each MBP has been characterized by relating the bending angle and the tip position to the input pressure and certain rules that link the design constitutive parameters to the bending behavior have been derived. Finally, different design and manufacturing parameters for the MBP with the best bending performance (R-type) have been varied to further improve its flexibility.As explained in Because elements made using FFF technology are anisotropic , and also fabricating MBPs with this technology is inexpensive  and automated , it has been decided to manufacture and empirically evaluate 4 differently shaped MBPs with the aim to find the shape that shows the best performance in terms of bending angle.Each MBP consists of an EAC, an embedded L-junction to direct air flow to the extensible portion, an inextensible portion with a height of 3 mm, and an extensible portion equipped with several pneumatic chambers. The difference between the 4 MBPs is limited to the shape and geometry of the extensible portion . While eDesign for additive manufacturing (DfAM) is a technique based on the idea to design and optimize a product which will be manufactured through AM techniques in order to improve its properties . An easyThe EAC embedded in the soft actuator structure has been designed for printing with its longitudinal axis perpendicular to the build plate to ensure air tightness at the pneumatic pipe interface. With this design choice, it is necessary to direct the air flow toward the extensible portion which is achieved through an embedded L-junction that can switch the air flow from the EAC to the pneumatic chambers .Apart from ensuring the absence of air leakage at the interface between EAC and pneumatic pipe, the authors also made sure that there is no leakage into the extensible portion. This is crucial for finding a suitable thickness of the pneumatic chamber walls . Both poThe proposed MBPs have been designed using the DfAM approach:As described in After fabrication, the four MBPs were tested to link bending angle and tip position in 2D space to pressure input. The setup consisted of an air compressor, a rigid frame to which the MBP was attached in front of a square millimeter grid used for the optical readings, and a Canon EOS D400 digital camera  to record the tip position and bending angle .Starting from an input pressure of 0 bar (rest condition), the pressure was increased with step of 1 bar till it reaches the maximum value of 4 bar; at each pressure step, one image has been captured to measure the bending angle and the tip position.The R- and S-types were the most flexible and exhibited very similar bending angles and tip displacements. At 1 bar, their bending angles only differed by 0.1°. At higher pressures of 2 and 3 bar, the S-type is lightly more rigid than the R-type, while at 4 bar, the bending angles are again very similar (41.3° for R-type and 41.4° for S-type). D- and B-type were the least flexible and had comparable bending angles between 0 and 3 bar, while at 4 bar, the D-type was more flexible than the B-type and, however, less flexible than both R- and S-types. Overall, the R-type thus turned out to be the best MBP as it is the most flexible between 0 to 3 bar and equally flexible at 4 bar as the S-type.From the experimental phase, several considerations about the relationship among MBPs bending behavior and constitutive design parameters can be drawn. When pressurized, the chamber walls, aligned with the air flow , tend to stretch and the walls perpendicular to the air flow  tend to expand.Consequently, it is possible to translate this consideration in the maximization, for each pneumatic chamber, of the ratio  involve five adjacent extruded lines. By testing this new kind of R-type, its air tightness has been proved.The novel important feature discovered in this paper is that the air tightness of MBPs manufactured via FFF technology does not depend on the wall thickness as for PneuNets fabricated by molding, but it depends on the number of adjacent extruded lines that make up the chamber wall. So, the key printing parameter that needs to be tuned to avoid air leakage is “line width,” which is related to actuator design in the following way: the wall thickness of each MBP should be equal to line width value set in slicing software multiply for four or five times. This proves how DfAM is crucial for advanced applications involving FFF technology.There is thus a direct correlation between “line width” printing parameter and MBP air tightness, and the knowledge of this relationship is the enabling key to fabricate 3D-printed soft robots with improved performance. For the 3D printer employed in this research, namely, Ultimaker 3, the smallest available nozzle diameter is 0.25 mm. For other commercial dual-extruder 3D printers, nozzles with a diameter of 0.1 mm are available; it means that it should be possible to fabricate soft actuators with values of wall thickness lesser than 1 mm .Starting from this new minimum thickness values, it will be possible to further increase the bending performance following two ways: (i) increasing the active bending length of the R-type from 80 to over 100 mm  and (ii) increasing the number of the chambers for a given active length.Following these approaches, optimized air-tight pneumatic actuators with further improved bending performance could be easily fabricated via FFF technology and employed in several applications .This work is a first, preliminary study in the field of the soft actuators made via FFF technology, showing (i) a repeatable methodology to fabricate air-tight actuators with embedded air connector and (ii) an empirical method to choose the most performing actuator shape; future investigation are needful to reduce the gap in terms of bending performance with actuators made with traditional technologies. Although the purposed version is characterized by a bending angle of 72.9° when a pressure of 4 bar is supplied, other actuator such as the self-healing actuator of Terryn et al.  exhibits2 factorial plan, we could show that only one printing orientation can ensure the absence of air leaks in the 3D-printed air connector. By comparing four different 3D-printed MBP shapes, the authors found that the best performance was achieved with the R-type MBP characterized by a bending angle of 41.3° when a pressure of 4 bar was supplied. In addition, from the experimental data, the authors outlined two design rules needful to better understand why some actuator shapes result in more performance than others. In the shape selection phase, the minimum wall thickness able to ensure air tightness was 1.6 mm; by using a Design for Additive Manufacturing approach (DfAM), it has been possible to reduce the minimum wall thickness up to 1 mm, ensuring the total actuator air tightness at the same time. The new improved R-type actuator is resulted being more flexible compared to the first version: the bending angle has been improved by 76.7%, switching from 41.3 to 72.9° when a pressure of 4 bar was supplied. Line width was found to be the main parameter affecting air tightness of soft actuators made via FFF; by reducing this parameter by using nozzles with a lesser diameter , it is possible to decrease wall thickness leading to an improvement of the actuator flexibility. The authors show experimentally that the chamber walls need to consist of at least four to five adjacent extruded lines of filament to ensure air tightness. Future work might focus on improvement of MBP bending performance to reduce the gap with molded-based counterparts, which result into more flexibility , by studying other parameters such as the distance between chambers, the chamber dimensions, the thickness of the inextensible portion, or the usage of more flexible materials. Furthermore, future studies could examine how to exploit the optimized MBP for several practical applications such as grasping, locomotion or rehabilitation.In this paper, a new manufacturing approach for soft actuators based on the inexpensive FFF approach has been presented. A novel 3D-printed air connector with the following features was developed: (i) it can be easily embed in soft robots made with FFF technology as it can be manufactured in the same printing cycle as the soft robot, (ii) it is completely air tight at the interface between the pneumatic pipe and the soft robot, and (iii) it enables to overcome assembly problems due to the usage of marketable air connectors. Using a 2


Effective brief treatments for methamphetamine use disorders (MAUD) are urgently needed to complement longer more intensive treatments in low and middle income countries, including South Africa. To address this gap, the purpose of this randomised feasibility trial was to determine the feasibility of delivering a six-session blended imaginal desensitisation, plus motivational interviewing (IDMI) intervention for adults with a MAUD.We enrolled 60 adults with a MAUD and randomly assigned them 1:1 to the IDMI intervention delivered by clinical psychologists and a control group who we referred to usual care. Feasibility measures, such as rates of recruitment, consent to participate in the trial and retention, were calculated. Follow-up interviews were conducted at 6 weeks and 3 months post-enrollment.Over 9 months, 278 potential particiants initiated contact. Following initial screening 78 (28%) met inclusion criteria, and 60 (77%) were randomised. Thirteen of the 30 participants assigned to the treatment group completed the intervention. Both psychologists were highly adherent to the intervention, obtaining a fidelity rating of 91%. In total, 39 (65%) participants completed the 6-week follow-up and 40 (67%) completed the 3-month follow-up. The intervention shows potential effectiveness in the intention-to-treat analysis where frequency of methamphetamine use was significantly lower in the treatment than in the control group at both the 6 week and 3-month endpoints. No adverse outcomes were reported.This feasibility trial suggests that the locally adapted IDMI intervention is an acceptable and safe intervention as a brief treatment for MAUD in South Africa. Modifications to the study design should be considered in a fully powered, definitive controlled trial to assess this potentially effective intervention.Trial registration The trial is registered with the Pan African Clinical Trials Registry  Substance use disorders represent a major public health problem, both globally and in South Africa. Substance use contributes significantly to the global burden of disease, accounting for 11% of total health burden . In the MA use is associated with several negative sequelae. These include a range of psychiatric symptoms such as depression and suicide, as well as serious medical conditions such as cardiac arrhythmias and myocardial infarction –8. In adGiven the psychological and public health implications associated with MA use, researchers from high-income countries have investigated the efficacy of a variety of psychological treatments for MA use . ContingThis is also true for South Africa, where community-based studies have found that although people who use MA would generally meet diagnostic criteria for a severe substance use disorder and recognise the need to get treatment , 17, lesOne brief treatment with potential for use in South Africa to treat MAUD is a manualized programme that includes components of cognitive-behavioural therapy, motivational interviewing, and imaginal exposure developed by Grant et al. . ImaginaThe primary objectives of this study were to (i) examine the feasibility of a six-session brief IDMI treatment for South Africans with MAUD as well as; (ii) the feasibility of study procedures including the performance of primary and secondary outcome measures to inform a fully powered trial. A second objective was to explore the initial effect of this IDMI intervention on MA use.This paper has been written in accordance with the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement: extension to randomised pilot and feasibility trials  and the Sixty participants were recruited through several avenues including referral from health care services, local non-government organisations (NGOs) and advertisements in local newspapers. Eligible participants were between 18 and 65 years of age; had at least a grade 9 education (a proxy for English literacy), met Diagnostic and Statistical Manual fourth edition (DSM-IV) criteria for MA abuse or dependence according to the Mini-International Psychiatric Interview (MINI) substance use module, and self-reported MA as their drug of choice. Patients with other co-occurring substance use disorders were not excluded. Exclusion criteria included participants meeting criteria for bipolar disorder, suicidality, schizophrenia (including psychosis) and antisocial personality disorder (as assessed through the MINI).See Fig. All participants who met criteria and consented to participate in the study completed an interviewer-administered baseline questionnaire on self-reported substance use and mental and physical health. They were then randomly assigned to the IDMI treatment or control group (1:1). The treatment group received the six-session treatment, while the control group were referred to local substance use treatment centres for treatment.Follow-up interviews were conducted at 6 weeks and 3 months following study enrolment, at which time the baseline questionnaire was re-administered. Grocery vouchers of R50 (approximately $5) were given to participants at each research assessment. To limit attrition, telephone and text message reminders were sent to participants. Participants were also compensated for any travel expenses.Participants were randomly allocated in a 1:1 ratio to either the intervention or comparison arm. The randomisation sequence was prepared by the data manager (using a computer programme) and allocation done by a trial manager. To limit a socially desirable response set, a research assistant who was not involved in the recruitment of the participants and is not working at the hospital conducted the follow-up assessment and was blinded to the treatment allocation.The IDMI sessions included:Session 1: A condensed form of motivational enhancement therapy. Included aneEvaluation of why you want to quit using MA and monitoring your MA use. In this session, the client and the therapist worked together to explore the level of motivation to quit MA use and facilitated change talk by using elements from a motivational interviewing framework.Session 2: Financial planning. In this session, the client and therapist worked together to identify financial concerns (debt for example) associated with MA use and explored strategies to help improve the client’s financial situation.Session 3: Behavioural intervention, preparation for MA use triggers. In this session, strategies to resist against MA use triggers were developed for implementation.Session 4: Exposure therapy (via guided imagery). In this session, the therapist spent approximately 20 minutes asking the client to visualize and describe a typical day of MA use and all the senses, thoughts, emotions, and behaviours involved in MA use. At the peak of the client’s urge during the exposure (imagery), consequences of actions are introduced as well as coping mechanisms to help deal with these urges. This imagery process is written as a script and audio recorded for the client to listen to at home.Session 5: Impulsive beliefs: cognitive therapy. This session involved the therapist and client working together to identify any thinking errors or erroneous beliefs that the client had which perpetuated his/her MA use. The goal was to learn how to develop healthy beliefs related to MA use.Session 6: Relapse prevention. This session involved a review of all the skills and information learned throughout this programme. It focused on preparing the client for future triggers that will occur and which tempt him/her to engage in MA use. We did not formally evaluate knowledge gained.Session 7: Family involvement . This session was optional and only completed at the client’s discretion. It involved a discussion with the client and his/her family and the best role(s) all parties could play in the rehabilitation of the client.Participants randomized to the control arm were referred to a specialised, registered outpatient rehabilitation centre that was most convenient for them to attend. All outpatient facilities provide a combination of motivational interviewing and cognitive behavioural-based counselling that incorporated both individual and group counselling sessions.Two clinical psychologists with more than 5 years’ experience delivering cognitive behavioural therapy were recruited and trained to deliver the intervention. The clinicians received 3 full days of training in the treatment. Debriefing also occurred with the principal investigator as needed. To ensure intervention fidelity, all sessions were audio recorded and a random sample of 15 sessions from each psychologist was checked for fidelity using an intervention checklist that focused on intervention content. Both psychologists were highly adherent to the intervention, obtaining a fidelity rating of 91%.The schedule of data collection is shown in Fig. The performance of the primary outcome (frequency of MA use) was measured using the timeline follow-back method (TLFB) . ParticiThe Penn Alcohol Craving Scale (PACS) (modified for MA dependence) is a reliable and valid five-item self-administered instrument for assessing craving for alcohol. Frequency, intensity, and duration of thoughts about MA use are assessed along with ability to resist use [sist use . The PACsist use  and the sist use . The PACClinical Global Impression (Severity) scale (CGI)  is a commonly used measure of symptom severity, treatment response and the efficacy of treatments in treatment studies of patients with mental disorders. Although the tools reliability and validity has not been assessed in a substance using population it has demonstrated strong psychometric properties in different populations. For example, an investigation into the psychometric properties of the CGI among people living with schizophrenia found that the reliability of CGI was high  and the correlation coefficients between the CGI and the Global Assessment of Functioning was high (> 0.75) [(> 0.75) .Hamilton Rating Scale for Depression (HAM-D)  The HAM-D has been used internationally to assess the overall severity of depressive symptomatology and has shown reasonable validity and reliability. For example, in a systematic review of 70 published studies that used the HAM-D and found adequate internal consistency ranging from 0.46 to 0.97 and test-retest reliability ranging from 0.81 to 0.98 [ to 0.98 .Hamilton Rating Scale for Anxiety (HAM-A)  The HAM-A was developed to measure the severity of anxiety symptoms. The scale consists of 14 items, each defined by a series of symptoms, and measures both psychic anxiety  and somatic anxiety . The scale is often used in randomised controlled trials (RCTs) and has shown high interrater reliability (ICC = 0.74) and concurrent validity [validity .Sheehan Disability Scale (SDS) was developed to assess functional impairment in three inter-related domains; work/school, social and family life. Each of the 3 response items is scored on a 10-point Likert scale [rt scale . A studyrt scale .Descriptive statistics were used to report on all feasibility outcomes. To index the relative effects of the two treatment conditions descriptive statistics were also generated for the overall sample and by treatment group. Baseline variables were tested for differences between those who completed the 3-month evaluation and those who did not using chi-square tests for categorical variables, or Fisher’s Exact where cell sizes were small, and t-tests for continuous variables, or Mann–Whitney–Wilcoxon tests if normality assumptions were not met. Linear mixed-effects regression models with repeated measures were used to assess differences in outcome measures over time between groups, with fixed effects for baseline variables that were different between groups, time, treatment group, and treatment by time interaction, and random effects for participant. The regression coefficient of interest is the treatment by time interaction. The primary regression analysis used an intention-to-treat approach with last observation carried forward (LOCF) to impute scores for missing data values. A secondary regression analysis only used data from those who completed the 3-month follow-up (no imputation). All testing was two-sided and a significance level of 0.05 was used throughout. Analyses were conducted in SAS v9.4  and R v3.2.2.A total of 278 individuals who use MA were pre-screened for possible study inclusion. From these patients, 200 (72%) were excluded. Among those who were excluded, 63 (31%) never arrived for their appointment, 30 (15%) did not have a grade nine education 7 (4%) had previously been diagnosed with a severe mental disorder. Twenty-three (11%) were receiving treatment elsewhere, 33 (16%) had not used MA in the previous 2 weeks, 25 (13%) reported that heroin was their drug of choice and 19 (10%) were living with a partner who was using.The remaining 78 participants were assessed for study eligibility in person, where a further 18 people were excluded as they had a severe mental illness and did not report MA as their drug of choice. All participants that were eligible consented to take part and were randomly allocated. The 60 eligible patients were then randomly allocated to either the intervention or control condition. There were no refusals and concerns from participants regarding randomisation and project staff reported confidence in the randomisation and blinding process, particularly as the follow-up assessment was conducted by an individual who did not work at the hospital where the intervention sessions were being conducted. Recruitment for this feasibility trial took 9 months, approximately seven participants were recruited per month.Table Of the 30 participants who were randomised to the intervention group, 26 completed session one, 24 completed two sessions, 21 completed three sessions, 18 completed four sessions, 15 completed five sessions and 13 (43%) completed all six sessions. The reasons provided for treatment suspension included: imprisonment (n = 3), employment (n = 5) and loss of communication (n = 9). For the control group, 10 of the 30 participants attended at least one session at the outpatient facility, with a maximum of 3 sessions they were referred to. Three of the 30 participants were admitted to an inpatient treatment centre.In total, 39 (65%) participants completed the 6-week follow-up and 40 (67%) completed the 3-month follow-up. Age at time of first use and age at baseline were the only variables that distinguished between participants who completed the 3-month follow-up and those who did not . There were no significant differences between groups in terms of follow-up rates at 6-weeks and 3 months. See Table Improvements on all outcomes over time were observed for both the intervention group and the control group  initiated treatment. Among those who initiated treatment, 45% completed at least four group sessions, 30% early recovery skills training (minimum eight group sessions), and 13% completed the full Matrix programme . Other sIdentifying methods to optimise treatment retention is crucial when considering the implementation of a definitive randomized control trial. To address this concern, we are considering using mobile technology to deliver the intervention. Given the availability of smart phones in this context, technology-assisted interventions may provide a viable alternative to some of the face-to-face treatments . In our Second, results from this feasibility trial provide guidance on potentially useful outcome measures and provide some indications of preliminary effect sizes that could help sample size calculations for a larger, more definitive trial. Despite limitations, results also suggest that this intervention may be an efficacious intervention for reducing frequency of MA use. In this feasibility RCT, the intervention significantly reduced frequency of MA use in comparison to usual care. Participants in the intervention group reported significantly fewer days of MA use compared to the control group at both the 6 week and 3-month follow-up assessments. These findings are consistent with the available literature on the effectiveness of CBT-based approaches , where fHowever, the intervention effect appears to diminish over time. This drop off is not surprising given evidence that after 90 day of treatment MA users are particularly vulnerable for relapse. It has been argued that this period is associated with anhedonia that arises as neurotransmitter systems recover after extended periods of MA use . FurtherWhile our findings provide preliminary evidence that a six-session brief treatment holds promise for facilitating changes in MA use, in addition to efforts aimed at retention and intervention effect, further amendments to the study design will need to be considered when progressing towards a future definitive trial. First, participants in the control condition received a referral to existing specialist outpatient facilities where variations in treatments and dosage were reported for the very limited number of participants who accessed any treatment. The lack of uniformity in the treatment provided to the control group could influence the internal validity of the study potentially compromising the results. Further consideration on the most appropriate comparison group is essential when taking this to a definitive trial. Second, relying on self-reports of MA use as an outcome is problematic. Consideration must be given to the use of sophisticated biological markers of MA use (such as hair sample testing) that allow for assessments of the levels of MA use (and not just the presence or absence of metabolites) is warranted given the harm reduction rather than abstinence focus of the intervention. Third, grocery vouchers were given to participants at each assessment and treatment session and transport costs to attend intervention sessions were covered. This could have potentially influenced participants motivation to participate in the study and could have contributed to the better retention rates in the intervention group (as the control group were not incentivised to attend treatment). Given that this type of incentive is unlikely to be provided in a real-world setting, it is recommended that these incentives are not provided in a definitive trial. Finally, this intervention was delivered by master’s level psychologists, of which there are few in the public service. Future studies should explore whether this brief treatment could be task-shared to registered counsellors and community health workers, given that it is both structured and manualised. In South Africa, there is a small but growing body of literature to show that with training and ongoing supervision, community health workers are able to deliver a range of evidence-based psychological treatments .We also acknowledge that an intervention, such as the one described, cannot be considered a “solution” in isolation. It does not address the systemic issues within which substance use disorders arise, such as high levels of unemployment and social inequality, which may have a maintaining effect on continued problematic use . AdequatThe results of the study suggest that it is feasible to successfully identify and recruit participants to participate in a brief IDMI treatment for MA use delivered by master’s level clinical psychologists. Our findings provide preliminary evidence that a six-session brief treatment holds promise for facilitating changes in MA use should concerns around retention and intervention effect be addressed. Findings provide evidence to support progression to a larger more definitive trial, pending proposed changes to the recruitment, intervention and retention protocols.


Aim of the study: To assess the efficacy of a novel technique  in the management of non-responsive fecal incontinence in children born with anorectal malformations (ARMs). Methods: Following ethical committee approval (CHPED-MAR-18-02), anal-lipofilling was proposed to patients with fecal incontinence not responsive to medications or bowel management , then a prospective study was conducted. Anal-lipofilling consisted of three phases: lipoaspiration from the abdominal wall, processing of the lipoaspirate with a Lipogems system and intersphincteric injection of the processed fat tissue via endosonographic assistance. A questionnaire based on Krickenbeck’s scale (KS) was administered to the patients to evaluate the clinical outcome. Main Results: Four male patients  underwent the anal-lipofilling procedure at a mean age of 13.0 ± 4.2 yrs. There were no complications during or after the procedure. From an initial assessment of the patients there was an improvement in the bowel function at a median follow up of 6 months, with better scores at KS (100% Soiling grade three pre-treatment vs. 75% grade one post-treatment). Conclusions: Even if our Study is preliminary, echo-assisted anal-lipofilling could be considered as a feasible and safe alternative technique in the management of the fecal incontinence in non-responding ARMs patients. More studies are still necessary to support the validity of the implant of autologous adipose tissue in the anal sphincter as a therapy for fecal incontinence in children born with ARMs. The management of fecal incontinence is one of the most challenging aspects in the follow-up of patients with anorectal malformation (ARM) after undergoing surgery. Incontinence affects these patients’ social acceptance and therefore determines enormous repercussions on their psychology .The instruments the surgeon can count on have not improved in recent years and are essentially based on the use of regular enemas and osmotic laxatives.Recently, in other disciplines like plastic surgery and orthopedic surgery, the use of adipose tissue has taken place in the repair of tissue damage ,3,4,5,6.Some authors have tried the use of an autologous fat graft in treating adults’ fecal incontinence and reported positive results of their preliminary experience ,8.This background led us to think about a possible application in the management of incontinence in our type of patients.Therefore, we treated four patients operated on for ARM in our center suffering from fecal incontinence with echo-assisted autologous intersphincteric injection of autologous microfragmented adipose tissue .In addition, considering our increasing experience on endoanal ultrasonography, such injections were performed via endoanal-US guidance to guarantee a more precise transplantation site.We recorded a preliminary result of this technique in order to decide whether or not it can take place in the follow up of these patients.A retrospective study was conducted. All patients operated on for ARM, suffering from fecal incontinence with no or poor benefit from bowel management and treated in our center with echo-assisted anal-lipofilling were considered but those with less than 6-months follow-up were excluded from the study .To the selected patients were administered a questionnaire about fecal incontinence before and after every procedure of anal-lipofilling; fecal incontinence was evaluated with Krickenbeck’s scale (KS)  that is 1. Voluntary bowel movements (or the ability of patients to feel and hold the defecatory stimulus) recorded as “absent” (indicated as 1.0) or “present” (1.1);2. Soiling that, if present, is stratified in three grades: once or twice per week (2.1), every day with no social problems (2.2) and every day with social problems (2.3). Absence of soiling will be indicated as 2.0;3. Constipation that, if present, is divided too in three grades: manageable with changes in diet (3.1), requires laxatives (3.2), resistant to laxatives and diet (3.3). Absence of constipation will be reported as 3.0.Questionnaire recorded any changes in frequencies of bowel management.Anal-lipofilling technique: The patient is positioned supine; in our experience, general anesthesia is required. Prophylactic antibiotics are given intravenously prior to skin incision. An 11-blade scalpel is used to make a stab incision in the subcutaneous tissue. A solution of Epinephrine 2 mcg/mL is injected subcutaneously using an 18-Gauge cannula followed by 10 min resting period to allow an adequate emulsification. The adipose tissue is then harvested with the lipo-suction cannula connected to a 10 mL Vaclok syringe A. This s®) containing 5 stainless steel marbles is connected to 2 hoses. The hose attached to the blue size reduction filter is connected to a bag of normal saline. The gray size reduction filter on the opposite end of the cylinder is attached to a hose connected to a waste bag, which rests on the floor. The cylinder is then rotated so that the gray filter points upward. Both the blue filter hose and waste hose are opened to allow the cylinder to fill with normal saline while holding it vertically and shaking intermittently to remove air bubbles. Both the hoses are then clamped closed once the cylinder is filled completely. The 20 mL syringe containing the lipoaspirate is connected to the blue filter. The adipose tissue is injected into the processing cylinder through the blue filter with the clamp on the gray waste side open. With the blue filter pointing up, both clamps are opened to allow elimination of blood and oily impurities into the waste bag. Once the fluid is transparent, the shaking process will begin. Both the hoses are clamped closed, and the cylinder is shaken for 30 s to allow the action of the steel spheres to emulsify and microfracture the adipose tissue  with a BK-medical flexfocus 800 US system .The aspiration and the processing of the adipose tissue was performed by a plastic surgeon of our institute while the injection by a pediatric surgeon of our equip.Possible described complications of this procedure could be visible irregularities of the lipoaspiration site , seromas, local infection and extremely rare major complications such as fat embolism syndrome  and extended infection.Patients that underwent echo-assisted anal-lipofilling were discharged the day after the procedure.We treated four patients with intersphincteric injection of autologous adipose tissue . The patients were all male, three recto-urethral fistulas (75%), and one recto-perineal fistula (25%) and underwent the first anal-lipofilling at a mean age of 13 ± 4.2 yrs (range: 8–17 yrs). All patients underwent colonostomy open at birth, postero-sagittal anorettoplasty (PSARP) between 2 and 4 months of life and colonostomy closure about a month after the PSARP.All four patients suffered of total fecal incontinence and presented the same score at Krickenbeck’s scale: 1.0, 2.3, 3.0 and needed an enema every day to help bowel control.The total number of procedures performed was nine and the mean number of procedures per patient was 2.0 ± 1.3 (range: 1–4).Three patients treated (75%) showed a significant improvement in continence with a KS score of 1.0, 2.1, 3.0 after every single procedure and a reduction in the number of enemas from once daily to one or two weekly .One patient (25%) did not benefit from the anal-lipofilling, no changes on the KS recorded before and after the procedure .The mean interval between the procedures in the ones who underwent more than one anal-lipofilling was 343.8 ± 220.1 days (range 203–733 days); the re-do was determined by the progressive loss of efficacy of the previous procedure.No complications were recorded during and after the procedure.Fecal incontinence is a major problem in ARM management after surgical correction and the older is the patient the more important becomes the follow up due to social and psychological repercussions .Nowadays bowel management is the assessed and only way to help these patients to control their bowel function, but it is an invasive and not always tolerable procedure ,11. The Some authors have tried the use of autologous fat graft in treating adults’ fecal incontinence and reported positive results of their preliminary experience.For instance, Gentile M. et al.  observedAdditionally, Jeong H. et al.  comparedAccording to preliminary results of this procedure in adults’ incontinence reported in the literature and the wide use of autologous adipose tissue transplant in other disciplines, we decided to apply this technique to pediatric patients affected by ARM.We performed a total of nine lipofilling procedures from 2016 and we recorded a preliminary result from the follow up and the parent’s opinions.In three patients out of four treated, anal-lipofilling improved the continence with less episodes of loss of bowel contents, a decrease in number of enemas  and parents were extremely satisfied of the results.From the KS scores, it seems that the procedure does not influence the ability of patient to feel the urge to defecate, but since this disorder could be related to neurological impairment of sacral fibers due to the ARM itself, it is reasonable it could not be solved by an injection of adipose tissue.It is difficult at this moment in time to have a certain explanation of the way this procedure works for fecal continence. A valid explanation could be that the injections, due to a mass-effect, helps the continence of the anal sphincter increase the pressure needed for defecation and so reducing the episodes of fecal loss, thus acting as a bulking agent.Furthermore, it has been postulated that adipose staminal cells maybe somehow involved in increasing the amount of muscle cells of the anal sphincter thanks to their differentiation potential, but it is not currently documentable in our population of patients.Endoanal-US guidance has never been used in this procedure and we believe it could be of some advantage thanks to the precise site of injection—that is the intersphincteric plane.The anal-lipofilling seems to have a time-related efficacy that could be explained by the partial reabsorption of the adipose tissue injected; considering that when the parents came back to our institution to report a reduction in the effects we shortly after programmed and performed a new one, we could assume the average interval between procedures as the average duration of the effects of the anal-lipofilling (in our cohort of study: 343.8 ± 220.1 days).No complications were recorded.We are aware our results are limited to the paucity of patients enrolled.Nevertheless, our preliminary outcomes encourage us to continue proposing this novel technique to our patients.It is necessary to understand if the anal-lipofilling works better on secondary overflow incontinence or on true incontinence due to intrinsic sphincteric deficiency in order to improve patients’ selection.Moreover, the next step of our study will include both pre- and post-operative ano-rectal manometry evaluation.Our preliminary results on the anal-lipofilling technique are encouraging—75% of patients treated improved their continence with less episodes of involuntary fecal loss with no complications recorded.More studies are needed to assess the exact mechanism of action, to better evaluate the duration of the effects and, therefore, define an adequate follow-up.


Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting up to six million people in the United States and more than 35 million individuals worldwide. Thromboembolism, including stroke, represents the most common AF-related morbidity and mortality and data indicate that anticoagulation can mitigate this risk by 65%. Our understanding of thromboembolism in AF, however, remains incomplete, and the mechanisms by which AF increases thromboembolic risk are areas of ongoing investigation and debate. Current guidelines do not differentiate between the frequency and duration of AF episodes (AF burden) when selecting which patients with AF should be treated with anticoagulation for thromboembolic risk reduction. Recent data, primarily using cardiac implantable electronic devices (CIEDs) such as pacemakers, implantable cardioverter-defibrillators, and implantable loop recorders, however, have challenged this longstanding notion that AF burden does not influence thromboembolic risk. Continuous and automated cardiac rhythm monitoring via CIEDs with accurate and rapid acquisition and transmission of rhythm data also affords the opportunity to study the relationship between AF burden and thromboembolism and novel ways to reduce thromboembolic risk while minimizing the risk associated with chronic anticoagulation use. This manuscript will review the associations between subclinical, CIED-detected atrial arrhythmias and thromboembolic events. It will also discuss the emergence of “tailored anticoagulation,” an anticoagulation strategy wherein CIEDs and remote AF monitoring are employed to allow dynamic administration of oral anticoagulation only around episodes of AF, and the holding of anticoagulation during prolonged periods of sinus rhythm when the thromboembolic risk associated with AF is presumably very low. Continuous and automated cardiac rhythm monitoring with accurate and rapid acquisition and transmission of rhythm data via CIEDs also affords the opportunity to study the relationship between AF burden and thromboembolism and novel ways to reduce thromboembolic risk while minimizing the risk associated with chronic anticoagulation use.Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting up to six million people in the United States8 A clearer association between what was at the time termed “auricular fibrillation” and atrial thrombosis was not appreciated, however, until the 1930s.9 Although a clear association between AF and thromboembolism was observed in patients with rheumatic heart disease and mitral stenosis,10 the link between AF and thromboembolism in patients without rheumatic heart disease was not well-recognized until a seminal analysis of the Framingham Heart Study was conducted in the 1970s, which demonstrated that chronic AF without rheumatic heart disease was associated with a more than fivefold increase in the risk of stroke.11 In the 1980s, a link between paroxysmal AF and increased rates of thromboembolic complications in chronic versus paroxysmal AF was observed.12 Multiple large clinical trials have since confirmed a clear association between AF and thromboembolism in patients with paroxysmal, persistent, or chronic AF and a reduction in thromboembolic complications with the use of anticoagulation.17 Yet, despite the wealth of evidence supporting an association between AF and thromboembolism, the actual mechanism(s) of stroke and systemic embolism in patients with AF remain unclear and under investigation.6William Wood first described a left atrial thrombus in a patient with mitral stenosis more than 200 years ago.2 score, one of the most ubiquitous scoring systems in all of medicine, has long been the gold standard for assessing thromboembolic risk associated with AF and the need for anticoagulation.18 More recently, the updated CHA2DS2-VASc score has been validated and incorporated into the most recent AF guidelines of all major cardiovascular societies.19 Both scoring systems include the risk factors of congestive heart failure, hypertension, diabetes mellitus, and prior stroke or transient ischemic attack. However, the CHA2DS2-VASc score emphasizes the important relationship between age and thromboembolism, assigning two risk points for age ≥ 75 years and one risk point for age ≥ 65 years . The CHA2DS2-VASc score also adds female gender and vascular disease as thromboembolic risk factors, although controversy exists about the relative risk associated with these risk factors in comparison with others . The main strength of the newer CHA2DS2-VASc score is its ability to identify a specific low-risk population (score: 0 points) who have a very low thromboembolic risk and who can reasonably be treated without systemic anticoagulation. Unfortunately, only 5% to 10% of the AF population (and no women with AF) meet this criteria.20The CHADS2DS2-VASc score ≥ 2, systemic anticoagulation with an oral anticoagulant with either adjusted-dose warfarin or a new direct oral anticoagulant (DOAC) is indicated. For patients with a CHA2DS2-VASc score of 1, European guidelines recommend anticoagulation, whereas US guidelines suggest that either anticoagulation, aspirin use, or no anticoagulation are equally appropriate options. Controversy also exists regarding whether those with a CHA2DS2-VASc score of 2 due to certain risk factors require anticoagulation, because, although all risk factors in the score are given relatively equal weight (with the exception of age > 75 years and a history of stroke or transient ischemic attack), some studies have suggested that all risk factors may not be equal in terms of their influence on thromboembolic risk.22There is overall consensus that, in patients with a CHA2/CHA2DS2-VASc scoring systems is the frequency and/or duration of AF episodes (AF burden). Furthermore, current guidelines do not consider AF burden when evaluating a patient’s risk of thromboembolism and their need for systemic anticoagulation. There is therefore inconsistency in the current AF guidelines, where the decisions to initiate and continue anticoagulation are independent of AF burden, but thromboembolic risk in the pericardioversion period is thought to remain relatively low for the first 48 hours.7 This “48-hour rule,” where it is acceptable to perform a cardioversion without first excluding a left atrial thrombus via transesophageal echocardiogram in the first 48 hours, however, is based on a relatively small, nonrandomized study,23 and no randomized controlled trial data exist to definitively support 48 hours as being a “safe” cutoff time period for thrombus formation. In fact, more recent data obtained from patients with pacemakers and ICDs that have the ability to precisely detect short, subclinical, and asymptomatic AF episodes have demonstrated that the risk of thromboembolism in AF begins to increase much earlier than at 48 hours after AF onset (see below).Notably absent from the CHADS24 Asymptomatic AF recurrences are even more common following catheter ablation for AF.26It would seem logical that AF-associated intracardiac thrombus formation should be a time-dependent phenomenon. However, this has been difficult to prove due to the fact that episodes of AF can be asymptomatic and it can therefore be difficult to determine the exact onset of an AF episode by patient report. In fact, multiple studies have demonstrated that patient-reported symptomatic AF episodes are poorly correlated with device-detected AF episodes. In the Suppression of Paroxysmal Atrial Tachyarrhythmias (SOPAT) trial, only 46% of AF episodes detected on event monitors were symptomatic.27 and the Stroke Prevention in AF (SPAF) study28 found no significant difference in thromboembolic risk in patients with paroxysmal or chronic AF. Studies that have investigated rhythm control of AF, such as the AF Follow-up Investigation of Rhythm Management (AFFIRM) study, also demonstrated a significantly increased risk of stroke in patients who stopped anticoagulation despite being in sinus rhythm, although, in retrospect, this is likely secondary to the fact that antiarrhythmic therapy for AF is not 100% effective and many of these patients may have had asymptomatic AF that was not clinically detected.29 Multiple other observational studies have also found no significant differences in stroke rates between those with paroxysmal and persistent AF.30Additionally, until recently, there were data showing that AF burden did not influence the risk of thromboembolism associated with AF. Older studies such as the AF Clopidogrel Trial with Irbesartan for Prevention of Vascular Events (ACTIVE W)31However, all of these studies defined paroxysmal AF with surface electrocardiograms (ECGs) performed during physician visits that occurred months apart, and, as such, these studies therefore incompletely assessed AF burden and likely underestimated the true frequency and duration of AF episodes. These studies also suffer from limitations in statistical power; a large number of patients and events are needed to find a difference in thromboembolic events among those with paroxysmal and persistent/chronic AF. In fact, a more recent secondary analysis of the very large Apixaban for Reduction in Stroke and Other Thromboembolic Events in AF (ARISTOTLE) trial with more than 18,000 patients revealed a lower risk of thromboembolic events in patients with paroxysmal AF versus in those with persistent/permanent AF..32CIEDs, including pacemakers, ICDs, and ILRs, offer a precise method of defining AF burden that does not rely on patient-reported symptoms or frequency of surface ECGs. Although algorithms for AF detection are not perfect , they have improved substantially and, coupled with automatic remote monitoring capabilities, they allow for accurate and near-real-time detection of AF burden .41 In a secondary analysis of the Mode Selection Trial (MOST), which followed 312 patients with dual-chamber pacemakers for a median of 27 months, atrial high-rate episodes (AHREs) lasting five minutes or more were associated with a significant increase in the risk of death or nonfatal stroke .33 A similar study using a prospective registry of 725 patients with dual-chamber pacemakers followed for a median of 22 months found that AF episodes lasting between five minutes and 24 hours in length were not associated with a significant increase in thromboembolic risk, but that episodes lasting more than 24 hours were independently associated with a threefold increase in the hazard of thromboembolic events .34Several studies have taken advantage of these advances in continuous cardiac rhythm monitoring to investigate risk thresholds for AF burden and thromboembolic risk 2 score of 2.3 ± 1.1 for a mean of 2.5 years. In this population, subclinical AHREs [defined as an atrial rate of more than 190 beats per minute (bpm) lasting for more than six minutes as detected on the CIED] were discovered in 25% of patients. The annual rate of thromboembolism was 1.7% in patients with AHREs lasting more than six minutes versus 0.7% in patients without such episodes . Additionally, if the longest AHRE was less than 17.7 hours, then the annual rate of stroke or systemic embolism was 1.2%, versus a rate of 4.9% if the longest AHRE recorded was more than 17.7 hours. The total duration but not total number of AHREs correlated with thromboembolic risk, suggesting that the total duration of all AF episodes was more important than AF episode frequency in defining “AF burden” and its relationship with thromboembolic risk.37 Notably, the absolute risk of thromboembolism observed in ASSERT was lower than that observed in other studies investigating thromboembolic risk in AF.42 It is also difficult to draw direct comparisons between the results from ASSERT and other modern AF trials because none of the ASSERT patients were on anticoagulation at the time of enrollment and only 18% received anticoagulation during follow-up,37 while anticoagulation is the standard of care for clinically recognized AF.The Asymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF Reduction Atrial Pacing Trial (ASSERT) monitored 2,580 patients aged older than 65 years with dual-chamber pacemakers or ICDs, no history of AF, and a CHADS2 score was seen only in patients with intermediate thromboembolic risk (CHADS2 score: 1–2), but not in patients with low (CHADS2 score: 0) or high (CHADS2 score: ≥ 3) scores . Interestingly, thromboembolic risk was similar (5.0%) between patients with a CHADS2 score of 1 and continuous AF and those with higher CHADS2 scores and any AF burden. Similarly, patients with a CHADS2 score of 2 and no AF had a low risk of thromboembolism (0.8%) equivalent to the risk in a patient with a CHADS2 score of 1 and short episodes of AF or that in a patient with a CHADS2 score of 0 and any AF burden.35 These results support the concept that patients who have a low-to-intermediate risk of thromboembolism might be safe without continuous anticoagulation during long periods with a very low burden of AF or during prolonged periods of sinus rhythm.35Further support for an association between AF burden and thromboembolism was seen in a prospective study of 568 patients after dual-chamber pacemaker implantation. During one year of follow-up, 14 patients (2.5%) experienced a thromboembolic event. A relationship between AF burden and CHADS43Newer-generation external cardiac monitors have also demonstrated an association between AF burden and thromboembolism. The Real-world Heart Monitoring Strategy, Evaluation, Treatment Patterns and Health Metrics in AF (RHYTHM) study was a retrospective evaluation of patients with paroxysmal AF who underwent continuous ECG monitoring for up to two weeks using the ZIO® system . Each twofold increase in AF burden was associated with a 33% increase in thromboembolism independent of other stroke risk factors.2 risk factor and a pacemaker or ICD with the ability to record AF episodes/AHREs over 1.4 years of follow-up. The study demonstrated increased thromboembolic risk in patients with AHREs lasting more than 5.5 hours versus those with AHREs lasting less than 5.5 hours (2.1% versus 1.1%).36 However, among 40 patients who developed a thromboembolic event during the study, only 11 had an AHRE detected within one month prior to thromboembolism. Another study of 560 patients with heart failure and biventricular ICDs noted similar findings. They found that patients with AHREs lasting more than 3.8 hours per day had a significantly increased risk of stroke or systemic embolism  in comparison with those without AHREs. However, only three of the 11 patients with thromboembolism were in AF at the time of stroke.38 Even in the ASSERT trial, where there was a clear relationship between subclinical AHREs, a clear temporal association between episodes of AHREs and thromboembolism was not observed: 51 patients had a thromboembolic event but only 26 (51%) of these individuals had subclinical AHREs identified around the time of the event. Furthermore, of these 26 patients with identified AHREs, only four had AHREs within 30 days and only one had AHREs at the time of thromboembolism. Importantly, the CHADS2 and CHA2DS2-VASc scores in the patients who experienced thromboembolism were 2.8 ± 1.1 and 4.5 ± 1.2, respectively.44However, not all studies evaluating AF burden with CIEDs have found a clear association between short AHREs and thromboembolism. The Prospective Study of the Clinical Significance of Atrial Arrhythmias Detected by Implanted Device Diagnostics (TRENDS) study evaluated 2,486 patients with at least one CHADS32 This not only limited the accuracy of stroke diagnosis but also impaired the adjudication of the mechanism of the stroke (thromboembolic versus other). Furthermore, those with very high CHADS2 and CHA2DS2-VASc scores make up an overall sicker population with elevated rates of stroke, even without AF.45 This again raises the possibility that, in some patients, atrial stasis from AF may not be the primary driver for AF-related thromboembolism; perhaps, the presence of AF is a marker for other pro-inflammatory and potentially hypercoagulable states that then cause thromboembolism.6 In these cases and, in certain patients with particularly elevated thromboembolic risk factors, AF burden may not be the critical determinant for thromboembolic risk.This conflicting data on the associations between CIED-detected AF burden/AHREs and the timing of thromboembolic events likely stems from several limitations within these studies. First, stroke diagnosis was often defined by clinical examination and not magnetic resonance imaging due to the presence of CIEDs in these patients.Although multiple studies have demonstrated an association between short AHREs and increased thromboembolic risk, it is not clear how to manage patients who only have subclinical AHREs detected on CIEDs (excluding those with cryptogenic stroke where it is accepted that anticoagulation would be warranted). As noted above, there has not been a clear and consistent temporal association between these subclinical AHREs and thromboembolism and further investigations into whether or not treatment of these episodes with anticoagulation are planned.2DS2-VASc criteria. Notably, patients with prior documented clinical AF or long episodes of subclinical AF will be excluded and patients with prior thromboembolic events will not be excluded from enrollment, respectively. Anticipated enrollment is approximately 4,000 patients. Subjects will be randomized in a 1:1 ratio to aspirin or apixaban in a blinded manner. The primary endpoint of the study is a composite of stroke or systemic embolism.46The Apixaban for the Reduction of Thromboembolism in Patients with Device-detected Subclinical AF (ARTESiA) trial (NCT01938248) is a prospective, multicenter, double-blind, randomized controlled trial recruiting patients with any subclinical AF (defined as an AF episode lasting more than six minutes but less than 24 hours) on a CIED  and additional stroke risk factors as defined by the CHA47Similarly, the Non-vitamin K Antagonist Oral Anticoagulants in Patients with AHREs (NOAH-AFNET 6) trial (NCT02618577) is a randomized study comparing the composite outcome of stroke, systemic embolism, and cardiovascular death in patients with subclinical AF  noted on a pacemaker or ICD and additional thromboembolic risk factors. Patients will be randomized to receive treatment with edoxaban or no anticoagulation. Estimated enrollment is approximately 3,400 patients.Although our understanding of the mechanistic links between AF burden and stroke remain incomplete, based on the above concepts, several trials have aimed to utilize advances in remote monitoring to help guide dynamic use of anticoagulation based on a patient’s AF burden (“tailored anticoagulation”). The concept of tailored anticoagulation is therefore based on the idea that, in select patients with low-to-moderate thromboembolic risk factors, and during prolonged periods of sinus rhythm or in the setting of a very low burden of AF, the risk of thromboembolism is sufficiently low such that continuous anticoagulation is not warranted and, that, during these periods, the patient is exposed to the risks of continuous anticoagulation without a significant benefit in reducing AF-related thromboembolism. Based on the use of DOACs with an onset of action in hours instead of in days as would be expected with warfarin and, with the availability of CIEDs with remote monitoring capabilities, it should therefore be possible to anticoagulate patients promptly around episodes of AF while avoiding the need for anticoagulation when AF is not present.2 score, including high-risk individuals. As a result, the burden of AF, which prompted the initiation of anticoagulation with warfarin (as the study took place before the widespread availability of DOACs), and the duration of anticoagulation use after AF diagnosis varied based on the CHADS2 score. Unfortunately, the IMPACT study was discontinued prematurely due to an absence of benefit.48 In retrospect, this study likely failed due to low rates of AF ; low rates of thromboembolism (only 69 patients experienced a thromboembolic event); and the fact that warfarin was the primary method of anticoagulation, with a suboptimal time in therapeutic range of approximately 59%.49The Randomized Trial of Anticoagulation Guided by Remote Rhythm Monitoring in Patients With ICD and Resynchronization Devices (IMPACT) multicenter study was the first investigation into tailored anticoagulation. This study did not require a diagnosis of AF for enrollment and also allowed the inclusion of patients with any CHADS2 score: 1.3 ± 0.5) with implanted Reveal XT™  ILRs; nonpermanent AF on a DOAC ; and a CHADS2 score of 1 to 2. Patients could only be enrolled if they had no episodes of AF lasting more than one hour in the two months prior to enrollment. Time on anticoagulation and rates of bleeding and stroke were assessed. Patients made daily remote transmissions using their ILR to assess for AF episodes. After a 60-day run-in with no AF episodes lasting one hour or more, anticoagulation was discontinued and aspirin was started. DOACs were continued or restarted for 30 days following any AF episodes lasting one hour or more.More recent pilot studies using DOACs in low- to-intermediate risk patients with a low burden of AF, however, have shown more promising results. The Rhythm Evaluation for Anticoagulation with Continuous Monitoring (REACT.COM) pilot study was a multicenter single-arm study that enrolled 59 patients  patients, resulting in 1,472 days on anticoagulation. This represented a 94% reduction in the time on anticoagulation as compared with continuous anticoagulation regardless of AF burden. Two traumatic major bleeds occurred during the trial, both of which happened while patients were on aspirin therapy alone. No strokes or deaths occurred. One “definite” and two “possible” transient ischemic attacks were observed; all three of these patients were not on anticoagulation at the time of their respective neurologic events and all three had no significant AF episodes around the time of diagnosis.2 score < 3. Inclusion criteria included a low burden of AF (< 30 minutes per day and less than six continuous minutes per episode for ≥ 30 days before enrollment as documented on pacemaker or ICD). Patients were randomized to a device-tailored treatment arm or control arm, the latter of which was continuous anticoagulation regardless of AF burden. Those assigned to device-tailored treatment sent twice weekly and AF-alert transmissions to their physicians. Patients were able to discontinue anticoagulation after 30 days of freedom from both a single AF episode of six minutes or more and a total daily AF burden of six hours or more. The tailored anticoagulation arm experienced a 74.6% reduction in time on anticoagulation as compared with standard of care with no reported transient ischemic attacks or strokes. There were two hemorrhagic events each in the control arm (n = 16) and the interventional arm (n = 48), although none of these four patients were on anticoagulation at the time of bleeding.The Tailored Anticoagulation for Noncontinuous AF (TACTIC-AF) pilot study was a similar multicenter randomized controlled study of remote monitoring via dual-chamber pacemakers and ICDs to allow for the intermittent use of DOACs in patients with paroxysmal AF and a CHADS51 It is important to note that these two studies were very small and underpowered to detect adverse outcomes such as stroke and that larger randomized controlled trials are needed before tailored anticoagulation can be adopted into routine clinical practice. Further study of tailored anticoagulation is warranted.The results of the REACT.COM and TACTIC-AF pilot studies demonstrate the feasibility and overall safety of tailored anticoagulation in patients with a low burden of AF and low-to-intermediate thromboembolic risk factors. A recent analysis of the REACT.COM data has also demonstrated that tailored anticoagulation can be cost-effective.21 This can result in both false positives  or false negatives . Noise, electromagnetic interference, or oversensing can also cause false detection of AHREs. Therefore, due to these limitations, in general, AHRE electrograms need to be adjudicated to ensure that they are consistent with AF and not another arrhythmia or a false-positive detection. As future technology and detection algorithms improve, review/adjudication of electrograms will likely become less important. Additionally, the Reveal XT™  ILR used in the REACT.COM trial can take up to two minutes to define an episode as AF, depending on how irregular it is. Some short episodes of AF may therefore be missed by ILRs versus by pacemakers or ICDs.Current-generation pacemakers and ICDs primarily detect AF by measuring the rate of atrial activation at the position of the right atrial lead and comparing it with a cutoff . Rate-related detection is utilized because localized right atrial activation during AF can often be quite regular, even when the surface ECG demonstrates true AF. As a result, all detected AHREs may not represent AF; some could represent organized atrial tachycardias/flutters or other reentrant supraventricular tachycardias. Current-generation ILRs (and some newer single-chamber ICDs) do not have the ability to assess atrial activity and therefore rely on irregularity of RR intervals to define episodes of AF.51 tailored anticoagulation is likely associated with significant indirect costs that have not yet been well-quantified. These indirect costs are primarily related to the time and additional personnel required to ensure that all patients are transmitting device data on a regular basis and that their devices are actively communicating with the clinic, with the need to quickly inform patients if they have any AF detected, and with the time required for clinicians to review electrograms to confirm AHRE detections represent AF. However, as AF detection algorithms improve and as CIEDs increase integration with smartphones and other personal device applications, these costs are expected to decrease over time.Although the cost-effectiveness of tailored anticoagulation in the REACT.COM study has been shown to be favorable,Despite the high prevalence of AF and a clear benefit associated with anticoagulation in patients with clinically manifest AF, it remains unclear how to optimally treat patients with short, subclinical device-detected AHREs. The optimal cutoff point for treating these episodes also remains unknown. Data suggest, however, that continuous AF episodes lasting more than a few hours but less than 48 hours are associated with increased thromboembolic risk, with the absolute risk likely modulated by individual patient risk factors. Studies investigating the treatment of these short, subclinical AHREs are currently enrolling patients.The currently accepted approach to anticoagulation in AF is incomplete and contradictory. AF burden does not factor in the decision to anticoagulate for AF, yet AF episodes lasting up to 48 hours are thought to be associated with a thromboembolic risk that is low enough to defer transesophageal echocardiogram prior to cardioversion. Recent data, however, have challenged this cornerstone principle of AF management. The availability of continuous atrial arrhythmia monitoring with automatic remote transmission of arrhythmia data and rapidly acting oral anticoagulants has allowed the concept of tailored anticoagulation, wherein some lower-risk patients with a relatively low burden of AF may be able to safely start and stop oral anticoagulation based on their AF burden, to emerge. Preliminary data suggest that tailored anticoagulation is feasible and safe. Further studies will be required, however, before it can be adopted into routine clinical practice.


Staphylococcus aureus , Stenotrophomonas maltophilia, Enterococcus faecalis, Staphylococcus epidermidis, and Pseudomonas aeruginosa were chosen for the wound infection study. All the bacteria were enumerated in the wound dressing and in the wound tissue under the dressing. Using colony-forming unit (CFU) assays, over 7 logs of inhibition (100%) was found for all the bacterial strains on the material of the OS-coated wound dressing and in the tissue under that dressing. Confocal laser scanning microscopy along with IVIS spectrum in vivo imaging confirmed the CFU results. Thus, the dressing acts as a reservoir for a biofilm, which causes wound infection. The same results were obtained after soaking the dressing in PBS at 37 °C for three months before use. These results suggest that an OS coating on polyester dressing is both effective and durable in blocking wound infection.The dressing material of a wound plays a key role since bacteria can live in the bandage and keep re-infecting the wound, thus a bandage is needed that blocks biofilm in the bandage. Using an in vivo wound biofilm model, we examined the effectiveness of an organo-selenium (OS)-coated polyester dressing to inhibit the growth of bacteria in a wound.  Se-AAEMA (22% [wt/wt] selenium) stock solution was dissolved and diluted in 99.99% 2-(methacryloyloxy)-ethyl acetoacetate (AAEMA) to yield the 1% Se-AAEMA (wt/wt), used for the coating. Then, 100% ivory polyester fabric purchased from a local Walmart store (#M30-23) was cut into 4 inch x 4 inch square pieces and soaked in sterilized distilled water overnight. The washed polyester dressing was then dried at 37 °C in an oven and coated with AAEMA or Se-AAEMA. Briefly, the dressings were soaked in AAEMA or Se-AAEMA for 30 min. Excess AAEMA or Se-AAEMA was removed from the dressings by passing the soaked bandage through a roller press . The AAEMA or Se-AAEMA polyester dressings were then sprayed with HS. aureus AH133 (TTUHSC laboratory strain) was used. This is a lab strain that constitutively expresses green fluorescent protein from a plasmid (pCM11) in the presence of 1 μg/mL erythromycin [Pseudomonas aeruginosa strain PAO1/pMRP9-1was also grown. This strain carries the plasmid pMRP9-1 that contains the gene that codes for the green fluorescent protein [S. aureus and S. epidermidis clinical isolates were obtained from leg wounds or abscess wounds from the Clinical lab at Texas Tech University Health Sciences Center under an approved Institutional Review Board protocol of the Texas Tech University Medical Center in Lubbock, Texas. Staphylococcus aureus Lux Xen29 was also used, a strain with a plasmid containing a gene that codes for the luciferase protein [Pseudomonas aeruginosa PAO1 Lux Xen5 strain was available at our lab at Texas Tech University Health Sciences Center [Stenotrophomonas maltophilia ATCC® 53199™ was available at our lab at Texas Tech University Health Sciences Center. All bacterial stock was stored at −80 °C.All strains were grown in Luria Bertani (LB) Broth, Mueller Hinton Broth, or on LB Agar plates at 37 °C. hromycin . Pseudomasmid pCM in the p protein . To mains Center . Finally600) of 0.1 (107 CFU/mL), and serially diluted 10-fold. All PBS assay solutions contained 150 μM reduced glutathione . Ten microliter aliquots containing 102 to 103 colony-forming units were added to the bandages. They were a stack (3 pieces of one square centimeter) containing either AAEMA (control treated with AAEMA with no selenium—listed in the figures as untreated dressing) polyester dressing, or Se-AAEMA test polyester dressing. After the bacterial inoculum was absorbed into the dressings, they were placed on LB agar plates, and the plates were incubated at 37 °C for 24 h. Biofilms were then quantified by determining the CFU per square centimeter of dressing by the following procedure. After incubation, each stack of dressing was rinsed with sterile PBS and then was transferred to a sterile 1.5-mL microcentrifuge tube containing 1 mL of PBS (pH = 7.4) for enumeration of bacteria. The tubes were placed in a water bath sonicator for 5-10 min to loosen the cells within the dressing and then vigorously vortexed 3 times for 1 min to detach the cells. Suspended cells were serially diluted (10-fold) in PBS, and 10-μL aliquots of each dilution were spotted onto LB Agar plates. In addition, the remaining 900-μL zero dilution sample was plated on a different LB Agar plate. Thus, the equation for back calculating the bacterial concentration was CFU × dilution factor × 100, with the exception of the 900-μL sample, which was calculated as CFU × 1. This means that if only one bacterium was originally in the tube, we would have a 90% chance of detecting it. All experiments were done in triplicate, and all measurements were repeated three times.Bacteria were grown overnight, and washed once with PBS (pH 7.4). They were then re-suspended in PBS (pH 7.4) to an optical density  was placed on the wound. The dressings were secured in place by applying a clear OPSITE dressing over the back of the mouse. Aliquots containing 102 to 103 CFU of bacteria in 20 μL were injected in the area between the bandage and the wound. The mice were monitored twice a day for signs of infection or distress. The dressings were removed, and the connective tissue around the wound and the tissue under the wound  was then dissected and removed. The extracted dressings and all the dissected tissue were gently rinsed in PBS and homogenized in PBS. Excess PBS was drained from the dressing by touching it to a sterile filter paper and the dressing was then transferred to a sterile homogenized tube containing 2 mL of PBS for enumeration of bacteria by either determination of CFU or by confocal microscopy. All experiments were done at least in triplicate.Six adult female Balb C mice (including a control group) weighing 20–24 g were anesthetized using a mixture of isoflurane and oxygen, and their backs were shaved. Shaved areas were completely cleansed with 95% ethanol. A flap of skin was lifted and a 1.0-cm2 in a closed chamber) and the connective tissue around the wound and the tissue under the wound  was then dissected and removed. This was then homogenized and used for a CFU assay in a manner similar to that used for the dressing above.Tissue: At the end of the experiment (5 days), the mouse was euthanized . The dressings were homogenized to loosen the cells within the biofilm and then vigorously vortexed 3 times for 1 min to detach the cells. Suspended cells were serially diluted (10-fold) in sterile 1× PBS (pH 7.4), and 10-μL aliquots of each dilution were spotted onto LB Agar plates. Bacterial counts were determined as described above. The results were reported as attached CFU per dressings recovered from each mouse. All experiments were done in triplicate.At the end of the in vivo experiment (5 days), the mice were euthanized, and the tissue of the wounds was removed. The tissue was weighed, and it was then homogenized. The CFU assay was performed in a manner similar to the assay used for the dressing above. The results were reported as attached CFU per gram of tissue. All experiments were done in at least triplicate.The pieces of polyester dressings at the end of the in vivo 5-day incubation were assayed as described above for the CFU assays. AAEMA control and Se-AAEMA polyester dressing segments from three mice of each group were also examined for the presence of biofilm by confocal laser scanning microscopy (CLSM) using an Olympus Fluoview FV300 . Animals were treated in accordance with the protocol approved by the Institutional Animal Care and Use Committee at Texas Tech University Health Sciences Center in Lubbock, TX, USA.Staphylococcus aureus Lux Xen29 or Pseudomonas aeruginosa Lux Xen5 and observed at day 5 after treatment. The mice were lightly anesthetized, and the infected wounds were visualized using an IVIS Lumina XR system with Living Image software . This instrument allowed us to directly detect pathogenic infections in living animals by producing images through bioluminescence. After imaging, the mice were euthanized, and the gauze dressing and wound tissues were recovered. The samples were then analyzed by the CFU assay as described above. Imaging experiments were conducted at the Texas Tech University Health Sciences Center Image Analysis Core Facility . All experiments were done in triplicate.Mice were also infected with either One square-centimeter strips of the organo-selenium-containing polyester dressing were completely immersed in 1.0 mL of PBS in sterile glass tubes and incubated at 37 °C for a month. At the end of the incubation period, the pieces were removed, dried, sterilized by dried autoclaving, and utilized in the in vitro biofilm assay, as described above, for determination of the durability of the anti-biofilm activity of the coating.® version 4.03  with 95% confidence intervals (CIs) of the difference. Comparisons of the in vivo biofilms formed on Se-free and Se-AAEMA polyester dressings were analyzed by a two-tailed unpaired t-test to determine significant differences. All experiments were done at least in triplicate.Results of the CFU assays were analyzed with PrismStenotrophomonas maltophilia, Enterococcus faecalis, Staphylococcus epidermidis and Pseudomonas aeruginosa), when compared with the control bandage coated with AAEMA containing no selenium. This result was true for all bacteria, whether Gram-negative or Gram-positive.For the bandages coated with organo-selenium in the form of 1% Se-AAEMA see , after 2As can be seen in Staphylococcus aureus, Pseudomonas aeruginosa, and two different clinical strains of MRSA. These results are confirmed by confocal laser scanning microscopy in Different bacteria were injected under a polyester bandage dressing, either with or without a selenium coating, which covered a mouse wound model. These were then allowed to grow for 5 days. As shown in Staphylococcus aureus Lux Xen29 or Pseudomonas aeruginosa Lux Xen5 under the polyester bandage and observed at day 5 after treatment. The actual growth of bacteria with this gene present is seen in In order to image the growth of bacteria in the wound, bacteria with the Lux gene were used. Mice were infected with either S. aureus GFP AH133 with the 1% Se-AAEMA coating. These results were confirmed by visualization with the confocal laser scanning microscope  used to coat a polyester bandage could block bacterial attachment to the bandage and influence biofilm formation in a wound. Selenium is unique amongst the elements in its ability to be attached to an organic molecule with a covalent bond and yet still retain its ability to catalyze the formation of superoxide radicals. This is done by selenium donating an electron to oxygen to form superoxide, resulting in the oxidation of the selenium atom. The oxidized selenium atom can then react with sulfhydryl groups present in all body fluids, such as glutathione, to become reduced, resulting in oxidization of the sulfhydryl (disulfide bond formation). This completes the catalytic cycle by essentially taking an electron from sulfur and giving it to oxygen. The advantage of this mechanism is that the selenium remains unchanged and attached to the polymer yet creates a local layer of superoxide on the surface of the material. However, the half-life of superoxide is short and does not travel far. It is probably due to this short half-life that previous studies have shown that there is no toxic effect upon nearby mammalian cells ,4.Based upon the mechanism described above, we expected the selenium coating to block bacterial attachment to the dressing. However, we were interested to find that the coating on the bandage also inhibited biofilm formation in the wound as well, even though the bacteria were injected into the area between the bandage and the wound. Since selenium does not leave the bandage and the half-life of the generated superoxide is very short (milliseconds at best), we expected the selenium mechanism to have more limited effects upon the wound tissue, especially during the 5 days of the experiment. One possible mechanism for the effect of the selenium coating on wound infection is that biofilm formation in a typical wound requires instigation by biofilm formation on the bandage. After the injection of the bacteria, the organisms that initially go into the wound are probably destroyed by the normal host cell defense mechanisms. Those bacteria that invade the control bandage, however, can form a biofilm on the bandage. This biofilm can release planktonic bacteria and toxins over time and continuously re-infect the wound. During this re-infection, toxins will kill cells in the wound, and these dead or compromised cells can serve as a matrix for biofilm formation in the wound itself. However, with the selenium-coated bandage, there is no biofilm formation in the bandage since the coating kills 100% of the bacteria that attempt to attach to the bandage. This serves to protect the wound from re-infection. Thus, a selenium-coated bandage should allow the wound requisite time to heal without biofilm formation. This was also confirmed by bioluminescence, which offers a method for monitoring infections in vivo over a period of several days. It is sensitive and non-invasive and requires fewer animals than conventional methodologies. It showed no infection developing in the selenium bandage or the wound over time.Organo-selenium monomers can be polymerized into a coating on polyester fabric, which is suitable for medical wound dressings. Organo-selenium-coated polyester dressings significantly inhibited biofilm formation by all bacteria tested (both Gram-negative and Gram-positive). Of importance was the fact that the selenium coating not only inhibited biofilm formation in the dressing but also inhibited biofilm formation in an inoculated wound over a 5-day period. The organo-selenium coating on the polyester dressing was also found to be stable after long soaking, and the inhibitory effect on bacterial biofilm remained. In future experiments, we plan to test the incorporation of the organo-selenium monomer into the polyester polymer itself rather than just coating it on the surface of the dressing. This would likely make a superior dressing that avoids problems with surface wear, leaching, or abrasion, and would allow for more flexibility in manufacturing.