International evaluation of an AI system for breast cancer screening.

Screening mammography aims to identify breast cancer at earlier stages of the disease, when treatment can be more successful1. Despite the existence of screening programmes worldwide, the interpretation of mammograms is affected by high rates of false positives and false negatives2. Here we present an artificial intelligence (AI) system that is capable of surpassing human experts in breast cancer prediction. To assess its performance in the clinical setting, we curated a large representative dataset from the UK and a large enriched dataset from the USA. We show an absolute reduction of 5.7% and 1.2% (USA and UK) in false positives and 9.4% and 2.7% in false negatives. We provide evidence of the ability of the system to generalize from the UK to the USA. In an independent study of six radiologists, the AI system outperformed all of the human readers: the area under the receiver operating characteristic curve (AUC-ROC) for the AI system was greater than the AUC-ROC for the average radiologist by an absolute margin of 11.5%. We ran a simulation in which the AI system participated in the double-reading process that is used in the UK, and found that the AI system maintained non-inferior performance and reduced the workload of the second reader by 88%. This robust assessment of the AI system paves the way for clinical trials to improve the accuracy and efficiency of breast cancer screening.

The effects of bariatric surgery on cardiac function: a systematic review and meta-analysis.

INTRODUCTION: Obesity is associated with alterations in cardiac structure and haemodynamics leading to cardiovascular mortality and morbidity. Culminating evidence suggests improvement of cardiac structure and function following bariatric surgery. OBJECTIVE: To evaluate the effect of bariatric surgery on cardiac structure and function in patients before and after bariatric surgery. METHODS: Systematic review and meta-analysis of studies reporting pre- and postoperative cardiac structure and function parameters on cardiac imaging in patients undergoing bariatric surgery. RESULTS: Eighty studies of 3332 patients were included. Bariatric surgery is associated with a statistically significant improvement in cardiac geometry and function including a decrease of 12.2% (95% CI 0.096-0.149; p < 0.001) in left ventricular (LV) mass index, an increase of 0.155 (95% CI 0.106-0.205; p < 0.001) in E/A ratio, a decrease of 2.012 mm (95% CI 1.356-2.699; p < 0.001) in left atrial diameter, a decrease of 1.16 mm (95% CI 0.62-1.69; p < 0.001) in LV diastolic dimension, and an increase of 1.636% (95% CI 0.706-2.566; p < 0.001) in LV ejection fraction after surgery. CONCLUSION: Bariatric surgery led to reverse remodelling and improvement in cardiac geometry and function driven by metabolic and haemodynamic factors.

Clinicopathological Predictors of Positive Resection Margins in Breast-Conserving Surgery.

BACKGROUND: Ductal carcinoma in situ (DCIS) is associated with risk of positive resection margins following breast-conserving surgery (BCS) and subsequent reoperation. Prior reports grossly underestimate the risk of margin positivity with IBC containing a DCIS component (IBC + DCIS) due to patient-level rather than margin-level analysis. OBJECTIVE: The aim of this study was to delineate the relative risk of IBC + DCIS compared with pure IBC (without a DCIS component) on margin positivity through detailed margin-level interrogation. METHODS: A single institution, retrospective, observational cohort study was conducted in which pathology databases were evaluated to identify patients who underwent BCS over 5 years (2014-2019). Margin-level interrogation included granular detail into the extent, pathological subtype and grade of disease at each resection margin. Predictors of a positive margin were computed using multivariate regression analysis. RESULTS: Clinicopathological details were examined from 5454 margins from 909 women. The relative risk of a positive margin with IBC + DCIS versus pure IBC was 8.76 (95% confidence interval [CI] 6.64-11.56) applying UK Association of Breast Surgery guidelines, and 8.44 (95% CI 6.57-10.84) applying the Society of Surgical Oncology/American Society for Radiation Oncology guidelines. Independent predictors of margin positivity included younger patient age (0.033, 95% CI 0.006-0.060), lower specimen weight (0.045, 95% CI 0.020-0.069), multifocality (0.256, 95% CI 0.137-0.376), lymphovascular invasion (0.138, 95% CI 0.068-0.208) and comedonecrosis (0.113, 95% CI 0.040-0.185). CONCLUSIONS: Compared with pure IBC, the relative risk of a positive margin with IBC + DCIS is approximately ninefold, significantly higher than prior estimates. This margin-level methodology is believed to represent the impact of DCIS more accurately on margin positivity in IBC.

Patient safety incidents in endoscopy: a human factors analysis of nonprocedural significant harm incidents from the National Reporting and Learning System (NRLS).

BACKGROUND: Despite advances in understanding and reducing the risk of endoscopic procedures, there is little consideration of the safety of the wider endoscopy service. Patient safety incidents (PSIs) still occur. We sought to identify nonprocedural PSIs (nPSIs) and their causative factors from a human factors perspective and generate ideas for safety improvement. METHODS: Endoscopy-specific PSI reports were extracted from the National Reporting and Learning System (NRLS). A retrospective, cross-sectional human factors analysis of data was performed. Two independent researchers coded data using a hybrid thematic analysis approach. The Human Factors Analysis and Classification System (HFACS) was used to code contributory factors. Analysis informed creation of driver diagrams and key recommendations for safety improvement in endoscopy. RESULTS: From 2017 to 2019, 1181 endoscopy-specific PSIs of significant harm were reported across England and Wales, with 539 (45.6%) being nPSIs. Five categories accounted for over 80% of all incidents, with "follow-up and surveillance" being the largest (23.4% of all nPSIs). From the free-text incident reports, 487 human factors codes were identified. Decision-based errors were the most common act prior to PSI occurrence. Other frequent preconditions to incidents were focused on environmental factors, particularly overwhelmed resources, patient factors, and ineffective team communication. Lack of staffing, standard operating procedures, effective systems, and clinical pathways were also contributory. Seven key recommendations for improving safety have been made in response to our findings. CONCLUSIONS: This was the first national-level human factors analysis of endoscopy-specific PSIs. This work will inform safety improvement strategies and should empower individual services to review their approach to safety.

Assessing interventional radiology specialty knowledge and perception amongst Tanzanian medical students before and after exposure to an immersive curriculum.

AIMS: This study aims to assess the impact that delivering an introductory interventional radiology (IR) lecture series has on the knowledge and perception of the specialty among medical students in a resource-limited setting with, until recently, no IR presence. MATERIALS AND METHODS: An introductory four-hour lecture series in IR was delivered to third-year medical students in Tanzania. Prior to and following the lecture series, participants completed a 27-item paper-based survey assessing their knowledge and perception of the specialty. RESULTS: Out of a class of 213, the pre- and post-lecture survey was returned by 148 (69.5%) and 151 (70.9%) respondents, respectively. 94.5% of respondents indicated that they were aware of IR as a specialty. Among respondents, 97.3% expressed interest in having IR lectures integrated into their curriculum, compared to 29.0% that reported having any prior IR training. 27.3% believed their knowledge in IR compared to other specialties was either "good" or "excellent", which improved to 43.3% (p<0.001). Identification that IR physicians consult patients directly, have outpatient clinics, have inpatient beds, and do rounds improved from 55.4% to 81.1% (p<0.001), 49.7% to 60.3% (p=0.066), 48.3% to 66.7% (p=0.001), and 52.0% to 66.2% (p=0.013), respectively. CONCLUSION: By introducing short lectures on IR-relevant topics, knowledge and perception of IR improved among Tanzanian medical students. Early education and exposure to IR should be prioritized to promote the continued growth of the specialty in this setting.

Artificial Intelligence in Surgery: The Future is Now.

Background Clinical Artificial intelligence (AI) has reached a critical inflection point. Advances in algorithmic science and increased understanding of operational considerations in AI deployment are opening the door to widespread clinical pathway transformation. For surgery in particular, the application of machine learning algorithms in fields such as computer vision and operative robotics are poised to radically change how we screen, diagnose, risk-stratify, treat and follow-up patients, in both pre- and post-operative stages, and within operating theatres. Summary In this paper, we summarise the current landscape of existing and emerging integrations within complex surgical care pathways. We investigate effective methods for practical use of AI throughout the patient pathway, from early screening and accurate diagnosis to intraoperative robotics, post-operative monitoring and follow-up. Horizon scanning of AI technologies in surgery is used to identify novel innovations that can enhance surgical practice today, with potential for paradigm shifts across core domains of surgical practice in the future. Any AI-driven future must be built on responsible and ethical usage, reinforced by effective oversight of data governance, and of risks to patient safety in deployment. Implementation is additionally bound to considerations of usability and pathway feasibility, and the need for robust healthcare technology assessment and evidence generation. While these factors are traditionally seen as barriers to translating AI into practice, we discuss how holistic implementation practices can create a solid foundation for scaling AI across pathways. Key Messages The next decade will see rapid translation of experimental development into real-world impact. AI will require evolution of work practices, but will also enhance patient safety, enhance surgical quality outcomes, and provide significant value for surgeons and health systems. Surgical practice has always sat on a bedrock of technological innovation. For those that follow this tradition, the future of AI in surgery starts now.

Impact of Axillary Lymph Node Dissection and Sentinel Lymph Node Biopsy on Upper Limb Morbidity in Breast Cancer Patients: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate the impact of axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) on upper limb (UL) morbidity in breast cancer patients. BACKGROUND: Axillary de-escalation is motivated by a desire to reduce harm of ALND. Understanding the impact of axillary surgery and disparities in operative procedures on postoperative arm morbidity would better direct resources to the point of need and cement the need for de-escalation strategies. METHODS: Embase, MEDLINE, CINAHL, and PsychINFO were searched from 1990 until March 2020. Included studies were randomized-controlled and observational studies focusing on UL morbidities, in breast surgery patients. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The prevalence of UL morbidity comparing SLNB and ALND at <12 months, 12 to 24 months, and beyond 24 months were analyzed. RESULTS: Sixty-seven studies were included. All studies reported a higher rate of lymphedema and pain after ALND compared with SLNB. The difference in lymphedema and pain prevalence between SLNB and ALND was 13.7% (95% confidence interval: 10.5-16.8, P <0.005) and 24.2% (95% confidence interval: 12.1-36.3, P <0.005), respectively. Pooled estimates for prevalence of reduced strength and range of motion after SLNB and ALND were 15.2% versus 30.9% and 17.1% versus 29.8%, respectively. Type of axillary surgery, greater body mass index, and radiotherapy were some of the predictors for UL morbidities. CONCLUSIONS: Prevalence of lymphedema after ALND was higher than previously estimated. ALND patients experienced greater rates of lymphedema, pain, reduced strength, and range of motion compared with SLNB. The findings support the continued drive to de-escalate axillary surgery.

The Use of Wearable Activity Monitors to Measure Upper Limb Physical Activity After Axillary Lymph Node Dissection and Sentinel Lymph Node Biopsy.

BACKGROUND: We suspect that morbidity from both sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) has been inadequately evaluated to date. Current methodologies are subjective and susceptible to bias. Objective assessment using wearable activity monitors (WAMs) would allow quantitative analysis of recovery by measuring physical activity (PA) and could provide evidence for axillary de-escalation. PATIENTS AND METHODS: A prospective, single center, observational study was conducted from February 2020 to May 2022. Consecutive patients undergoing breast and/or reconstructive surgery and axillary surgeries were identified from the operating schedules. Patients wore WAMs for an average of 3 days prior to surgery and up to 2 weeks following surgery. In total, 56 patients with breast cancer were recruited, of whom 35 underwent SLNB and 21 ALND. RESULTS: Patients who underwent ALND experienced significantly worse PA compared with those who underwent SLNB in week 2 (median 66.4% versus 72.7%, p = 0.015). Subgroup analysis revealed significantly lower PA in simple mastectomy (Mx)-ALND versus Mx-SLNB (median 90.3% versus 70.5%, p = 0.015) in week 2. The PA for SLNB did not return to baseline at 2 weeks after surgery. CONCLUSIONS: Compared with SLNB, ALND results in a lower PA level in week 2. The findings also indicate that SLNB has a protracted effect on PA levels, which extend to 2 weeks postoperatively. Monitoring recovery objectively following breast cancer surgery provides patients and surgeons with more information regarding the predicted outcomes of their surgery, which can drive the development of a personalized rehabilitation program.

Development of the "Teamwork in Endoscopy Assessment Module for Endoscopic Non-Technical Skills" (TEAM-ENTS) behavioral marker system.

BACKGROUND: Non-technical skills (NTS) are integral to team performance and subsequent quality and safety of care. Behavioral marker systems (BMSs) are now increasingly used in healthcare to support the training and assessment of team NTS. Within gastrointestinal endoscopy, this is an area of novel research. The aims of this study were to define the core relevant NTS for endoscopy teams and develop a preliminary framework for a team-based BMS known as TEAM-ENTS (Teamwork in Endoscopy Assessment Module for Endoscopic Non-Technical Skills). METHODS: This study was conducted in two phases. In phase 1, a literature review of team-based BMSs was performed to inform an interview study of core endoscopy team members. Cognitive task analysis was used to break down the NTS relevant to endoscopy teams. Framework analysis generated the structure for the preliminary TEAM-ENTS framework. In phase 2, a modified Delphi process was undertaken to refine the items of the framework. RESULTS: Seven consultant endoscopists and six nurses were interviewed. The final coding framework consisted of 88 codes grouped into five overarching categories. In total, 58 participants were recruited to the Delphi panel. In the first round, nine elements and 37 behavioral descriptors did not meet consensus. Following item adjustment, merging and deletion, all remaining items met consensus thresholds after the second round. The refined TEAM-ENTS BMS consists of five categories, 16 elements, and 47 behavioral descriptors. CONCLUSIONS: The refined TEAM-ENTS behavioral marker system was developed to reflect the core NTS relevant to endoscopy teams. Future studies will aim to fully validate this tool.

Population health: transformation will happen at the speed of trust.

The societal shocks at the beginning of the 2020s have yet again brought into focus fundamental issues of inequality and distrust. These two corrosive and inter-related factors are the root cause of what inhibits our progress on issues such as improving population health and sustainable healthcare. Based on evidence, the authors provide their perspective to suggests three policy proposals; create a new power social movement for better health and equality; delegation of `old power' to City Mayors; handing over power and privilege to communities. This is the only way we will break the cycle of decreasing trust and increasing inequality and build a happier, healthier, and more resilient society.

Healthy city: global systematic scoping review of city initiatives to improve health with policy recommendations.

BACKGROUND: Global health will increasingly be determined by cities. Currently over half of the world's population, over 4 billion people, live in cities. This systematic scoping review has been conducted to understand what cities are doing to improve health and healthcare for their populations. METHODS: We conducted a systematic search to identify literature on city-wide initiatives to improve health. The study was conducted in accordance with PRISMA and the protocol was registered with PROSPERO (CRD42020166210). RESULTS: The search identified 42,137 original citations, yielding 1,614 papers across 227 cities meeting the inclusion criteria. The results show that the majority of initiatives were targeted at non-communicable diseases. City health departments are making an increasing contribution; however the role of mayors appears to be limited. CONCLUSION: The collective body of evidence identified in this review, built up over the last 130 years, has hitherto been poorly documented and characterised. Cities are a meta-system with population health dictated by multiple interactions and multidirectional feedback loops. Improving health in cities requires multiple actions, by multiple actors, at every level. The authors use the term 'The Vital 5'. They are the five most important health risk factors; tobacco use; harmful alcohol use; physical-inactivity, unhealthy diet and planetary health. These 'Vital 5' are most concentrated in deprived areas and show the greatest increase in low and middle income countries. Every city should develop a comprehensive strategy and action plan to address these 'Vital 5'.

Vagal Nerve Therapy in the Management of Obesity: A Systematic Review and Meta-Analysis.

INTRODUCTION: The vagus nerve has an important role in satiety, metabolism, and autonomic control in upper gastrointestinal function. However, the role and effects of vagal nerve therapy on weight loss remain controversial. This systematic review and meta-analysis assessed the effects of vagal nerve therapy on weight loss, body mass index (BMI), and obesity-related conditions. METHODS: MEDLINE, EMBASE, and CINAHL databases were searched for studies up to April 2022 that reported on percentage excess weight loss (%EWL) or BMI at 12 months or remission of obesity-related conditions following vagal nerve therapy from January 2000 to April 2022. Weighted mean difference (WMD) was calculated, meta-analysis was performed using random-effects models, and between-study heterogeneity was assessed. RESULTS: Fifteen studies, of which nine were randomised controlled trials, of 1,447 patients were included. Vagal nerve therapy led to some improvement in %EWL (WMD 17.19%; 95% confidence interval [CI]: 10.94-23.44; p < 0.001) and BMI (WMD -2.24 kg/m2; 95% CI: -4.07 to -0.42; p = 0.016). There was a general improvement found in HbA1c following vagal nerve therapy when compared to no treatment given. No major complications were reported. CONCLUSIONS: Vagal nerve therapy can safely result in a mild-to-moderate improvement in weight loss. However, further clinical trials are required to confirm these results and investigate the possibility of the long-term benefit of vagal nerve therapy as a dual therapy combined with standard surgical bariatric interventions.

Perceptions of chief clinical information officers on the state of electronic health records systems interoperability in NHS England: a qualitative interview study.

BACKGROUND: In the era of electronic health records (EHR), the ability to share clinical data is a key facilitator of healthcare delivery. Since the introduction of EHRs, this aspect has been extensively studied from the perspective of healthcare providers. Less often explored are the day-to-day challenges surrounding the procurement, deployment, maintenance, and use of interoperable EHR systems, from the perspective of healthcare administrators, such as chief clinical information officers (CCIOs). OBJECTIVE: Our study aims to capture the perceptions of CCIOs on the current state of EHR interoperability in the NHS, its impact on patient safety, the perceived facilitators and barriers to improving EHR interoperability, and what the future of EHR development in the NHS may entail. METHODS: Semi-structured interviews were conducted between November 2020 - October 2021. Convenience sampling was employed to recruit NHS England CCIOs. Interviews were digitally recorded and transcribed verbatim. A thematic analysis was performed by two independent researchers to identify emerging themes. RESULTS: Fifteen CCIOs participated in the study. Participants reported that limited EHR interoperability contributed to the inability to easily access and transfer data into a unified source, thus resulting in data fragmentation. The resulting lack of clarity on patients' health status negatively impacts patient safety through suboptimal care coordination, duplication of efforts, and more defensive practice. Facilitators to improving interoperability included the recognition of the need by clinicians, patient expectations, and the inherent centralised nature of the NHS. Barriers included systems usability difficulties, and institutional, data management, and financial-related challenges. Looking ahead, participants acknowledged that realising that vision across the NHS would require a renewed focus on mandating data standards, user-centred design, greater patient involvement, and encouraging inter-organisational collaboration. CONCLUSION: Tackling poor interoperability will require solutions both at the technical level and in the wider policy context. This will involve demanding interoperability functionalities from the outset in procurement contracts, fostering greater inter-organisation cooperation on implementation strategies, and encouraging systems vendors to prioritise interoperability in their products. Only by comprehensively addressing these challenges would the full potential promised by the use of fully interoperable EHRs be realised.

Duodenal-Jejunal Bypass Liner for the management of Type 2 Diabetes Mellitus and Obesity: A Multicenter Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to examine the clinical efficacy and safety of the duodenal-jejunal bypass liner (DJBL) while in situ for 12 months and for 12 months after explantation. SUMMARY BACKGROUND DATA: This is the largest randomized controlled trial (RCT) of the DJBL, a medical device used for the treatment of people with type 2 diabetes mellitus (T2DM) and obesity. Endoscopic interventions have been developed as potential alternatives to those not eligible or fearful of the risks of metabolic surgery. METHODS: In this multicenter open-label RCT, 170 adults with inadequately controlled T2DM and obesity were randomized to intensive medical care with or without the DJBL. Primary outcome was the percentage of participants achieving a glycated hemoglobin reduction of ≥20% at 12 months. Secondary outcomes included weight loss and cardiometabolic risk factors at 12 and 24 months. RESULTS: There were no significant differences in the percentage of patients achieving the primary outcome between both groups at 12 months [DJBL 54.6% (n = 30) vs control 55.2% (n = 32); odds ratio (OR) 0.93, 95% confidence interval (CI): 0.44-2.0; P = 0.85]. Twenty-four percent (n = 16) patients achieved ≥15% weight loss in the DJBL group compared to 4% (n = 2) in the controls at 12 months (OR 8.3, 95% CI: 1.8-39; P = .007). The DJBL group experienced superior reductions in systolic blood pressure, serum cholesterol, and alanine transaminase at 12 months. There were more adverse events in the DJBL group. CONCLUSIONS: The addition of the DJBL to intensive medical care was associated with superior weight loss, improvements in cardiometabolic risk factors, and fatty liver disease markers, but not glycemia, only while the device was in situ. The benefits of the devices need to be balanced against the higher rate of adverse events when making clinical decisions. TRIAL REGISTRATION: ISRCTN30845205. isrctn.org; Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership reference 12/10/04.

Diagnostic Accuracy of Nipple Discharge Fluid Cytology: A Meta-Analysis and Systematic Review of the Literature.

BACKGROUND: Nipple discharge is the third most frequent complaint of women attending rapid diagnostic breast clinics. Nipple smear cytology remains the single most used diagnostic method for investigating fluid content. This study aimed to conduct a systematic review and meta-analysis of the diagnostic accuracy of nipple discharge fluid assessment. METHODS: The study incorporated searches for studies interrogating the diagnostic data of nipple discharge fluid cytology compared with the histopathology gold standard. Data from studies published from 1956 to 2019 were analyzed. The analysis included 8648 cytology samples of women with a presenting complaint of nipple discharge. Both hierarchical and bivariate models for diagnostic meta-analysis were used to attain overall pooled sensitivity and specificity. RESULTS: Of 837 studies retrieved, 45 fulfilled the criteria for inclusion. The diagnostic accuracy of the meta-analysis examining nipple discharge fluid had a sensitivity of 75 % (95 % confidence interval [CI], 0.74-0.77) and a specificity of 87 % (95 % CI, 0.86-0.87) for benign breast disease. For breast cancer, it had a sensitivity of 62 % (95 % CI, 0.53-0.71) and a specificity 71 % (95 % CI, 0.57-0.81). Furthermore, patients presenting with blood-stained discharge yielded an overall malignancy rate of 58 % (95 % CI, 0.54-0.60) with a positive predictive value (PPV) of 27 % (95 % CI, 0.17-0.36). CONCLUSIONS: Pooled data from studies encompassing nipple discharge fluid assessment suggest that nipple smear cytology is of limited diagnostic accuracy. The authors recommend that a tailored approach to diagnosis be required given the variable sensitivities of currently available tests.

The Measurement of Cognitive Workload in Surgery Using Pupil Metrics: A Systematic Review and Narrative Analysis.

INTRODUCTION: Increased cognitive workload (CWL) is a well-established entity that can impair surgical performance and increase the likelihood of surgical error. The use of pupil and gaze tracking data is increasingly being used to measure CWL objectively in surgery. The aim of this review is to summarize and synthesize the existing evidence that surrounds this. METHODS: A systematic review was undertaken in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A search of OVID MEDLINE, IEEE Xplore, Web of Science, Google Scholar, APA PsychINFO, and EMBASE was conducted for articles published in English between 1990 and January 2021. In total, 6791 articles were screened and 32 full-text articles were selected based on the inclusion criteria. A narrative analysis was undertaken in view of the heterogeneity of studies. RESULTS: Seventy-eight percent of selected studies were deemed high quality. The most frequent surgical environment and task studied was surgical simulation (75%) and performance of laparoscopic skills (56%) respectively. The results demonstrated that the current literature can be broadly categorized into pupil, blink, and gaze metrics used in the assessment of CWL. These can be further categorized according to their use in the context of CWL: (1) direct measurement of CWL (n = 16), (2) determination of expertise level (n = 14), and (3) predictors of performance (n = 2). CONCLUSIONS: Eye-tracking data provide a wealth of information; however, there is marked study heterogeneity. Pupil diameter and gaze entropy demonstrate promise in CWL assessment. Future work will entail the use of artificial intelligence in the form of deep learning and the use of a multisensor platform to accurately measure CWL.

Coverage of the Coeliac Artery During Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis.

OBJECTIVE: To investigate the clinical impact of coeliac artery (CA) coverage during thoracic endovascular aortic repair (TEVAR). METHODS: This systematic review and meta-analysis was conducted according to the PRISMA guidelines. Electronic databases were searched from 1989 to 2020 for studies reporting visceral ischaemia, spinal cord ischaemia (SCI), 30 day/in hospital mortality, endoleaks, re-intervention, and caudal stent graft migration following CA coverage in patients undergoing TEVAR. Meta-analysis was conducted using random effects modelling. The quality of the evidence was graded using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Fifteen observational studies with 236 patients (108 male, age range 61.3 - 79 years) were included. The pooled visceral ischaemia rate was 13% with significant heterogeneity between studies (95% confidence intervals [CI] 4 - 24; I2 = 72%, p < .001). The SCI rate was 5% (95% CI 2 - 9; I2 = 0%); the 30 day/in hospital mortality was 4% (95% CI 1 - 7; I2 = 0%); the overall endoleak rate was 21% (95% CI 13 - 29; I2 = 35%) with a 5% (95% CI 0 - 13; I2 = 38%) rate of type Ib and 2% (95% CI 0 - 8; I2 = 43%) rate of type II endoleak from retrograde CA flow. The re-intervention rate was 13% (95% CI 6 - 22; I2 = 54%); the caudal stent graft migration rate was 3% (95% CI 0 - 9, I2 = 0%). The certainty of the body of evidence was judged to be very low for all outcomes. CONCLUSION: CA coverage during TEVAR is associated with high rates of visceral ischaemia, spinal cord ischaemia, 30 day/in hospital mortality, endoleaks, and re-intervention. Although the literature is of poor quality and questions remain over effects estimates, there is evidence that CA coverage should be avoided if at all possible, during TEVAR. REGISTRATION: PROSPERO registration number 244084.

A case for improved assessment of gut permeability: a meta-analysis quantifying the lactulose:mannitol ratio in coeliac and Crohn's disease.

BACKGROUND: A widely used method in assessing small bowel permeability is the lactulose:mannitol test, where the lactulose:mannitol ratio (LMR) is measured. However, there is discrepancy in how the test is conducted and in the values of LMR obtained across studies. This meta-analysis aims to determine LMR in healthy subjects, coeliac and Crohn's disease. METHODS: A literature search was performed using PRISMA guidance to identify studies assessing LMR in coeliac or Crohn's disease. 19 studies included in the meta-analysis measured gut permeability in coeliac disease, 17 studies in Crohn's disease. Outcomes of interest were LMR values and comparisons of standard mean difference (SMD) and weighted mean difference (WMD) in healthy controls, inactive Crohn's, active Crohn's, treated coeliac and untreated coeliac. Pooled estimates of differences in LMR were calculated using the random effects model. RESULTS: Pooled LMR in healthy controls was 0.014 (95% CI: 0.006-0.022) while pooled LMRs in untreated and treated coeliac were 0.133 (95% CI: 0.089-0.178) and 0.037 (95% CI: 0.019-0.055). In active and inactive Crohn's disease, pooled LMRs were 0.093 (95% CI: 0.031-0.156) and 0.028 (95% CI: 0.015-0.041). Significant differences were observed in LMR between: (1) healthy controls and treated coeliacs (SMD = 0.409 95% CI 0.034 to 0.783, p = 0.032), (2) healthy controls and untreated coeliacs (SMD = 1.362 95% CI: 0.740 to 1.984, p < 0.001), (3) treated coeliacs and untreated coeliacs (SMD = 0.722 95% CI: 0.286 to 1.157, p = 0.001), (4) healthy controls and inactive Crohn's (SMD = 1.265 95% CI: 0.845 to 1.686, p < 0.001), (5) healthy controls and active Crohn's (SMD = 2.868 95% CI: 2.112 to 3.623, p < 0.001), and (6) active Crohn's and inactive Crohn's (SMD = 1.429 (95% CI: 0.580 to 2.278, p = 0.001). High heterogeneity was observed, which was attributed to variability in protocols used across different studies. CONCLUSION: The use of gut permeability measurements in screening and monitoring of coeliac and Crohn's disease is promising. LMR is useful in performing this function with significant limitations. More robust alternative tests with higher degrees of clinical evidence are needed if measurements of gut permeability are to find widespread clinical use.

Effective cleaning of endoscopic lenses to achieve visual clarity for minimally invasive abdominopelvic surgery: a systematic review.

OBJECTIVE: To review the recently available interventions to achieve optimal visual clarity in laparoscopic abdominopelvic surgery compared to conventional cleaning alternatives. Currently, there is no consensus on the most effective method for the cleaning of endoscopic lenses used in minimally invasive abdominopelvic surgery. METHODS: Literature searching for articles relevant to answering a predefined research question was performed in December 2019 and involved searching of the electronic databases of MEDLINE, the Cochrane Registry, and EMBASE. Basic search terms were derived using the PICO (population, intervention, comparator and outcomes) framework and through a scoping search of literature via MEDLINE. A manual search of Google Scholar and citation screening of eligible studies was also performed to ensure the identification and inclusion of all pertinent studies to address the research question. RESULTS: Among conventional and readily available methods, the most effective approaches involved heated sterile water, heating of laparoscope lenses, and surfactant solutions, including FRED and Ultra-Stop, while evaluations of all novel devices and methods were more effective than controls, which included lens wiping systems and air and carbon dioxide flow systems. While the former surgical techniques were consistently associated with superior lens cleaning ability and/or defogging capability and subsequent optical clarity of images within the surgical field, no methods conferred any meaningful effects upon other clinically important outcomes, such as operative time, costs, complication rates and length of stay, suggesting that decision making concerning the selection of lens cleaning method/device should suit the preferences of the instrument operator and/or the responsible surgeon. CONCLUSIONS: We demonstrated that a range of endoscopic lens cleaning methods and devices can be used to achieve sufficient optical clarity of the laparoscopic surgical field through either preventing lenses from fogging and/or facilitating the inter-operative cleaning of fouled lenses. Despite the various methods evaluated in this review, there were no significant differences in complication rates between the intervention and control groups.

Clinical outcomes of single-stage versus two-stage laparoscopic Roux-en-y gastric bypass in the management of obesity (BMI ≥ 50 kg/m2): a retrospective cohort study.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) in patients with obesity, BMI ≥ 50 kg/m2, can be a challenging operation. Weight loss with intra-gastric balloon (IGB) insertion prior to LRYGB may improve operative outcomes. METHODS: Between June 2000 and June 2020, patients with a BMI ≥ 50 kg/m2 underwent either IGB insertion followed by LRYGB (two-stage group), or LRYGB as the definitive bariatric procedure (single-stage group) in our institution. The two-stage procedure was adopted for high risk individuals. Primary outcome measures were percentage total weight loss (%TWL) at 24 months, length of stay and postoperative morbidity. Propensity score analysis was used to account for differences between groups. RESULTS: A total of 155 (mean age 42.9 years ± 10.60; mean BMI 54.6 kg/m2 ± 4.53) underwent either the two-stage (n = 30) or single-stage procedure (n = 125) depending on preoperative fitness. At 6 months following LRYGB, there was a significant difference in %TWL between the groups in a matched analysis (11.9% vs 23.7%, p < 0.001). At 24 months, there was no difference in %TWL (32.0% vs 34.7%, p = 0.13). Median hospital stay following LRYGB was 2.0 (1-4) days with the two-stage vs 2.0 (0-14) days for the single-stage approach (p = 0.75). There was also no significant difference in complication rates (p = 0.058) between the two groups. CONCLUSIONS: There was no difference in weight loss after one or two-stage procedures in the treatment of patients with a BMI ≥ 50 kg/m2 super obesity in a propensity score weighted analysis at 24 months. Length of stay and perioperative complications were similar for high risk patients; however, the two-stage approach was associated with delayed weight loss. Single-stage management is recommended for moderate risk patients, particularly with significant metabolic disorders, whilst two-stage approach is a safe and feasible pathway for high risk individuals.