Overview of trials on artificial intelligence algorithms in breast cancer screening - A roadmap for international evaluation and implementation

Accumulating evidence from retrospective studies demonstrate at least non-inferior performance when using AI algorithms with different strategies versus double-reading in mammography screening. In addition, AI algorithms for mammography screening can reduce work load by moving to single human reading. Prospective trials are essential to avoid unintended adverse consequences before incorporation of AI algorithms into UK's National Health Service (NHS) Breast Screening Programme (BSP). A stakeholders' meeting was organized in Newnham College, Cambridge, UK to undertake a review of the current evidence to enable consensus discussion on next steps required before implementation into a screening programme. It was concluded that a multicentre multivendor testing platform study with opt-out consent is preferred. AI thresholds from different vendors should be determined while maintaining non-inferior screening performance results, particularly ensuring recall rates are not increased. Automatic recall of cases using an agreed high sensitivity AI score versus automatic rule out with a low AI score set at a high sensitivity could be used. A human reader should still be involved in decision making with AI-only recalls requiring human arbitration. Standalone AI algorithms used without prompting maintain unbiased screening reading performance, but reading with prompts should be tested prospectively and ideally provided for arbitration.

471 Assessing the Accuracy and Bias of Digital Symptom Checkers with Myocardial Infarction Patients

Aim

The accuracy and safety of symptom checkers in diagnosing and triaging patients is of concern; especially those with life-threatening conditions. The study's aims were to: 1. assess the accuracy of symptom checkers in diagnosing and triaging myocardial infarctions (MI) and, 2. determine whether differences in gender or presentation type exist.

Method

This prospective diagnostic accuracy study assessed 8 symptom checkers using 100 MI patients of various presentations: typical or atypical. The ability of a symptom checker in providing MI as the first diagnosis (D1) and the first 3 (D3) diagnoses were diagnostic accuracy measures. Triage advice was deemed correct if the symptom checker recommended seeking emergency treatment.

Results

Symptom checkers correctly diagnosed 48.0±31.4% of cases with MI first. D3 accuracy was 72.6±20.2%. Mean triage accuracy was 82.6±12.6%.

24.0±16.2% of atypical cases had a correct primary diagnosis. D3 accuracy for atypical MI was 43.8±20.6%, significantly lower than that of typical MI (p<0.01). Atypical case triage accuracy was 52.7±20.0%, significantly lower than typical cases (84.2±14.7%, p<0.01).

10.0% of the atypical female cases were diagnosed correctly with MI as the first diagnosis. Female atypical cases had significantly lower accuracy than typical female cases for all accuracy measures (p<0.01).

Conclusions

Symptom checkers generally provide low accuracy for diagnosing MI. Approximately 20% of cases were under-triaged. Results varied between symptom checkers: patients who presented with atypical symptoms tended to be under-diagnosed and under-triaged, especially those who were female. This demonstrated potential gender bias and therefore raises questions regarding symptom checker regulation and safety.

Trends and associated factors for Covid-19 hospitalisation and fatality risk in 2.3 million adults in England

The Covid-19 mortality rate varies between countries and over time but the extent to which this is explained by the underlying risk in those infected is unclear. Using data on all adults in England with a positive Covid-19 test between 1st October 2020 and 30th April 2021 linked to clinical records, we examined trends and risk factors for hospital admission and mortality. Of 2,311,282 people included in the study, 164,046 (7.1%) were admitted and 53,156 (2.3%) died within 28 days of a positive Covid-19 test. We found significant variation in the case hospitalisation and mortality risk over time, which remained after accounting for the underlying risk of those infected. Older age groups, males, those resident in areas of greater socioeconomic deprivation, and those with obesity had higher odds of admission and death. People with severe mental illness and learning disability had the highest odds of admission and death. Our findings highlight both the role of external factors in Covid-19 admission and mortality risk and the need for more proactive care in the most vulnerable groups.

Differential diagnosis of a thyroid mass, facial malar rash and ptosis on the flora in the primavera by Sandro Botticelli (1445-1510)

PURPOSE

The Primavera is considered amongst the greatest and controversial artistic masterpieces worldwide painted by renaissance artist Sandro Botticelli. The aim was to identify any underlying medical foundations for the painting.

METHODS

Observational study.

RESULTS

The painting reveals, a 'butterfly' malar rash, bilateral ptosis and a clear neck swelling consistent with a goitre in the figure of Flora. This could be explained by concomitant Graves' disease and systemic lupus erythematosus, or other presentations of multiple autoimmune syndrome.

CONCLUSION

These findings highlight the likely presentation of the earliest pictorial depictions of thyroid disease with systemic lupus erythematosus and emphasize the exactitude of depiction demonstrated by Botticelli in renaissance era.

Strategy for improved characterization of human metabolic phenotypes using a COmbined Multi-block Principal components Analysis with Statistical Spectroscopy (COMPASS)

MOTIVATION

Large-scale population omics data can provide insight into associations between gene-environment interactions and disease. However, existing dimension reduction modelling techniques are often inefficient for extracting detailed information from these complex datasets.

RESULTS

Here, we present an interactive software pipeline for exploratory analyses of population-based nuclear magnetic resonance spectral data using a COmbined Multi-block Principal components Analysis with Statistical Spectroscopy (COMPASS) within the R-library hastaLaVista framework. Principal component analysis models are generated for a sequential series of spectral regions (blocks) to provide more granular detail defining sub-populations within the dataset. Molecular identification of key differentiating signals is subsequently achieved by implementing Statistical TOtal Correlation SpectroscopY on the full spectral data to define feature patterns. Finally, the distributions of cross-correlation of the reference patterns across the spectral dataset are used to provide population statistics for identifying underlying features arising from drug intake, latent diseases and diet. The COMPASS method thus provides an efficient semi-automated approach for screening population datasets.

AVAILABILITY AND IMPLEMENTATION

Source code is available at https://github.com/cheminfo/COMPASS.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

O41 Quantifying the burden of survivorship associated with infra-renal abdominal aortic aneurysm repair: a systematic review

Introduction

Survivorship encompasses the physical, psychological, social, functional and economic experience of living with a chronic condition for both patients and their caregivers. It comprises 9 distinct domains and remains understudied in non-oncological pathologies, including infra-renal abdominal aortic aneurysmal disease (IRAAA). This review aims to quantify the extent to which existing IRAAA literature addresses the burden of survivorship in patients following surgical intervention.

Method

The databases; MEDLINE, EMBASE and PsychINFO, were searched from 1989 through to July 2020. Randomised controlled trials, observational studies and case series studies were included. Eligible studies had to detail outcomes related to survivorship following IRAAA surgery. Due to heterogeneity between studies and outcomes, no meta-analysis was conducted. Study quality was assessed with specific risk of bias tools.

Result

112 studies were included and only 4 of the 9 domains of survivorship have been previously studied—treatment complications, physical functioning, co-morbidities and caregivers. The available evidence is of variable quality; the majority of studies display a moderate to high risk of bias, are of an observational study design, are based within a limited number of countries and consist of an insufficient follow up period.

Conclusion

This review highlights the absence of robust evidence regarding survivorship following IRAAA surgery, regardless of repair modality. Consequently, contemporary treatment guidelines are reliant upon historic quality of life data that is narrow in scope and non-representative of contemporary clinical practice. As such, there is an urgent need to re-evaluate the scope and methodology associated with this research theme moving forwards.

Take-home Message

There is an urgent need to re-evaluate the scope and methodology associated with traditional quality of life centred IRAAA studies moving forwards in order to better empower patient decision making as well as inform treatment guidelines and health policy initiatives.

Obese patients and robotic colorectal surgery: systematic review and meta-analysis

BACKGROUND

Obesity is a major health problem, demonstrated to double the risk of colorectal cancer. The benefits of robotic colorectal surgery in obese patients remain largely unknown. This meta-analysis evaluated the clinical and pathological outcomes of robotic colorectal surgery in obese and non-obese patients.

METHODS

MEDLINE, Embase, Global Health, Healthcare Management Information Consortium (HMIC) and Midwives Information and Resources Service (MIDIRS) databases were searched on 1 August 2018 with no language restriction. Meta-analysis was performed according to PRISMA guidelines. Obese patients (BMI 30 kg/m2 or above) undergoing robotic colorectal cancer resections were compared with non-obese patients. Included outcome measures were: operative outcomes (duration of surgery, conversion to laparotomy, blood loss), postoperative complications, hospital length of stay and pathological outcomes (number of retrieved lymph nodes, positive circumferential resection margins and length of distal margin in rectal surgery).

RESULTS

A total of 131 full-text articles were reviewed, of which 12 met the inclusion criteria and were included in the final analysis. There were 3166 non-obese and 1420 obese patients. A longer duration of surgery was documented in obese compared with non-obese patients (weighted mean difference -21·99 (95 per cent c.i. -31·52 to -12·46) min; P < 0·001). Obese patients had a higher rate of conversion to laparotomy than non-obese patients (odds ratio 1·99, 95 per cent c.i. 1·54 to 2·56; P < 0·001). Blood loss, postoperative complications, length of hospital stay and pathological outcomes were not significantly different in obese and non-obese patients.

CONCLUSION

Robotic surgery in obese patients results in a significantly longer duration of surgery and higher conversion rates than in non-obese patients. Further studies should focus on better stratification of the obese population with colorectal disease as candidates for robotic procedures.

Remote wireless vital signs monitoring on the ward for early detection of deteriorating patients: A case series

INTRODUCTION

Remote wireless monitoring is a new technology that allows the continuous recording of ward patients' vital signs, supporting nurses by measuring vital signs frequently and accurately. A case series is presented to illustrate how these systems might contribute to improved patient surveillance.

METHODS AND RESULTS

Five hospitals in three European countries installed a remote wireless vital signs monitoring system on medical or surgical wards. Heart rate, respiratory rate and temperature were measured by the system every 2 min. Four cases of (paroxysmal) atrial fibrillation are presented, two cases of sepsis and one case each of pyrexia, cardiogenic pulmonary edema and pulmonary embolisms. All cases show that the remote monitoring system revealed the first signs of ventilatory and circulatory deterioration before a change in the trends of the respective values became obvious by manual vital signs measurement.

DISCUSSION

This case series illustrates that a wireless remote vital signs monitoring system on medical and surgical wards has the potential to reduce time to detect deteriorating patients.

Hypothyroidism in the "Arnolfini Portrait" (1434) by Jan Van Eyck (1390-1441)

BACKGROUND

The Arnolfini portrait painted by Jan van Eyck in 1434 remains one of the most puzzling yet alluring paintings of prerenaissance western art.

PURPOSE

The painting is renowned for its exactitude in brush strokes, textures and the distinctive morphology of the main character Arnolfini. The nature of these requires pathological consideration.

METHODS

Diagnostic and pathological analysis of the painting.

RESULTS

A number of pathological abnormalities are noted in the face of the main character including loss of outer third of the eyebrow (Sign of Hertoghe), bilateral ptosis and melasma of the forehead. These together support a diagnosis of hypothyroidism.

CONCLUSIONS

This novel diagnosis offers an additional perspective to this enigmatic portrait, and can add to the comprehension of the method, origin and pathological associations of this prominent painting from a genius artist.

Anastomotic leaks can be detected within 5 days following ileorectal anastomosis: a case-controlled study in patients with familial adenomatous polyposis

AIM

To determine the earliest time point at which anastomotic leaks can be detected in patients undergoing total colectomy with primary ileorectal anastomosis for familial adenomatous polyposis.

METHOD

This was a case-controlled study of 10 anastomotic leak patients vs 20 controls following laparoscopic total colectomy with ileorectal anastomosis for familial adenomatous polyposis (from 96 consecutive patients between 2006 and 2013). Panel time-series data regression was performed using a double subscript structure to include both variables. A generalized least squares multivariate approach was applied in a random effects setting to calculate correlations for observations, with anastomotic leak being the dependent variable. Univariate and multivariate regression calculations were then performed according to individual observations at each recorded time point. Time-series analysis was used to determine when a variable became significant in the leak group.

RESULTS

Multivariate analysis identified a significant difference between leak and control groups in mean heart rate (P < 0.001), mean respiratory rate (P = 0.017) and mean urine output (P = 0.001). Time-point analysis showed that heart rate was significantly different between leak and control groups at postoperative day 4.25. Multivariate analysis identified a significant difference between groups in alanine transaminase (P = 0.006), bilirubin (P = 0.008), creatinine (P = 0.001), haemoglobin (P < 0.001) and urea (P = 0.007). There were no differences between groups with regard to markers of inflammation such as albumin, white blood cell count, neutrophil count and C-reactive protein.

CONCLUSION

Anastomotic leaks can be detected early (within 4.5 days of surgery) through changes in physiological, blood test and observational parameters, providing an opportunity for early intervention in these patients to salvage the anastomosis.

Network meta-analysis of protocol-driven care and laparoscopic surgery for colorectal cancer

BACKGROUND

Laparoscopic approaches and standardized recovery protocols have reduced morbidity following colorectal cancer surgery. As the optimal regimen remains inconclusive, a network meta-analysis was undertaken of treatments for the development of postoperative complications and mortality.

METHODS

MEDLINE, Embase, trial registries and related reviews were searched for randomized trials comparing laparoscopic and open surgery within protocol-driven or conventional perioperative care for colorectal cancer resection, with complications as a defined endpoint. Relative odds ratios (ORs) for postoperative complications and mortality were estimated for aggregated data.

RESULTS

Forty trials reporting on 11 516 randomized patients were included with the network. Open surgery within conventional perioperative care was the index for comparison. The OR relating to complications was 0·77 (95 per cent c.i. 0·65 to 0·91) for laparoscopic surgery within conventional care, 0·69 (0·48 to 0·99) for open surgery within protocol-driven care, and 0·43 (0·28 to 0·67) for laparoscopic surgery within protocol-driven care. Sensitivity analyses excluding trials of low rectal cancer and those with a high risk of bias did not affect the treatment estimates. Meta-analyses demonstrated that mortality risk was unaffected by perioperative strategy.

CONCLUSION

Laparoscopic surgery combined with protocol-driven care reduces colorectal cancer surgery complications, but not mortality. The reduction in complications with protocol-driven care is greater for open surgery than for laparoscopic approaches. Registration number: CRD42015017850 (https://www.crd.york.ac.uk/PROSPERO).

Role of metabolic phenotyping in understanding obesity and related conditions in Gulf Co-operation Council countries

Obesity is a major health concern in the Middle East and the incidence is rising in all sections of the population. Efforts to control obesity through diet and lifestyle interventions, and by surgical means, have had limited effect, and the gene-environment interactions underpinning the development of obesity and related pathologies such as metabolic syndrome, cardiovascular disease and certain cancers are poorly defined. Lifestyle, genetics, inflammation and the interaction between the intestinal bacteria and host metabolism have all been implicated in creating an obesogenic environment. We summarize the role of metabolic and microbial phenotyping in understanding the aetiopathogenesis of obesity and in characterizing the metabolic responses to surgical and non-surgical interventions, and explore the potential for clinical translation of this approach.

Metabolic phenotype-microRNA data fusion analysis of the systemic consequences of Roux-en-Y gastric bypass surgery

Background/Objectives:

Bariatric surgery offers sustained marked weight loss and often remission of type 2 diabetes, yet the mechanisms of establishment of these health benefits are not clear.

Subjects/Methods:

We mapped the coordinated systemic responses of gut hormones, the circulating miRNAome and the metabolome in a rat model of Roux-en-Y gastric bypass (RYGB) surgery.

Results:

The response of circulating microRNAs (miRNAs) to RYGB was striking and selective. Analysis of 14 significantly altered circulating miRNAs within a pathway context was suggestive of modulation of signaling pathways including G protein signaling, neurodegeneration, inflammation, and growth and apoptosis responses. Concomitant alterations in the metabolome indicated increased glucose transport, accelerated glycolysis and inhibited gluconeogenesis in the liver. Of particular significance, we show significantly decreased circulating miRNA-122 levels and a more modest decline in hepatic levels, following surgery. In mechanistic studies, manipulation of miRNA-122 levels in a cell model induced changes in the activity of key enzymes involved in hepatic energy metabolism, glucose transport, glycolysis, tricarboxylic acid cycle, pentose phosphate shunt, fatty-acid oxidation and gluconeogenesis, consistent with the findings of the in vivo surgery-mediated responses, indicating the powerful homeostatic activity of the miRNAs.

Conclusions:

The close association between energy metabolism, neuronal signaling and gut microbial metabolites derived from the circulating miRNA, plasma, urine and liver metabolite and gut hormone correlations further supports an enhanced gut-brain signaling, which we suggest is hormonally mediated by both traditional gut hormones and miRNAs. This transomic approach to map the crosstalk between the circulating miRNAome and metabolome offers opportunities to understand complex systems biology within a disease and interventional treatment setting.

Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies

BACKGROUND

Coronary revascularization in female patients presents several challenges, including smaller target vessels and smaller conduits. Furthermore, late presentation and more co-morbidities than males may increase complication rates. The aim of this study was to assess whether off-pump coronary artery bypass (OPCAB) improves outcomes when compared to on-pump coronary artery bypass (ONCAB) in the female population.

METHODS

A systematic literature review identified six observational studies, incorporating 23313 patients (n=9596 OPCAB, 13717 ONCAB). These were meta-analyzed using random effects modeling. Heterogeneity, subgroup analysis, quality scoring and publication bias were assessed. The primary endpoints were 30-day mortality and major cardiac, respiratory and renal complications. Secondary endpoints were the number of grafts per patient.

RESULTS

No statistically significant difference was observed in 30-day mortality between the OPCAB and ONCAB groups (4.8% vs. 0.7%; OR 0.96; 95% CI [0.41, 2.24], p=0.92). Significant inter-study heterogeneity was also present (I2=94%) and was not explained by study size or quality. Peri-operative myocardial infarction (OR 0.65; 95% CI [0.51, 0.84], p=0.0009) was significantly lower with OPCAB without significant heterogeneity; however, OPCAB did not significantly alter other morbidity outcomes. OPCAB was associated with a trend towards fewer grafts per patient than ONCAB.

CONCLUSIONS

OPCAB is a safe alternative to ONCAB in the surgical revascularisation of female patients and may reduce post-operative myocardial infarction (MI). However, this does not translate into a reduction in 30-day mortality and OPCAB does not significantly improve other cardiovascular, renal or neurological outcomes. Late outcome data remains lacking and a well-structured, randomized trial is required to answer vital questions regarding the effect of OPCAB on women in the long-term.

Neuropsychological assessment as a predictor of weight loss in obese adolescents

BACKGROUND

Obese individuals are known to be more impulsive than their normal-weight counterparts. Impulsivity has been postulated to be a predictor of weight loss.

DESIGN

A pre-post study was designed to determine for the first time whether impulsivity changed with weight loss during a lifestyle and physical activity intervention programme lasting 2-8 weeks.

SUBJECTS

Fifty-three obese adolescents with a body mass index (BMI) of 33.75 ± 7.9 attending a residential camp were tested and compared at baseline with 50 non-obese adolescents with a mean BMI of 20.6 ± 2.3.

MEASUREMENTS

Inhibitory control was measured with the CANTAB (Cambridge Cognition, Cambridge, UK) Stop Signal Task. MATLAB (The Mathswork Inc., Natick, MA, USA) was used to measure the temporal discounting constant.

RESULTS

The obese group was more impulsive than the normal weight adolescents. BMI reduced significantly from 33.76 kg m(-2) to 30.93 kg m(-2) after completing camp. The stop signal reaction time (SSRT) decreased from 225.38 ± 94.22 to 173.76 ± 107.05 ms (n=47, P=0.0001). A reduction in inhibitory control during camp was predictive of those who showed the greatest reduction in BMI (Wilks' Lambda=0.9, F(1,50)=4.85, P=0.034). The number of weeks in camp (Wilks' Lambda=0.83, F(1,50)=9.826, P=0.003) and the age of the adolescents (Wilks' Lambda=0.87, F(1,50)=5.98, P=0.02) were significantly associated with a reduction in inhibitory control as measured by the SSRT. A longer stay in camp was associated with a greater reduction in SSRT (B=25.45, t=2.02, P=0.05). Increasing age had a significant moderating role in the reduction of inhibitory control (B=-0.3, t=-0.034, P=0.05). Temporal discounting for monetary reward also fell significantly during camp.

CONCLUSION

This study highlights the potential to identify those who are obese by using an easy-to-measure psychometric test. Furthermore, it is the first study to report a reduction in impulsivity and an improvement in well-being as part of a government-approved residential camp for obese adolescents. The potential mechanisms for change in impulsivity with weight are discussed.

Does off-pump coronary revascularization reduce mortality in re-operative coronary artery surgery? A meta-analysis of observational studies

BACKGROUND

Re-operative coronary artery bypass grafting (CABG) is a challenging operation that is often performed in a high-risk patient group. Avoiding cardiopulmonary bypass (CPB) in these patients is hypothesised to be advantageous due to the reduced invasiveness and physiological stress of off-pump coronary artery bypass grafting (OPCAB). The aims of this study were to assess whether OPCAB may improve outcomes in patients undergoing re-operative CABG.

METHODS

Twelve studies, incorporating 3471 patients, were identified by systematic literature review. These were meta-analysed using random-effects modelling. Primary endpoints were 30-day and mid-term mortality. Secondary endpoints were completeness of revascularization, mean number of grafts per patient and the effect of intra-operative conversion on mortality.

RESULTS

A significantly lower rate of 30-day mortality was observed with OPCAB (OR 0.51, 95% CI [0.35, 0.74]), however, no difference was demonstrated in mid-term mortality. Significantly less complete revascularization and mean number of grafts per patient were observed in the OPCAB group. Meta-regression revealed no change in 30-day mortality when the effect of conversion from one technique to the other was assessed.

CONCLUSIONS

Off-pump techniques may reduce early mortality in selected patients undergoing re-operative CABG; however, this does not persist into mid-term follow-up. OPCAB may also lead to intra-operative conversion and, although this did not affect outcomes in this study, these results are constrained by the limited data available. Furthermore, OPCAB may increase target vessel revascularization and, consequently, incomplete revascularization which, whilst not reflected in the short-term outcomes, requires longer-term follow-up in order to be fully assessed.

Safety of training and assessment in operating theatres--a systematic review and meta-analysis

OBJECTIVE

Procedural outcomes can be used to assess the performance of specialists and trainees. This article establishes a systematic evidence base for the safety of training in the operating theatre. It also explores the possibility of using early, intermediate and late procedural outcomes of cardiac surgical operations to evaluate the performance of the clinicians and the healthcare system.

METHODS

Medline, EMBASE and PsycINFO databases were searched. Comparative studies evaluating quality indicators of cardiac surgical procedures (coronary artery bypass grafting (CABG) and valve surgery) were included. guidelines from the preferred reporting items for systematic reviews and meta-analyses (PRISMA) were used.

RESULTS

Fourteen studies met the inclusion criteria. For CABG, meta-analysis of outcomes did not show any significant differences between the technical and non-technical skills of trainees versus specialists apart from bypass time (less for specialists) and intensive care unit (ICU) length of stay (less for trainees). Studies reporting outcomes on valve surgery also did not report any statistically significant differences amongst the outcomes.

CONCLUSION

This systematic review did not discern any significant differences between the procedural outcomes of trainees and specialists, which indicates that trainees are safe to operate under senior supervision. In addition, this article recommends that various procedural outcomes can be used to evaluate the performance of clinicians and healthcare systems. Prospective studies need to be performed, taking into account the specific contribution of trainees and specialists during the procedure. This will give a clearer indication of safety and performance of trainees and specialists in the operating theatre.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Metabolic surgery: an evolution through bariatric animal models

Metabolic surgery was developed through the application and experience gained from bariatric or weight loss procedures. Much of our knowledge from the procedures comes from the study of animal models, where they have revealed anatomic feasibility, systemic physiological elements and cellular metabolic effects. The first generation of operation included the jejunoileal bypass and partial ileal bypass that led to the development of the current procedures including Roux-en-Y gastric bypass, biliopancreatic diversion, adjustable gastric banding and sleeve gastrectomy. These operations carry significant metabolic benefits and can reduce the risk of diabetes, heart disease and cancer. Further insights from these animal models can reveal genetic, molecular and systemic effects that can enhance and develop the next generation of metabolic operations.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Pulmonary homograft endocarditis 19 years after a Ross procedure

We report the case of a patient with acute pulmonary homograft endocarditis secondary to Streptococcus agalactiae from a cat-bite. He had undergone a Ross procedure nineteen years earlier. In view of unremitting infection with large pulmonary trunk and right pulmonary artery vegetations, the patient underwent successful pulmonary vegetectomy and homograft replacement.

Antimicrobial prophylaxis for endocarditis: emotion or science?

Yet another guideline on the prevention of infective endocarditis has been published, this time limiting prophylaxis to high-risk patients.

William Penny Brookes (1809-1895): forgotten Olympic Lord of the Rings

The contribution of Dr William Penny Brookes (1809-1895) to the Olympic Games is scarcely reported in the medical literature. Presented here is a brief report of his life and work. Furthermore, the need to promote public health and fitness through the Olympics is re-emphasised.

Sensitizing the insensitive

Lithium is still the treatment of choice in bipolar affective disorder. The patient presented here represents an example of the possible severity of metabolic defects resulting from lithium use. In this case, it caused severe intractable nephrogenic diabetes insipidus (NDI). Our case report draws attention to 2 important messages. The first is the complexity in treating psychiatric patients that is often not borne out in the medical literature. The second is the role and power of pharmacological augmentation. While the role of these agents has been appreciated for some time, the use of carbamazepine and of drug combinations is not as well recognized. We emphasize the clinical features of NDI, lithium's metabolic sequelae and furthermore collate the most up-to-date account of the signalling effects conferred by these agents in a summary diagram.