Bariatric surgery reverses ventricular repolarisation heterogeneity in obesity: mechanistic insights into fat-related arrhythmic risk

Background

Obesity is a growing global health problem that confers higher risks of atrial arrhythmias and sudden cardiac death. Despite this, the proarrhythmic substrate in obesity and its reversibility with weight loss has not been studied in-depth.

Purpose

To characterise the proarrhythmic substrate in obese patients, and its reversibility with bariatric surgery, using electrocardiographic imaging (ECGi).

Methods

ECGi was performed in 16 obese patients pre-bariatric surgery (PreSurg; mean age 43±12 years, 13 female) and 16 age- and sex-matched non-obese (lean) individuals (42±11 years). 12 of the 16 obese patients also underwent ECGi after bariatric surgery (PostSurg). Over 2000 atrial and ventricular epicardial electrograms were computed using high density body surface mapping (256-lead ECG) and heart-torso geometries from cardiac magnetic resonance imaging, by solving the inverse problem of electrocardiography. Local atrial and ventricular epicardial activation times (AT) were calculated as the steepest downslope of their respective activation complexes, and local ventricular repolarisation times (RT) as the steepest upslope of the T-wave. Atrial activation gradients (ATG) and ventricular repolarisation gradients (RTG) were calculated as the maximum difference within 10 mm radius divided by the corresponding distance.

Results

Body mass index was greater in PreSurg vs lean (46.7±5.5 vs 22.8±2.6 kg/m2, p<0.0001) and decreased with surgery (PostSurg 36.8±6.5 kg/m2, p<0.0001). Epicardial adipose tissue (EAT) was greater in PreSurg vs lean (83±56 vs 28±13 ml, p<0.0001) and decreased post-surgery (PostSurg 69±45 ml, p=0.0010). Total atrial AT was prolonged in PreSurg vs lean (62±15 vs 46±12 ms, p=0.0028), which persisted post-surgery (PostSurg 67±15 ms, p=0.86). Atrial ATG were also greater in PreSurg vs lean (26±11 vs 14±8 ms, p=0.0007) and did not change with weight loss (PostSurg 25±12, p=0.44). Ventricular RTG were greater in PreSurg vs lean (26±11 vs 15±7 ms/mm, p=0.0024) and decreased with weight loss (PostSurg 19±8, p=0.0009). Ventricular RTG were similar between PostSurg and lean (p=0.20). EAT from lean and PreSurg individuals correlated with atrial ATG (r=0.36, p=0.044) and ventricular RTG (r=0.54, p=0.0014). Ventricular AT were similar between lean (31±6 ms), PreSurg (34±5 ms) and PostSurg (35±9 ms); all p>0.05.

Conclusion

Steep ventricular repolarisation gradients and prolonged atrial activation contribute to the proarrhythmic substrate in obesity. Ventricular repolarisation gradients correlate with epicardial adiposity and both regress post-bariatric surgery. By contrast, atrial activation remains prolonged after weight loss. These results provide mechanistic insights into obesity-related arrhythmic risks and their reversibility with weight loss following bariatric surgery.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): British Heart FoundationNational Institute for Health Research (NIHR) Imperial Biomedical Research Centre (BRC).

Bariatric surgery reduces ventricular repolarisation gradients in obese patients - results from an electrocardiographic imaging study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research (NIHR) British Heart Foundation

Background

Obesity confers higher risks of atrial arrhythmias and is associated with abnormal ventricular repolarisation. Despite this, the proarrhythmic substrate in obesity and its reversibility with weight loss has not been studied in-depth.

Purpose

To characterise the proarrhythmic substrate in obese patients, and its reversibility with bariatric surgery, using electrocardiographic imaging (ECGi).

Methods

ECGi was performed in 8 obese patients before (PreOb) and after (PostOb) bariatric surgery (mean age 39+/-11years, 7 female), and in 8 age- and sex-matched non-obese controls (NOb) (40+/-11 years). ECGi recordings were made at rest, on exercise, and during recovery from exercise. For ECGi analysis, >2000 atrial and ventricular epicardial electrograms were calculated from body surface potential recordings from 256 sites and information from cardiac magnetic resonance imaging, by solving the inverse problem. Local atrial and ventricular epicardial activation times (AT) were calculated as the steepest downslope of their respective activation complexes, and local ventricular repolarisation times (RT) as the steepest upslope of the T-wave. Atrial activation gradients (ATG) and ventricular repolarisation gradients (RTG) were calculated as the maximum difference within 10mm radius divided by the corresponding Euclidean distance.

Results

BMI was greater in PreOb vs NOb (46.6+/-4.8 vs 23.8+/-2.6kg/m2, p<0.0001) and decreased with surgery (PostOb 35.3+/-4.2kg/m2, p<0.0001). Total atrial AT was prolonged in PreOb vs NOb (68+/-12 vs 45+/-10ms, p=0.016) and did not change post-surgery (PreOb vs PostOb: 68+/-12 vs 67+/-16ms, p=0.81). Atrial ATG were also greater in PreOb vs NOb: max 254+/-111 vs 106+/-58ms, p=0.035; mean 24+/-6 vs 12+/-6ms, p=0.0087) and did not change with weight loss (PreOb vs PostOb: max 254+/-111 vs 222+/-69ms/mm, p=0.61; mean 24+/-6 vs 21+/-7ms/mm, p=0.52). Ventricular RTG were greater in PreOb vs NOb (max: 287+/-73 vs 131+/-89ms/mm, p=0.012; mean: 33+/-10 vs 17+/-9ms/mm, p=0.0052). Ventricular RTG decreased with weight loss (PreOb vs PostOb: max 287+/-73 vs 151+/-54ms/mm, p=0.0070; mean: 33+/-10 vs 21+/-8ms/mm, p=0.018), and were similar between PostOb and NOb (max, p=0.81; mean p=0.58). Ventricular AT and RT were non-different in NOb, PreOb and PostOb.

Conclusion

Obesity is associated with pro-arrhythmic electrophysiological remodelling, including steeper ventricular repolarisation gradients and slower atrial activation. At 6 months post-bariatric surgery, there was a reduction in ventricular repolarisation gradients though atrial conduction abnormalities persisted. These findings provide a mechanistic insight into obesity-related arrhythmic risks and its potential reversibility with weight loss surgery.

Increasing adiposity and metabolic dysfunction prolong QTc interval and increase risk of ventricular arrhythmias: results from the UK Biobank

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research

Background/purpose: Small-scale studies have associated obesity and metabolic ill-health with QTc interval prolongation. Whether these associations are modulated by an underlying genetic predilection and translate into higher risks of ventricular arrhythmias (VA) is unknown.

Methods

 Using the UK Biobank and adjusted multivariate regression analysis, we studied the associations between QTc and clinical measures of adiposity and metabolic ill-health. A polygenic risk score was used to determine whether these associations are modulated by a genetic predilection for QTc prolongation. We compared QTc between four clinical phenotypes defined according to presence (+) or absence (-) of obesity (Ob), and metabolic ill-health (MU). Logistic regression was used to calculate odds ratios (OR) for VA amongst these groups.

Results

 23,683 individuals (11,563 male, mean age 61.0 + 7.5years) had ECG and clinical data available. QTc prolongs with increasing body mass index (0.76ms/kg/m2, 95%CI: 0.68-0.83ms/kg/m2), body fat (0.45ms/%, 95%CI:0.39-0.50ms/%), hip girth (0.35ms/cm, 95%CI:0.31-0.39ms/cm) and waist girth (0.32ms/cm, 95%CI:0.29-0.35ms/cm); all p < 0.001. Genetically determined repolarisation reserve has no significant modulatory effect on the QTc-prolonging effects of increasing adiposity. Referenced to Ob-MU-, Ob + MU- and Ob-MU+ independently prolong QTc to a comparable extent, and Ob + MU+ has an additive effect on QTc prolongation. With reference to Ob-MU-, OR for VA in Ob-MU+ males and females were 5.96 (95%CI:4.70-7.55) and 5.10 (95%CI:3.34-7.80), respectively. OR for Ob + MU+ were 6.99 (95%CI:5.72-8.54) and 3.56 (95%CI:2.66-4.77) in males and females, respectively, (all p < 0.001, see Table).

Conclusion

 Adiposity and metabolic perturbation prolong QTc to a similar extent, and their co-existence exerts an additive effect. These effects are independent of genetically determined repolarisation reserve. Despite their comparable QTc prolonging effects, metabolic ill-health is associated with higher OR for VA than obesity. VA in obesity and metabolic dysfunctionReference phenotypeOb + MU-Ob-MU+Ob + MU+Ob-MU+male1.10(0.87-1.39)ns5.96 (4.70-7.55)***6.99(5.72-8.54)***female0.87(0.64-1.18)ns5.10(3.34-7.80)***3.56(2.66-4.77)***Ob + MU-male--6.01(4.98-7.26)***female--5.61(4.18-7.52)***Ob + MU+male--1.25(1.05-1.49)*female--1.16(0.80-1.68)nsOb, obese; MU, metabolically unhealthy; +, presence; -, absence; ns, non-significant; *p < 0.05; ***p < 0.001. Abstract Figure. QTc in obesity and metabolic dysfunction

190 Determinants of Psychological Well-Being in Healthcare Workers During the Covid-19 Pandemic: A Multinational Cross-Sectional Study

Introduction

The Covid-19 pandemic has placed unprecedented pressures on healthcare systems globally, impacting working conditions, safety attitudes and the psychological well-being of healthcare workers. This cross-sectional study explores the prevalence and predictors of anxiety/depression amongst healthcare workers in the UK, Singapore, and Poland.

Method

From 22 March to 18 June 2020, healthcare workers from the UK, Singapore and Poland were invited to complete a self-administered questionnaire on psychological well-being. Anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS). Other components of the questionnaire include demographic information, Safety Attitudes Questionnaire (SAQ) measuring safety culture and the Oldenburg Burnout Inventory (OLBI) to measure burnout. Multivariate logistic regression was used to determine predictors of anxiety and depression.

Results

Of 3537 healthcare workers who participated in the study, 701 (20%) screened positive for anxiety and 389 (11%) for depression. Significant predictors of depression and anxiety include low SAQ score, nursing role, redeployment, burnout, and depression. There was significant overlap between anxiety and depression. The doctor role was protective.

Conclusions

Our findings demonstrate a significant burden of anxiety and depression amongst healthcare workers during Covid-19. These findings highlight the impact of Covid-19 on psychological well-being and suggests which groups would benefit from targeted support.

Obstructive Sleep Apnea in Obese Patients: a UK Population Analysis

Background

Obstructive sleep apnea (OSA) is an increasingly common disorder associated with increased cardiovascular disease, mortality, reduced productivity, and an increased risk of road traffic accidents. A significant proportion of patients with OSA in the UK are undiagnosed. This study aims to identify risk factors for OSA in an obese cohort.

Method

A population-based study was conducted of obese patients (BMI ≥ 30 kg/m²) from the Clinical Practice Research Datalink (CPRD). A logistic regression model was used to calculate odds ratios (ORs) for developing OSA according to other clinicopathological characteristics. Multivariate analysis was conducted of individual factors that affect the propensity to develop OSA. Statistical significance was defined as p < 0.050.

Results

From 276,600 obese patients identified during a data extraction of the CPRD in July 2017, the prevalence of OSA was 5.4%. The following risk factors were found to be independently associated with increased likelihood of OSA: male sex (OR = 3.273; p < 0.001), BMI class II (OR = 1.640; p < 0.001), BMI class III (OR = 3.768; p < 0.001), smoking (OR = 1.179; p < 0.001), COPD (OR = 1.722; p < 0.001), GERD (OR = 1.557; p < 0.001), hypothyroidism (OR = 1.311; p < 0.001), acromegaly (OR = 3.543; p < 0.001), and benzodiazepine use (OR = 1.492; p < 0.001). Bariatric surgery was associated with reduced risk of OSA amongst this obese population (OR = 0.260; p < 0.001).

Conclusions

In obese patients, there are numerous comorbidities that are associated with increased likelihood of OSA. These factors can help prompt clinicians to identify undiagnosed OSA. Bariatric surgery appears to be protective against developing OSA.

1349Effect of bariatric surgery on long-term cardiovascular outcomes in patients with obesity: a nation-wide nested cohort study

Background

Obesity is a cardinal risk factor for the development of atherosclerotic cardiovascular disease. Bariatric surgery is an effective method of achieving weight reduction and improving control of cardiovascular risk factors in patients with obesity. However, the effect of bariatric surgery on long-term cardiovascular outcomes has yet to be defined.

Purpose

The aim of this study is to evaluate the effect of bariatric surgery on long-term risk of major adverse cardiovascular events in a large population of patients with obesity.

Methods

A nested cohort study was carried out; including the 3,701 patients of the Clinical Practice Research Datalink database who had undergone bariatric surgery, and 3,701 age, gender and BMI matched controls. The primary endpoint was the composite of fatal or non-fatal myocardial infarction; and fatal or non-fatal acute ischaemic stroke. Secondary endpoints included all-cause mortality, new diagnosis of heart failure, fatal or non-fatal myocardial infarction, and fatal or non-fatal acute ischaemic stroke. Data was analysed using a Cox proportional hazards model to account for multiple covariates.

Results

Patients were followed up for a median of 11.2 years; 20.3% of the population were female, the median age was 36 years and median BMI was 40.4 kg/m2. Patients who had undergone bariatric surgery had a significantly lower occurrence of the primary composite outcome (HR 0.450; 95% CI 0.312–0.671, p<0.001, NNT=62); this was driven by a reduction in myocardial infarction (HR 0.444; 95% CI 0.302–0.654, p<0.001, NNT=64) and not in acute ischaemic stroke (HR 0.528; 95% CI 0.159–1.751, p=0.296). A significant reduction was observed in rates all-cause mortality (HR 0.254; 95% CI 0.183–0.353; p<0.001, NNT=27) and of new diagnosis of heart failure (HR 0.519; 95% CI 0.311–0.864, p=0.012, NNT=153).

Table 1. Primary and secondary endpoints during follow-up Events No Bariatric Surgery Bariatric Surgery HR 95% CI p (n=3,701) (n=3,701) Primary endpoint 93 37 0.458 0.312–0.671 <0.001 Secondary endpoints   All-cause mortality 182 45 0.254 0.183–0.353 <0.001   Heart failure 46 22 0.519 0.311–0.864 0.012   Fatal or non-fatal myocardial infarction 93 36 0.444 0.302–0.654 <0.001   Fatal or non-fatal ischaemic stroke 9 4 0.528 0.159–1.751 0.296

Adjusted primary endpoint rates

Conclusion

The results of this large, nation-wide nested cohort study support the role of bariatric surgery in reducing the risk of major cardiovascular events, all-cause mortality and new onset of heart failure in patients with obesity.

Surgical options for glycaemic control in Type 1 diabetes

In recent years, bariatric surgery, also referred to as metabolic surgery, has become the most successful treatment option in those with Type 2 diabetes and obesity. There are some similarities in the pathological pathways in Type 1 and Type 2 diabetes, but the use of surgery in Type 1 diabetes remains unestablished and controversial. The treatment and management of Type 1 diabetes can be very challenging but recent advances in surgical interventions and technology has the potential to expand and optimize treatment options. This review discusses the current status of some surgical options available to people with Type 1 diabetes. These include implantable continuous glucose monitoring systems, continuous intraperitoneal insulin infusion pumps, closed-loop insulin delivery systems (also known as the artificial pancreas system) utilizing the latter two modalities of glucose monitoring and insulin delivery, and bariatric or metabolic surgery. Whole pancreas and islet transplantation are beyond the scope of this review but are briefly discussed.

Prospective Risk Factor Analysis for the Development of Post-operative Urinary Retention Following Ambulatory General Surgery

Aims

Post-operative urinary retention (POUR) is a common cause of unplanned admission following day-case surgery and has negative effects on both patient and surgical institution. We aimed to prospectively evaluate potential risk factors for the development of POUR following day-case general surgical procedures.

Methods

Over a 24-week period, consecutive adult patients undergoing elective day-case general surgery at a single institution were prospectively recruited. Data regarding urinary symptoms, comorbidities, drug history, surgery and perioperative anaesthetic drug use were collected. The primary outcome was the incidence of POUR, defined as an impairment of bladder voiding requiring either urethral catheterisation, unplanned overnight admission or both. Potential risk factors for the development of POUR were analysed by logistic regression.

Results

A total of 458 patients met the inclusion criteria during the study period, and data were collected on 382 (83%) patients (74.3% male). Sixteen patients (4.2%) experienced POUR. Unadjusted analysis demonstrated three significant risk factors for the development of POUR: age ≥ 56 years (OR 7.77 [2.18–27.78], p = 0.002), laparoscopic surgery (OR 3.37 [1.03–12.10], p = 0.044) and glycopyrrolate administration (OR 5.56 [2.00–15.46], p = 0.001). Male sex and lower urinary tract symptoms were not significant factors. Multivariate analysis combining type of surgery, age and glycopyrrolate use revealed that only age ≥ 56 years (OR 8.14 [2.18–30.32], p = 0.0018) and glycopyrrolate administration (OR 3.48 [1.08–11.24], p = 0.0370) were independently associated with POUR.

Conclusions

Patients aged at least 56 years and/or requiring glycopyrrolate—often administered during laparoscopic procedures—are at increased risk of POUR following ambulatory general surgery.

Electronic supplementary material

The online version of this article (10.1007/s00268-018-4697-4) contains supplementary material, which is available to authorized users.

Obesity surgery and risk of cancer

BACKGROUND

Obesity increases the risk of several types of cancer. Whether bariatric surgery influences the risk of obesity-related cancer is not clear. This study aimed to uncover the risk of hormone-related (breast, endometrial and prostate), colorectal and oesophageal cancers following obesity surgery.

METHODS

This national population-based cohort study used data from the Hospital Episode Statistics database in England collected between 1997 and 2012. Propensity matching on sex, age, co-morbidity and duration of follow-up was used to compare cancer risk among obese individuals undergoing bariatric surgery (gastric bypass, gastric banding or sleeve gastrectomy) and obese individuals not undergoing such surgery. Conditional logistic regression provided odds ratios (ORs) with 95 per cent confidence intervals.

RESULTS

In the study period, from a cohort of 716 960 patients diagnosed with obesity, 8794 patients who underwent bariatric surgery were matched exactly with 8794 obese patients who did not have surgery. Compared with the no-surgery group, patients who had bariatric surgery exhibited a decreased risk of hormone-related cancers (OR 0·23, 95 per cent c.i. 0·18 to 0·30). This decrease was consistent for breast (OR 0·25, 0·19 to 0·33), endometrium (OR 0·21, 0·13 to 0·35) and prostate (OR 0·37, 0·17 to 0·76) cancer. Gastric bypass resulted in the largest risk reduction for hormone-related cancers (OR 0·16, 0·11 to 0·24). Gastric bypass, but not gastric banding or sleeve gastrectomy, was associated with an increased risk of colorectal cancer (OR 2·63, 1·17 to 5·95). Longer follow-up after bariatric surgery strengthened these diverging associations.

CONCLUSION

Bariatric surgery is associated with decreased risk of hormone-related cancers, whereas gastric bypass might increase the risk of colorectal cancer.

Comparison of gaze behaviour of trainee and experienced surgeons during laparoscopic gastric bypass

Background

Eye tracking presents a novel tool that could be used to profile skill levels in surgery objectively. The primary aim of this study was to identify differences in gaze behaviour between expert and junior surgeons performing a laparoscopic Roux-en-Y gastric bypass (LRYGB) for obesity.

Methods

This prospective observational study used a lightweight eye-tracking apparatus to determine the difference in gaze behaviours between expert (more than 75 procedures) and junior (75 or fewer procedures) surgeons at defined stages of LRYGB. Primary endpoints were normalized dwell time and fixation frequency. Secondary endpoints were blink rate, maximum pupil size and rate of pupil change.

Results

A total of 20 procedures (12 junior, 8 expert) were analysed. Compared with juniors, experts showed a prolonged dwell time on the screen during angle of His dissection (median (range) 91·20 (83·40–94·40) versus 68·95 (59·80–87·60) per cent; P = 0·001), formation of the retrogastric tunnel (91·50 (85·80–95·50) versus 73·60 (34·60–90·50) per cent; P = 0·001) and gastric pouch formation (86·95 (83·60–90·20) versus 67·60 (37·10–80·00) per cent P &lt; 0·001). Juniors had a greater blink frequency throughout all recorded segments (P &lt; 0·010) and had a larger maximum pupil size during all recorded operative segments (P &lt; 0·010). Rate of pupil change was greater in juniors in all analysed segments (P &lt; 0·010).

Conclusion

These results suggest that experts display more focused attention on significant stimuli, alongside experiencing a reduced mental workload and having increased concentration. This has the potential for future use in validation of surgical skill in high-stakes assessment.

Aneurysmal Bone Cyst of Skull

An aneurysmal bone cyst is a benign lesion usually involving the long bones, vertebrae including odontoid, hypoid and mandible. Skull is a rare site for aneurysmal bone cyst. Only 3% occur in the cranium and sites of involvement include temporal, occipital, orbital, frontal, parietal, ethmoids and sphenoid bones in order of frequency. We report two cases of aneurysmal bone cysts in occipital bone and maxilla. We discuss the radiological features, surgical findings and emphasize the role of endovascular management in these lesions.

CT Cisternography of Paradoxical Cerebrospinal Fluid Rhinorrhea after Operation for Acoustic Neuroma

Cerebrospinal fluid (CSF) rhinorrhea after acoustic neuroma surgery is a well-known complication. CT cisternography can be used to demonstrate the entry of CSF from cerebellopontine angle cistern into the mastoid air cells, middle ear and then into nasopharynx via Eustachian tube. We report a case of paradoxical CSF rhinorrhea after surgery for acoustic neuroma in which the path of CSF leak was accurately demonstrated using CT cisternography.

Endovascular Treatment of Intracranial Aneurysms: Long-Term Follow-up

Endovascular treatment of intracranial aneurysms is increasingly used and has evolved as an alternative to surgical clipping. However, its long-term efficacy has yet to be established. This retrospective hospital based (tertiary teaching hospital) study aimed to identify factors that might be important in predicting initial efficacy of this treatment and a long-term follow-up to study the clinical and angiographic results of treated aneurysms. A total of 80 aneurysms in 78 patients were treated and analyzed, and the percentage of occlusion calculated. Overall, 51/80 (64 %) cases were treated with selective endovascular coil occlusion and 29/80 (36 %) by parent artery occlusion. The shape of the aneurysm rest was noted on the immediate post treatment and follow-up angiograms. Immediate and follow-up clinical status was also noted using the Glasgow outcome scale. The clinical and radiological changes on follow-up were assessed and possible factors involved were analyzed. Of the 50 patients of intracranial aneurysms that underwent selective aneurysm coiling, good immediate outcome (Glasgow outcome scale 1 and 2) was seen in 36/50 (72 %) cases. Narrow necked aneurysms showed a good immediate result (90–100 % packing) in all cases 28/28 (100 %). Amongst the wide necked aneurysms, good packing (90–100 %) was achieved in 17/23 (73 %) cases. Amongst the cases treated with parent artery occlusion, complete occlusion was noted in 20/29 (69 %) cases. No subarachnoid hemorrhage was seen in any of the followed up cases of coiled aneurysms. A statistically significant relationship was noted between aneurysm neck size and immediate angiographic outcome. Long-term angiographic recurrences were found more often in large aneurysms. Endovascular treatment of intracranial aneurysms is a safe and effective treatment modality that offers protection from recurrent subarachnoid hemorrhage.

From Dyadic Ties to Information Infrastructures: Care-Coordination between Patients, Providers, Students and Researchers. Contribution of the Health Informatics Education Working Group

OBJECTIVE

To share how an effectual merging of local and online networks in low resource regions can supplement and strengthen the local practice of patient centered care through the use of an online digital infrastructure powered by all stakeholders in healthcare. User Driven Health Care offers the dynamic integration of patient values and evidence based solutions for improved medical communication in medical care.

INTRODUCTION

This paper conceptualizes patient care-coordination through the lens of engaged stakeholders using digital infrastructures tools to integrate information technology. We distinguish this lens from the prevalent conceptualization of dyadic ties between clinician-patient, patient-nurse, clinician-nurse, and offer the holistic integration of all stakeholder inputs, in the clinic and augmented by online communication in a multi-national setting.

METHODS

We analyze an instance of the user-driven health care (UDHC), a network of providers, patients, students and researchers working together to help manage patient care. The network currently focuses on patients from LMICs, but the provider network is global in reach. We describe UDHC and its opportunities and challenges in care-coordination to reduce costs, bring equity, and improve care quality and share evidence.

CONCLUSION

UDHC has resulted in coordinated global based local care, affecting multiple facets of medical practice. Shared information resources between providers with disparate knowledge, results in better understanding by patients, unique and challenging cases for students, innovative community based research and discovery learning for all.

The role of bile acids in reducing the metabolic complications of obesity after bariatric surgery: a systematic review

BACKGROUND

Bariatric surgery is currently the most efficacious treatment for obesity and its associated metabolic co-morbidities, such as diabetes. The metabolic improvements occur through both weight-dependent and weight-independent mechanisms. Bile acids (BAs) have emerged as key signalling molecules that have a central role in modulating many of the physiological effects seen after bariatric surgery. This systematic review assesses the evidence from both human and animal studies for the role of BAs in reducing the metabolic complications of obesity following bariatric surgery.

METHODS

We conducted a systematic search of Medline and Embase databases to identify all articles investigating the role of BAs in mediating the metabolic changes observed following bariatric surgery in both animal and human studies. Boolean logic was used with relevant search terms, including the following MeSH terms: 'bile acids and salts', 'bariatric surgery', 'metabolic surgery', 'gastrointestinal tract/surgery' and 'obesity/surgery'.

RESULTS

Following database searches (n=1197), inclusion from bibliography searches (n=2) and de-duplication (n=197), 1002 search results were returned. Of these, 132 articles were selected for full-text review, of which 38 articles were deemed relevant and included in the review. The findings support the effects of BAs on satiety, lipid and cholesterol metabolism, incretins and glucose homoeostasis, energy metabolism, gut microbiota and endoplasmic reticulum stress following bariatric surgery. Many of these metabolic effects are modulated through the BA receptors FXR and TGR5. We also explore a possible link between BAs and carcinogenesis following bariatric surgery.

CONCLUSIONS

Overall there is good evidence to support the role of BAs in the metabolic effects of bariatric surgery through the above mechanisms. BAs could serve as a novel therapeutic pharmacological target for the treatment of obesity and its associated co-morbidities.

Optimization of cone beam CT exposure for pre-surgical evaluation of the implant site

OBJECTIVES

The aim of this study was to investigate the possibility of reducing patient X-ray dose in the course of implant site evaluation.

METHODS

Retrospective practice-based study using a Morita F170 Accuitomo cone beam CT (CBCT) scanner with variable exposure parameters and operating a small cylindrical field of view of 4 cm diameter and 4 cm height. 6 experienced dental surgeons scored the image quality of dental scans on a 5-point scale for adequacy in providing the required information in 2 categories: bone height from alveolar crest to the relevant anatomical structure and bone width.

RESULTS

Lower-dose protocols only marginally affected the preference of the reviewers of the resulting images.

CONCLUSIONS

There is potential to reduce patient dose very significantly in CBCT examinations for implant site evaluation.

Systematic review of the application of quality improvement methodologies from the manufacturing industry to surgical healthcare

Background

The demand for the highest-quality patient care coupled with pressure on funding has led to the increasing use of quality improvement (QI) methodologies from the manufacturing industry. The aim of this systematic review was to identify and evaluate the application and effectiveness of these QI methodologies to the field of surgery.

Methods

MEDLINE, the Cochrane Database, Allied and Complementary Medicine Database, British Nursing Index, Cumulative Index to Nursing and Allied Health Literature, Embase, Health Business™ Elite, the Health Management Information Consortium and PsycINFO® were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Empirical studies were included that implemented a described QI methodology to surgical care and analysed a named outcome statistically.

Results

Some 34 of 1595 articles identified met the inclusion criteria after consensus from two independent investigators. Nine studies described continuous quality improvement (CQI), five Six Sigma, five total quality management (TQM), five plan-do-study-act (PDSA) or plan-do-check-act (PDCA) cycles, five statistical process control (SPC) or statistical quality control (SQC), four Lean and one Lean Six Sigma; 20 of the studies were undertaken in the USA. The most common aims were to reduce complications or improve outcomes (11), to reduce infection (7), and to reduce theatre delays (7). There was one randomized controlled trial.

Conclusion

QI methodologies from industry can have significant effects on improving surgical care, from reducing infection rates to increasing operating room efficiency. The evidence is generally of suboptimal quality, and rigorous randomized multicentre studies are needed to bring evidence-based management into the same league as evidence-based medicine.

The role of robotic assisted laparoscopy for oesophagogastric oncological resection; an appraisal of the literature

The introduction of surgical robotics to the field of surgical oncology brings with it an expectation not only of improved vision, instrumentation, and precision but also as a result, a potential for improved oncological outcomes. The current interest in the field of oesophagogastric oncology is explored in this review together with the benefits, real and potential, that robotic assistance offers surgical cancer resection as well as some of the limiting factors which may be hampering its uptake into current surgical practice. A systematic review of all the published literature up until April 2010 was examined across the field of esophageal and gastric cancer resection. A quantitative assessment of the oncological, operative, and functional outcomes was determined from each procedure. The level of evidence behind the results was determined using the Oxford Centre for Evidence-based Medicine Levels of Evidence; Therapy and Prevention. Three hundred and five cases from 19 independent studies were included for review. Nine studies explored the outcomes from robotic-assisted esophagectomy and eight, the robotic-assisted gastrectomy. Two articles included small case series of both procedures. The level of evidence was predominantly based on case series or expert opinion (Level 4 or 5) with only three unmatched or poorly matched comparative trials (Level 4) with no randomized trials evident. Improved operative outcomes and hospital stays were demonstrated with a reduction of 2 days when the robotic-assisted gastrectomy technique was employed compared with the open. No improvement in oncological outcomes could be identified with the use of the robot for either oesophageal or gastric cancer resection; however, in terms of short-term oncological outcomes, these were at least equivalent to the open approach for oesophageal cancer and early stage gastric cancer. Robotic-assisted laparoscopic surgery is a feasible technique to use to perform a safe and oncologically sound resection for oesophageal and early gastric cancer. Operative benefits appear to be encouragingly similar to the laparoscopic approach with some demonstration of improvement over the open technique despite a prolonged operative time. However, the level of evidence is suboptimal and more randomized controlled trials and long-term survival studies within a framework of measured and comparable outcomes is required.

Prognostic significance of circulating tumour cells following surgical resection of colorectal cancers: a systematic review

Background:

The role of adjuvant chemotherapy after resection of colorectal cancers (CRCs) is well understood for patients with stage-I or stage-III disease. Its efficacy for those with stage-II disease remains much less clear. Many investigators have sought to identify prognostic markers that might clarify which patients have the highest risk of recurrence and would, therefore, be most likely to benefit from chemotherapy. This systematic review examines evidence for the use of peripherally sampled, circulating tumour cells (CTCs) as such a prognostic marker.

Methods:

A comprehensive literature search was used to identify studies reporting on the significance of CTCs in the postoperative blood of CRC patients.

Results:

Fourteen studies satisfied the inclusion criteria. Six of the nine studies that took blood samples 24 h or more postoperatively found detection of postoperative CTCs to be an independent predictor of cancer recurrence.

Conclusion:

The presence of CTCs in peripheral blood at least 24 h after resection of CRCs is an independent prognostic marker of recurrence. Further studies are needed to clarify the optimal time point for blood sampling and determine the benefit of chemotherapy in CTC-positive patients with stage-II disease.

Microtechnologies in implant and restorative dentistry: A stroll through a digital dental landscape

This is an explanatory article introducing the combination of various technologies used in implant and restorative dentistry. The aim of the article is to provide an overview of some of the techniques supporting the restorative treatment plan at various stages to provide contemporary, state-of-the-art bridgework based on dental implants. It is a discussion of the way existing technologies used in fields of engineering and medicine are brought together to form a complete process.

"Swimming worms in a bare cistern": a sign for moyamoya disease. A case report

Moyamoya disease is a rare cerebrovascular occlusive disorder most often found among the Japanese. It is angiographically defined as a progressive steno-occlusion of the bilateral internal carotid arteries with characteristic abnormal vascular networks, so-called Moyamoya vessels, at the base of the brain. MRI is the initial investigation of choice and we describe an MRI sign to diagnose Moyamoya disease warranting digital subtraction angiography.

Laparoscopic approach to incarcerated and strangulated inguinal hernias

INTRODUCTION

Acute inguinal hernias are a common presentation as surgical emergencies, which have been routinely managed with open surgery. In recent years, the laparoscopic approach has been described by several authors but has been controversial amongst surgeons. We describe the laparoscopic approach to incarcerated/strangulated inguinal hernias based on a review of the literature with regards to its feasibility in laparoscopically managing the acute hernia presentation.

METHODS

A systematic literature search was carried out including Medline with PubMed as the search engine, and Ovid, Embase, Cochrane Collaboration, and Google Scholar databases to identify articles reporting on laparoscopic treatment, reduction, and repair of incarcerated or strangulated inguinal hernias from 1989 to 2008.

RESULTS

Forty-three articles were found, and 7 were included according to the inclusion criteria set. Articles reporting on the use of laparoscopy for the evaluation of the hernia but not reducing and repairing it, the use of the open technique, elective hernia repairs, pediatric series, review articles, and other kinds of hernias were excluded after title and abstract review. This resulted in 16 articles that were reviewed in full. Of these 16 articles, 7 reported on the use of the laparoscopic approach exclusively. From these 7 studies, there were 328 cases reported, 6 conversions, average operating time of 61.3 minutes (SD+/-12.3), average hospital stay of 3.8 days (SD+/-1.2), 34 complications (25 of which were reported as minor), and 17 bowel resections performed either laparoscopically or through a minilaparotomy incision guided laparoscopically.

CONCLUSION

The laparoscopic repair is a feasible procedure with acceptable results; however, its efficacy needs to be studied further, ideally with larger multicenter randomized controlled trials.

Acute onset hemichorea-hemiballism. MRI signal abnormality in a metabolically normal patient. A case report

Abnormal signals involving the basal ganglia on MR images have been reported with new-onset hemichorea-hemiballism, typically in elderly Asian patients. The most common cause is a vascular lesion, but many cases are reported in association with hyperglycemia. We describe one case of acute onset chorea-hemiballism with abnormal MRI signal in the basal ganglia but with no systemic abnormality.

General surgical manifestations of Marfan's syndrome

Marfan's syndrome can manifest as various general surgical pathologies (herniae, diverticulosis, bowel obstruction and abdominal vasculature aneurysms). These pathologies often have abnormal presentations, and in some cases can be life-threatening.

Worster-drought syndrome with ectopic neurohypophysis and pituitary hypoplasia. A case report

Worster-Drought syndrome (WDS) (congenital bilateral perisylvian syndrome, congenital pseudobulbar paresia) is characterized by neuronal migration defect, pseudobulbar paralysis, epilepsy, neuromotor retardation and perisylvian dysplasia. Pituitary abnormalities are rare disorders. We describe one case with an interesting association of congenital bilateral perisylvian syndrome with pituitary hypoplasia and posterior pituitary ectopia.

Spontaneous Extensive Spinal Epidural Abscess without Any Identifiable Risk Factor. A Case Report

Spinal epidural abscess is a rare medical emergency which if left untreated results in catastrophic and irreversible neurological damage. Risk factors (compromised immunity, spinal column disruption, source of infection) are present in the majority of patients. We describe a case of spontaneous spinal epidural abscess with any identifiable risk factor.

Persistent trigeminal artery with bilateral ophthalmoplegia and contralateral internal carotid artery occlusion. A case report

The most frequent persistent embryonic communication between the vertebrobasilar and carotid systems in adult life is a persistent trigeminal artery (PTA). Several anatomic variants of PTA have been described. The other associations of PTA mainly include aneurysm and vascular steal phenomena between basilar and carotid systems. We describe an interesting case of PTA with bilateral ophthalmoplegia and contralateral occlusion of the internal carotid artery.

WITHDRAWN: Meta-analysis: the use of adhesion prevention membranes in abdominal surgery

Ahead of Print article withdrawn by publisher.

Does laparoscopic surgery offer adequate clearance in rectal cancer?--A discussion

Currently in the UK, the national institute of clinical excellence (NICE), only advocates laparoscopic surgery for rectal cancer as part of commissioned clinical trials. Laparoscopic teaching, training and techniques have evolved greatly and offer many benefits to patients, whilst remaining technically demanding to surgeons still on the slope of the learning curve. Can such minimally invasive techniques be used with the same results as open surgery in the treatment of rectal cancer? Are laparoscopic colorectal surgeons able to achieve the same clearance of tumours and so avoid recurrence at the same rate compared to conventional techniques? The discussion to follow, aims to shed some light on such questions and briefly review some of the literature. If laparoscopic anterior resections and abdominoperineal resections achieve the same results as open procedures, then should these techniques be more widely taught and practised? Surely the peri-operative cost of these laparoscopic procedures does not over shadow the potential outcome from much less traumatic surgery?

Fluoroscopic-guided balloon dilatation and stenting in tracheal stenosis with metallic self-expandable stents and long-term follow-up results

The purpose of this study was to assess the safety and long-term efficacy of self-expandable stents in the treatment of benign tracheal stenosis. Nine patients (seven men) with tracheal stenosis (including one with fistula) of varied cause were treated by fluoroscopically guided balloon dilatation and stenting with self-expandable metallic stents. The procedure was carried out under topical spray in eight patients and under general anaesthesia in one patient. The patients were followed up for a period ranging between 13 and 60 months. In eight of the nine patients, satisfactory positioning of the stent was achieved at the first instance, with immediate relief of dyspnoea. One patient with innominate artery aneurysm died 16 days after the procedure because of renal failure. At 1 month of follow up, six out of eight (75%) of our live patients were without any respiratory embarrassment. This dyspnoea-free result reached almost 90% by the end of 1 year especially so in the fibrous strictures. Four out of the eight live patients (50%) had cough for 2 months and two (25%) had mild blood-tinged sputum treated by inhalation and mucolytic agents. Secondary intervention was required in one patient at 1 month because of recurrent symptoms. The patient with tracheo-oesophageal fistula required surgical intervention because of fracture of the stent. Fluoroscopically guided balloon dilatation and stenting of the tracheal stenosis is an effective non-surgical therapy resulting in cure of fibrous strictures and palliation in cases of malignancy.

Strictureplasty vs resection in small bowel Crohn's disease: an evaluation of short-term outcomes and recurrence

AIM

To compare postoperative adverse events and recurrence following strictureplasty or bowel resection in patients with small bowel Crohn's disease (CD).

METHOD

A literature search was performed to identify studies published between 1980 and 2006 comparing outcomes of CD patients undergoing either strictureplasty or bowel resection. Hazard ratios were calculated from Kaplan-Meier plots of cumulative recurrence data. Quality assessment of the included studies was performed. Random-effect meta-analytical techniques were employed. Sensitivity analysis and assessment of heterogeneity were performed.

RESULTS

Seven studies comprising 688 CD patients (strictureplasty n = 311, 45%; resection with or without strictureplasty n = 377, 55%) were included. Patients undergoing strictureplasty alone had a lower risk of developing postoperative complications than those who underwent resection (OR = 0.60, 95% CI: 0.31-1.16) although this was not statistically significant (P = 0.13). Surgical recurrence after strictureplasty was more likely than after resection (OR = 1.36, 95% CI: 0.96-1.93, P = 0.09). Patients who had a resection had a significantly longer recurrence-free survival than those undergoing strictureplasty alone (HR = 1.08, 95% CI: 1.02-1.15, P = 0.01).

CONCLUSION

Patients with small bowel CD undergoing strictureplasty alone may have fewer postoperative complications than those undergoing a concomitant bowel resection. However, surgical recurrence maybe higher following strictureplasty alone than with a concomitant small bowel resection. Patients may require appropriate preoperative counselling regarding the pros and cons of each operative technique.

Preoperative embolization of hypervascular head and neck tumours

The embolization of vascular tumours of the head and neck has become an important adjunct to the surgical treatment of these tumours. A vascular tumour in the head and neck region in a surgically treatable patient may be a candidate for embolization. Palliative embolization may be the sole treatment for high risk patients. Reducing intraoperative bleeding may shorten surgery time thus decreasing morbidity and mortality. The purpose of this study is to assess the efficacy of embolization as an adjunct to surgery or as a curative measure in the management of hypervascular head and neck tumours. We retrospectively reviewed the records of 46 consecutive patients (27 men and 16 women; mean age, 37.8 years) with 48 hypervascular head and neck tumours that had undergone preoperative transarterial, direct puncture or combined mode of embolization. Diagnosis of tumours was made on the basis of findings of imaging studies. The 46 patients underwent embolization either through transarterial route, by direct puncture technique or both direct puncture and arterial route. The devascularization reached 90-95% with the use of NBCA. The amount of devascularization reached by transarterial particle embolization is a little lesser. One patient (carotid body tumour) developed mild unilateral seventh, ninth and 10th cranial nerve palsy after transarterial embolization, transient hemiparesis was seen in another patient (nasopharyngeal angiofibroma). Both patients improved completely with steroids and had no deficit on follow up. One patient developed delayed glue migration into the middle cerebral artery territory 6 h after the procedure with no reported increase in size of the lesion in the following 5 years. Preoperative embolization of hypervascular tumour of head and neck region appears to be safe and improves the chance of complete removal during surgery with minimal blood loss.

Diagnostic precision of magnetic resonance imaging for preoperative prediction of the circumferential margin involvement in patients with rectal cancer

OBJECTIVE

Circumferential margin involvement (CMI) is an important prognostic indicator for patients with rectal cancer. This meta-analysis aims at evaluating the diagnostic precision of magnetic resonance imaging (MRI) for the preoperative evaluation of CMI in patients with rectal cancer.

METHOD

Quantitative meta-analysis was performed comparing MRI against histology after total mesorectal excision. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver operating characteristic (SROC) curves and subgroup analysis were undertaken. Study quality and heterogeneity were evaluated. Meta-regression meta-analysis was used to evaluate the significance of the difference in relative DORs.

RESULTS

Nine studies evaluating 529 patients were included. Pooled results showed an overall sensitivity and specificity for MRI detecting CMI preoperatively of 94% and 85% respectively. The SROC analysis demonstrated an overall weighted area under the curve (AUC) of 0.92 (DOR 57.21, 95% CI 18.21-179.77), without significant heterogeneity between the studies (Q-value 14.66, P = 0.06). Good study quality further increased the sensitivity and specificity of MRI. The use of a 1.5 Tesla coil, a phased array coil and the inclusion of two interpreters also resulted in high preoperative diagnostic precision. Meta-regression meta-analysis showed a significant difference in the DOR for studies published in or since 2003 (P = 0.019).

CONCLUSION

Magnetic resonance imaging can accurately predict CMI preoperatively for rectal cancer in single units and this is reproducible across different centres. This strategy has important implications for selection of patients for adjuvant therapy prior to surgery.

Ossified Posterior Longitudinal Ligament with an Atypical Clinical Presentation in an Indian Male

Ossification of the posterior longitudinal ligament is an uncommon disorder mostly seen in the Japanese population and hence termed by some the “Japanese disease”. Ossification of the posterior longitudinal ligament is more common in the cervical spine2. Clinically it is usually asymptomatic, but serious neurological deficits have been seen in some patients2. The ossified mass composed of lamellar bone and focal calcified cartilage expands in volume causing spinal canal stenosis and cord compression. Morphologically, four forms of ossification of the posterior longitudinal ligament have been described: continuous, segmental, mixed and rarely a focal retrodiscal form4. CT scan is the method of choice for detecting the presence and extent of the ossified mass. MR imaging is helpful in depicting the nature of cord compression such as myelomalacia, edema, demyelination or cyst formation and root sleeve involvement.

Magnetic resonance colonography vs computed tomography colonography for the diagnosis of colorectal cancer: an indirect comparison

OBJECTIVE

The primary aim of this study was to use meta-regression techniques to compare the diagnostic accuracy of computed tomography colonography (CTC) and magnetic resonance colonography (MRC), compared with conventional colonoscopy for patients presenting with colorectal cancer (CRC).

METHOD

Quantitative meta-analysis was performed using prospective studies reporting comparative data between CTC and MRC individually to conventional colonoscopy. Study quality was assessed and sensitivities, specificities, diagnostic odds ratios (DOR) were calculated. Summary receiver operating characteristic (SROC) curves and sensitivity analysis were utilized. Meta-regression was used to indirectly compare the two modalities following adjustment for patient and study characteristics.

RESULTS

Overall sensitivity and specificity for CTC (0.96, 95% CI 0.92-0.99; 1.00, 95% CI 0.99-1.00 respectively) and MRC (0.91, 95% CI 0.79-0.97; 0.98, 95% CI 0.96-0.99 respectively) for the detection of CRC was similar. Meta-regression analysis showed no significant difference in the diagnostic accuracy of both modalities (beta=-0.64, P=0.37 and 95% CI of 0.12-2.39). Both tests showed high area under the SROC curve (CTC=0.99; MRC=0.98), with high DORs (CTC=1461.90, 95% CI 544.89-3922.30; MRC=576.41, 95% CI 135.00-2448.56). Factors that enhanced the overall accuracy of MRC were the use intravenous contrast, faecal tagging and exclusion of low-quality studies. No factors improved diagnostic accuracy from CTC except studies with more than 100 patients (AUC=1.00, DOR=2938.35, 95%CI 701.84-12 302.91).

CONCLUSION

This meta-analysis suggested that CTC and MRC have similar diagnostic accuracy for detecting CRC. Study quality, size and intravenous/intra-luminal contrast agents affect diagnostic accuracies. For an exact comparison to be made, studies evaluating CTC, MRC and colonoscopy in the same patient cohort would be necessary.