Rates of Bile Acid Diarrhoea After Cholecystectomy: A Multicentre Audit.

INTRODUCTION: Bile acid diarrhoea (BAD) can occur due to disruption to the enterohepatic circulation, e.g. following cholecystectomy. Post-cholecystectomy diarrhoea has been reported in 2.1-57.2% of patients; however, this is not necessarily due to BAD. The aim of this study was to determine the rates of bile acid diarrhoea diagnosis after cholecystectomy and to consider investigation practices. METHODS: A retrospective analysis of electronic databases from five large centres detailing patients who underwent laparoscopic cholecystectomy between 2013 and 2017 was cross-referenced with a list of patients who underwent 75SeHCAT testing. A 7-day retention time of <15% was deemed to be positive. Patient demographics and time from surgery to investigation were collected and compared for significance (p < 0.05). RESULTS: A total of 9439 patients underwent a laparoscopic cholecystectomy between 1 January 2013 and 31 December 2017 in the five centres. In total, 202 patients (2.1%) underwent investigation for diarrhoea via 75SeHCAT, of which 64 patients (31.6%) had a 75SeHCAT test result of >15%, while 62.8% of those investigated were diagnosed with bile acid diarrhoea (BAD). In total, 133 (65.8%) patients also underwent endoscopy and 74 (36.6%) patients had a CT scan. Median time from surgery to 75SeHCAT test was 672 days (SD ± 482 days). DISCUSSION/CONCLUSION: Only a small proportion of patients, post-cholecystectomy, were investigated for diarrhoea with significant time delay to diagnosis. The true prevalence of BAD after cholecystectomy may be much higher, and clinicians need to have an increased awareness of this condition due to its amenability to treatment. 75SeHCAT is a useful tool for diagnosis of bile acid diarrhoea.

An evaluation of operative self-assessment by UK postgraduate trainees.

BACKGROUND: Surgeons in training undertake procedure-based assessment (PBA) with their trainers. Time pressures limit when this occurs. Self-assessment would provide additional opportunities but requires evaluation of your own skills and knowledge. AIM: To investigate the validity of a self-assessment PBA in the operating theatre and evaluate learning needs and change in practice identified. METHODS: In a prospective study, postgraduate UK trainees performed a self-assessment PBA after formally reflecting on appendicectomy surgery. Later, they performed their usual external assessment PBA on the same case and outcomes were compared. Learning outcomes were analysed independently by two trainers. RESULTS: There were 25 trainees (14 males), of age 29 years (25-33). They had performed a median of five previous appendicectomies (2-21) after a median three years of speciality training (range 1-4). There were no significant differences in global summary scores, trainee satisfaction or learning outcomes between external and self-assessment PBAs. Construct validity of the self-assessment PBA was demonstrated. The self-assessment PBA was more likely to identify non-technical skills. CONCLUSION: Our results suggest self-assessment PBA is valid for formative assessment. It identified a wide range of learning outcomes. Self-assessment PBA would help trainees maximise every learning opportunity and practice self-assessment skills.

Effect of Preoperative Weight Loss and Baseline Comorbidity on Short-Term Complications and Reoperations After Laparoscopic Roux-en-Y Gastric Bypass in 2,067 Patients.

PURPOSE: Decreasing popularity of Roux-en-Y gastric bypass (RYGB) in bariatric-metabolic surgery may be due to higher perceived peri-operative complications. There are few studies on whether preoperative weight loss can reduce complications or reoperations following RYGB. We investigated this using a standardised operative technique. MATERIALS AND METHODS: Retrospective single-centre study of RYGB from 2004 to 2019 using a prospective database. Preoperative behavioural management included intentional weight loss. Maximum preoperative weight, weight on the day of operation, and Obesity-Surgery Mortality Risk Score (OS-MRS) class were recorded. Short-term outcomes (post-operative stay, 30-day complication and reoperation rates) were analysed. RESULTS: In 2,067 RYGB patients (1,901 primary and 166 revisional), median preoperative total body weight loss (TWL) was 6.2% (IQR: 2.5-10.7%). The median age was 46 (interquartile range (IQR) 38-54) and 80.4% were female (n=1,661). For primary surgery, the median body mass index (BMI) was 47.6 kg/m2 (IQR: 43.1-53.3). Excluding the 100-procedure learning curve, the complication rate for primary cases was 4.4% and reoperation rate of 2.8% and one peri-operative mortality (0.06%). OS-MRS ≥2 (class B or C) predicted higher risk of complications (6.1%) compared to those with a score <2 (class A) (3.8%, p=0.021), but not reoperations. Five percent preoperative TWL did not decrease complications compared to <5% TWL. Patients with ≥10% TWL had greater baseline risk and had an increased risk of complications (6.6% vs 3.7%, p=0.017) and reoperations (4.5% vs 2.7%, p<0.001). CONCLUSIONS: RYGB performed using a standardised technique has low overall risk. The influence of preoperative weight loss on outcomes was inconsistent.

Remission of type 2 diabetes after gastric bypass and banding: mechanisms and 2 year outcomes.

OBJECTIVE: To investigate the rate of type 2 diabetes remission after gastric bypass and banding and establish the mechanism leading to remission of type 2 diabetes after bariatric surgery. SUMMARY BACKGROUND DATA: Glycemic control in type 2 diabetic patients is improved after bariatric surgery. METHODS: In study 1, 34 obese type 2 diabetic patients undergoing either gastric bypass or gastric banding were followed up for 36 months. Remission of diabetes was defined as patients not requiring hypoglycemic medication, fasting glucose below 7 mmol/L, 2 hour glucose after oral glucose tolerance test below 11.1 mmol/L, and glycated haemoglobin (HbA1c) <6%. In study 2, 41 obese type 2 diabetic patients undergoing either bypass, banding, or very low calorie diet were followed up for 42 days. Insulin resistance (HOMA-IR), insulin production, and glucagon-like peptide 1 (GLP-1) responses after a standard meal were measured. RESULTS: In study 1, HbA1c as a marker of glycemic control improved by 2.9% after gastric bypass and 1.9% after gastric banding at latest follow-up (P < 0.001 for both groups). Despite similar weight loss, 72% (16/22) of bypass and 17% (2/12) of banding patients (P = 0.001) fulfilled the definition of remission at latest follow-up. In study 2, within days, only bypass patients had improved insulin resistance, insulin production, and GLP-1 responses (all P < 0.05). CONCLUSIONS: With gastric bypass, type 2 diabetes can be improved and even rapidly put into a state of remission irrespective of weight loss. Improved insulin resistance within the first week after surgery remains unexplained, but increased insulin production in the first week after surgery may be explained by the enhanced postprandial GLP-1 responses.

A mechanistic study and review of volatile products from peroxidation of unsaturated fatty acids: an aid to understanding the origins of volatile organic compounds from the human body.

The assessment of volatile compounds (VOCs) for disease diagnosis is a growing area of research. There is a need to provide hard evidence i.e. biochemical routes, to justify putative VOC biomarkers, as in many cases this remains uncertain, which weakens their authenticity. Recently reports of volatile hydrocarbons and or aldehydes in bodily fluids and breath have been attributed to oxidative stress, although as discussed here, fewer compounds have been reported than expected from a mechanistic examination. Oxidative stress can result from many disease states which produce inflammation, and a better understanding of the interconnection between oxidative stress and the release of VOCs from target diseased and healthy organs could greatly help diagnoses. It is generally considered that oxidation of unsaturated fatty acids are a major source of these VOCs. An investigation listing the many possible volatile oxidation products has not been undertaken. This is described here using a mechanistic analysis (based on the literature) of the compounds derived from molecular cleavage and the results compared with a recent review of all the VOCs emanating from the human body, which satisfactorily explains the presence of at least 100 VOCs. Six important unsaturated fatty acids, oleic, palmitoleic, linoleic, linolenic, arachidonic, and cervonic acids have been shown to be capable of producing up to 18 n+6 unique breakdown products (where n = the number of alkene double bonds in the fatty acid hydrocarbon chain), in total 299 compounds. In many cases these have not been reported. We suggest several reasons for this: these VOCs have not been expected, so researchers are not looking for them and importantly some are not present in the mass spectral libraries, or they are too low a concentration to have been detected, or are not present. Furthermore a theoretical explanation for the origins of branched aldehydes and other compounds arising from bacterial oxidative metabolism of unsaturated fatty acids are described.

Paid work increases and state benefit claims decrease after bariatric surgery.

BACKGROUND: Bariatric surgery is a clinically effective treatment for obesity and has been shown to be cost-effective. The impact of bariatric surgery on the subsequent ability to work and the uptake of state-funded benefits is not well documented. METHODS: A consecutive series of 79 patients who had undergone laparoscopic Roux-en-Y gastric bypass (LRYGBP) or laparoscopic adjustable gastric banding (LAGB) were surveyed to assess changes in their ability to work and the number and type of state benefits claimed after surgery. RESULTS: 59 patients (75%) responded, median age 45, median follow-up 14 months. There was a 32% increase in the number of respondents in paid work after surgery (P<0.05). The mean weekly hours worked increased from 30.1 to 35.8 hours (P<0.01). Respondents also reported a decrease in obesity-related physical and emotional constraints on their ability to do work (P<0.01). Fewer patients claimed state benefits postoperatively (P<0.01). CONCLUSION: More patients perform paid work after LRYGBP and LAGB than beforehand, and the number of weekly hours they work increases. After surgery, patients claim fewer state benefits.

Preoperative surgical briefings do not delay operating room start times and are popular with surgical team members.

OBJECTIVES: : This study was carried out to evaluate the introduction of preoperative safety briefings on operating theater start times. In addition, we assessed staff attitudes toward the safety briefings. Lack of time, motivation, and a negative perception in staff are often cited as barriers to the implementation of safety briefings. METHODS: : The preoperative safety briefing consisted of a 5- to 10-minute meeting between anesthetic staff, surgeons, and nursing staff to discuss the operating list before the commencement of surgery. Using the hospital database, the operating theater start times were obtained for 2 months before and after the introduction of the safety briefings. A questionnaire using a 5-point Likert scale was distributed to the operating room theater staff to evaluate attitudes toward the safety briefing. RESULTS: : There was no statistical difference in operating theater start time after the introduction of the safety briefing. The questionnaire responses from 37 theater staff demonstrated positive attitudes toward the safety briefings including agreeing strongly with factors affecting patient safety and communication. This included 97% replying that the safety briefing highlighted potential patient problems, whereas 89% believed it improved communication. CONCLUSIONS: : The safety briefings were popular among staff and did not delay the operating theater start time.

The gut hormone response following Roux-en-Y gastric bypass: cross-sectional and prospective study.

BACKGROUND: Bariatric surgery is the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. Although there is increasing interest in the gut hormone changes after gastric bypass, the long-term changes have not been fully elucidated. METHODS: Thirty-four participants were studied cross-sectionally at four different time points, pre-operatively (n = 17) and 12 (n = 6), 18 (n = 5) and 24 months (n = 6) after laparoscopic Roux-en-Y gastric bypass. Another group of patients (n = 6) were studied prospectively (18-24 months). All participants were given a standard 400 kcal meal after a 12-h fast, and plasma levels of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were correlated with changes in appetite over 3 h using visual analogue scores. RESULTS: The post-operative groups at 12, 18 and 24 months had a higher post-prandial PYY response compared to pre-operative (p < 0.05). This finding was confirmed in the prospective study at 18 and 24 months. There was a trend for increasing GLP-1 response at 18 and 24 months, but this did not reach statistical significance (p = 0.189) in the prospective study. Satiety was significantly reduced in the post-operative groups at 12, 18 and 24 months compared to pre-operative levels (p < 0.05). CONCLUSIONS: Roux-en-Y gastric bypass causes an enhanced gut hormone response and increased satiety following a meal. This response is sustained over a 24-month period and may partly explain why weight loss is maintained.

Gut hormones as mediators of appetite and weight loss after Roux-en-Y gastric bypass.

OBJECTIVE: To evaluate the physiologic importance of the satiety gut hormones. BACKGROUND: Controversy surrounds the physiologic role of gut hormones in the control of appetite. Bariatric surgery remains the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. METHODS: We correlated peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) changes within the first week after gastric bypass with changes in appetite. We also evaluated the gut hormone responses of patients with good or poor weight loss after gastric bypass. Finally, we inhibited the gut hormone responses in gastric bypass patients and then evaluated appetite and food intake. RESULTS: Postprandial PYY and GLP-1 profiles start rising as early as 2 days after gastric bypass (P < 0.05). Changes in appetite are evident within days after gastric bypass surgery (P < 0.05), and unlike other operations, the reduced appetite continues. However, in patients with poor weight loss after gastric bypass associated with increased appetite, the postprandial PYY and GLP-1 responses are attenuated compared with patients with good weight loss (P < 0.05). Inhibiting gut hormone responses, including PYY and GLP-1 after gastric bypass, results in return of appetite and increased food intake (P < 0.05). CONCLUSION: The attenuated appetite after gastric bypass is associated with elevated PYY and GLP-1 concentrations, and appetite returns when the release of gut hormones is inhibited. The results suggest a role for gut hormones in the mechanism of weight loss after gastric bypass and may have implications for the treatment of obesity.