Background: In many clinical trials, the outcome variables are often binary (or categorical), and the main interest is to investigate any relationship between these categorical outcomes and intervention strategies for measuring the effect size and strength of association. The two frequently applied statistical methods used for this purpose are the relative risk (RR) and odds ratio (OR). The aim of this paper is to explore the fundamental concepts, definitions, computational methods, interpretations, differences, and lastly the relationship between RR and OR in the context of gastroesophageal reflux disease (GERD) following two bariatric (weight loss) procedures, namely laparoscopic vertical sleeve gastrectomy (LVSG) vs. laparoscopic Roux-en-Y gastric bypass (LRYGB). Methods: From January 2015 to March 2024, several electronic databases were searched for randomized controlled trials (RCTs) comparing LVSG and LRYGB and their effects on postoperative GERD at 5-year follow-up. Computation of OR and RR was undertaken to determine this impact, the differences in the effect size and strength of association between these two methods, and to demonstrate the differences between these two concepts. Results: Our analysis has demonstrated that GERD is far more common in patients' population following a LVSG compared to LRYGB. The RR for GERD is 4.96 times higher for the LVSG cohort compared to the LRYGB group. Similarly, the OR has revealed that the odds of GERD for LVSG patients is 6.4 times that of LRYGB patients at 5-year follow-up. Conclusions: Although both OR and RR have demonstrated a large effect size and strong association for GERD following LVSG compared to LRYGB, the OR strength of association is more convincing. The results suggest the primary use of OR is the right approach, as it is showing greater strength of association between exposure, i.e., LVSG, and outcome, i.e., GERD at 5-year follow-up in our analysis.

OBJECTIVE:This systematic review was conducted to evaluate the preoperative prevalence of primary esophageal motility disorders and gastroesophageal reflux disease in patients with morbid obesity before bariatric surgery. BACKGROUND:The use of esophageal manometry ± 24-hour pH study before bariatric surgery was explored. MATERIAL AND METHODS:Articles on preoperative conventional or high-resolution manometry ± 24-hours pH-study or both before bariatric surgery between 1999 and 2023 were identified using the Medline, PubMed, EMBASE, Cochrane Register of Systematic Reviews, and Science Citation Index. The search terms were selected for each search engine to optimize the published literature and meet the inclusion criteria. The modified AXIS was used as a critical appraisal tool to assess the quality of studies. RESULTS:Thirty-three studies performing preoperative esophageal manometry ± pH studies or both were identified. Various manometric abnormalities have been described by the authors depending on the type of technique used. Twenty-two studies undertook a 24-hour ambulatory pH study to identify abnormal acid exposure. Twenty studies performed preoperative gastroscopy. The incidence of hiatal hernia varied from 5.4% to 52.6%, and reflux esophagitis from 4.4% to 42%. CONCLUSIONS:The preoperative prevalence of PEMD and GERD was significant in patients with morbid obesity. This implies that the selection of the most appropriate bariatric procedure needs to be tailored not only for weight reduction but also for the prevention of further deterioration in esophageal motor function and GERD and its future consequences, such as Barrett's esophagus, erosive esophagitis, and esophageal adenocarcinoma, in both the short and long term.

LVSG seems to increase the risk of GERD despite significant weight loss. We compared pre- and postoperative esophageal function test data (in conjunction with the BMI loss) to evaluate the impact of post-LVSG on lower esophageal sphincter pressure (LESP), lower esophageal sphincter length (LESL), and DeMeester Score (DMS). Articles analyzing esophageal manometry ±24 h pH-study pre- and post-LVSG were identified using electronic databases from 1999 to 2023. The Critical Appraisal Skills Programme Checklist for Cohort Studies was used for quality assessment. The DerSimonian and Laird random effects model was used for continuous data analysis. Heterogeneity was assessed using the Cochrane Q statistic and I2 index. Leave one out sensitivity analysis was undertaken to assess the robustness and validity of our analysis. Egger’s test was used to evaluate potential publication bias in our meta-analysis. Nineteen studies totaling 668 patients were evaluated (F = 445, M = 131). A significant reduction of 3.82 mm Hg in LESP was observed after LVSG based on 16 studies (WMD 3.82, 95% CI 1.74, 5.90; p < 0.001, I2 = 88.6%). LESL did not reveal any significant difference between pre- and post-LVSG based on nine studies (WMD 0.05, 95% CI –0.15, 0.26; p = 0.625, I2 = 83.1%). DMS showed a significant increase of 11.72 post LVSG based on 12 studies (WMD –11.72, 95% CI –17.15 to –6.30; p < 0.001, I2 = 91.5%). Significant BMI loss of 13.26 kg/m2 was observed post LVSG based on 12 studies (WMD 13.26, 95% CI 11.65 to 14.88, Z = 16.07, p < 0.001). LVSG is associated with a significant decrease in LESP and a significant increase in the DMS post-LVSG, leading to the worsening or development of new GERD symptoms despite significant BMI reduction. The limitations of our meta-analysis include small sample sizes, short follow-up, heterogeneity, lack of data on some confounders and inadequate quality of some studies.

To compare 5-year gastroesophageal reflux outcomes following Laparoscopic Vertical Sleeve Gastrectomy (LVSG) and Laparoscopic Roux-en-Y gastric bypass (LRYGB) based on high quality randomized controlled trials (RCTs). We conducted a sub-analysis of our systematic review and meta-analysis of RCTs of primary LVSG and LRYGB procedures in adults for 5-year post-operative complications (PROSPERO CRD42018112054). Electronic databases were searched from January 2015 to July 2021 for publications meeting inclusion criteria. The Hartung-Knapp-Sidik-Jonkman random effects model was utilized to estimate weighted mean differences where meta-analysis was possible. Bias and certainty of evidence was assessed using the Cochrane Risk of Bias Tool 2 and GRADE. Four RCTs were included (LVSG n = 266, LRYGB n = 259). An increase in adverse GERD outcomes were observed at 5 years postoperatively in LVSG compared to LRYGB in all outcomes considered: Overall worsened GERD, including the development de novo GERD, occurred more commonly following LVSG compared to LRYGB (OR 5.34, 95% CI 1.67 to 17.05; p = 0.02; I2 = 0%; (Moderate level of certainty); Reoperations to treat severe GERD (OR 7.22, 95% CI 0.82 to 63.63; p = 0.06; I2 = 0%; High level of certainty) and non-surgical management for worsened GERD (OR 3.42, 95% CI 1.16 to 10.05; p = 0.04; I2 = 0%; Low level of certainty) was more common in LVSG patients. LVSG is associated with the development and worsening of GERD symptoms compared to LRYGB at 5 years postoperatively leading to either introduction/increased pharmacological requirement or further surgical treatment. Appropriate patient/surgical selection is critical to minimize these postoperative risks.

BACKGROUND:To evaluate 5-year effect of laparoscopic vertical sleeve gastrectomy (LVSG) versus laparoscopic roux-en-Y gastric bypass (LRYGB) on gastroesophageal reflux disease (GERD) solely based on randomized controlled trials (RCTs). METHODS:A systematic review and meta-analysis of 5-year postoperative GERD data comparing LVSG and LRYGB in adults were undertaken. Electronic databases were searched from January 2015 to March 2024 for publications meeting inclusion criteria. The Hartung-Knapp-Sidik-Jonkman random effects model was applied to estimate pooled odds ratio where meta-analysis was possible. Bias and certainty of evidence were assessed using the Cochrane Risk of Bias Tool 2 and GRADE. RESULTS:Five RCTs were analysed (LVSG n = 554, LRYGB n = 539). LVSG was associated with increased adverse GERD outcomes compared to LRYGB at 5 years. The odds for revisional surgery to treat GERD in LVSG patients were 11 times higher compared to LRYGB (OR 11.47, 95% CI 1.83 to 71.69; p = 0.02; I2 = 0% High level of certainty). Similarly pharmacological management for increasing GERD was significantly more frequent in LVSG patients compared to LRYGB (OR 3.89, 95% CI 2.31 to 6.55; p ≤ 0.01; I2 = 0% Moderate level of certainty). Overall, LVSG was associated with significantly more interventions (both medical and surgical) for either worsening GERD and/or development of de novo GERD compared to LRYGB (OR 5.98, 95% CI 3.48 to 10.29; p ≤ 0.01; I2 = 0%) Moderate level of certainty). CONCLUSIONS:The development and worsening of GERD symptoms are frequently associated with LVSG compared to LRYGB at 5 years postoperatively requiring either initiation or increase of pharmacotherapy or failing that revisional bariatric surgery. Appropriate patient/surgical selection is crucial to reduce these postoperative risks of GERD.

Background: Laparoscopic vertical sleeve gastrectomy (LVSG) is now the most commonly performed bariatric procedure; however, it remains to be elucidated if it delivers equivalent long-term comorbid disease resolution outcomes similar to the longer established laparoscopic Roux-en-Y gastric bypass (LRYGB). We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to investigate the comparative 5-year outcomes of both procedures. Methods: Electronic databases (Pubmed, EMBASE, CINAHL) were searched for RCTs conducted in adults (>18y) that compared the 5-year- outcomes of LVSG to LRYGB and described comorbidity outcomes were included. Where data allowed, effect sizes were calculated using the Hartung-Knapp-Sidik-Jonkman estimation method for random effects model. Presence of bias was assessed with Cochrane Risk of Bias 2.0 and funnel plots, and certainty of evidence evaluated by GRADE. The study prospectively registered with PROSPERO (CRD42018112054). Results: Three RCTs (LVSG=254, LRYGB=255) met inclusion criteria and reported on chronic disease outcomes. Improvement and/or resolution of hypertension favoured LRYGB (odds ratio 0.49, 95% CI 0.29, 0.84; P =0.03). Trends favoring LRYGB were seen for type 2 diabetes and dysplidemia, and LVSG for sleep apnea and back/joint conditions ( P >0.05). The certainty of evidence associated with each assessed outcome ranged from low to very low, in the setting of ‘some’ to ‘high’ bias assessed as being present. Conclusion: Both LRYGB and LVSG are effective in providing long-term improvements in commonly experienced obesity-related comorbidities; however, the limited certainty of the evidence does not allow for strong clinical conclusions to be made at this time regarding benefit of one procedure over the other.

Background: There is a paucity of data that compares the relative complication profiles of laparoscopic vertical sleeve gastrectomy (LVSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) at 5 years. Objectives: The aim was to compare late complications of LVSG and LRYGB. Methods: We updated our previous systematic review and meta-analysis of randomized controlled trials of primary LVSG and LRYGB procedures in adults, to review late (5 years) complication outcomes (PROSPERO 112054). Electronic databases were searched from January 2015 to July 2021 for publications meeting inclusion criteria. The Hartung-Knapp-Sidik-Jonkman random effects model was utilized to estimate weighted mean differences where meta-analysis was possible. Bias and certainty of evidence was assessed using the Cochrane risk of bias tool and Grading of Recommendations, Assessment, Development and Evaluations. Results: Four randomized controlled trials met the inclusion criteria (n=531; LVSG=272, LRYGB=259). No late treatment-related mortality was reported with either procedure. A significant reduction in surgical reoperations (odds ratio: 0.47, 95% confidence interval: 0.27-0.82, P=0.01) and endoscopic interventions (odds ratio: 0.29, 95% confidence interval: 0.12-0.71, P=0.02) were reported at 5 years post-LVSG relative to LRYGB. Reoperations were more frequently performed for reflux management in LVSG and for internal hernia repairs in LRYGB. Complications requiring medical management were common following both procedures. Limitations included few eligible studies for inclusion, and varying definitions of medically managed complications. Conclusions: LRYGB is associated with a higher proportion of surgical and endoscopic interventions at 5 years compared with LVSG. More high-quality, long-term studies are required to further elucidate both surgical and nutritional long-term outcomes post these procedures.

Osland, Emma J. MPhil; Yunus, Rossita M. PhD; Khan, Shahjahan PhD; Memon, Muhammed A. FACS Author Information

In the era of evidence-based decision-making, systematic reviews (SRs) are being widely used in many health care policies, government programs, and academic disciplines. SRs are detailed and comprehensive literature review of a specific research topic with a view to identifying, appraising, and synthesizing the research findings from various relevant primary studies. A SR therefore extracts the relevant summary information from the selected studies without bias by strictly adhering to the review procedures and protocols. This paper presents all underlying concepts, stages, steps, and procedures in conducting and publishing SRs. Unlike the findings of narrative reviews, the synthesized results of any SRs are reproducible, not subjective and bias free. However, there are a number of issues related to SRs that directly impact on the quality of the end results. If the selected studies are of high quality, the criteria of the SRs are fully satisfied, and the results constitute the highest level of evidence. It is therefore essential that the end users of SRs are aware of the weaknesses and strengths of the underlying processes and techniques so that they could assess the results in the correct perspective within the context of the research question.

Beyond any doubts, the whole world is moving too fast to embrace the artificial intelligence and machine learning technologies to benefit from big data. Consequently, the use of unprecedented volume and intensity of data is becoming more and more an integral part of everyday life of modern science and citizens. The reality is that many of the next generation digital technologies will be data driven, internet dependent and satellite guided. Starting from driver-less vehicles to store-less shopping platforms and delivery of personalised services will be digitised based on data guided evidence. In fact, data revolution is already here, and we are increasingly being exposed to various technologies that are dependent on results from analysis and prediction of data. The role of statistics and computing algorithms in the process are crucial and it will continue to grow. The policymakers in government offices, health services, technology centres and business establishments are moving towards evidence-based decision-making which is predominantly guided by data synthesis and analytics. This paper covers various aspects of data including its dimensions and diversities, sources, owners and methods of analysis, and statistical and computational essence leading to the new paradigm of science, data.

Obesity is now considered to be a global endemic with its prevalence having nearly tripled worldwide between 1975 and 2016 (1). In 2016, over 1.9 billion adults aged 18 years and over (39% men and 10% women) were overweight (1). Of these >650 million adults, i.e., approximately 11% men and 15% women were obese (1). In 2010, overweight and obesity were estimated to cause 3.4 million deaths, 4% of years of life lost, and 4% of disability-adjusted life-years (DALYs) worldwide (2). Furthermore, raised body mass index (BMI) is a major risk factor for noncommunicable diseases such as cardiovascular disease (CVD) (particularly heart disease and stroke); diabetes; musculoskeletal disorders (mainly osteoarthritis); and numerous types of cancers (i.e., endometrial, cervical, breast, ovarian, prostate, liver, gallbladder, thyroid, kidney, colon and leukemia) (3). As obesity prevalence continues to increase, so too will the associated disease burden and health care costs, posing a crippling financial burden to any health care system. Utilization of bariatric surgical procedures have been proposed as cost effective and efficacious strategies to manage obesity-related chronic disease and metabolic conditions in moderately to severely obese people (4-7). For this focused issue on bariatric surgery, a number of bariatric physicians, surgeons, dieticians, psychologists and epidemiologists have come together to address the impact of various bariatric procedures, not just on short and long term weight loss, but in terms of longevity, quality of life, as well as the impact on various co-morbidities and cancers. However, as with all surgical procedures—especially those in a high-risk bariatric population—bariatric procedures are not undertaken without a degree of risk of complications that may lead to further burden on the health system and diminished postoperative quality of life. Dr. Caltabiano from Cairns, Australia undertook an online survey to assess obesity health-related quality of life and body image satisfaction in a group of individuals having undergone bariatric surgery. Her conclusions suggested that body image concerns were more important predictors for well-being post bariatric surgery than weight loss. It is therefore essential that the importance of body image assessment preand post-bariatric surgery should be addressed as a part of psychological assessment and support. Dr. El-Beheiry and colleagues from Manitoba, Canada undertook a survey of primary care physicians (PCPs) referral to assess their knowledge and perception of a provincial bariatric surgery program in Manitoba. The authors found knowledge deficit by the PCPs in discussing the role of bariatric surgery and therefore extremely small number of patients were referred for these lifesaving surgeries. They feel continuing medical education activities targeted to PCPs most likely will improve the knowledge deficit. Dr. Furbetta and colleagues from Pisa, Italy have provided us a detail history and impact of laparoscopic adjustable gastric banding (LAGB) on weight loss surgery. Although the LAGB has seen a relative decline in utilization compared to other procedures, it remains widely practiced by the surgical community because of its simplicity and reversibility, and has demonstrated a reasonable success rate over a prolong period of time and low complication sequalae. Furthermore, as it does not have any significant impact on the anatomy of the stomach, further resectional surgeries such as laparoscopic vertical sleeve gastrectomy (LVSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) can be undertaken if required at a later date. Drs. Khaitan and Shea from Ohio, USA have provided a review on the most popular and contemporary laparoscopic bariatric procedure, the LVSG. According to these authors, short term outcomes have certainly been promising in terms of weight loss and resolution of comorbid conditions. Long term outcomes are still evolving, but do demonstrate durable weight loss for a significant number of patients. There are certain concerns with the LVSG in the long term which includes the development or worsening of gastroesophageal reflux disease (GERD) and weight regain. Randomized controlled trials comparing LVSG and laparoscopic Roux-en-Y gastric bypass with five-year comparison data show equivalent results for both of these procedures with very low complication rates encouraging more surgeons to adopt LVSG as the procedure of choice because of its technical simplicity. Drs. Aly and Mori from Melbourne, Australia, have provided an illuminating review on the role LRYGB in the Super Obese (BMI >50 kg/m) with its technical challenges. According to these authors there remain many concerns regarding the safety and efficacy of LRYGB in these patients. They have therefore suggested two step approach such as LVSG as the first step followed by LRYGB to achieve a better success and mitigate the risk of complications with a more complicated procedure in this population of patients. Dr. Aleman and colleagues, from Florida, USA have examined the controversies surrounding a more recently introduced bariatric procedure, the one-anastomosis gastric bypass (OAGB). The authors believe that based on the available evidence, this technique poses a challenge to LRYGB in its establishment as a standard of care procedure. The anatomical configuration following surgery especially the afferent limb length, the metabolic implications of its hypo-absorptive nature, and lack of long-term data needs further scrutiny. Hence, prospective studies with long-term follow-up (>5 years) can bypass these concerns and allow the progression of the clinical practice of OAGB. Dr. Gollisch and Raddatz from Gottingen, Germany have tackled the topic of endoscopic intragastric balloon which is ideally utilized for overweight and moderately obese patient with a limited range of BMI (e.g., 27 to 37 kg/m). This 1

Bariatric surgery is increasingly being utilized to manage obesity and obesity related comorbidities, but may lead to the development of micronutrient deficiencies postoperatively. The anatomical, physiological, nutritional and behavioral reasons for micronutrient vulnerabilities are reviewed, along with recommendations for routine monitoring and replacement following surgery. The role the dietitian and their contribution in the postoperative identification, prevention and management of micronutrient vulnerabilities in bariatric patients is described. Specific considerations such as the nutritional and dietetic management of pregnant and lactating women post-bariatric surgery is also discussed.

Peptic ulcer disease (PUD), which affects 4 million people worldwide annually, has a perforation rate of between 2% to 14%. Perforated peptic ulcer (PPU) carries a substantial morbidity and mortality. Surgical repair remains the treatment of choice for a PPU. This literature review includes the latest updates in laparoscopic repair techniques for a PPU and also focuses on its causation, clinical features, diagnostic workup, laparoscopic and open surgical techniques, outcomes, and future perspectives. An extensive review of the literature was performed, and the most recent meta-analyses and reviews concerning the topic were considered. No substantial differences were found in postoperative mortality between the open and laparoscopic approaches for patients with a PPU. Furthermore, a laparoscopic repair lead to statistically significantly less postoperative pain and carried a lower risk of wound infection. Hence, a laparoscopic repair is justified, where situationally appropriate, as the treatment of choice.

This paper extends the work of Elal-Olivero (2010) on the alpha-skew normal (ASN) distribution. The extension is a multivariate version of Elal-Olivero’s univariate case. Then we study the statistical properties of the new extension such as marginal and conditional distribution, closure under convolution with normal random variate. Furthermore, we illustrate the performance of the distribution using simulated data obtained from the generalized distribution via the Metropolis-Hasting algorithm.

Background: To explore the perioperative outcomes, safety, and effectiveness of minimally invasive esophagectomy (MIE) versus open esophagectomy (OE). Materials and Methods: Randomized controlled comparing MIE versus OE were searched from PubMed and other electronic databases between January 1991 and March 2019. Thirteen outcome variables were analyzed. Random effects model was used to calculate the effect size. The meta-analysis was prepared in accordance with PRISMA guidelines. Results: Four randomized controlled trials totaling 569 patients were analyzed. For MIE, there was a significantly reduction of 67% in the odds of pulmonary complications. For operating time, MIE was nonsignificantly 29 minutes longer. MIE was associated with nonsignificantly less blood loss of 443.98 mL. There was nonsignificant 60% reduction in the odds of total complications and 51% reduction in the odds of medical complications favoring MIE group. For delayed gastric emptying, there was a nonsignificant reduction of 75% in the odds ratio favoring the MIE group. For postoperative anastomotic leak, there was a nonsignificant increase of 48% in the odds ratio for MIE group. For gastric necrosis, chylothorax, reintervention and 30-day mortality, no difference was observed for both groups. There was a nonsignificant reduction in the length of hospital stay of 7.98 days and intensive care unit stay of 2.7 days favoring MIE. Conclusions: MIE seems to be superior to OE for only pulmonary complications. All the other perioperative variables were comparable however, the trend is favoring the MIE. Therefore, the routine use of MIE presently may only be justifiable in high volume esophagogastric units.

With the rapidly increasing prevalence of obesity globally, the practice of bariatric surgery is being adopted routinely to prevent the development of chronic conditions as well as some forms of cancers associated with obesity. Gastroesophageal reflux disease (GERD) is one of those chronic conditions. Furthermore, there is accumulating data that obesity is associated with complications related to longstanding GERD such as erosive esophagitis (EE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC). Central obesity, rather than body mass index (BMI), appears to be more closely associated with these complications. It should be expected, therefore, that weight loss procedures should result in improvement in GERD symptoms and its associated complications. However, in reality the different bariatric surgical procedures have unpredictable effects on an established GERD and may even produce GERD symptoms for the very first time (de novo). In this review, we explore the literature studying the effects of bariatric surgical operations on GERD. Roux-en-Y gastric bypass appears to have the most beneficial effect on GERD. On the other hand, laparoscopic sleeve gastrectomy and laparoscopic adjustable gastric banding (LAGB) are linked with long-term increased prevalence of GERD. We argue that GERD is an extremely important preoperative consideration for any patient undergoing bariatric surgery and therefore should be thoroughly investigated objectively (with 24-hour pH study and high-resolution manometry) to select the most suitable bariatric procedure for patients for their long-term success.

This issue focuses on laparoendoscopic surgery for benign esophagogastric conditions. What could be more timely?