Higher Edmonton Obesity Staging System scores are independently associated with postoperative complications and mortality following bariatric surgery: an analysis of the MBSAQIP

Phenotyping of Obesity Treatment Candidates: A Narrative Review

PURPOSE OF REVIEW

This review explores characterizing candidates for obesity treatments including pharmacotherapy, endoscopic bariatric therapies, and metabolic bariatric surgery (MBS), focusing on established clinical parameters for diagnosing obesity beyond body mass index alone.

RECENT FINDINGS

Existing literature primarily provides rates for fat mass percentage (i.e., a marker for adiposity quantity), waist circumference (i.e., a marker for adiposity distribution), and C-reactive protein levels (i.e., a marker for adiposity functionality) among obesity treatment candidates. Limited data on abnormal values and sex-based differentiation exist. The literature indicates high central-tendency measures for fat mass percentage and waist circumference, while C-reactive protein levels vary. Data on the Edmonton Obesity Staging System (i.e., a marker for adiposity-related disease severity) is predominantly available for MBS candidates. Future studies in obesity interventions should improve screening and diagnosis of obesity by incorporating sex-specific considerations and providing abnormal value rates for measurements to enhance understanding of patients' characteristics.

Changes in use and hospital outcomes of bariatric surgery in Spain (2016-2022): analysis of the role of type 2 diabetes using propensity score matching

INTRODUCTION

The objectives of this study were to examine temporal trends in the incidence of bariatric surgery (Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG)) in patients with and without type 2 diabetes mellitus (T2DM). Outcomes of hospitalization and the impact of T2DM on these outcomes were also analyzed.

RESEARCH DESIGN AND METHODS

We performed an observational study with the Spanish national hospital discharge database. Obese patients with and without T2DM who underwent RYGB and SG between 2016 and 2022 were identified. Propensity score matching (PSM) and logistic regression were used to compare patients with and without T2DM and to evaluate the effect of T2DM and other variables on outcomes of surgery. A variable "severity" was created to cover patients who died in hospital or were admitted to the intensive care unit (ICU).

RESULTS

A total of 32,176 bariatric surgery interventions were performed (28.86% with T2DM). 31.57% of RYGBs and 25.53% of SG patients had T2DM. The incidence of RYGB and SG increased significantly between 2016 and 2022 (p<0.001), with a higher incidence in those with T2DM than in those without (incidence rate ratio 4.07 (95% CI 3.95 to 4.20) for RYGB and 3.02 (95% CI 2.92 to 3.14) for SG). In patients who underwent SG, admission to the ICU and severity were significantly more frequent in patients with T2DM than in those without (both p<0.001). In the multivariate analysis, having T2DM was associated with more frequent severity in those who received SG (OR 1.23; 95% CI 1.07 to 1.42).

CONCLUSIONS

Between 2016 and 2022, bariatric surgery procedures performed in Spain increased in patients with and without T2DM. More interventions were performed on patients with T2DM than on patients without T2DM. RYGB was the most common procedure in patients with T2DM. The presence of T2DM was associated with more severity after SG.

Revisional bariatric surgery for gastroesophageal reflux disease: characterizing patient and procedural factors and 30-day outcomes for a retrospective cohort of 4412 patients

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a well-established potential consequence of bariatric surgery and can require revisional surgery. Our understanding of the population requiring revision is limited. In this study, we aim to characterize patients requiring revisional surgery for GERD to understand their perioperative risks and identify strategies to improve their outcomes.

METHODS

Using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) registry, a retrospective cohort of patients who required revisional surgery for GERD in 2020 was identified. Multivariable logistic regression modelling was used to assess correlations between baseline characteristics and morbidity.

RESULTS

4412 patients required revisional surgery for GERD, encompassing 24% of all conversion procedures. In most cases, patients underwent sleeve gastrectomy (SG) as their original surgery (n = 3535, 80.1%). The revisional surgery for most patients was a Roux-en-Y gastric bypass (RYGB) (n = 3722, 84.4%). Major complications occurred in 527 patients (11.9%) and 10 patients (0.23%) died within 30 days of revisional surgery. Major complications included anastomotic leak in 31 patients (0.70%) and gastrointestinal bleeding in 38 patients (0.86%). Multivariable analyses revealed that operative length, pre-operative antacid use, and RYGB were predictors of major complications.

CONCLUSION

GERD is the second most common indication for revisional surgery in patients who have undergone bariatric surgery. Patients who underwent SG as their initial procedure were the primary group who required revisional surgery for GERD; most underwent revision via RYGB. Further inquiry is needed to tailor operative approaches and pre-operative optimization for revisional surgery patients.

Development of the national bariatric prioritization tool in Aotearoa New Zealand

BACKGROUND

Bariatric surgery is a proven effective method of reducing obesity and reversing or preventing obesity-related comorbidities. The aim of this study is to describe the development of a tool to assist with the prioritization of patients with obesity for bariatric surgery. The tool would meet the criteria for being evidence-based, fair, implementable and transparent.

METHODS

The development of the tool involved a validated step-by-step process based on the consensus of clinical judgement of the New Zealand Ministry of Health working party. The process involved elicitation of criteria, clinical ranking of vignettes and creation of weightings using the 1000Minds® tool. The concurrent validity was tested by comparing tool rankings of vignettes to clinical judgement rankings.

RESULTS

Four major criteria (impact on life, likelihood of achieving maximum benefit with respect to control of diabetes, duration of benefit and surgical risk) are used to characterize the need and potential to benefit. The impact on life criterion has the largest weighting (up to 44.3%). There was good concurrent validity with a correlation coefficient r = 0.67.

CONCLUSION

The tool as presented is evidence-based, transparent and internally valid. The next step is to assess the predictive validity of the tool using real patient data to evaluate the effectiveness of the tool and determine what modifications may be required.

Does the National Bariatric Prioritization Tool predict health outcomes?

BACKGROUND

The National Bariatric Prioritization Tool (NBPT), developed in Aotearoa New Zealand (AoNZ), has not been validated using real patient data. The aim was to determine the predictive validity of the NBPT on health outcomes.

METHODS

An observational study was undertaken of consecutive patients undergoing elective bariatric surgery at Middlemore Hospital using the NBPT from December 2014 to December 2016. The primary outcome was the correlation between prioritization score and percentage total weight loss (%TWL) at 18 months follow-up, with secondary outcomes being correlation with change in HbA1c, lipids, resolution of OSA, resolution of hypertension, and reduction in arthritis medications. Equity of access was measured by the relationship to age group, gender and ethnicity.

RESULTS

There were 294 patients included. There was no correlation between %TWL and prioritization score (correlation -0.09, P = 0.14). The benefit score correlated with %TWL (correlation 0.25, P < 0.0001). There were correlations between prioritization score and HbA1c reduction (correlation 0.28, P < 0.0001), resolution of OSA (correlation 0.20, P < 0.001) and resolution of hypertension (correlation 0.20, P < 0.001). There was a significant difference in prioritization score based on ethnicity, with Māori and Pasifika scoring higher than New Zealand European (P = 0.0023).

CONCLUSIONS

While the NBPT does not correlate with %TWL, it may have predictive validity through correlations with improvement of comorbidities such as diabetes, OSA and hypertension. Given higher rates of obesity and comorbidities in Māori and Pasifika, the higher scores may suggest the tool may be used to achieve equity of access. Further modifications should be considered to optimize outcomes.

Does ASA classification effectively risk stratify patients undergoing bariatric surgery: a MBSAQIP retrospective cohort of 138,612 of patients

INTRODUCTION

It is important to appropriately risk stratify bariatric surgery patients, as these patients often have obesity-related comorbidities which can increase postoperative complication risk but also benefit the most from bariatric surgery. We aimed to evaluate the utility of risk stratification using ASA class for bariatric surgery patients and assessed predictive factors of postoperative complications.

METHODS

The 2020 MBSAQIP database was analyzed, and an ASA-deemed high-risk cohort (class IV) and normal-risk (ASA class II and III) cohort were compared. Univariate analysis was performed to characterize differences between cohorts and to compare complication rates. Multivariate logistic regression analysis was performed to determine factors associated with increased odds of postoperative complications.

RESULTS

We evaluated 138 612 patients with 5380 (3.9%) considered high-risk and 133 232 (96.1%) normal-risk. High-risk patients were more likely to be older (46.2 ± 12.0vs.43.4 ± 11.9, p < 0.001), male (30.9%vs.18.4%, p < 0.001), have higher BMI (51.4 ± 10.2vs.44.9 ± 7.4, p < 0.001), and have more comorbidities. High-risk patients were more likely to have increased 30-day serious complications (4.5%vs.2.8%, p < 0.001) and death (0.2%vs.0.1%, p = 0.001) but not anastomotic leak (0.2%vs.0.2%, p = 0.983). Multivariate models showed ASA class IV patients were at higher odds for any serious complication by 30 days (aOR 1.36, 95%CI 1.18-1.56, p < 0.001) but not for death (aOR 1.04, 95%CI 0.49-2.21, p = 0.921). The factor independently associated with the highest odds of complication in both models was functional status preoperatively (partially dependent aOR 2.06, 95%CI 1.56-2.72, p < 0.001; fully dependent aOR 3.19, 95%CI 1.10-9.28, p = 0.033 for any serious complication; partially dependent aOR 5.08, 95%CI 2.16-12.00, p < 0.001 for death).

CONCLUSIONS

While elevated ASA class correlates with increased serious complications, pre-operative functional status appears to have a much greater contribution to odds of serious complications and mortality. These findings question the utility of using ASA to risk stratify patients peri-operatively and provides evidence for using a simpler and more practical functional status approach.

Preoperative preparation and premedication of bariatric surgical patient

The prevalence of obesity has tripled worldwide over the past four decades. The United States has the highest rates of obesity, with 88% of the population being overweight and 36% obese. The UK has the sixth highest prevalence of obesity. The problem of obesity is not isolated to the developed world and has increasingly become an issue in the developing world as well. Obesity carries an increased risk of many serious diseases and health conditions, including type 2 diabetes, heart disease, stroke, sleep apnea, and certain cancers. Our ability to take care of this population safely throughout the perioperative period begins with a thorough and in-depth preoperative assessment and meticulous preparation. The preoperative assessment begins with being able to identify patients who suffer from obesity by using diagnostic criteria and, furthermore, being able to identify patients whose obesity is causing pathologic and physiologic changes. A detailed and thorough anesthesia assessment should be performed, and the anesthesia plan individualized and tailored to the specific patient's risk factors and comorbidities. The important components of the preoperative anesthesia assessment and patient preparation in the patient suffering from obesity include history and physical examination, airway assessment, medical comorbidities evaluation, functional status determination, risk assessment, preoperative testing, current weight loss medication, and review of any prior weight loss surgeries and their implications on the upcoming anesthetic. The preoperative evaluation of this population should occur with sufficient time before the planned operation to allow for modifications of the preoperative management without needing to delay surgery as the perioperative management of patients suffering from obesity presents significant practical and organizational challenges.