Three-year weight outcomes from a bariatric surgery registry in a large integrated healthcare system

RESULTS OF MECHANIC VERSUS MOTORIZED STAPLER USED IN GASTRIC SURGERY: PROSPECTIVE STUDY

BACKGROUND

Mechanic sutures represent an enormous benefit for digestive surgery in decreasing postoperative complications. Currently, the advantages of motorized stapler are under evaluation.

AIMS

To compare the efficacy of mechanic versus motorized stapler in gastric surgery, analyzing rate of leaks, bleeding, time of stapling, and postoperative complications.

METHODS

Ninety-eight patients were submitted to gastric surgery, divided into three groups: laparoscopic sleeve gastrectomy (LSG) (n=47), Roux-en-Y gastric bypass (LRYGB) (n=30), and laparoscopic distal gastrectomy (LDG) (n=21). Motorized staplers were employed in 61 patients. The number of firings, number of clips, time of total firings, total time to complete the surgery, and postoperative outcome were recorded in a specific protocol.

RESULTS

Patients submitted to LSG, LRYGB, and LDG recorded a shorter time to complete the procedure and a smaller number of firings were observed using motorized stapler (p<0.0001). No differences were identified regarding the number of clips used in patients submitted to LSG. In the group that used mechanic stapler to complete gastrojejunostomy, jejuno-jejuno-anastomosis, and jejunal transection, it was observed more prolonged time of firing and total time for finishing the procedure (p=0.0001). No intraoperative complications were found comparing the two devices used. Very similar findings were noted in the group of patients undergoing LDG.

CONCLUSIONS

The motorized stapler offers safety and efficacy as demonstrated in prior reports and is relevant since less total time of surgical procedure without intraoperative or postoperative complications were confirmed.

Sex- and operation-dependent effects on 5-year weight loss results of bariatric surgery

BACKGROUND

Weight loss response after bariatric surgery is highly variable, and several demographic factors are associated with differential responses to surgery. Preclinical studies demonstrate numerous sex-specific responses to bariatric surgery, but whether these responses are also operation dependent is unknown.

OBJECTIVE

To examine sex-specific weight loss outcomes up to 5 years after laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

SETTING

Single center, university, United States.

METHODS

Retrospective, observational cohort study including RYGB (n = 5057) and vertical SG (n = 2041) patients from a single, academic health center. Percentage total weight loss (TWL) over time was examined with generalized linear mixed models to determine the main and interaction effects of surgery type on weight loss by sex.

RESULTS

TWL demonstrated a strong sex-by-procedure interaction, with women having a significant advantage with RYGB compared with SG (adjusted difference at 5 yr: 8.0% [95% CI: 7.5-8.5]; P < .001). Men also experienced greater TWL over time with RYGB or SG, but the difference was less and clinically insignificant (adjusted difference at 5 yr: 2.9% [2.0-3.8]; P < .001; P interaction between sex and procedure type = .0001). Overall, women had greater TWL than men, and RYGB patients had greater TWL than SG patients (adjusted difference at 5 yr: 3.1% [2.4-3.2] and 6.9% [6.5-7.3], respectively; both P < .0001). Patients with diabetes lost less weight compared with those without (adjusted difference at 5 yr: 3.0% [2.7-3.2]; P < .0001).

CONCLUSIONS

Weight loss after bariatric surgery is sex- and procedure-dependent. There is an association suggesting a clinically insignificant difference in weight loss between RYGB and SG among male patients at both the 2- and 5-year postsurgery time points.

Prediction Model for Chronological Weight Loss After Bariatric Surgery in Korean Patients

Purpose

This study aimed to develop a predictive model for monitoring chronological weight loss during the early postoperative period following bariatric surgery in Korean patients with morbid obesity.

Materials and Methods

The baseline characteristics and postoperative weight loss outcomes were collected for up to 24 months after surgery in patients who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). The factors influencing weight loss outcomes were analyzed, and longitudinal percentile charts were plotted using quantile regression models adjusted for the identified independent factors.

Results

The analysis included 491 and 274 patients who underwent SG and RYGB, respectively, of whom 225 (29.4%) were men. A positive association was found between the maximum percentage of total weight loss (%TWL) and female sex, body mass index (BMI) ≥40, and age <40 years. Among patients who reached nadir BMI or had at least 12 months of follow-up data (n=304), 7.6% exhibited inadequate weight loss (TWL <20%). The predictors of insufficient weight loss were older age (>40 years), male sex, and psychological problems. Centile charts were generated for the entire cohort, incorporating age, sex, and the type of procedure as covariates.

Conclusion

The percentile charts proposed in the present study can assist surgeons and healthcare providers in gauging patients' progress toward their weight loss goals and determining the timing of adjunctive intervention in poor responders during early postoperative follow-up.

Socio-Demographic and Preoperative Clinical Factors Associated With 5-Year Weight Trajectories After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

Objective

To determine whether socio-demographic and preoperative clinical factors contribute to the percent total body weight loss (%TBWL) after bariatric surgery (BS).

Background

BS is the most effective long-term treatment for medically complicated obesity. More information is needed about the factors that contribute to postoperative %TBWL in large and ethnically diverse cohorts.

Methods

This retrospective study conducted in the Kaiser Permanente Northern California region included 7698 patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between January 2009 and March 2015. Trajectory analyses were conducted from 5-year follow-up data to assign patients to "low," "average," or "high" postoperative %TBWL groups. We then evaluated whether age, sex, race/ethnicity, neighborhood deprivation index and preoperative body mass index (BMI)/weight loss, diabetes, hypertension, and sleep apnea contributed to postoperative %TBWL using logistic regression models.

Results

Of 7698 patients (83.2% women), 48.6% underwent a RYGB and 51.4% underwent a SG. Postoperative %TBWL trajectories over 5 years were obtained in 6229 (81%) of 7698 eligible patients. About 27.8% and 29.3% of patients followed the "low" postoperative %TBWL trajectory, for RYGB and SG, respectively. Men, older patients, and Asian, Black, and Hispanic/Latino patients were more likely to be classified in the low postoperative %TBWL group. Patients showing lower postoperative %TBWL had a lower preoperative BMI (but lost less weight before surgery) and were more likely to have preoperative comorbidities.

Conclusions

This study confirms and extends prior findings of the effects of several demographic and preoperative clinical factors on postoperative weight loss. Findings could improve the support of patients to achieve desired surgical outcomes.

Racial differences after bariatric surgery: 24-month follow-up of a randomized, controlled trial for postoperative loss-of-control eating

BACKGROUND

While some bariatric surgery outcomes vary by race/ethnicity, less is known about racial/ethnic differences in loss-of-control (LOC) eating and psychosocial outcomes post-surgery.

OBJECTIVE

This prospective study examined and extended initial short-term findings regarding racial differences in post-bariatric surgery LOC eating and weight loss to longer-term outcomes through 24-month follow-ups.

SETTING

Academic medical center in the United States.

METHODS

Participants were 140 patients (46.4% non-White) in a 3-month randomized, controlled trial for LOC eating performed about 6 months after bariatric surgery. Participants were reassessed at 6, 12, 18, and 24 months after treatment ended (about 33 mo after surgery). Doctoral assessors administered the Eating Disorder Examination-Bariatric Surgery Version interview to assess LOC eating and eating-disorder psychopathology at 12- and 24-month follow-ups. The Beck Depression Inventory II was repeated, and measured weight was obtained at all follow-ups.

RESULTS

White patients had significantly greater percent excess weight loss at all follow-ups than non-White patients (p < .03). White patients reported significantly more LOC eating at 12- (p = .004) and 24-month (p = .024) follow-ups and significantly greater eating disorder psychopathology at 12-month follow-up (p < .028). Racial groups did not differ significantly in eating disorder psychopathology at 24-month follow-ups or in Beck Depression Inventory II depression scores at any follow-ups.

CONCLUSIONS

Our findings suggest that among patients with LOC eating after bariatric surgery, non-White patients attain a lower percent excess weight loss than White patients but have comparable or better outcomes in LOC eating, associated eating disorder psychopathology, and depression over time.

Weight Reduction Percentile Charts: 2-Year Follow-up Results of OAGB and RYGB Post Bariatric Surgery

PURPOSE

Using a single percentile chart provides us with high standards for the evaluation and accurate investigation of sufficient weight loss after bariatric surgery, counseling, and treating patients in an evidence-based way. Creating percentile charts of weight loss for gastric bypass is the aim of this study.

MATERIALS AND METHODS

This retrospective study was based on data from patients who underwent RYGB or OAGB from February 2008 to February 2020. The lambda-mu-sigma (LMS) method was used to estimate the reduction in body mass index (BMI) and six other metrics measured throughout post-operative follow-up. Percentile charts for various metrics have been presented for the first 2 years' post-surgery. We applied a bootstrap sampling method to evaluate percentile validity.

RESULTS

We recruited 2579 and 1943 patients who underwent OAGB (75% female) and RYGB (84% female) and were between the ages of 18 and 70 years. The preoperative BMI of patients in the OAGB group was higher than in the RYGB group. Concerning RYGB weight reduction results, the maximum percentage of excess weight loss (%EWL) occurs 18 months after surgery and is steady at 24 months. Far above 50%, EWL is achieved after 6 months. OAGB weight loss follows the same trend as RYGB; at 6 months, the %EWL values are slightly higher than RYGB.

CONCLUSIONS

We present the first bariatric weight loss percentile chart for OAGB. It allows evaluation of sufficient and insufficient weight loss at any post-operative point in a visual aspect. Furthermore, it predicts prospective outcomes and guides patient monitoring.

Breaking down silos: the multifaceted nature of obesity and the future of weight management

The continued global increase in the prevalence of obesity prompted a meeting at the Royal Society of London investigating causal mechanisms of the disease, 'Causes of obesity: theories, conjectures, and evidence' in October 2022. Evidence presented indicates areas of obesity science where there have been advancements, including an increased understanding of biological and physiological processes of weight gain and maintenance, yet it is clear there is still debate on the relative contribution of plausible causes of the modern obesity epidemic. Consensus was reached that obesity is not a reflection of diminished willpower, but rather the confluence of multiple, complex factors. As such, addressing obesity requires multifactorial prevention and treatment strategies. The accumulated evidence suggests that a continued focus primarily on individual-level contributors will be suboptimal in promoting weight management at the population level. Here, we consider individual biological and physiological processes within the broader context of sociodemographic and sociocultural exposures as well as environmental changes to optimize research priorities and public health efforts. This requires a consideration of a systems-level approach that efficiently addresses both systemic and group-specific environmental determinants, including psychosocial factors, that often serve as a barrier to otherwise efficacious prevention and treatment options. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Altered Estrous Cyclicity and Feeding Neurocircuitry, but Not Cardiovascular Indices in Female Offspring from Dams with Previous Vertical Sleeve Gastrectomy Surgery

Metabolic syndrome (MetS), which includes obesity, diabetes, hypertension, hyperlipidemia, and fatty-liver disease, affects more than two-thirds of the U.S. population. Surgical weight loss has been popularized in the last several decades as a means to produce significant weight loss and improvements in the comorbidities of MetS. Women are by far the most common recipients of these surgeries (more than 85%). Women of childbearing age are very likely to pursue surgical weight loss to improve their reproductive function and fertility for childbearing purposes. Significant research using pre-clinical models from our laboratory and clinical data from around the world suggest that surgical weight loss before pregnancy may have negative consequences for offspring. The present study investigates the metabolic endpoints in female-rodent offspring born to dams who had previously received vertical sleeve gastrectomy (VSG) before pregnancy. Comparisons were made to offspring from lean and obese dams. In the adult offspring of either maternal VSG or sham surgery, no differences in body weight, body fat, or lean body mass between groups were identified. The blood pressure measured in a subset of female offspring showed no differences between the VSG and the sham groups. Estrus cyclicity measured by lavage on serial days showed altered cycles in the VSG offspring compared to the controls. For animals that had previously only been exposed to chow, rats were fasted overnight and then given a 1 g meal of either chow or a novel high-fat diet (HFD). The animals were euthanized and paraformaldehyde (PFA)-perfused to perform brain immunohistochemistry for c-Fos, an immediate-early gene activated by novel stimuli. In the VSG rats exposed to either the chow or the HFD meal, the c-Fos-activated cells were significantly blunted in the nucleus of the solitary tract (p < 0.05), the paraventricular nucleus of the hypothalamus (PVN) (p < 0.05), and the dorsal medial nucleus of the hypothalamus (DMH) (p < 0.05) in comparison to the sham controls. These data suggest that the hypothalamic wiring within the brain that controls the response to nutrients and reproductive function was significantly altered in the VSG offspring compared to the offspring of the dams that did not receive weight-loss surgery.

Preoperative and early adjuvant weight loss medications in bariatric surgery patients with body mass index over 60 or suboptimal initial response to surgery

BACKGROUND

Few studies have examined the adjuvant use of antiobesity medications with surgery, especially in the pre- and early postoperative periods.

OBJECTIVE

Evaluate the impact of adjuvant pharmacotherapy on bariatric surgery outcomes.

SETTING

University hospital, United States.

METHODS

A retrospective chart review of patients receiving adjuvant pharmacotherapy for obesity treatment and bariatric surgery. Patients received pharmacotherapy either preoperatively if their body mass index was >60, or in the first or second postoperative years for suboptimal weight loss. Outcome measures included percentage of total body weight loss as well as comparison with the expected weight loss curve as determined by the Metabolic and Bariatric Surgery Risk/Benefit Calculator.

RESULTS

A total of 98 patients were included in the study, with 93 (94.9%) undergoing sleeve gastrectomy and 5 (5.1%) undergoing Roux-en-Y gastric bypass surgery. During the study period, patients were prescribed phentermine and/or topiramate. At postoperative year 1, patients who received pharmacotherapy preoperatively lost 31.3% of their total body weight (TBW) compared with 25.3% TBW for patients with suboptimal weight loss who received medication in the first postoperative year, and 20.8% TBW for patients who did not receive any antiobesity medication in the first postoperative year. Using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) curve for comparison, patients receiving medication preoperatively weighed 2.4% less than expected, whereas patients receiving medication during the first postoperative year weighed 4.8% higher than expected.

CONCLUSION

For patients having bariatric surgery who fall below the expected MBSAQIP weight loss curve, early initiation of antiobesity medications can improve the weight loss, with preoperative pharmacotherapy having the greatest effect.

Neighborhood deprivation and residential property values do not affect weight loss at 1 or 3 years after bariatric surgery

OBJECTIVE

This study examined the association between individual- and neighborhood-level sociodemographic factors and surgical weight loss at 1 year (short term) and 3 years (long term).

METHODS

Data were obtained from the baseline survey of the BELONG (Bariatric Experience Long Term) prospective longitudinal cohort study. Individual-level self-reported data on sex, race and ethnicity, education, and household income were obtained by survey. Data from the 2010 US Census were used to calculate area Neighborhood Deprivation Index score and median value of owner-occupied housing units at the census tract level.

RESULTS

Patients (N = 1341) had a mean age of 43.4 (SD 11.3) years, were mostly female (86%), were mostly Black or Hispanic (52%), had some college education (83%), and had annual household incomes ≥$51,000 (55%). Percentage total weight loss was 25.8% (SD 9.0%) at year 1 and 22.2% (SD 10.5%) at year 3. Race and ethnicity and age were significant predictors of weight loss at 1 and 3 years with a small effect of self-reported household income at year 1. There were no significant associations between census tract-level Neighborhood Deprivation Index score or value of owner-occupied housing units and weight loss at either time point.

CONCLUSIONS

Health systems could improve the chances of weight-loss maintenance after surgery by addressing factors related to racial and ethnic disparities and to income disparities.

Pharmaco-endoscopic therapy for weight regain post-gastric bypass: a case report

About 1 in every 4 patients who undergo bariatric surgery regains significant amount of weight some time along their journey, posing it as a serious problem that needs to be addressed in a pandemic of obesity. Lifestyle modification, anti-obesity medications, and bariatric endoscopy are multiple therapeutic options that can be used to support any weight loss attempt. A 53-year-old woman with morbid obesity who responded adequately to gastric-bypass regained significant weight 8 years later. We initially approached her post-operative weight regain in a behavioral, pharmacologic non-invasive manner; however, she failed to appropriately respond to several anti-obesity medications. Upper endoscopy revealed a dilated gastric pouch and gastro-jejunal anastomosis (GJA) that was reduced using argon plasma coagulation (APC), but also with a modest response. We then added liraglutide to her APC endo-therapy sessions and subsequentially patient started losing significantly more weight. For selective post-bariatric surgery weight re-gainers, endoscopic and pharmaco-therapy combined may be needed for more effective results.

Bariatric Surgery in Kidney Transplant Candidates and Recipients: Experience at an Asian Center

Background

Kidney transplant (KT) candidates and recipients with obesity experience more frequent complications such as infection, poorer allograft outcomes, diabetes, and mortality, limiting their eligibility for transplantation. Bariatric surgery (BS) is not commonly performed among KT patients given concerns about immunosuppression absorption, wound healing, infections, and graft outcomes. Its role has not been described before in an Asian KT patient setting.

Methods

A retrospective review of patients who underwent BS at the largest KT center in Singapore from 2008 to 2020 was conducted. Metabolic outcomes, immunosuppression doses, graft outcomes, and mortality were studied.

Results

Seven patients underwent BS and KT (4 underwent BS before KT, 3 underwent BS after KT; 4 underwent sleeve gastrectomy, 3 underwent gastric bypass). Mean total weight losses of 23.8% at 1 year and 18.6% at 5 years post-BS were achieved. Among the five patients with diabetes, glycemic control improved after BS. There were no deaths in the first 90 days or graft loss in the first year after KT and BS. Patients who underwent BS after KT had no significant changes in immunosuppression dose.

Conclusion

BS can be safely performed in KT recipients and candidates and results in sustainable weight losses and improvements in metabolic comorbidities. Although no major complications were observed in our study, close monitoring of this complex group of patients is imperative.

Bariatric Surgery and Risk of Death in Persons With Chronic Kidney Disease

OBJECTIVE

A retrospective cohort study investigated the association between having surgery and risk of mortality for up to 5 years and if this association was modified by incident ESRD during the follow-up period. Summary of Background Data: Mortality risk in individuals with pre-dialysis CKD is high and few effective treatment options are available. Whether bariatric surgery can improve survival in people with CKD is unclear.

METHODS

Patients with class II and III obesity and pre-dialysis CKD stages 3-5 who underwent bariatric surgery between January 1, 2006 and September 30, 2015 (n = 802) were matched to patients who did not have surgery (n = 4933). Mortality was obtained from state death records and ESRD was identified through state-based or healthcare system-based registries. Cox regression models were used to investigate the association between bariatric surgery and risk of mortality and if this was moderated by incident ESRD during the follow-up period.

RESULTS

Patients were primarily women (79%), non-Hispanic White (72%), under 65 years old (64%), who had a body mass index > 40kg/m 2 (59%), diabetes (67%), and hypertension (89%). After adjusting for incident ESRD, bariatric surgery was associated with a 79% lower 5-year risk of mortality compared to matched controls (hazard ratio = 0.21; 95% confidence interval: 0.14-0.32; P < 0.001). Incident ESRD did not moderate the observed association between surgery and mortality (hazard ratio = 1.59; 95% confidence interval: 0.31-8.23; P =0.58).

CONCLUSIONS

Bariatric surgery is associated with a reduction in mortality in pre-dialysis patients regardless of developing ESRD. These findings are significant because patients with CKD are at relatively high risk for death with few efficacious interventions available to improve survival.

Evaluating the Bariatric Safety Net: Analysis of Socioeconomic Factors and Outcomes at a Bariatric Safety Net Program Compared to an Affiliated Private Center

PURPOSE

Obesity is prevalent among economically disadvantaged and racially underrepresented populations. It has been suggested that socioeconomic factors, race, and lifestyle habits are important factors associated with weight loss and comorbidity remission after bariatric surgery. This study analyzes outcomes of bariatric surgery at a private hospital (PH) versus an affiliated safety-net hospital (SNH).

METHODS

Retrospective review of laparoscopic sleeve gastrectomies (LSG) performed by the same surgeons at a PH and SNH in a large metropolitan setting. Demographics, socioeconomic status, insurance status, weight metrics, and perioperative outcomes were compared. A postoperative telephone survey was conducted to study dietary and lifestyle differences between cohorts.

RESULTS

Of the 243 LSG performed, 141 (58%) occurred at PH versus 102 (42%) at SNH. Most patients at SNH were Hispanic, lower socioeconomic status, and had government-sponsored insurance. Based off the results from the postoperative telephone survey, there were no significant differences in dietary and lifestyle habits between both cohorts. Postoperative weight loss outcomes were similar across cohorts. The two groups had similar percent excess weight loss (EWL) at all time points up to 36 months and similar rates of failure to achieve 50% EWL at 12 months. However, patients at PH had greater resolution of diabetes and hypertension after surgery.

CONCLUSION

Our study demonstrates outcomes after bariatric surgery are similar at a PH and its affiliated SNH. Despite differences in race and socioeconomic factors between the two cohorts, perioperative outcomes, short-term postoperative weight loss, and weight loss failure rates were equivalent between SNH and PH patients.

Comparative Safety and Effectiveness of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy for Weight Loss and Type 2 Diabetes Across Race and Ethnicity in the PCORnet Bariatric Study Cohort

Importance

Bariatric surgery is the most effective treatment for severe obesity; yet it is unclear whether the long-term safety and comparative effectiveness of these operations differ across racial and ethnic groups.

Objective

To compare outcomes of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) across racial and ethnic groups in the National Patient-Centered Clinical Research Network (PCORnet) Bariatric Study.

Design, Setting, and Participants

This was a retrospective, observational, comparative effectiveness cohort study that comprised 25 health care systems in the PCORnet Bariatric Study. Patients were adults and adolescents aged 12 to 79 years who underwent a primary (first nonrevisional) RYGB or SG operation between January 1, 2005, and September 30, 2015, at participating health systems. Patient race and ethnicity included Black, Hispanic, White, other, and unrecorded. Data were analyzed from July 1, 2021, to January 17, 2022.

Exposure

RYGB or SG.

Outcomes

Percentage total weight loss (%TWL); type 2 diabetes remission, relapse, and change in hemoglobin A1c (HbA1c) level; and postsurgical safety and utilization outcomes (operations, interventions, revisions/conversions, endoscopy, hospitalizations, mortality, 30-day major adverse events) at 1, 3, and 5 years after surgery.

Results

A total of 36 871 patients (mean [SE] age, 45.0 [11.7] years; 29 746 female patients [81%]) were included in the weight analysis. Patients identified with the following race and ethnic categories: 6891 Black (19%), 8756 Hispanic (24%), 19 645 White (53%), 826 other (2%), and 783 unrecorded (2%). Weight loss and mean reductions in HbA1c level were larger for RYGB than SG in all years for Black, Hispanic, and White patients (difference in 5-year weight loss: Black, -7.6%; 95% CI, -8.0 to -7.1; P < .001; Hispanic, -6.2%; 95% CI, -6.6 to -5.9; P < .001; White, -5.9%; 95% CI, -6.3 to -5.7; P < .001; difference in change in year 5 HbA1c level: Black, -0.29; 95% CI, -0.51 to -0.08; P = .009; Hispanic, -0.45; 95% CI, -0.61 to -0.29; P < .001; and White, -0.25; 95% CI, -0.40 to -0.11; P = .001.) The magnitude of these differences was small among racial and ethnic groups (1%-3% of %TWL). Black and Hispanic patients had higher risk of hospitalization when they had RYGB compared with SG (hazard ratio [HR], 1.45; 95% CI, 1.17-1.79; P = .001 and 1.48; 95% CI, 1.22-1.79; P < .001, respectively). Hispanic patients had greater risk of all-cause mortality (HR, 2.41; 95% CI, 1.24-4.70; P = .01) and higher odds of a 30-day major adverse event (odds ratio, 1.92; 95% CI, 1.38-2.68; P < .001) for RYGB compared with SG. There was no interaction between race and ethnicity and operation type for diabetes remission and relapse.

Conclusions and Relevance

Variability of the comparative effectiveness of operations for %TWL and HbA1c level across race and ethnicity was clinically small; however, differences in safety and utilization outcomes were clinically and statistically significant for Black and Hispanic patients who had RYGB compared with SG. These findings can inform shared decision-making regarding bariatric operation choice for different racial and ethnic groups of patients.

Adherence of Obese Patients from Poland and Germany and Its Impact on the Effectiveness of Morbid Obesity Treatment

This study aimed to investigate and compare the adherence of patients treated for morbid obesity living in Poland and Germany. Methods: A cross-sectional international multicenter survey design was adopted. The study involved 564 adult subjects treated for morbid obesity at selected healthcare facilities in Germany (210 participants) and Poland (354 participants). A validated, custom-made questionnaire based on the literature related to this issue was used. Results: The degree of adherence was higher, but not statistically significant, among Polish patients (83.82% vs. 78.33%, p = 0.26140). Patient adherence was associated with gender, age, level of education, duration of obesity, number of health professionals involved in obesity treatment, and type of obesity treatment (p < 0.05). A positive correlation was observed in the case of age, level of education, and a growing number of health professionals involved in obesity treatment, whereas a negative correlation was observed in the case of the duration of obesity. Patients who underwent bariatric surgery significantly more often followed medical recommendations regarding lifestyle changes, compared to obese participants treated only conservatively. Adherence in the field of obesity treatment significantly increases the percentage of total weight loss and excess weight loss due to applied obesity treatment among both Polish and German groups (p < 0.001). Both the percentage of total weight loss and that of excess weight loss were significantly higher in the group of adherent patients compared to the nonadherent patients (p < 0.00001). The levels of perceived anxiety, stress, and depression were significantly higher in nonadherent patients in both countries. Conclusions: These findings confirm the role of adherence in the effective and satisfactory treatment of morbid obesity. There is a great need to improve patient adherence to overcome the consequences of the obesity pandemic.

FOOD TOLERANCE AND NUTRITIONAL RISK AFTER SLEEVE GASTRECTOMY AND ROUX-EN-Y GASTRIC BYPASS IN ELDERLY PATIENTS WITH SEVERE OBESITY: A PROSPECTIVE, RANDOMIZED CONTROLLED TRIAL

BACKGROUND

Bariatric surgery is still controversial in elderly patients with severe obesity. Most publications focus on safety and early clinical outcomes. Food tolerance and nutritional postoperative risk is unknown for this population.

METHODS

Thirty-six elderly patients with severe obesity were recruited for an open-label randomized trial from September 2017 to May 2019 comparing laparoscopic sleeve gastrectomy (LSG) to Roux-en-Y Gastric Bypass (LRYGB). Food tolerance was accessed by Quality of Alimentation (QoA) questionnaire and data on weight loss, body composition, and nutritional risk were collected between 6 and 24 months after surgery.

RESULTS

Comparing LSG to LRYGB patients, the latter had higher total weight loss (22% vs 31%, P=0.01) and excess weight loss (53% vs 68%, P=0.01). Food tolerance to eight food groups was similar between groups (14 vs 15 points, P=0.270), as Suter score (23 vs 25, P=0.238). Daily protein intake was below recommendation in both groups (40 vs 51 g/d, P=0.105). Nutritional risk, evaluated through Standardized Phase Angle (-1.48 vs -1.99, P=0.027), was worse for LRYGB group.

CONCLUSION

Food tolerance and adequacy of food consumption were similar in both groups. LRYGB patients had higher nutritional risk.

Remission and Relapse of Hypertension After Bariatric Surgery: A Retrospective Study on Long-Term Outcomes

To compare hypertension remission and relapse after bariatric surgery compared with usual care.

Background

The effect of Roux-en-Y gastric bypass and sleeve gastrectomy on hypertension remission and relapse has not been studied in large, multicenter studies over long periods and using clinical blood pressure (BP) measurements.

Methods

This retrospective cohort study was set in Kaiser Permanente Washington, Northern California, and Southern California. Participants included 9432 patients with hypertension 21-65 years old who underwent bariatric surgery during 2005-2015 and 66,651 nonsurgical controls matched on an index date on study site, age, sex, race/ethnicity, body mass index, comorbidity burden, diabetes status, diastolic and systolic BP, and number of antihypertensive medications.

Results

At 5 years, the unadjusted cumulative incidence of hypertension remission was 60% (95% confidence interval [CI], 58-61%) among surgery patients and 14% (95% CI, 13-14%) among controls. At 1 year, the adjusted hazard ratio for the association of bariatric surgery with hypertension remission was 10.24 (95% CI, 9.61-10.90). At 5 years, the adjusted hazard ratio was 2.10 (95% CI, 1.57-2.80). Among those who remitted, the unadjusted cumulative incidence of relapse at 5 years after remission was 54% (95% CI, 51-56%) among surgery patients and 78% (95% CI 76-79%) among controls, although the adjusted hazard ratio was not significant (hazard ratio, 0.71; 95% CI, 0.46-1.08).

Conclusions

Bariatric surgery was associated with greater hypertension remission than usual care suggesting that bariatric surgery should be discussed with patients with severe obesity and hypertension. Surgical patients who experience remission should be monitored carefully for hypertension relapse.

Cohort profile: The Bariatric Experience Long Term (BELONG): a long-term prospective study to understand the psychosocial, environmental, health and behavioural predictors of weight loss and regain in patients who have bariatric surgery

PURPOSE

The Bariatric Experience Long Term (BELONG) prospective study cohort was created to address limitations in the literature regarding the relationship between surgical weight loss and psychosocial, health, behaviour and environmental factors. The BELONG cohort is unique because it contains 70% gastric sleeve and 64% patients with non-white race/ethnicity and was developed with strong stakeholder engagement including patients and providers.

PARTICIPANTS

The BELONG cohort study included 1975 patients preparing to have bariatric surgery who completed a baseline survey in a large integrated health system in Southern California. Patients were primarily women (84%), either black or Hispanic (59%), with a body mass index (BMI) of 45.1±7.4 kg/m², age 43.3±11.5 years old, and 32% had at least one comorbidity.

FINDINGS TO DATE

A total of 5552 patients were approached before surgery between February 2016 and May 2017, and 1975 (42%) completed a baseline survey. A total of 1203 (73%) patients completed the year 1 and 1033 (74%) patients completed the year 3 postoperative survey. Of these survey respondents, 1341 at baseline, 999 at year 1, and 951 at year 3 were included in the analyses of all survey and weight outcome data. A total of 803 (60% of eligible patients) had survey data for all time points. Data collected were self-reported constructs to support the proposed theoretical model. Height, weight and BMI were abstracted from the electronic medical record to obtain the main outcomes of the study: weight loss and regain.

FUTURE PLANS

We will collect self-reported constructs and obtain height, weight and BMI from the electronic medical record 5 years after bariatric surgery between April 2022 and January 2023. We will also collect patient experiences using focus groups of 8-12 patients each throughout 2022.

Changes in adipokine levels and metabolic profiles following bariatric surgery

BACKGROUND

Bariatric surgery is considered to be the most effective treatment option for weight reduction in obese patients. Abdominal obesity is frequently accompanied by metabolic syndrome (MS). Adipokines are cell signaling proteins that have direct impact upon the metabolic homeostasis. The purpose of this analysis was to evaluate the effect of bariatric surgery, including laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LRYGB) on the adipokine levels and metabolic profile as well as MS and status of type 2 diabetes (T2D).

METHODS

We analyzed anthropometric parameters, blood levels of adipokines, vitamins, lipids and inflammatory markers in 30 bariatric surgery patients with obesity of class II or III 1 month before and 1 year after surgery as well as in 60 obese patients from general practice (GP) and 15 patients with normal body mass (control).

RESULTS

The BMI was significantly higher among patients before surgery and GP patients in comparison to control and post-surgery patients. The levels of glucose, cholesterol and LDL-cholesterol, triglyceride and hs-CRP were the highest in patients before surgery but decreased significantly after surgery, while the level of HDL-cholesterol increased after surgery. The levels of adiponectin increased and that of leptin decreased after surgery. The significant difference in the concentration of resistin was revealed between LSG and LRYGB methods. The relationship between resistin and vitamin D was also found. The patients with MS and T2D displayed significantly greater reduction in lipid markers and adipokine levels than the rest of patients.

CONCLUSION

Remarkable changes in levels of adipokines after bariatric surgery appear like increase in adiponectin and decrease in leptin levels. Significant improvement in anthropometric parameters, metabolic and inflammatory markers occurs, suggesting high potential for reduction of metabolic syndrome and risk for type 2 diabetes. We have shown for the first time ever that level of vitamin D may be involved in resistin regulation.

Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy in Young Adults: a Dutch Registry Study

BACKGROUND

The most commonly performed bariatric procedures worldwide are Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), yet outcomes following these procedures in young adults are limited. Therefore, the objective of this study was to compare weight loss outcomes between RYGB and SG in young adults.

METHODS

This is a nationwide retrospective cohort study of young adults, aged 18-25 years, who underwent RYGB or SG between 2015 and 2019, with data from the Dutch Audit Treatment of Obesity (DATO). The primary outcome was weight loss expressed as percentage total weight loss (%TWL) in a period of 3 years after surgery. Secondary outcomes were the incidence of complications (< 30 days) and progression of obesity-related comorbidities.

RESULTS

In total, 2313 patients were included, 1246 in the RYGB group and 1067 in the SG group. Percentage TWL was significantly higher in the RYGB group compared to the SG group at 1, 2, and 3 years after surgery (respectively 2.4%, 2.9%, and 3.3% higher, p < 0.001). RYGB was associated with an on-average 2.75 higher %TWL compared to SG in females (p < 0.001), although this was not seen in males (β = 0.63, p = 0.514). No differences were found in the incidence of complications, nor the progression of obesity-related comorbidities except for gastroesophageal reflux disease (GERD). There was more improvement or resolution of GERD in the RYGB group (95.2% vs. 56.3%, p < 0.001).

CONCLUSION

Similar numbers of RYGB and SG were performed in young adults, whereas RYGB was associated with greater weight loss in the short- and midterm, particularly in females.

Perinatal outcomes after bariatric surgery

BACKGROUND

Bariatric surgery is a widely used treatment option for obesity that often provides long-term weight control and health benefits. Although a growing number of women are becoming pregnant after bariatric surgery, only a few population-based studies have assessed the impact thereof on perinatal outcomes.

OBJECTIVE

This study aimed to examine the association between bariatric surgery and adverse perinatal outcomes in pregnant women and to examine whether the risk for adverse perinatal outcomes is modified by the postsurgery weight, gestational weight gain, type of bariatric surgery, timing of pregnancy after bariatric surgery, and maternal comorbidities.

STUDY DESIGN

A retrospective cohort study was performed with the use of the Bariatric Surgery Registry and hospital inpatient and outpatient physician encounter records. The International Classification of Diseases, Ninth and Tenth Revision codes from hospitalizations during pregnancy and infant birth records were used to ascertain the outcomes of interest. Women eligible for BS who delivered at ≥20 weeks of gestation (n=20,213) at Kaiser Permanente Southern California hospitals (January 1, 2007 to December 31, 2018) were included in the study. Adjusted odds ratios were derived from logistic regression models with inverse probability of treatment weighting to adjust for confounding using propensity scores.

RESULTS

Bariatric surgery was associated with a reduction in the risks for gestational diabetes (adjusted odds ratio, 0.60; 95% confidence interval, 0.53-0.69; P<.001), preeclampsia (adjusted odds ratio, 0.53; 95% confidence interval, 0.46-0.61; P<.001), chorioamnionitis (adjusted odds ratio, 0.45; 95% confidence interval, 0.32-0.63; P<.001), cesarean delivery (adjusted odds ratio, 0.65; 95% confidence interval, 0.59-0.72; P<.001), large for gestational age neonate (adjusted odds ratio, 0.23; 95% confidence interval, 0.19-0.29; P<.001), macrosomia (adjusted odds ratio, 0.24; 95% confidence interval, 0.19-0.30; P<.001), and neonatal intensive care unit admission (adjusted odds ratio, 0.70; 95% confidence interval, 0.61-0.81; P<.001). However, bariatric surgery was also associated with a significantly increased risk for small for gestational age neonates (adjusted odds ratio, 2.46; 95% confidence interval, 2.16-2.79; P<.001). The risk for the adverse outcomes is independent of the time interval between the surgery and subsequent pregnancy.

CONCLUSION

These data suggest that there are many pregnancy outcome benefits for women with severe obesity who undergo bariatric surgery; however, women who have undergone bariatric surgery before pregnancy should be monitored closely to reduce the risk for small for gestational age neonates and postpartum hemorrhage.

Minimum Threshold of Bariatric Surgical Weight Loss for Initial Diabetes Remission

OBJECTIVE

There are few studies testing the amount of weight loss necessary to achieve initial remission of type 2 diabetes mellitus (T2DM) following bariatric surgery and no published studies with use of weight loss to predict initial T2DM remission in sleeve gastrectomy (SG) patients.

RESEARCH DESIGN AND METHODS

With Cox proportional hazards models we examined the relationship between initial T2DM remission and percent total weight loss (%TWL) after bariatric surgery. Categories of %TWL were included in the model as time-varying covariates.

RESULTS

Of patients (N = 5,928), 73% were female; mean age was 49.8 ± 10.3 years and BMI 43.8 ± 6.92 kg/m2, and 57% had Roux-en-Y gastric bypass (RYGB). Over an average follow-up of 5.9 years, 71% of patients experienced initial remission of T2DM (mean time to remission 1.0 year). With 0-5% TWL used as the reference group in Cox proportional hazards models, patients were more likely to remit with each 5% increase in TWL until 20% TWL (hazard ratio range 1.97-2.92). When categories >25% TWL were examined, all patients had a likelihood of initial remission similar to that of 20-25% TWL. Patients who achieved >20% TWL were more likely to achieve initial T2DM remission than patients with 0-5% TWL, even if they were using insulin at the time of surgery.

CONCLUSIONS

Weight loss after bariatric surgery is strongly associated with initial T2DM remission; however, above a threshold of 20% TWL, rates of initial T2DM remission did not increase substantially. Achieving this threshold is also associated with initial remission even in patients who traditionally experience lower rates of remission, such as patients taking insulin.

Retrospective comparative study of the effectiveness of bariatric surgery on 3-year outcomes in the real-world clinical setting

BACKGROUND

Bariatric surgery has shown an improvement in obesity and obesity-related disease in many clinical trials and single center studies. However, real-world data, including data from non-centers of excellence, is sparse.

OBJECTIVES

To provide clinical outcomes of patients who underwent bariatric surgery in real-world clinical setting.

SETTING

Academic Institution.

METHODS

Adults with obesity undergoing Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and a control group (CG) between 2007 and 2019 were identified. The CG represented patients with a previous visit to a bariatric surgeon without a subsequent surgery. Cohorts were matched on age, gender, ethnicity, baseline body mass index (BMI), and presence of diabetes and hypertension. Groups were compared in terms of co-morbidities, weight loss, and chronic conditions for three years.

RESULTS

A total of 61 313 patients were identified. From these, 14 916 RYGB and 20 867 SG patients were matched to the CG (n = 16 562). The median BMI loss three years after surgery was 28.7% (interquartile range [IQR] 20.8%-36.2%) and 20.5% (IQR 13.5%-28.6%) for RYGB and SG groups, respectively. The CG had a median BMI loss of 6.7% with IQR of 20.4% decrease to 1.78% gain. At three years postoperatively, HbA1C decreased by 13% for RYGB and 5.9% for the SG group. The probabilities of remission from diabetes, hypertension, and low high-density lipoprotein cholesterol were significantly higher among patients who had surgery compared to the CG. For both RYGB and SG, the estimated probabilities of remission were similar.

CONCLUSION

This study shows that bariatric surgery performed in the real-world clinical setting is an effective therapy for various expressions of the metabolic syndrome with results that are comparable to randomized control trials.

Systemic and Environmental Contributors to Obesity Inequities in Marginalized Racial and Ethnic Groups

Obesity is a multifactorial disease that disproportionally affects diverse racial and ethnic groups. Structural racism influences racial inequities in obesity prevalence through environmental factors, such as racism and discrimination, socioeconomic status, increased levels of stress, and bias in the health care delivery system. Researchers, clinicians, and policy makers must work to address the environmental and systematic barriers that contribute to health inequities in the United States. Specifically, clinicians should quantitatively and qualitatively assess environmental and social factors and proactively engage in patient-centered care to tailor available treatments based on identified needs and experiences.

Does bariatric surgery reduce future hospital costs? A propensity score-matched analysis using UK Biobank Study data

OBJECTIVES

To estimate the hospital costs among persons with obesity undergoing bariatric surgery compared with those without bariatric surgery.

METHODS

We analysed the UK Biobank Cohort study linked to Hospital Episode Statistics, for all adults with obesity undergoing bariatric surgery at National Health Service hospitals in England, Scotland, or Wales from 2006 to 2017. Surgery patients were matched with controls who did not have bariatric surgery using propensity scores approach with a ratio of up to 1-to-5 by year. Inverse probability of censoring weighting was used to correct for potential informative censoring. Annual and cumulative hospital costs were assessed for the surgery and control groups.

RESULTS

We identified 348 surgical patients (198 gastric bypass, 73 sleeve gastrectomy, 77 gastric banding) during the study period. In total, 324 surgical patients and 1506 matched control participants were included after propensity score matching. Mean 5-year cumulative hospital costs were €11,659 for 348 surgical patients. Compared with controls, surgical patients (n = 324) had significantly higher inpatient expenditures in the surgery year (€7289 vs. €2635, P < 0.001), but lower costs in the subsequent 4 years. The 5-year cumulative costs were €11,176 for surgical patients and €8759 for controls (P = 0.001).

CONCLUSIONS

Bariatric surgery significantly increased the inpatient costs in the surgery year, but was associated with decreased costs in the subsequent 4 years. However, any cost savings made up to 4 years were not enough to compensate for the initial surgical expenditure.

Centile Charts for Monitoring of Weight Loss Trajectories After Bariatric Surgery in Asian Patients

BACKGROUND

Following bariatric surgery, accurate charting of weight loss and regain is crucial. Various preoperative factors affect postoperative weight loss, including age, sex, ethnicity, and surgical type. These are not considered by current weight loss metrics, limiting comparison of weight loss outcomes between patients or centers and across time.

METHODS

Patients (n=1022) who underwent sleeve gastrectomy (n=809) and gastric bypass (n=213) from 2008 to 2020 in a single center were reviewed. Weight loss outcomes (% total weight loss) were measured for 60 months postoperatively. Longitudinal centile lines were plotted using the post-estimation predictions of quantile regression models, adjusted for type of procedure, sex, ethnicity, and baseline BMI.

RESULTS

Median regression showed that %TWL was 1.0% greater among males than females (β = +1.1, 95% CI: +0.6 to +1.7, P = <0.0001). Participants who underwent SG had less %TWL compared to GB (β = -1.3, 95% CI: -1.9 to -0.8, P < 0.0001). There was a trend towards less %TWL among the Indian and Malay participants compared to Chinese. Age and diabetes were not significant predictors. Reference centile charts were produced for the overall cohort, as well as specific charts adjusted for type of bariatric procedure, sex, ethnicity, and baseline BMI.

CONCLUSION

Centile charts provide a clinically relevant method for monitoring of weight trajectories postoperatively and aid in realistic and personalised goal setting, and the early identification of "poor responders". This is the first study to present post-bariatric surgery centile charts for an Asian cohort.

Association of Bariatric Surgery With Vascular Outcomes

IMPORTANCE

Bariatric surgical weight loss is associated with reduced cardiovascular mortality; however, the mechanisms underlying this association are incompletely understood.

OBJECTIVES

To identify variables associated with vascular remodeling after bariatric surgery and to examine how sex, race, and metabolic status are associated with microvascular and macrovascular outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based longitudinal cohort included 307 individuals who underwent bariatric surgery. Participants were enrolled in the bariatric weight loss program at Boston Medical Center, a large, multi-ethnic urban hospital, with presurgical and postsurgical assessments. Data were collected from December 11, 2001 to August 27, 2019. Data were analyzed in September 2019.

EXPOSURE

Bariatric surgery.

MAIN OUTCOMES AND MEASURES

Flow-mediated dilation (FMD) and reactive hyperemia (RH) (as measures of macrovascular and microvascular function, respectively) and clinical variables were measured preoperatively at baseline and at least once postoperatively within 12 months of the bariatric intervention.

RESULTS

A total of 307 participants with obesity (mean [SD] age, 42 [12] years; 246 [80%] women; 199 [65%] White; mean [SD] body mass index, 46 [8]) were enrolled in this study. Bariatric surgery was associated with significant weight loss and improved macrovascular and microvascular function across subgroups of sex, race, and traditional metabolic syndrome (mean [SD] pre- vs postsurgery weight: 126 [25] kg vs 104 [25] kg; P < .001; mean [SD] pre- vs postsurgery FMD: 9.1% [5.3] vs 10.2% [5.1]; P < .001; mean [SD] pre- vs postsurgery RH: 764% [400] vs 923% [412]; P < .001). Factors associated with change in vascular phenotype correlated most strongly with adiposity markers and several metabolic variables depending on vascular territory (eg, association of weight change with change in RH: estimate, -3.2; 95% CI, -4.7 to -1.8; association of hemoglobin A1c with change in FMD: estimate, -0.5; 95% CI, -0.95 to -0.05). While changes in macrovascular function among individuals with metabolically healthy obesity were not observed, the addition of biomarker assessment using high-sensitivity C-reactive protein plasma levels greater than 2 mg/dL identified participants with seemingly metabolically healthy obesity who had low-grade inflammation and achieved microvascular benefit from weight loss surgery.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that bariatric intervention is associated with weight loss and favorable remodeling of the vasculature among a wide range of individuals with cardiovascular risk. Moreover, differences in arterial responses to weight loss surgery by metabolic status were identified, underscoring heterogeneity in physiological responses to adiposity change and potential activation of distinct pathological pathways in clinical subgroups. As such, individuals with metabolically healthy obesity represent a mixed population that may benefit from more refined phenotypic classification.

Racial disparities in bariatric surgery postoperative weight loss and co-morbidity resolution: a systematic review

While bariatric surgery is an accepted treatment for morbid obesity, the impact of race on surgical outcomes remains unclear. This systematic review aims to compare differences in weight loss and co-morbidity outcomes among various races after bariatric surgery. PubMed, Medline, and SCOPUS databases were queried to identify publications that included more than 1 racial group and reported weight loss outcomes after bariatric surgery. A total of 52 studies were included. Non-Hispanic black (NHB) patients comprised between 5.5% and 69.7% and Hispanic patients comprised between 4.7% and 65.3% of the studies' populations. Definitions of weight loss success differed widely across studies, with percent excess weight loss being the most commonly reported outcome, followed by percent total weight loss and change in body mass index (BMI). Statistical analyses also varied, with most studies adjusting for age, sex, preoperative weight, or BMI. Some studies also adjusted for preoperative co-morbidities, including diabetes mellitus, hypertension, and hyperlipidemia, or socioeconomic status, including income, education, and neighborhood poverty. The majority of studies found less favorable weight loss in NHB compared to Hispanic and non-Hispanic white (NHW), patients while generally no difference was found between Hispanic and NHW patients. The trend also indicates no association between race and resolution of obesity-related co-morbidities. Racial minorities lose less weight than NHW patients after bariatric surgery, although the factors associated with this discrepancy are unclear. The heterogeneity in reporting weight loss success and statistical analyses amongst the literature makes an estimation of effect size difficult. Generally, racial disparity was not seen when examining co-morbidity resolution after surgery. More prospective, robust, long-term studies are needed to understand the impacts of race on bariatric surgery outcomes and ensure successful outcomes for all patients, regardless of race.

The influence of preoperative carbohydrate loading on postoperative outcomes in bariatric surgery patients: a randomized, controlled trial

BACKGROUND

Preoperative carbohydrate loading is a component of Enhanced Recovery After Surgery (ERAS) protocols, but there is limited literature in bariatric surgery patients.

OBJECTIVES

The objective of this study was to characterize the impact of preoperative carbohydrate loading on postoperative bariatric surgery outcomes.

SETTING

University Hospital.

METHODS

Patients undergoing a primary minimally invasive Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2018 and 2020 were randomized to standard management or intervention. Standard management patients were nothing by mouth (NPO) after midnight prior to surgery. Intervention patients consumed 2 carbohydrate drinks: 1 the night before and another 3 hours prior to surgery. Primary outcomes analyzed included postoperative nausea and vomiting (PONV), length of stay, and overall complications.

RESULTS

In total, 134 patients were analyzed: 64 intervention (47.8%) and 70 (52.2%) standard. In the end, 7% and 15% of patients were lost to follow-up at 6-weeks and 3-months, respectively. There was no statistically significant difference in length of stay (2.0 ± 1.2 vs 2.1 ± .9 d; P = .65) or postoperative outcomes between the 2 groups. There were no episodes of aspiration among the intervention group. Among RYGB patients, intervention patients had a shorter duration of nausea compared with standard patients. There was no significant difference in glycemic control among patients with and without diabetes.

CONCLUSIONS

Preoperative carbohydrate drinks can be administered to bariatric surgery patients without significant risks. Carbohydrate loading preoperatively can decrease the duration of PONV in RYGB patients. Carbohydrate drinks can be safely included in bariatric ERAS protocols for patients with and without diabetes, although the benefits remain unknown.

Racial Disparities in Bariatric Surgery Complications and Mortality Using the MBSAQIP Data Registry

Background

Racial disparities in postoperative complications have been demonstrated in bariatric surgery, yet the relationship of race to complication severity is unknown.

Study Design

Adult laparoscopic primary bariatric procedures were queried from the 2015 and 2016 MBSAQIP registry. Adjusted logistic and multinomial regressions were used to examine the relationships between race and 30-day complications categorized by the Clavien-Dindo grading system.

Results

A total of 212,970 patients were included in the regression analyses. For Black patients, readmissions were higher (OR = 1.39, p < 0.0001) and the odds of a Grade 1, 3, 4, or 5 complication were increased compared with White patients (OR = 1.21, p < 0.0001; OR = 1.21, p < 0.0001; OR = 1.22, p = 0.01; and OR = 1.43, p = 0.04) respectively. The odds of a Grade 3 complication for Hispanic patients were higher compared with White patients (OR = 1.59, p < 0.0001).

Conclusion

Black patients have higher odds of readmission and multiple grades of complications (including death) compared with White patients. Hispanic patients have higher odds of a Grade 3 complication compared with White patients. No significant differences were found with other races. Specific causes of these disparities are beyond the limitations of the dataset and stand as a topic for future inquiry.

Understanding the Bariatric Patient Perspective in the National Patient-Centered Clinical Research Network (PCORnet) Bariatric Study

BACKGROUND

In 2016, the Patient-Centered Outcomes Research Institute funded the National Patient Centered Clinical Research Network (PCORnet) Bariatric Study (PBS). Understanding the experience of postoperative patients was a key component of this study.

METHODS

Nine focus groups were conducted in Southern California, Louisiana, Pennsylvania, and Ohio and in a national advocacy conference for patients with obesity. Participants were identified and recruited in both clinical and community settings. Focus group transcripts were analyzed using an iterative inductive-deductive approach to identify global overarching themes.

RESULTS

There were 76 focus group participants. Participants were mostly women (81.4%), had primarily undergone gastric sleeve (47.0%), were non-Hispanic white (51.4%), had some college education (44.3%), and made $100,000 annual income or less (65.7%). Qualitative findings included negative reactions patients received from friends, family, and co-workers once they disclosed that they had bariatric surgery to lose weight; and barriers to follow-up care included insurance coverage, emotional and situational challenges, and physical pain limiting mobility.

CONCLUSIONS

These findings confirm the other qualitative findings in this area. The approach to bariatric surgery should be expanded to provide long-term comprehensive care that includes in-depth postoperative lifetime monitoring of emotional and physical health.

Five-year Longitudinal Cohort Study of Reinterventions After Sleeve Gastrectomy and Roux-en-Y Gastric Bypass

OBJECTIVE

To compare the long-term risks of reintervention following sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) in a large surgical cohort.

BACKGROUND

The use of SG has increased dramatically relative to RYGB for the treatment of obesity. However, long-term risks following SG compared with RYGB have not been adequately defined in a large population-based study.

METHODS

A retrospective longitudinal cohort study of all adult health-plan members undergoing SG or RYGB for obesity in a multistate integrated health care system from January 2005 through September 2015. The risks of nutritional, endoscopic, radiologic, and surgical reintervention as well as the overall risk of any reinterventions at 1, 3, and 5 years were identified using diagnosis and procedure codes from comprehensive electronic medical records.

RESULTS

The study included 15,319 patients who underwent SG and 19,954 patients who underwent RYGB with a follow-up of 79.2%. The overall risk of any reintervention at 5 years was 21.3% for SG and 28.3% for RYGB (P < 0.0001). After adjustment, SG was associated with fewer reinterventions through 5 years than RYGB (hazard ratio, 0.78; 95% confidence interval, 0.74-0.84). When comparing subcategories, SG also had a lower risk of nutritional, endoscopic, radiologic, and surgical reinterventions when examined versus RYGB. The findings for risks of reinterventions were consistent across clinical subgroups.

CONCLUSION

SG has significantly lower risk of reintervention in all categories studied when compared with RYGB at 5-year follow-up. The long-term safety profile of LSG compared with RYGB should be an essential part of the discussion in patient-centered decision making when choosing between bariatric procedure options.

Banding the Pouch with a Non-adjustable Ring as Revisional Procedure in Patients with Insufficient Results After Roux-en-Y Gastric Bypass: Short-term Outcomes of a Multicenter Cohort Study

BACKGROUND

After laparoscopic Roux-en-Y gastric bypass (RYGB), approximately 10-35% of patients with morbid obesity regain weight after an initial good result or fail to achieve a sufficient amount of weight loss. Patients in which conservative measures are not successful may potentially benefit from revisional surgery.

OBJECTIVE

To evaluate the effect of a non-adjustable ring placed around the gastric pouch in patients with insufficient weight loss or weight regain after RYGB.

SETTING

Four specialized bariatric hospitals in The Netherlands, Germany, and Switzerland.

METHODS

From 2011 to 2017, 79 patients underwent revisional surgery using a non-adjustable silicone ring because of insufficient results after RYGB. Data on weight loss and complications up to 2 years after revisional surgery was collected and analyzed retrospectively.

RESULTS

A follow-up percentage of 86% after 1 year and 61% after 2 years was achieved. In 75% of patients, further weight regain was prevented. Percentage total body weight loss improved by 7 to 26% 1 year after revisional surgery and remained stable during 2 years of follow-up. The additional weight loss effect of placing a non-adjustable ring was more pronounced in patients with an initial good result after primary RYGB. Eighteen (23%) rings were removed, most often due to dysphagia.

CONCLUSION

Especially for patients who experience weight regain after initial good weight loss, placing a non-adjustable silicone ring around the gastric pouch results in modest improvements in weight loss. To prevent the risk of ring removal due to dysphagia, surgeons should take notice not to place the ring too tight around the gastric pouch during revisional surgery.

Population Diversity Challenge the External Validity of the European Randomized Controlled Trials Comparing Laparoscopic Gastric Bypass and Sleeve Gastrectomy

INTRODUCTION

Two randomized controlled trials (RCTs) from Europe recently showed similar weight loss and rates of type 2 diabetes (T2D) remission following laparoscopic gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). However, results from observational studies in the United States (US) have discordant results. We compared 1-year weight loss and T2D remission between LRYGB and LSG in a heterogeneous patient cohort from the US, albeit with similar inclusion and exclusion criteria to the European RCTs.

METHODS

Logistic regression was used to propensity match LSG and LRYGB patients according to age, gender, race, preoperative BMI, and T2D. Inclusion and exclusion criteria were adopted from the two European RCTs. Demographic, anthropometric, weight outcomes, and comorbidities prevalence were compared at baseline and 1-year follow-up.

RESULTS

We included 278 patients (139 LSG and 139 RYGB; median age 42 years, 89% female, 57% black race, 22% with public health insurance, and 25% with T2D). One year after surgery, mean %EWL was 77.3 ± 19.5% with LRYGB and 63.1 ± 21% with LSG (P < 0.001). Mean %TWL was 34.2 ± 7.3% after LRYGB and 28.1 ± 8.2% after LSG, (P < 0.001). The proportion of patients who achieved T2D remission was comparable between surgeries (LRGYB: 68.6% vs. LSG: 66.7%, P = 0.89). LSG, older age, black race, and higher preoperative BMI were independently associated with lower %EWL. Independent correlates of weight loss were different for LRYGB and LSG.

CONCLUSIONS

Weight loss, but not the likelihood of T2D remission, was greater with LRYGB than LSG in a diverse patient cohort in the US. Further research efforts connecting population diversity to discordant results across studies is needed to better counsel patients with regards to expected postoperative outcomes.

Weight loss and adherence to postoperative follow-up after vertical gastrectomy for obesity treatment

Purpose

To analyze the effectiveness of vertical gastrectomy in the treatment of obese patients, adherence to clinical follow-up and the influence of factors such as gender and age.

Methods

This is a retrospective, observational and descriptive study, conducted with patients undergoing vertical gastrectomy, operated at Hospital São Domingos, between January 2016 and July 2018.

Results

Most patients undergoing vertical gastrectomy were female (n = 193, 72.28%) and had a mean age of37.11 ± 8.96 years old. The loss of follow-up was 56.18%. Among adherent patients (n = 117; 43.82%), most patients were female (n = 89; 76.07%) and had a mean age of 37.92 ± 9.85 years old. The mean body mass index (BMI) of the adherents in the preoperative was 37.85 ± 3.72 kg/m². Both BMI and excess weight (EW) showed a statistically significant difference between pre- and postoperative period. Percentage of excess weight loss (% EWL) was satisfactory for 96.6% of adherent patients. Older patients had a statistically significant lower % EWL compared to the other groups.

Conclusions

Vertical gastrectomy was effective in the treatment of obese patients, with significant weight loss.

Bariatric Surgical Alterations in Tolerability, Enjoyment and Cravings in the Diet (BSATED) instrument: A new scale to measure food preferences following bariatric surgery

Bariatric surgery is associated with changing food preferences, but it is not known whether these changes differ by type of operation or are associated with weight loss. The current study presents validation results for a new 27-item scale, Bariatric Surgical Alterations in Tolerability, Enjoyment and Cravings in the Diet (BSATED). This scale measured enjoyment, craving, and intolerance changes for nine food and beverage categories common to dietary habits in the Southern California region of the U.S. one year following bariatric surgery in the Bariatric Experience Long Term (BELONG) study. Validation of BSATED was done using exploratory factor analyses, construct validity with other conceptually related survey instruments, and criterion validity using hypothesized differences for operation type and percent total weight loss (%TWL) at 12-18 months after surgery. Participants (n = 999) were 86% female, 41% non-Hispanic White, with a mean age of 43.1 ± 11.3 years and a body mass index (BMI) of 43.4 ± 6.8 kg/m² at the time of surgery. Participants reported less enjoyment and craving for high-fat meats (62%), grains (54%), candy and other desserts (e.g. candy bars, chocolate, ice cream) (52%), and sweet baked goods (48%) 12 months after surgery. These changes were more common among participants undergoing Roux-en-Y gastric bypass (RYGB) compared to those receiving sleeve gastrectomy (SG). Participants who reported decreased enjoyment and craving for foods and beverages that post-bariatric patients are counseled to reduce or avoid had greater %TWL at 12-18 months following surgery (p < .001 and p = .003 respectively). The foods and beverages in BSATED that post-bariatric patients are counseled to reduce or avoid could be used to understand how changes in enjoyment, craving and tolerability of these foods/beverages contribute to weight loss following surgery.

The relationship between kidney function and body mass index before and after bariatric surgery in patients with chronic kidney disease

BACKGROUND

Improvements in kidney function post-bariatric surgery may be related to weight loss-independent effects.

OBJECTIVES

To characterize the dynamic relationship between body mass index (BMI) and estimated glomerular filtration rate (eGFR) before and after bariatric surgery in patients with chronic kidney disease (CKD).

SETTING

Kaiser Permanente Southern California (KPSC) health system.

METHODS

We conducted an observational, retrospective cohort study of patients with CKD stage 3 or higher who received bariatric surgery at the KPSC health system between 2007-2015. Bariatric surgery procedures included primary Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) procedures. Outcomes consisted of mean trajectory estimates and correlations of BMI and eGFR taken between 2 years before and 3 years after surgery. Multivariate functional mixed models were used to estimate how BMI and eGFR trajectories evolved jointly.

RESULTS

A total of 619 RYGB and 474 SG patients were included in the final analytic sample. The measurements were available before surgery for a median time of 1.9 years for SG and 1.8 years for RYGB patients. Median follow-up times after surgery were 2.8 years for both SG and RYGB patients. The mean age at the time of surgery was 58 years; 77% of patients were women; 56% of patients were non-Hispanic White; the mean BMI was 44 kg/m²; 60% of patients had diabetes mellitus; and 84% of patients had hypertension. Compared to the presurgery eGFR declines, the postsurgery declines in eGFR were 57% slower (95% credible interval [CrI], 33%-81%) for RYGB patients and 55% slower (95% CrI, 25%-75%) for SG patients. The mean correlation between BMI and eGFR was negligible at all time points.

CONCLUSION

Though bariatric surgery slowed declines in eGFR up to 3 years after surgery, changes in eGFR tracked poorly with changes in BMI. This study provides evidence that the kidney-related benefits of bariatric surgery may be at least partly independent of weight loss. Confirming this hypothesis could lead to mechanistic insights and new treatment options for CKD.

Outcomes in racial and ethnic minorities after revisional robotic-assisted metabolic and bariatric surgery: an analysis of the MBSAQIP database

BACKGROUND

Robotic-assisted metabolic and bariatric surgery (MBS) is being performed with increased frequency in the United States, including for revisional MBS. However, little is known about perioperative outcomes between racial and ethnic cohorts after revisional robotic-assisted MBS.

OBJECTIVE

The goal of our study was to determine if there are racial differences in outcomes after robotic-assisted revisional MBS.

SETTING

University Hospital, United States.

METHODS

Using the 2015-2017 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database, we identified patients undergoing revisional MBS by a robotic-assisted approach. Univariate analyses were performed of unmatched and matched racial and ethnic cohorts, comparing black versus white patients and Hispanic versus white patients.

RESULTS

Of 2027 robotic-assisted revisional MBS cases in the database, 1922 were included in our analysis, including 67%, 22.6%, and 10.4% white, black, and Hispanic patients, respectively. At baseline, there were some differences in patient characteristics between racial and ethnic cohorts. After propensity matching, outcomes between black and white patients were similar, except for higher rates of superficial surgical site infection among white patients (P = .05) and higher rates of organ space surgical site infection in black patients (P = .05). Outcomes were also similar between matched white and Hispanic patients, except for a higher bleeding in white patients (2% versus 0%, P = .04). There were no mortality or morbidity differences between racial and ethnic cohorts.

CONCLUSION

Morbidity and mortality after robotic-assisted revisional MBS do not seem to be mediated by race or ethnicity.

Weight loss during medical weight management does not predict weight loss after bariatric surgery: a retrospective cohort study

BACKGROUND

Many bariatric surgical centers mandate achieving weight loss targets through medical weight management (MWM) programs before offering bariatric surgery, but the evidence for this is unclear.

OBJECTIVES

To examine the relationship between weight changes during (1) MWM, and (2) preoperative low-energy-diet (LED), and weight changes at 12 and 24 months after surgery.

SETTING

Multicenter community- and acute-based MWM services referring to one regional bariatric center, United Kingdom.

METHODS

A retrospective cohort study of patients who attended MWM and then underwent a primary laparoscopic bariatric procedure (adjustable gastric banding [LAGB], or Roux-en-Y gastric bypass [RYGB]) in a single bariatric center in the United Kingdom between 2013 and 2015. Data were collected from patient electronic records.

RESULTS

Two hundred eight patients were included (LAGB n = 128, RYGB n = 80). Anthropometric data were available for 94.7% and 88.0% of participants at 12 and 24 months, respectively. There was no relationship between weight loss during MWM and after surgery at either 12 or 24 months. Weight loss during the preoperative LED predicted greater weight loss after LAGB (β = .251, P = .006) and less weight loss after RYGB (β = -.390, P = .003) at 24 months, after adjusting for age, sex, ethnicity, baseline weight, and LED duration.

CONCLUSIONS

Weight loss in MWM does not predict greater weight loss outcomes up to 24 months after LAGB or RYGB. Greater weight loss during the preoperative LED predicted greater weight loss after LAGB and less weight loss after RYGB. Our results suggest that patients should not be denied bariatric surgery because of not achieving weight loss in MWM. Weight loss responses to preoperative LEDs as a predictor of postsurgical weight loss requires further investigation.

Effectiveness of Gastric Bypass Versus Gastric Sleeve for Cardiovascular Disease: Protocol and Baseline Results for a Comparative Effectiveness Study

Background

When compared with conventional weight loss strategies, bariatric surgery results in substantially greater durable weight loss and rates of disease remission.

Objective

The ENGAGE CVD (Effectiveness of Gastric Bypass versus Gastric Sleeve for Cardiovascular Disease) cohort study aimed to provide population-based, comprehensive, rigorous evidence for clinical and policy decision making regarding the choice between gastric bypass and gastric sleeve for overall cardiovascular disease (CVD) risk reduction, risk factor remission, and safety.

Methods

The cohort had 22,095 weight loss surgery patients from a large integrated health care system in Southern California assembled from 2009 to 2016 who were followed up through 2018. Bariatric surgery patients were followed up for the length of their membership in the health care system. Of the patients who had at least five years of follow-up (surgery between 2009 and 2013), 85.86% (13,774/16,043) could contribute to the outcome analyses for the ENGAGE CVD cohort.

Results

Patients in the ENGAGE CVD cohort were 44.6 (SD 11.4) years old, mostly women (17,718/22,095; 80.19%), with 18.94% (4185/22,095) non-Hispanic black and 41.80% (9235/22,095) Hispanic, and had an average BMI of 44.3 (SD 6.9) kg/m² at the time of surgery. When compared with patients who did not contribute data to the 5-year outcome analysis for the ENGAGE CVD cohort (2269/16,043; 14.14%), patients who contributed data (13,774/16,043; 85.86%) were older (P=.002), more likely to be women (P=.02), more likely to be non-Hispanic white (P<.001), more likely to have had an emergency department visit in the year before surgery (P=.006), less likely to have a mental illness before surgery (P<.001), and more likely to have had a CVD event at any time before surgery (P<.001).

Conclusions

This study had one of the largest populations of gastric sleeve patients (n=13,459). The 5-year follow-up for those patients who had surgery between 2009 and 2013 was excellent for a retrospective cohort study at 85.86% (13,774/16,043). Unlike almost any study in the literature, the majority of the ENGAGE CVD cohort was racial and ethnic minority, providing a rare opportunity to study the effects of bariatric surgery for different racial and ethnic groups, some of whom have the highest rates of severe obesity in the United States. Finally, it also used state-of-the-art statistical and econometric comparative effectiveness methods to mimic the effect of random assignment and control for sources of confounding inherent in large observational studies.

International Registered Report Identifier (IRRID)

RR1-10.2196/14936

Differential Metabolomic Signatures in Patients with Weight Regain and Sustained Weight Loss After Gastric Bypass Surgery: A Pilot Study

BACKGROUND

While Roux-en-Y gastric bypass (RYGB) is one of the most effective and durable treatment options for obesity and its comorbidities, it is complicated by long-term weight regain in over 20% of patients.

AIMS

We sought to determine the metabolite signatures of serum samples of patients with weight regain (RYGB-WR) after RYGB and features distinguishing these patients from patients with sustained weight loss (RYGB-SWL).

METHODS

We prospectively analyzed serum samples from 21 RYGB-WR patients, 14 RYGB-SWL patients, and 11 unoperated controls. The main outcome measure was their serum metabolite profile.

RESULTS

Weight regain after RYGB was associated with a unique serum metabolomic fingerprint. Most of the statistically different metabolites were involved in amino acid metabolism, one-carbon metabolism, and related nucleotide metabolism. A principal component analysis identified groups of metabolites that correlate with weight regain. Specifically, weight regain was associated with lower serum levels of metabolites related to the serine, glycine and threonine pathway, phenylalanine metabolism, tricyclic acid cycle, alanine and glutamate metabolism, and higher levels of other amino acids.

CONCLUSIONS

Weight regain after RYGB is associated with unique serum metabolite signatures. Metabolite profiling may eventually help us to identify markers that could differentiate the patients who will regain weight versus those who will likely sustain weight loss.

Pre-surgical stress and social support predict post-surgical percent excess weight loss in a population of bariatric surgery patients

Although bariatric surgery is an effective treatment of morbid obesity, many patients fail to lose significant weight or regain weight over time. This study examined pre-surgical psychosocial predictors (stress, social support for healthy eating, emotion regulation, and sleep quality/quantity) of three-month post-surgical percent excess weight loss (EWL) in a population of adult bariatric surgery patients. Overall, findings suggest higher levels of stress (B = -.248, p =.017) and less social support for healthy eating (B =.311, p =.013) predict lower three-month post-surgery percent EWL. Emotion regulation, and sleep measures did not predict post-surgery percent EWL. Therefore, level of stress and social support should be assessed prior to bariatric surgery and considered important pre-surgical intervention targets.

Effects of a High-Intensity Exercise Program on Weight Regain and Cardio-metabolic Profile after 3 Years of Bariatric Surgery: A Randomized Trial

Weight regain is one of the most common problems in the long-term after bariatric surgery. It is unknown if high-intensity exercise programs applied in late phases of post-surgical follow-up could counteract this trend. After a 3-year follow-up, 21 patients underwent sleeve gastrectomy were randomized into an exercise group (EG, n = 11), that performed a 5-month supervised exercise program, and a control group (CG, n = 10), that followed the usual care. Body composition, cardiorespiratory fitness, glycaemia and blood cholesterol were evaluated before and after the intervention. Finally, the EG repeated the evaluations 2 months after the end of the exercise program. Both groups reached their maximum weight loss at the first year after surgery and showed significant weight regain by the end of the follow-up. After the exercise program, the EG showed reductions in fat mass (-2.5 ± 2.6  kg, P < 0.05), glycaemia (-13.4 ± 8.7  mg·dL-1, P < 0.01) and blood cholesterol (-24.6 ± 29.1  mg·dL-1, P < 0.05), whereas the CG during the same period showed increases in weight (1.5 ± 1.3  kg, P < 0.05) and fat mass (1.8 ± 0.9, P < 0.01). Two months after the end of the program, EG had increases in weight (1.1 ± 1.2  kg, P < 0.05), fat mass (2.6 ± 2.2  kg, P < 0.01), glycaemia (8.2 ± 11.6  mg·dL-1, P < 0.05) and blood cholesterol (20.0 ± 22.1  mg·dL-1, P < 0.05), when compared with the values after the exercise program. Therefore, in the medium-term after sleeve gastrectomy exercise may contribute to prevent weight regain and to reduce fat mass, glycaemia, and blood cholesterol.

Male gender is an independent risk factor for patients undergoing laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass: an MBSAQIP® database analysis

BACKGROUND

Male patients undergoing bariatric surgery have (historically) been considered higher risk than females. The aim of this study was to examine the disparity between genders undergoing laparoscopic sleeve gastrectomy (SG) and laparoscopic Roux-en-Y gastric bypass (RYGB) procedures and assess gender as an independent risk factor.

METHODS

The MBSAQIP® Data Registry Participant User Files for 2015-2017 was reviewed for patients having primary SG and RYGB. Patients were divided into groups based on gender and procedure. Variables for major complications were grouped together, including but not limited to PE, stroke, and MI. Univariate and propensity matching analyses were performed.

RESULTS

Of 429,664 cases, 20.58% were male. Univariate analysis demonstrated males were older (46.48 ± 11.96 vs. 43.71 ± 11.89 years, p < 0.0001), had higher BMI (46.58 ± 8.46 vs. 45.05 ± 7.75 kg/m², p < 0.0001), and had higher incidence of comorbidities. Males had higher rates of major complications (1.72 vs. 1.05%; p < 0.0001) and 30-day mortality (0.18 vs. 0.07%, p < 0.0001). Significance was maintained after subgroup analysis of SG and RYGB. Propensity matched analysis demonstrated male gender was an independent risk factor for RYGB and SG, major complications [2.21 vs. 1.7%, p < 0.0001 (RYGB), 1.12 vs. 0.89%, p < 0.0001 (SG)], and mortality [0.23 vs. 0.12%, p < 0.0001 (RYGB), 0.10 vs. 0.05%; p < 0.0001 (SG)].

CONCLUSION

Males continue to represent a disproportionately small percentage of bariatric surgery patients despite having no difference in obesity rates compared to females. Male gender is an independent risk factor for major post-operative complications and 30-day mortality, even after controlling for comorbidities.