Factors contributing to weight loss success after bariatric procedures in patient over 65 years old: a multicenter retrospective cohort study

BACKGROUND

Although bariatric surgery in patients over 65 years of age gives comparable results to treatment in the younger population, there are still controversies regarding the indications for surgery, risk assessment, and choice between different types of surgery. The study aimed to identify the factors contributing to weight loss success after bariatric surgery in patients over 65 years of age.

MATERIAL AND METHODS

This is a retrospective, multicenter cohort study of patients with obesity aged over 65 years undergoing primary laparoscopic bariatric surgery in the years 2008-2022. Data came from 11 bariatric centers. Patients were divided into two groups: responders (R) who achieved more than 50% EWL and nonresponders (NR) who achieved less than 50% EWL. Both groups were compared. Uni- and multivariate logistic regression was used to identify predictors of weight loss success.

RESULTS

Out of 274 analyzed patients, the average BMI before surgery was 42.9 kg/m 2 . The most common obesity-related diseases were hypertension (85.1%) and type 2 diabetes (53.3%). Sleeve gastrectomy was the most frequently performed procedure (85.4%). Uni- and multivariate logistic regression analysis confirmed preoperative BMI (OR=0.9, 95% CI: 0.82-0.98, P =0.02), duration of diabetes >10 years (OR=0.3, 95% CI: 0.09-0.82, P =0.02), balloon placement (OR=10.6, 95% CI: 1.33-84.83, P =0.03), time since first visit (OR=0.9, 95% CI: 0.84-0.99, P =0.04), preoperative weight loss (OR=0.9, 95% CI: 0.86-0.98, P =0.01), and OAGB (OR=15.7, 95% CI: 1.71-143.99, P =0.02) to have a significant impact on weight loss success 1 year after bariatric surgery.

CONCLUSIONS

Patients with higher preoperative weight loss may have a poorer response to surgery. OAGB emerged as the most beneficial type of surgery in terms of weight loss. Intragastric balloon placement before surgery may be effective in patients above 65 years of age and may be considered as a two-stage approach.

Impact of Preoperative Weight Loss on 30-Day Complication Rate after Bariatric Surgery

BACKGROUND

The aim of this study is to evaluate the impact of preoperative weight loss on surgical outcomes and operating room (OR) times after primary bariatric procedures, including laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (RYGB).

STUDY DESIGN

A retrospective cohort study uses the 2021 MBSAQIP dataset. Preoperative total weight loss (TWL)% was calculated. Patients were then divided in to 4 groups: those with no weight loss, lost <0 to <5%, lost ≥5% to <10%, or lost ≥10% TWL preoperatively. These groups were then stratified into those with BMI less than 50 kg/m 2 and those with BMI 50 kg/m 2 or more and 30-day outcomes and OR times were compared.

RESULTS

Analysis included 171,010 patients. For BMI less than 50 kg/m 2 , preoperative weight loss led to no consistent improvement in surgical outcomes. Although >0% to <5% TWL led to a decrease in intra- and postoperative occurrences after RYGB and a decrease in reoperation rates after LSG, these observations were not seen in those with higher degree of weight loss. In patients with BMI 50 kg/m 2 or more, preoperative weight loss showed a consistent improvement in reintervention rates after LSG, and readmission rates after RYGB. There was no improvement in other outcomes, however, irrespective of degree of preoperative weight loss.

CONCLUSIONS

In patients undergoing primary bariatric surgery, preoperative weight loss does not lead to a consistent improvement in outcomes or OR times. In those with BMI 50 kg/m 2 or more, there may be improvement in select outcomes that is procedure-specific. Overall, these data do not support a uniform policy of preoperative weight loss, although selective use in some high-risk patients may be appropriate.

Exercise Across the Phases of Cancer Survivorship: A Narrative Review

Exercise has long been recognized as an important component of treatment for various diseases. However, the benefits and risks of exercise interventions must be carefully evaluated to ensure the former outweighs the latter. As cancer patients undergo diverse treatment modalities with distinct objectives, a systematic approach partitioning the cancer journey into distinct phases is necessary to inform tailored exercise prescriptions. This narrative review summarizes exercise benefits and mechanisms for cancer patients and survivors across four distinct survivorship periods-before surgery, after surgery and before adjuvant treatment, during nonsurgical treatment (adjuvant and neoadjuvant), and during extended survival. In summary, exercise reduces the risks of complications and declines in physical functioning while improving fatigue, quality of life, and the ability to manage treatment effects. Although additional research is warranted, existing evidence is sufficient to integrate exercise into clinical oncology practice and cancer survivorship programs.

Multimodal approach utilising a weight management programme prior to bariatric surgery in patients with BMI ≥50 kg/m2: A propensity score matching retrospective cohort study

We evaluated preoperative weight loss and days from initial consult to surgery in patients with BMI ≥50 kg/m2 who were and were not enrolled in medical weight management (MWM) prior to laparoscopic sleeve gastrectomy. We retrospectively identified patients with BMI ≥50 kg/m2 who had primary sleeve gastrectomy between 2014 and 2019 at two bariatric surgery centres in our healthcare system. Patients presenting after 2017 that received preoperative MWM (n = 28) were compared to a historical cohort of non-MWM patients (n = 118) presenting prior to programme initiation in 2017 on preoperative percent total body weight loss (%TBWL) and days from initial consult to surgery. A total of 151 patients (MWM, 33; non-MWM, 118) met inclusion criteria. BMI was significantly greater in MWM versus non-MWM (p = .018). After propensity score matching, median BMI at initial consult in non-MWM versus MWM no longer differed (p = .922) neither were differences observed on the basis of weight, age, sex, race or ethnicity. After PSM, MWM had significantly lower BMI at surgery (p = .018), lost significantly more weight from consult to surgery (p < .001) and achieved significantly greater median %TBWL from consult to surgery (p < .001). We noted no difference between groups on 6-month weight loss (p = .533). Days from initial consult to surgery did not differ between groups (p < .863). A preoperative MWM programme integrated into multimodal treatment for obesity in patients with a BMI ≥50 kg/m2 resulted in clinically significant weight loss without prolonging time to surgery.

Risk factors for bariatric surgery in patients over 65 years of age-a multicenter retrospective cohort study

PURPOSE

Societies are aging, life expectancy is increasing, and as a result, the percentage of elderly people in the population is constantly increasing. When qualifying patients over 65 years of age for bariatric surgery, the benefits and risks should be carefully assessed. Weighing risk factors against each other to improve the quality of life and better control of obesity-related diseases. The study aimed to determine risk factors for bariatric surgery among patients over 65 years of age.

METHODS

A multicenter, retrospective analysis of patients undergoing laparoscopic bariatric procedures from 2008 to 2022. The patients were divided into two groups: complicated (C) and uncomplicated (UC). Uni- and multivariate logistic regression analysis was performed to obtain significant, independent risk factors.

RESULTS

There were 20 (7.0%) patients in C group and 264 (93.0%) patients in UC group. The most common complication was intraperitoneal bleeding (8, 2.8). There was no postoperative mortality. The mean follow-up was 47.5 months. In a multivariate logistic regression analysis, length of stay and %EWL significantly corresponded to general complications (OR 1.173, OR 1.020). A higher weight loss before surgery lowered the risk for hemorrhagic events after surgery (OR 0.889). A longer length of stay corresponded to leak after surgery (OR 1.175).

CONCLUSIONS

Bariatric and metabolic surgery appears to be a safe method of obesity treatment in patients over 65 years of age. The most common complication was intraperitoneal bleeding. A prolonged hospital stay may increase the risk of leakage, while a higher weight loss before the surgery may lower the risk of bleeding.

The impact of a preoperative evaluation process on weight reduction and glycemic control in patients undergoing bariatric and metabolic surgery

Introduction

Metabolic surgery is a sustainable intervention for obesity and type 2 diabetes. Preoperative education optimizes weight loss and glycemic control outcomes.

Objective

This study aimed to determine the effect of a generalized preoperative evaluation process (PEP) in patients who underwent bariatric surgery on weight loss and glycemic control pre- and post-surgery.

Methods

Data were retrospectively collected and analyzed for patients with type 2 diabetes who underwent bariatric surgery between 2010 and 2016. Patients were categorized into two groups determined by participation in the PEP. The groups were named the PEP group and non-PEP group. The correlation among engagement in the PEP was determined using the chi-square test and t-test. Statistical analysis with p < 0.05 was deemed significant.

Results

129 patients were included in the study; 86 females (67%) and 43 males (33%). Fifty-nine patients (46%) engaged in the PEP and 70 (54%) patients did not engage in the PEP. A greater reduction in weight loss was observed in the PEP group versus the non-PEP group from initial enrollment to pre-surgery (14.3 ± 9.2 kg vs. 11.6 ± 9.2 kg; p = 0.11), and from pre-surgery to 2-years post-surgery (20.6 ± 14.8 kg vs. 16.9 ± 15.6 kg; p = 0.17). A greater reduction in HbA1c from initial enrollment to pre-surgery was seen in the PEP group versus the non-PEP group (0.90 ± 1.28% vs. 0.63 ± 1.07%); however, this was not maintained from pre-surgery to 2-year post-surgery (0.51 ± 1.18% vs. 0.70 ± 1.73%). In both cases, the statistical difference was insignificant.

Conclusion

The PEP was not associated with improvements in short-term weight loss or glycemic control pre-surgery and a 2-years post-surgery. Patients may benefit from individually tailored preoperative weight management strategies.

Addressing uncertainty about the role of structured lifestyle modification for metabolic surgery patients

There is good evidence that structured lifestyle modification programmes improve health in patients with metabolic and cardiovascular disorders, but there is no specific evidence that they improve outcomes in patients undergoing metabolic or obesity surgery. Despite expert consensus guidelines stating this fact, some healthcare systems still compel patients to participate in a structured lifestyle modification programme prior to metabolic or obesity surgery. There is a well-established need for individualised multidisciplinary dietetic and physical activity care for metabolic and obesity surgery patients, and the benefits of intentional weight loss prior to surgery are well proven, but these are distinct from potentially harmful requirements for patients to undertake compulsory structured lifestyle programmes of fixed duration, frequency and intensity, which may delay surgery and reinforce obesity stigma. A critical step in rejuvenating metabolic surgery is to reframe patient participation in structured lifestyle modification programmes as an opportunity for education and empowerment, not as an indicator of motivation or suitability for metabolic surgery. Large, well-designed and adequately powered clinical trials are needed to address uncertainties in the evidence base for these programmes. Given genuine equipoise, they will need to determine whether "surgery plus lifestyle" is superior to "surgery plus placebo". Moreover, they will need to determine the cost-effectiveness of these programmes and identify some of the factors giving rise to the substantial heterogeneity in responses to structured lifestyle modification.

Post-hepatectomy liver failure: A timeline centered review

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a leading cause of postoperative mortality after liver surgery. Due to its significant impact, it is imperative to understand the risk stratification and preventative strategies for PHLF. The main objective of this review is to highlight the role of these strategies in a timeline centered way around curative resection.

DATA SOURCES

This review includes studies on both humans and animals, where they addressed PHLF. A literature search was conducted across the Cochrane Library, Embase, MEDLINE/PubMed, and Web of Knowledge electronic databases for English language studies published between July 1997 and June 2020. Studies presented in other languages were equally considered. The quality of included publications was assessed using Downs and Black's checklist. The results were presented in qualitative summaries owing to the lack of studies qualifying for quantitative analysis.

RESULTS

This systematic review with 245 studies, provides insight into the current prediction, prevention, diagnosis, and management options for PHLF. This review highlighted that liver volume manipulation is the most frequently studied preventive measure against PHLF in clinical practice, with modest improvement in the treatment strategies over the past decade.

CONCLUSIONS

Remnant liver volume manipulation is the most consistent preventive measure against PHLF.

Perioperative management of Obstructive Sleep Apnoea: Present themes and future directions

PURPOSE OF REVIEW

Obstructive sleep apnoea (OSA) is an increasingly common pathology that all those involved in perioperative care will come across. Patients with the condition present a challenge at many stages along the perioperative journey, not least because many patients living with OSA are unaware of their diagnosis.Key interventions can be made pre, intra-, and postoperatively to improve outcomes. Knowledge of screening tools, diagnostic tests, and the raft of treatment options are important for anyone caring for these patients.

RECENT FINDINGS

Recent literature has highlighted the increasing complexity of surgical patients and significant underdiagnosis of OSA in this patient population. Work has demonstrated how and why patients with OSA are at a higher perioperative risk and that effective positive airways pressure (PAP) therapy can reduce these risks, alongside evidencing how best to optimise adherence to therapy, a key issue in OSA.

SUMMARY

OSA, and particularly undiagnosed OSA, presents a huge problem in the perioperative period. Perioperative PAP reduces the risk of postoperative complications but adherence remains an issue. Bespoke perioperative pathways should be developed to identify and optimise high risk patients, although at present evidence on how best to achieve this is lacking.

The effect of preoperative behaviour change interventions on pre- and post-surgery health behaviours, health outcomes, and health inequalities in adults: A systematic review and meta-analyses

BACKGROUND

Prehabilitation interventions are being delivered across surgical specialities to improve health risk behaviours leading to better surgical outcomes and potentially reduce length of hospital stay. Most previous research has focused on specific surgery specialities and has not considered the impact of interventions on health inequalities, nor whether prehabilitation improves health behaviour risk profiles beyond surgery. The aim of this review was to examine behavioural Prehabilitation interventions across surgeries to inform policy makers and commissioners of the best available evidence.

METHODS AND FINDINGS

A systematic review and meta-analysis of randomised controlled trials (RCTs) was conducted to determine the effect of behavioural prehabilitation interventions targeting at least one of: smoking behaviour, alcohol use, physical activity, dietary intake (including weight loss interventions) on pre- and post-surgery health behaviours, health outcomes, and health inequalities. The comparator was usual care or no treatment. MEDLINE, PubMed, PsychINFO, CINAHL, Web of Science, Google Scholar, Clinical trials and Embase databases were searched from inception to May 2021, and the MEDLINE search was updated twice, most recently in March 2023. Two reviewers independently identified eligible studies, extracted data, and assessed risk of bias using the Cochrane risk of bias tool. Outcomes were length of stay, six-minute walk test, behaviours (smoking, diet, physical activity, weight change, and alcohol), and quality of life. Sixty-seven trials were included; 49 interventions targeted a single behaviour and 18 targeted multiple behaviours. No trials examined effects by equality measures. Length of stay in the intervention group was 1.5 days shorter than the comparator (n = 9 trials, 95% CI -2.6 to -0.4, p = 0.01, I2 83%), although in sensitivity analysis prehabilitation had the most impact in lung cancer patients (-3.5 days). Pre-surgery, there was a mean difference of 31.8 m in the six-minute walk test favouring the prehabilitation group (n = 19 trials, 95% CI 21.2 to 42.4m, I2 55%, P <0.001) and this was sustained to 4-weeks post-surgery (n = 9 trials, mean difference = 34.4m (95%CI 12.8 to 56.0, I2 72%, P = 0.002)). Smoking cessation was greater in the prehabilitation group before surgery (RR 2.9, 95% CI 1.7 to 4.8, I2 84%), and this was sustained at 12 months post-surgery (RR 1.74 (95% CI 1.20 to 2.55, I2 43%, Tau2 0.09, p = 0.004)There was no difference in pre-surgery quality of life (n = 12 trials) or BMI (n = 4 trials).

CONCLUSIONS

Behavioural prehabilitation interventions reduced length of stay by 1.5 days, although in sensitivity analysis the difference was only found for Prehabilitation interventions for lung cancer. Prehabilitation can improve functional capacity and smoking outcomes just before surgery. That improvements in smoking outcomes were sustained at 12-months post-surgery suggests that the surgical encounter holds promise as a teachable moment for longer-term behavioural change. Given the paucity of data on the effects on other behavioural risk factors, more research grounded in behavioural science and with longer-term follow-up is needed to further investigate this potential.

Variation and outcomes of liver-reducing dietary regimens before bariatric surgery: a national retrospective cohort study

BACKGROUND

Liver-reducing diets (LRDs) are mandated prior to bariatric surgery, but there are no guidelines on their implementation.

OBJECTIVE

To establish the variation and effectiveness of LRDs utilized in clinical practice.

SETTING

A nationwide, multicenter, retrospective cohort study.

METHODS

A total of 1699 adult patients across 14 bariatric centers in the United Kingdom were included. Multilevel logistic regression models were developed to examine factors predictive of 5% weight loss.

RESULTS

Most centers (n = 9) prescribed an 800- to 1000-kcal diet, but the duration and formulation of diet was variable. Overall, 30.6% (n = 510) of patients achieved 5% weight loss during the LRD. After adjustment for preoperative weight, women had reduced odds (odds ratio [OR], .65; 95% confidence interval [CI], .48-.88; P = .005), while increasing age (OR, 1.01; 95% CI, 1.00-1.02; P = .043) and having type 2 diabetes (OR, 1.49; 95% CI, 1.16-1.92; P = .002) increased odds of 5% weight loss. A normal consistency food LRD (OR, .64; 95% CI, .42-.98; P = .041) and energy prescription of >1200 kcals/d (OR, .33; 95% CI, .13-.83; P = .019) reduced odds, while an LRD with a duration of 3 weeks (OR, 2.28; 95% CI, 1.02-5.09; P = .044) or greater increased odds of 5% weight loss.

CONCLUSIONS

There is wide variation in how LRDs are delivered in clinical practice, highlighting the need for an evidence-based consensus. Our findings suggest the optimal LRD before bariatric surgery contains 800 to 1200 kcals/d over a duration of 3 to 4 weeks. Further research is required to determine the optimal formulation of LRD and whether women may require a lower-energy LRD than men.

Prehabilitation of overweight and obese patients with dysglycemia awaiting bariatric surgery: Predicting the success of obesity treatment

Bariatric surgery offers the best health results in overweight and obese patients but is not a risk and/or complication-free treatment. In cases with additional hyperglycemia, the burden of surgery can be even higher and alter both short-term and long-term outcomes. Although bariatric surgery offers glycemic improvements and in the case of early onset diabetes disease remission, weight loss results are lower than for obese patients without diabetes. Different multimodal programs, usually including interventions related to patients’ performance, nutritional and psychological status as well as currently available pharmacotherapy before the surgery itself might considerably improve the immediate and late postoperative course. However, there are still no clear guidelines addressing the prehabilitation of obese patients with dysglycemia undergoing bariatric surgery and therefore no unique protocols to improve patients’ health. In this minireview, we summarize the current knowledge on prehabilitation before bariatric surgery procedures in patients with obesity and dysglycemia.

Intermittent Fasting: Potential Utility in the Treatment of Chronic Pain across the Clinical Spectrum

Dietary behavior can have a consequential and wide-ranging influence on human health. Intermittent fasting, which involves intermittent restriction in energy intake, has been shown to have beneficial cellular, physiological, and system-wide effects in animal and human studies. Despite the potential utility in preventing, slowing, and reversing disease processes, the clinical application of intermittent fasting remains limited. The health benefits associated with the simple implementation of a 12 to 16 h fast suggest a promising role in the treatment of chronic pain. A literature review was completed to characterize the physiologic benefits of intermittent fasting and to relate the evidence to the mechanisms underlying chronic pain. Research on different fasting regimens is outlined and an overview of research demonstrating the benefits of intermittent fasting across diverse health conditions is provided. Data on the physiologic effects of intermittent fasting are summarized. The physiology of different pain states is reviewed and the possible implications for intermittent fasting in the treatment of chronic pain through non-invasive management, prehabilitation, and rehabilitation following injury and invasive procedures are presented. Evidence indicates the potential utility of intermittent fasting in the comprehensive management of chronic pain and warrants further investigation.

A broad focus on additional programmes prior to bariatric surgery: A systematic review

Additional preoperative programmes may be beneficial for candidates who seek bariatric surgery, but there is no consensus on the optimal preparation. This systematic review aimed to summarize the effects of a preoperative programme on weight loss. A literature search was performed for Embase, Cinahl, PubMed and Cochrane Library. Studies on preoperative exercise, behaviour and/or diet programmes administered in adult patients in a bariatric trajectory measuring weight loss were included. Initial results yielded 2148 titles, 70 of which were thoroughly analysed and 37 articles were included, comprising 10 333 patients. Eleven out of 37 studies included postoperative weight loss as an outcome in interventions focused on diet (n = 5), behaviour (n = 2), exercise (n = 2) and a combination of interventions (n = 2). Only one study (9%) which administered exercise as a preoperative programme showed a significant effect on postoperative weight loss. In total, 33 studies included preoperative weight loss as an outcome, which was significant in 64% of the cases. It is difficult to draw conclusions from the investigated data as it was extremely heterogeneous concerning the intensity, duration and administration of a programme. Nevertheless, it seems that a preoperative weight loss programme seems beneficial in terms of preoperative weight loss, postoperative physical activity and improved mental health postinterventional. The use of a core outcome set is recommended for future studies.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update

Background

This is the second updated Enhanced Recovery After Surgery (ERAS®) Society guideline, presenting a consensus for optimal perioperative care in bariatric surgery and providing recommendations for each ERAS item within the ERAS® protocol.

Methods

A principal literature search was performed utilizing the Pubmed, EMBASE, Cochrane databases and ClinicalTrials.gov through December 2020, with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. After critical appraisal of these studies, the group of authors reached consensus regarding recommendations.

Results

The quality of evidence for many ERAS interventions remains relatively low in a bariatric setting and evidence-based practices may need to be extrapolated from other surgeries.

Conclusion

A comprehensive, updated evidence-based consensus was reached and is presented in this review by the ERAS® Society.

Preoperative Weight Loss as a Predictor of Bariatric Surgery Postoperative Weight Loss and Complications

BACKGROUND

The association between preoperative weight loss and bariatric surgery outcomes remains unclear. We explored the utility of preoperative weight loss as a predictor of postoperative weight loss success. Additionally, we examined the association of preoperative weight loss with perioperative complication rates.

METHODS

Retrospective chart review of patients who underwent primary sleeve gastrectomy or primary Roux-en-Y gastric bypass for weight loss at a single institution between January 2003 and November 2017. Additional follow-up was obtained by a postoperative standardized patient questionnaire. Statistical analysis consisted of bivariate and multivariate logistic regression analysis.

RESULTS

Our study included 427 patients. Majority were female (n = 313, 73.3%) and underwent sleeve gastrectomy (n = 261, 61.1%). Average age was 45.6 years, and average follow-up was 6.3 years. Greater preoperative weight loss was associated with decreased length of stay (1.8 vs 1.3 days) in patients who underwent sleeve gastrectomy. Multivariable regression analysis revealed that preoperative weight loss was not associated with postoperative weight loss.

CONCLUSIONS

Preoperative weight loss is not predictive of postoperative weight loss success after bariatric surgery. Greater preoperative weight loss was associated with a mild decreased in length of stay but was not associated with a reduction in operative time, overall complication rates, ICU admissions, or intraoperative complications. The inconclusive literature and our findings do not support the medical necessity of weight loss prior to bariatric surgery for the purpose of reducing surgical complications or predicting successful postoperative weight loss success.

Prehabilitation in adult patients undergoing surgery: an umbrella review of systematic reviews

BACKGROUND

The certainty that prehabilitation improves postoperative outcomes is not clear. The objective of this umbrella review (i.e. systematic review of systematic reviews) was to synthesise and evaluate evidence for prehabilitation in improving health, experience, or cost outcomes.

METHODS

We performed an umbrella review of prehabilitation systematic reviews. MEDLINE, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Joanna Briggs Institute's database, and Web of Science were searched (inception to October 20, 2020). We included all systematic reviews of elective, adult patients undergoing surgery and exposed to a prehabilitation intervention, where health, experience, or cost outcomes were reported. Evidence certainty was assessed using Grading of Recommendations Assessment, Development and Evaluation. Primary syntheses of any prehabilitation were stratified by surgery type.

RESULTS

From 1412 titles, 55 systematic reviews were included. For patients with cancer undergoing surgery who participate in any prehabilitation, moderate certainty evidence supports improvements in functional recovery. Low to very low certainty evidence supports reductions in complications (mixed, cardiovascular, and cancer surgery), non-home discharge (orthopaedic surgery), and length of stay (mixed, cardiovascular, and cancer surgery). There was low to very low certainty evidence that exercise prehabilitation reduces the risk of complications, non-home discharge, and length of stay. There was low to very low certainty evidence that nutritional prehabilitation reduces risk of complications, mortality, and length of stay.

CONCLUSIONS

Low certainty evidence suggests that prehabilitation may improve postoperative outcomes. Future low risk of bias, randomised trials, synthesised using recommended standards, are required to inform practice. Optimal patient selection, intervention design, and intervention duration must also be determined.

Effect of weight-loss diets prior to elective surgery on postoperative outcomes in obesity: A systematic review and meta-analysis

This systematic review investigated the effects of weight-loss diets before elective surgery on preoperative weight loss and postoperative outcomes in people with obesity. Electronic databases were searched from inception to May 2021. Inclusion criteria were prospective cohort or randomised controlled studies that compared effects of weight-loss diets to standard care on postoperative outcomes in adults with obesity awaiting surgery. Participants with cancer or undergoing bariatric surgery were excluded. Data on preoperative weight change, length of stay, postoperative complications and patient-reported outcome measures were extracted and synthesised in meta-analyses. One randomised controlled trial involving total knee arthroplasty and two that investigated general surgery were eligible that included 173 participants overall. Each study compared low-calorie diets using meal replacement formulas to usual care. There is very-low-quality evidence of a statistically significant difference favouring the intervention for preoperative weight loss (mean difference [MD] -6.67 kg, 95% confidence interval [CI] -12.09 to -1.26 kg; p = 0.02) and low-quality evidence that preoperative weight-loss diets do not reduce postoperative complications to 30 days (odds ratio [OR] 0.34, 95% CI 0.08-1.42; p = 0.14) or length of stay (MD -3.72 h, 95% CI -10.76 to 3.32; p = 0.30). From the limited data that is of low quality, weight loss diets before elective surgery do not reduce postoperative complications.

Elective Surgery in Adult Patients with Excess Weight: Can Preoperative Dietary Interventions Improve Surgical Outcomes? A Systematic Review

This systematic review summarises the literature regarding the impact of preoperative dietary interventions on non-bariatric surgery outcomes for patients with excess weight/obesity, a known risk factor for poor surgical outcomes. Four electronic databases were searched for non-bariatric surgery studies that evaluated the surgical outcomes of a preoperative diet that focused on weight/fat loss or improvement of liver steatosis. Meta-analysis was unfeasible due to the extreme heterogeneity of variables. Fourteen studies, including five randomised controlled trials, were selected. Laparoscopic cholecystectomy, hernia repair, and liver resection were most studied. Diet-induced weight loss ranged from 1.4 kg to 25 kg. Preoperative very low calorie diet (≤800 kcal) or low calorie diet (≤900 kcal) for one to three weeks resulted in: reduction in blood loss for two liver resection and one gastrectomy study (-27 to -411 mL, p < 0.05), and for laparoscopic cholecystectomy, reduction of six minutes in operating time (p < 0.05) and reduced difficulty of aspects of procedure (p < 0.05). There was no difference in length of stay (n = 7 studies). Preoperative ≤ 900 kcal diets for one to three weeks could improve surgical outcomes for laparoscopic cholecystectomy, liver resection, and gastrectomy. Multiple randomised controlled trials with common surgical outcomes are required to establish impact on other surgeries.

Expert opinion on the preoperative medical optimization of adults with diabetes undergoing metabolic surgery

Diabetes mellitus (DM) and obesity are interrelated in a complex manner, and their coexistence predisposes patients to a plethora of medical problems. Metabolic surgery has evolved as a promising therapeutic option for both conditions. It is recommended that patients, particularly those of Asian origin, maintain a lower body mass index threshold in the presence of uncontrolled DM. However, several comorbidities often accompany these chronic diseases and need to be addressed for successful surgical outcome. Laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are the most commonly used bariatric procedures worldwide. The bariatric benefits of RYGB and LSG are similar, but emerging evidence indicates that RYGB is more effective than LSG in improving glycemic control and induces higher rates of long-term DM remission. Several scoring systems have been formulated that are utilized to predict the chances of remission. A glycemic target of glycated hemoglobin < 7% is a reasonable goal before surgery. Cardiovascular, pulmonary, gastrointestinal, hepatic, renal, endocrine, nutritional, and psychological optimization of surgical candidates improves perioperative and long-term outcomes. Various guidelines for preoperative care of individuals with obesity have been formulated, but very few specifically focus on the concerns arising from the presence of concomitant DM. It is hoped that this statement will lead to the standardization of presurgical management of individuals with DM undergoing metabolic surgery.

Prehabilitation for Bariatric Surgery: A Randomized, Controlled Trial Protocol and Pilot Study

Bariatric surgery is the most efficacious treatment for obesity, though it is not free from complications. Preoperative conditioning has proved beneficial in various clinical contexts, but the evidence is scarce on the role of prehabilitation in bariatric surgery. We describe the protocol and pilot study of a randomized (ratio 1:1), parallel, controlled trial assessing the effect of a physical conditioning and respiratory muscle training programme, added to a standard 8-week group intervention based on therapeutical education and cognitive-behavioural therapy, in patients awaiting bariatric surgery. The primary outcome is preoperative weight-loss. Secondary outcomes include associated comorbidity, eating behaviour, physical activity, quality of life, and short-term postoperative complications. A pilot sample of 15 participants has been randomized to the intervention or control groups and their baseline features and results are described. Only 5 patients completed the group programme and returned for assessment. Measures to improve adherence will be implemented and once the COVID-19 pandemic allows, the clinical trial will start. This is the first randomized, clinical trial assessing the effect of physical and respiratory prehabilitation, added to standard group education and cognitive-behavioural intervention in obese patients on the waiting list for bariatric surgery. Clinical Trial Registration: NCT0404636.

Structured Lifestyle Modification Prior to Bariatric Surgery: How Much is Enough?

Many healthcare systems require patients to participate in a structured lifestyle modification programme prior to bariatric surgery, even though bariatric consensus guidelines do not recommend this. While there is good evidence that such programmes improve health in other conditions such as metabolic and cardiovascular diseases, there is no evidence that they improve outcomes after bariatric surgery. The distinction needs to be drawn between the well-established need for individualised multidisciplinary dietetic and physical activity care for bariatric surgical patients and the potential harms from mandating participation in compulsory structured lifestyle programmes of fixed duration, frequency and intensity, which may delay surgery, reinforce obesity stigma, or both. Large clinical trials might help to address some of the uncertainty and provide an evidence base for clinicians and policymakers.

Preoperative weight loss in women with obesity in gynaecologic oncology: A retrospective study

To retrospectively review the efficacy of short term supervised medical weight loss for women with obesity, body mass index (BMI ≥40 kg/m² ) in gynaecologic oncology, and the associated perioperative and pathologic outcomes. A retrospective study of a dedicated preoperative weight loss clinic for gynaecologic oncology patients from March to December 2019. Statistical analysis was performed with McNemar's test for correlated proportions, Pearson's correlation tests for continuous variables, and paired t-tests to compare means. Generalized estimating equations (GEE) were used to determine the factors associated with weight loss over time. A P-value of <.05 was used for statistical significance. Review of cases up-graded after surgery was performed by a gynaecologic pathologist. There were a total of 49 women included in the study. The most common referral reason was endometrioid carcinoma or hyperplasia of the endometrium (77.6%). Mean initial weight was 130.2 kg, and corresponding mean BMI 48.1 kg/m² . Patients attended on average nine preoperative weight loss visits. A significant difference between initial weight and weight at surgery was demonstrated, from 129.6 to 118.0 kg (8.4% weight loss) (P < .0001). This difference persisted to their post-surgical visit, with an additional mean loss of 1.89 kg (9.4% weight loss) (P = .044). The majority (92.1%) of patients with endometrial pathology had surgical management, and of these 85.7% were minimally invasive. Preoperative weight loss is a feasible option in gynaecologic oncology patients. Greater understanding of clinical significance, follow-up, and ideal target population for this intervention is needed.

Association of Preoperative Body Weight and Weight Loss With Risk of Death After Bariatric Surgery

IMPORTANCE

Perception of weight loss requirements before bariatric surgery varies among patients, physicians, and health insurance payers. Current clinical guidelines do not require preoperative weight loss because of a lack of scientific support regarding its benefits.

OBJECTIVE

To examine the association of preoperative body mass index (BMI) and weight loss with 30-day mortality after bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from 480 075 patients who underwent bariatric surgery from 2015 to 2017 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, which covers more than 90% of all bariatric surgery programs in the United States and Canada. Clinical and demographic data were collected at all participating institutions using a standardized protocol. Data analysis was performed from December 2018 to November 2019.

EXPOSURES

Preoperative BMI and weight loss.

MAIN OUTCOMES AND MEASURES

30-day mortality after bariatric surgery.

RESULTS

Of the 480 075 patients (mean [SD] age 45.1 [12.0] years; 383 265 [79.8%] women), 511 deaths (0.1%) occurred within 30 days of bariatric surgery. Compared with patients with a preoperative BMI of 35.0 to 39.9, the multivariable-adjusted odds ratios for 30-day mortality for patients with preoperative BMI of 40.0 to 44.9, 45.0 to 49.9, 50.0 to 54.9, and 55.0 and greater were 1.37 (95% CI, 1.02-1.83), 2.19 (95% CI, 1.64-2.92), 2.61 (95% CI, 1.90-3.58), and 5.03 (95% CI, 3.78-6.68), respectively (P for trend < .001). Moreover, compared with no preoperative weight loss, the multivariable-adjusted odds ratios for 30-day mortality for patients with weight loss of more than 0% to less than 5.0%, 5.0% to 9.9%, and 10.0% and greater were 0.76 (95% CI, 0.60-0.96), 0.69 (95% CI, 0.53-0.90), and 0.58 (95% CI, 0.41-0.82), respectively (P for trend = .003).

CONCLUSIONS AND RELEVANCE

In this study, even moderate weight loss (ie, >0% to <5%) before bariatric surgery was associated with a lower risk of 30-day mortality. These findings may help inform future updates of clinical guidelines regarding bariatric surgery.

Efficacy and safety of very low calorie ketogenic diet (VLCKD) in patients with overweight and obesity: A systematic review and meta-analysis

Very low calorie ketogenic diet (VLCKD) has been proposed as a promising option to achieve a significant weight loss in a short time period. We conducted a systematic review and meta-analysis to evaluate its efficacy and safety in patients with overweight and obesity. Four databases were searched on May 2019. Studies reporting data on body weight, body mass index (BMI), waist circumference, body composition, blood pressure, HbA1c, lipids, and markers of liver and kidney function were selected. Discontinuation was also assessed. Twelve studies were included. VLCKD was associated with weight losses of -10.0 kg (I² = 6%) and - 15.6 kg (I² = 37%) in studies with a ketogenic phase up to and of at least four weeks, respectively. The weight lost during the ketogenic phase was stable in the subsequent follow-up up to two years (p = 0.12). Also, VLCKD was associated with reductions of BMI (-5.3 kg/m²), waist circumference (-12.6 cm), HbA1c (-0.7%), total cholesterol (-28 mg/dl), triglycerides (-30 mg/dl), AST (-7 U/l), ALT (-8 U/l), GGT (-8 U/l), systolic and diastolic blood pressure (-8 and - 7 mmHg, respectively). No changes in LDL cholesterol, HDL cholesterol, serum creatinine, serum uric acid and serum potassium were found. Serum sodium increased during VLCKD (+1.6 mEq/l). The overall prevalence of patients discontinuing VLCKD was 7.5% and this was similar to patients undergoing a low calorie diet (p = 0.83). The present review supports the use of VLCKD as an effective strategy for the management of overweight and obesity. Future guidelines should include a specific recommendation for this intervention.

Lifestyle and pharmacologic management before and after bariatric surgery

As metabolic and bariatric surgery (MBS) increasingly becomes a treatment of choice for adolescents with severe obesity, there is a need to understand how to deliver pre- and postoperative care in ways that maximize long-term safety and efficacy. This article describes major pre- and postoperative goals, lifestyle modification targets, and, when necessary, pharmacologic management strategies for adolescents undergoing MBS. Three categories of evidence were used-studies of pre- and postoperative interventions and factors influencing MBS outcomes in adolescents, studies of pre- and postoperative associations and interventions in adults, and studies of non-surgical weight management applicable to adolescents pursuing MBS. Finally, priority areas for future research within this topic are identified.