Short-Term Preoperative Weight Loss and Postoperative Outcomes in Bariatric Surgery

Obesity Management Medications as Adjuncts to Metabolic and Bariatric Surgery: Consensus Recommendations from India

Obesity is a global health concern, with weight regain (WR) common after bariatric surgery. Clear guidelines on post-surgical medication use are essential. This expert consensus evaluates the role of obesity management medications (OMMs) in optimizing weight loss (WL) and preventing WR in individuals undergoing metabolic and bariatric surgery (MBS). Using a modified Delphi approach, a panel of 12 experts reviewed evidence and formulated consensus recommendations. Two voting rounds led to consensus on 11 of 15 statements, covering preoperative WL strategies and postoperative weight management. The recommendations guide OMM selection, timing, and effectiveness in enhancing WL outcomes. Integrating OMMs into bariatric care protocols can help clinicians improve long-term success rates in obesity management.

The effect of preoperative body weight loss on 5-year bariatric surgery outcomes

OBJECTIVES

This study aimed to evaluate the effect of preoperative total body weight loss (TBWL) following a structured 6-month lifestyle change programme (LCP) on the level of TBWL at 12 months and its maintenance at 60 months post bariatric surgery (BS), as well as its impact on operation time, hospital stay, surgical complications and obesity-associated pathology remission.

METHODS

This retrospective, single-centre study analysed patients undergoing primary BS between 2013 and 2014. Outcomes were compared between patients participating in the LCP (LCP group) and those receiving standard preoperative education (Control group: CG). Data collected included anthropometric measurements, obesity-related pathologies, surgical complications, and weight-related outcomes.

RESULTS

Among 340 BS procedures performed, 165 patients met the inclusion criteria; 59 in the LCP group and 106 in the CG. The mean age was 47 ( ± 11.6) years in the LCP group and 45 ( ± 11.1) years in the CG with no significant differences in baseline clinical characteristics. At surgery, the LCP group showed significant weight reduction (-5.9 kg vs. -0.72 kg in controls, p = 0.008) and their BMI was significantly lower (46.55 vs. 49.47 kg/m², p = 0.002). Postoperatively, weight-related outcomes [BMI and TBWL] were better in the LCP group at 1 and 5 years. Additionally, patients achieving a preoperative TBWL > 5% demonstrated a significantly lower weight and BMI, along with a higher postoperative TBWL. Surgical complications were minimal, with no significant differences in 30-day complication rates. We did not observe a greater resolution of comorbidities in patients who participated in the LCP or those who achieved a preoperative TBWL ≥ 5%.

CONCLUSIONS

While current evidence suggests that preoperative TBWL provides short-term benefits, our data suggest this may also be the case for TBWL in the long-term. Further research is needed to fully elucidate the role of preoperative TBWL in comorbidity resolution in BS patients.

Prescribing preoperative weight loss prior to major non-bariatric surgery for patients with elevated weight: a national provider survey (PREPARE provider survey)

Background

The surgical patient with obesity presents several challenges in intraoperative and postoperative care. We designed this cross-sectional survey to assess surgeon willingness to prescribe preoperative very low energy diets (VLEDs) and practice patterns in prescribing preoperative weight loss interventions for patients with obesity undergoing non-bariatric abdominal surgery.

Methods and findings

We conducted a cross-sectional survey of practicing surgeons in Canada who perform major non-bariatric abdominal surgery, reported in accordance with the Consensus-Based Checklist for Reporting of Survey Studies and utilizing non-probability convenience sampling. The primary outcome was willingness to prescribe preoperative VLED to obese patients undergoing major non-bariatric abdominal surgery for both benign and malignant indications. We created a multivariable proportional odds model to identify factors associated with willingness to prescribe VLEDs. A total of 78 participants completed and returned the survey (response rate 10.9%; mean age 43.54 ± 8.13 years; 48.72% female). Most surgeons (79.5%) felt that obesity significantly impacted the technical difficulty of their operations. We identified a disconnect between those surgeons who were willing prescribe VLEDs vs. those who actually prescribed them (78.2% vs. 30.8%, respectively). Approximately half of the surgeons reported being unfamiliar with VLEDs. Regression analysis identified practicing in academic institutions was associated with increased willingness to prescribe [odds ratio (OR) 3.71, 95% confidence intervals (CI) 1.01-13.7, p < 0.01].

Conclusion

Although the majority of surgeons feel that obesity adversely impacts perioperative care, only one-third routinely discuss preoperative VLEDs with their patients. Opportunities to increase awareness and evaluate the impact of VLEDs on patient outcomes remain high.

Intentional weight reduction before surgery - A systematic review

INTRODUCTION

Obesity may increase complexity of surgical procedures and increase the risk of perioperative complications. Weight reduction by the use of low energy diet (LED, ≤1200 kcal/day) or very low energy diet (VLED, ≤800 kcal/day) can reduce postoperative complications after bariatric surgery, but for most other types of surgery the evidence for its use remains uncertain. The aim of this systematic review was therefore to evaluate the scientific evidence in general for this routine.

METHODS

The Medline, Embase, Web of Science and Cochrane databases were searched up until November 20, 2024 using the Cochrane risk of bias assessment tool for observational studies and the NIH quality assessment of controlled intervention studies for randomized trials. Operation time, surgeon's perceived difficulty, intraoperative complications, postoperative complications and relevant efficacy measures for specific procedures were considered as endpoints. A random-effects model was used to pool effect sizes for the main analyses.

RESULTS

A total of 7053 studies were identified. After screening by title and abstract, followed by full text, 18 studies (9 RCTs and 9 observational studies) remained for the analyses including 854 patients who received the intervention and 979 controls. Preoperative LED/VLED resulted in an overall shorter operation time (standard mean difference 0.36, 95 % CI 0.14-0.59, p = 0.002), and reduced risk of postoperative complications after bariatric surgery, cholecystectomy, colorectal surgery and hernia repair (pooled RR 0.63, 95%CI 0.51-0.79, p < 0.001). Heterogeneity between studies was high for operation time but very low for complications. No difference was seen for intraoperative complications, while the data did not allow further analyses on perceived difficulty of surgery or efficacy outcomes.

CONCLUSION

The results support the use of LED/VLED for short-term preoperative weight reduction in patients with obesity planned for bariatric surgery and for those undergoing cholecystectomy, colorectal surgery and hernia repair. Further studies including a comparable control group are needed to evaluate its routine use for other surgical procedures.

REGISTRATION

The protocol of this study was preregistered at the International Prospective Register of Systematic Reviews, PROSPERO.

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.

Preoperative very low-energy diets for obese patients undergoing intra-abdominal colorectal surgery: a retrospective cohort study (RetroPREPARE)

BACKGROUND

Very low-energy diets (VLEDs) prescribed prior to bariatric surgery have been associated with decreased operative time, technical difficulty, and postoperative morbidity. To date, limited data are available regarding the impact of VLEDs prior to colorectal surgery. We designed this study to determine whether preoperative VLEDs benefit patients with obesity undergoing colorectal surgery.

METHODS

This is a single-center retrospective cohort study. Individuals undergoing elective colorectal surgery with a body mass index (BMI) of greater than 30 kg/m2 from 2015 to 2022 were included. The exposure of interest was VLEDs for 2-4 weeks immediately prior to surgery. The control group consisted of patients prior to January 2018 who did not receive preoperative VLED. The primary outcome was 30 day postoperative morbidity. Multivariable logistic regression modeling was used to determine associations with 30 day postoperative morbidity.

RESULTS

Overall, 190 patients were included, 89 patients received VLEDs (median age: 66 years; median BMI: 35.9 kg/m2; 48.3% female) and 101 patients did not receive VLEDs (median age: 68 years; median BMI: 32.1 kg/m2; 44.6% female). One-hundred four (54.7%) patients experienced 30 day postoperative morbidity. Multivariable regression analysis identified three variables associated with postoperative morbidity: VLEDs [odds ratio (OR) 0.22, 95% confidence intervals (CI) 0.08-0.61, P < 0.01], Charlson comorbidity index (OR 1.25, 95% CI 1.03-1.52, P = 0.02), and rectal dissections (OR 2.71, 95% CI 1.30-5.65, P < 0.01).

CONCLUSIONS

The use of a preoperative VLED was associated with a significant reduction in postoperative morbidity in patients with obesity prior to colorectal surgery. A high-quality randomized controlled trial is required to confirm these findings.

Early changes of microRNAs in blood one month after bariatric surgery

BACKGROUND

Changes in microRNAs (miRNAs) are relevant to bariatric surgery and its comorbidities. The characteristics of changes in miRNAs of the early postoperative period following both bariatric procedures, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), as well as the factors that related to the effectiveness of early weight loss remain unclear.

METHODS

We recruited 18 patients who performed SG and 15 patients who performed RYGB. Their preoperative and 1-month postoperative clinical data and fasting serum samples were collected, and the latter were analyzed by RNA-sequencing. Differential expression analysis of miRNAs was performed by the R-tool. Functional classification annotation and pathway enrichment analysis of targeted genes were analyzed by KOBAS software. The change profiles of miRNAs for both surgeries and their correlation with clinical characteristics and weight loss effectiveness were further analyzed.

RESULTS

A total of 85 differentially expressed miRNAs were identified before and after SG, while a total of 76 were found before and after RYGB. The target genes of these miRNAs were similar in the Gene Ontology enrichment analysis in SG and RYGB, and the enrichment analysis in the Kyoto Encyclopedia of Genes and Genomes was mainly related to metabolic pathways. Hsa-miR-493-5p, hsa-miR-184, and hsa-miR-3199 exhibited similar changes in SG and RYGB, and the former two were correlated with clinical characteristics. Hsa-miR-6729-5p, hsa-miR-4659b-5p, and hsa-miR-2277-5p were correlated with the weight loss effectiveness of SG, while hsa-miR-4662a-5p was correlated with the weight loss effectiveness of RYGB.

CONCLUSIONS

Short-term metabolic improvement and weight loss occurring after SG and RYGB surgery might be related to changes in miRNAs, which act on multiple biological pathways by regulating genes. In addition, some clinical characteristics and miRNAs were related to the effectiveness of early weight loss after SG and RYGB surgery.

CLINICAL TRIAL REGISTRATION

ChiCTR2200058333.

PReoperative very low-Energy diets for obese PAtients undergoing non-bariatric surgery Randomized Evaluation (PREPARE): a protocol for a pilot randomized controlled trial

BACKGROUND

Patients with obesity presenting in need of surgical intervention are at 2-to-sixfold higher risk of prolonged hospitalization, infectious morbidity, venous thromboembolism, and more. To mitigate some of these concerns, prescribed preoperative weight loss via very low-energy diets (VLEDs) has become a standard of care for patients with obesity undergoing bariatric surgery. While VLEDs have become standard prior to bariatric surgery, their application in other surgical settings remains limited. A large, definitive trial is required to resolve the uncertainty surrounding their use in these patients. Prior to a definitive trial to compare the efficacy of VLEDs in patients with obesity undergoing major non-bariatric surgery, we require a pilot trial. We argue a pilot trial will provide the following critical feasibility insights: (1) assessment of recruitment ability, (2) evaluation of adherence to VLED regimens, and (3) assessment of our ability follow patients completely.

METHODS

The proposed trial will be a multi-center, surgeon, outcome assessor, and data-analyst blinded, parallel pilot randomized controlled trial (RCT). Patients older than 18 years of age with a body mass index (BMI) of greater than 30 kg/m2 undergoing major elective non-bariatric surgery will be eligible for inclusion. Consecutive patients will be allocated 1:1 according to a computer-generated randomization schedule. Randomization will be stratified by center and will employ randomly permutated blocks. All patients in the intervention group will receive standard patient counseling on weight loss and an active VLED protocol. The preoperative VLED protocol will utilize commercially available weight loss products for three weeks preoperatively. The primary outcomes (randomization percentage, recruitment rate, intervention adherence, follow-up completion, network development) will assess feasibility. Descriptive statistics will be used to characterize the study sample.

DISCUSSION

The PREPARE pilot RCT will aim to provide feasibility and safety data that will allow for the successful completion of the definitive PREPARE trial that has the potential to provide practice changing data pertaining to the regular use of VLEDs as a means of pre-habilitation for patients with obesity undergoing major non-bariatric surgery.

TRIAL REGISTRATION

This study was registered on ClinicalTrials.gov (reference #NCT05918471) on June 23, 2023.

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.

Evaluate the Effects of Different Types of Preoperative Restricted Calorie Diets on Weight, Body Mass Index, Operation Time and Hospital Stay in Patients Undergoing Bariatric Surgery: a Systematic Review and Meta Analysis Study

Previous studies investigated low-calorie diets (LCD), very-low-calorie diets (VLCD), and very-low-calorie ketogenic diets (VLCKD) in relation to weight loss and outcomes for bariatric surgery patients. However, the overall effects of these diets on various outcomes remain unclear. This study aimed to assess the impact of preoperative restricted calorie diets on weight, body mass index (BMI), operation time (OT), and hospital stay (HS) in bariatric surgery patients. Seventeen articles were analyzed, revealing the highest weight loss (-8.62) and BMI reduction (-5.75) with VLCKD. Due to insufficient data, the impact of these diets on OT and HS could not be determined. Further interventional studies are required to determine the ideal preoperative diet that achieves optimal weight loss, patient compliance, tolerance, acceptance, and surgical outcomes.

Preoperative Weight Gain Is Not Related to Lower Postoperative Weight Loss, But to Lower Total Weight Loss up to 3 Years After Bariatric-Metabolic Surgery

INTRODUCTION

Weight loss prior to bariatric-metabolic surgery (BMS) is recommended in most bariatric centers. However, there is limited high-quality evidence to support mandatory preoperative weight loss. In this study, we will evaluate whether weight gain prior to primary BMS is related to lower postoperative weight loss.

METHODS

A retrospective analysis of prospectively collected data was performed. Preoperative weight loss (weight loss from start of program to day of surgery), postoperative weight loss (weight loss from day of surgery to follow-up), and total weight loss (weight loss from start of program to follow-up) were calculated. Five groups were defined based on patients' preoperative weight change: preoperative weight loss of >5 kg (group I), 3-5 kg (group II), 1-3 kg (group III), preoperative stable weight (group IV), and preoperative weight gain >1 kg (group V). Linear mixed models were used to compare the postoperative weight loss between group V and the other four groups (I-IV).

RESULTS

A total of 1928 patients were included. Mean age was 44 years, 78.6% were female, and preoperative BMI was 43.7 kg/m2. Analysis showed significantly higher postoperative weight loss in group V, compared to all other groups at 12, 24, and 36 months follow-up. Up to three years follow-up, highest total weight loss was observed in group I.

CONCLUSION

Weight gain before surgery should not be a reason to withhold a bariatric-metabolic operation. However, patients with higher preoperative weight loss have higher total weight loss. Therefore, preoperative weight loss should be encouraged prior to bariatric surgery.

Nutrition, Physical Activity, and Prescription of Supplements in Pre- and Post-bariatric Surgery Patients: An Updated Comprehensive Practical Guideline

Only in the USA, 315 billion dollars are spent annually on the medical cost of obesity in adult patients. Till now, bariatric surgery is the most effective method for treating obesity and can play an essential role in reducing the direct and indirect costs of obesity treatment. Nonetheless, there are few comprehensive guidelines which include nutrition, physical activity, and supplements, before and after surgery. The purpose of the present narrative review is to provide an updated and comprehensive practical guideline to help multidisciplinary teams. The core keywords include nutrition, diet, physical activity, exercise, supplements, macronutrients, micronutrients, weight reduction, bariatric surgery, Roux-en-Y Gastric Bypass, Sleeve Gastrostomy, Laparoscopic Adjustable Gastric Banding, and Biliopancreatic diversion with duodenal switch which were searched in databases including PubMed/Medline, Cochrane, and some other sources such as Google Scholar. We answered questions in five important areas: (a) nutritional strategies before bariatric surgery, (b) nutrition after bariatric surgery, (c) physical activity before and after bariatric surgery, (d) weight regain after bariatric surgery, and (e) micronutrient assessments and recommendations before and after bariatric surgery. Some new items were added in this updated guideline including "weight regain" and "pregnancy after bariatric surgery." Other fields were updated based on new evidence and guidelines.

The link between lymphocyte subpopulations in peripheral blood and metabolic variables in patients with severe obesity

Background

Obesity, a public health problem, is a state of metainflammation that influences the development of chronic degenerative diseases, particularly in patients with severe obesity.

Objective

The objective of this study was to evidence immunometabolic differences in patients with different degrees of obesity, including severe obesity, by determining correlations between lymphocyte subpopulations and metabolic, body composition, and clinical variables.

Methods

Peripheral blood immune cells (CD4+, CD8+ memory and effector T lymphocytes) were analyzed, and measures of body composition, blood pressure, and biochemical composition (glucose, glycated hemoglobin (HbA1c), insulin, C-reactive protein (CRP), and the lipid profile) were carried out in patients with different degrees of obesity.

Results

The patients were classified according to total body fat (TBF) percentage as normal body fat, class 1 and 2 obesity, class 3 obesity, and class 4 obesity. The greater the TBF percentage, the more pronounced the differences in body composition (such as a decrease in the fat-free mass (FFM) that is defined as sarcopenic obesity) and the immunometabolic profile. There was an increase of CD3+ T lymphocytes (mainly CD4+, CD4+CD62-, and CD8+CD45RO+ T lymphocytes) and an increase in the TBF percentage (severity of obesity).

Conclusions

The correlations between lymphocyte subpopulations and metabolic, body composition, and clinical variables demonstrated the existence of a chronic, low-intensity inflammatory process in obesity. Therefore, measuring the immunometabolic profile by means of lymphocyte subpopulations in patients with severe obesity could be useful to determine the severity of the disease and the increased risk of presenting obesity-associated chronic degenerative diseases.

Obesity in Adults: Position Statement of Polish Association for the Study on Obesity, Polish Association of Endocrinology, Polish Association of Cardiodiabetology, Polish Psychiatric Association, Section of Metabolic and Bariatric Surgery of the Association of Polish Surgeons, and the College of Family Physicians in Poland

Obesity in adults and its complications are among the most important problems of public health. The search was conducted by using PubMed/MEDLINE, Cochrane Library, Science Direct, MEDLINE, and EBSCO databases from January 2010 to December 2022 for English language meta-analyses, systematic reviews, randomized clinical trials, and observational studies from all over the world. Six main topics were defined in the joint consensus statement of the Polish Association for the Study on Obesity, the Polish Association of Endocrinology, the Polish Association of Cardio-diabetology, the Polish Psychiatric Association, the Section of Metabolic and Bariatric Surgery of the Society of Polish Surgeons, and the College of Family Physicians in Poland: (1) the definition, causes and diagnosis of obesity; (2) treatment of obesity; (3) treatment of main complications of obesity; (4) bariatric surgery and its limitations; (5) the role of primary care in diagnostics and treatment of obesity and barriers; and (6) recommendations for general practitioners, regional authorities and the Ministry of Health. This statement outlines the role of an individual and the adequate approach to the treatment of obesity: overcoming obstacles in the treatment of obesity by primary health care. The approach to the treatment of obesity in patients with its most common complications is also discussed. Attention was drawn to the importance of interdisciplinary cooperation and considering the needs of patients in increasing the long-term effectiveness of obesity management.

[Pharmacotherapy of obesity-Competition to bariatric surgery or a meaningful supplement?]

Obesity is a complex chronic disease and requires a long-term multimodal approach. The current treatment algorithm for treatment of obesity mainly consists of a stepwise approach, which starts with a lifestyle intervention followed by or combined with medication treatment, whereas bariatric surgery is often reserved for the last option. This article provides an overview of the currently available conservative medicinal treatment regimens and the currently approved medications as well as medications currently undergoing approval studies with respect to the efficacy and possible side effects. Special attention is paid to the importance of combination treatment of pharmacotherapy and surgery in the sense of a multimodal treatment. The data so far show that using a multimodal approach an improvement in the long-term weight loss and metabolic benefits can be achieved for the patients.

Preoperative Weight Loss as a Predictor of Short and Midterm Postoperative Weight Loss in Patients Undergoing Bariatric Surgery

Objective

To examine if preoperative weight loss correlates to postoperative weight loss 2 and 3 years after surgery.

Methods

A review was conducted of bariatric surgery patients who underwent either gastric bypass or sleeve gastrectomy during 2015-2018 and had 3-year follow-up data. Demographic and outcome data were collected. A best-fit regression model for weight loss was constructed.

Results

Eight hundred fifty-nine patients underwent surgery during the selected period, of which 199 patients (23%) were analyzed. Eighty-two percent of patients had gastric bypass and 82% were female. Preoperative percent excess weight loss (%EWL) was not significantly associated with 2- and 3-year postoperative %EWL (p = 0.18). Patients demonstrated significant weight regain at 3 years postoperatively versus 1 year (p < 0.01). Higher preoperative weight loss was associated with lower %EWL 3 years postoperatively versus 1 year (p = 0.04). Postoperative %EWL had a significant negative association with higher preoperative weight, diabetes, baseline use of a mobility device, and sleeve gastrectomy.

Conclusions

In a cohort of bariatric surgery patients, there was no statistically significant association between preoperative and midterm postoperative %EWL. Postoperative %EWL was negatively associated with several patient-specific factors and increasing time since operation.

Very low energy diets before nonbariatric surgery: A systematic review and meta-analysis

BACKGROUND

Very low energy diets serve as an intensive approach to weight loss in a short period of time. Although the preoperative use of very low energy diets to optimize patients with obesity before bariatric surgery is well established, the evidence for very low energy diets before other types of surgery remains unclear. The aim of this review was to determine the impact of preoperative very low energy diets on perioperative outcomes in nonbariatric surgery.

METHODS

Medline, EMBASE, CENTRAL, and PubMed were systematically searched from inception through to July 2021. Articles were included if they evaluated very low energy diets use before any type of nonbariatric surgery. The primary outcome was postoperative morbidity. Secondary outcomes included compliance, safety, and preoperative weight loss. A pairwise meta-analyses using inverse variance random effects was performed.

RESULTS

From 792 citations, 13 studies with 395 patients (mean age: 56.5 years, 55.8% female) receiving very low energy diets preoperatively in preparation for nonbariatric surgery were included. Mean duration of preoperative very low energy diets was 6.6 weeks (range, 0.42-17 weeks). Target daily caloric intake ranged from 450 kcal to 1,400 kcal. Compliance with very low energy diets ranged from 94% to 100%. The mean preoperative weight loss ranged from 3.2 kg to 19.2 kg. There were no significant differences in postoperative morbidity (odds ratio, 1.10; 95% confidence interval, 0.64-1.91; P = .72), operative time (standard mean difference -0.35; 95% confidence interval, 1.13-0.43, P = .38), or postoperative length of stay (standard mean difference 0.40, 95% confidence interval -0.11-0.91, P = .12) with very low energy diets.

CONCLUSION

Although the currently available evidence is heterogenous, preoperative very low energy diets are safe, well tolerated, and effectively induce preoperative weight loss in patients undergoing nonbariatric surgery for both benign and malignant disease. Further prospective studies are warranted.

Influence of preoperative weight loss on gastric wall thickness-analysis of laparoscopic sleeve gastrectomy histological material

PURPOSE

The variables possibly enabling the prediction of gastric wall thickness during laparoscopic sleeve gastrectomy remain undetermined. The aim of the study was to identify preoperative factors affecting gastric wall thickness in patients undergoing laparoscopic sleeve gastrectomy.

METHODS

The measurements of the double-wall thickness of gastric specimen excised during sleeve gastrectomy were taken at three locations after 15 s of compression with an applied pressure of 8 g/mm². Statistical calculations were used to determine the influence of preoperative weight loss and other perioperative parameters on gastric wall thickness.

RESULTS

The study involved one hundred patients (78 female; 22 male). The thickest tissue was observed at the antrum with the mean value 2.55 mm (range 1.77-4.0 mm), followed by the midbody, mean 2.13 mm (range 1.34-3.20 mm), and the fundus, mean 1.69 mm (range 0.99-2.69 mm). Positive relationships were found between gastric wall thickness and both preoperative weight loss and age in all three measured locations; p < 0.05. In a linear regression model, age and preoperative weight loss were found to be statistically significant and positive predictors of higher gastric wall thickness only at the antrum. Male patients were observed to have thicker gastric wall at all three locations as compared to female patients.

CONCLUSION

Preoperative weight loss should be considered an important factor influencing gastric wall thickness. Age and gender can also be helpful in predicting the varying tissue thickness. Anatomical region is a key factor determining thickness of the stomach walls.

Literature review on antiobesity medication use for metabolic and bariatric surgery patients from the American Society for Metabolic and Bariatric Surgery Clinical Issues Committee

The following literature search is in response to inquiries made to the American Society for Metabolic and Bariatric Surgery (ASMBS) regarding antiobesity medication (AOM) use in patients who are having or have already had metabolic and bariatric surgery (MBS). These recommendations are based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. This paper is not intended to establish a local, regional, or national standard of care. The paper will be revised in the future as additional evidence becomes available.

Ketogenic Diet for Preoperative Weight Reduction in Bariatric Surgery: A Narrative Review

Bariatric surgery (BS) is the most effective treatment in reducing weight and the burden of comorbidities in patients with severe obesity. Despite the overall low mortality rate, intra- and post-operative complications remains quite common. Weight loss before BS reduces surgical risk, but studies are inconclusive regarding which is the best approach to apply. In this review, we summarize the current evidence on the effect of a ketogenic diet (KD) before BS. All studies agree that KD leads to considerable weight loss and important improvements in terms of surgical risk, but populations, interventions and outcomes are very heterogeneous. KD appears to be a safe and effective approach to induce weight loss before BS. However, randomized controlled trials with better-defined dietary protocols and homogeneous outcomes are necessary in order to draw firm conclusions.

Higher Preoperative Weight loss Is Associated with Greater Weight Loss up to 12 Months After Bariatric Surgery

BACKGROUND

Prior research suggested presurgical weight loss is associated with greater total weight loss, resulting in a more effective bariatric intervention. We aimed to assess whether preoperative weight loss is a predictor for total weight loss, and which patient factors are associated with successful weight loss.

METHODS

All patients (N = 773) that underwent primary bariatric surgery between June 2017 and August 2019 were included in this single-center retrospective study. Outcome measures were preoperative weight loss (%preopWL) and total weight loss (%TWL) up to 1 year postoperatively. Patients were divided into 4 groups based on quartiles of %preopWL.

RESULTS

Total weight loss after 1, 6, and 12 months for the upper quartile was 16.9%, 33.4%, and 37.8%, and for the lower quartile 11.8%, 28.9%, and 35.2%, respectively (p < 0.001). Seven hundred fourteen patients (92.4%) were available for the 1-year follow-up. Preoperative weight loss was not associated with the incidence of complications. Independent factors predicting increased %preopWL were mandated preoperative weight loss program (MWP) (p < 0.001), older age (p = 0.005), weight measurement in the week before surgery (p = 0.031), and non-diabetic status (p = 0.010). Predictors for superior %TWL were MWP (p = 0.014), younger age (p = 0.001), non-diabetic status (p = 0.005), female gender (p = 0.001), higher Body Mass Index (p = 0.006), and banded gastric bypass (p = 0.001).

CONCLUSION

Higher preoperative weight loss is associated with persisting greater weight loss up to at least 12 months post-surgery. In order to optimize preoperative weight loss, we recommend extra preoperative support to younger and diabetic patients. We advise nutritional counseling and additional weight measurement in the week before surgery.

Effects of body mass index and serum albumin on overall survival in patients with cancer undergoing pancreaticoduodenectomy: a single-center retrospective cohort study

Objectives

We aimed to explore whether body mass index (BMI) and albumin were associated with overall survival (OS) in individuals who underwent pancreaticoduodenectomy (PD) for cancer.

Methods

Three-hundred twenty-nine consecutive patients who underwent PD for cancer were enrolled from January 2020 to December 2020. All clinicopathological information was extracted based on medical records. The survival follow-ups were regularly performed and ended on June 30, 2021. The Kaplan-Meier survival analysis and univariate and multivariate Cox proportional-hazards models were used to assess the association of BMI and albumin with OS.

Results

Of the 329 patients, 186 (56.5%) were male, and median age at admission was 65.0 (56.0–71.0) years. There were 258 patients (78.4%) with BMI < 25.0 kg/m² and 89 patients (27.05%) with albumin < 35.0 g/L respectively. In overall cohort, BMI < 25.0 kg/m² was associated with OS (adjusted HR = 3.516, 95% CI = 1.076–11.492, P = 0.037). In contrast, albumin < 35.0 g/L did not affect OS. Subgroup analysis showed, in patients with pancreas lesion, BMI < 25.0 kg/m² had a higher risk for OS compared to BMI ≥ 25.0 kg/m² (adjusted HR = 3.209, 95% CI = 0.985–10.451, P = 0.048), while albumin < 35.0 g/L was not linked to OS. In patients with lesion in ampulla of Vater, duodenum, or common bile duct, there was no significant association of BMI and albumin with OS.

Conclusions

BMI, rather than serum albumin, was associated with OS in patients who underwent PD for cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02678-z.

A Combination of Aerobic Exercise at Fatmax and Low Resistance Training Increases Fat Oxidation and Maintains Muscle Mass, in Women Waiting for Bariatric Surgery

PURPOSE

There is no consensus on the best exercise recommendation for women affected by severe obesity while they are waiting for bariatric surgery. For this reason, the effects of a combination of aerobic exercise performed at the intensity at which maximal fat oxidation is reached (Fatmax) with low-intensity resistance training were studied.

MATERIALS AND METHODS

Twenty sedentary middle-aged Caucasian women (43.2 ± 7.5 years, BMI = 46.5 ± 5.9 kg·m^-2) were allocated to a control group (CG, n = 10) that followed solely the conventional preoperative care or to an experimental group (EG, n = 10) that, in addition, performed a 12-week individualized and supervised physical activity program (PAP) that combined aerobic training at Fatmax with low-intensity resistance training.

RESULTS

After the PAP, maximal fat oxidation during exercise increased in the EG (0.187 ± 0.068 vs 0.239 ± 0.080 g·min^-1, p = 0.025, pre vs. post, respectively), but resting fat oxidation did not (0.088 ± 0.034 vs 0.092 ± 0.029 g·min^-1, p = 0.685, pre vs. post, respectively). Additionally, the resting metabolic rate in the EG was also unchanged (1869 ± 406 vs. 1894 ± 336 kcal; p = 0.827, pre vs. post, respectively), probably because of the effects of resistance training on the maintenance of fat-free mass. No significant changes were observed in the CG.

CONCLUSION

A PAP that combines aerobic exercise at Fatmax with low resistance training may counteract some of the deleterious side effects of the standard presurgical care of women waiting for bariatric surgery and increase maximal fat oxidation during exercise.

High-risk bariatric candidates: does red-flagging predict the post-operative course?

BACKGROUND

Standards for preoperative bariatric patient selection include a thorough psychological evaluation. Using patients "red-flagged" during preoperative evaluations, this study aims to identify trends in long-term follow-up and complications to further optimize bariatric patient selection.

METHODS

A multidisciplinary team held a case review conference (CRC) to discuss red-flagged patients. A retrospective chart review compared CRC patients to control patients who underwent bariatric surgery in the same interval. Patients under 18 years old, undergoing revisional bariatric surgery, or getting band placement were excluded. High-risk characteristics causing CRC inclusion, preoperative demographics, percent follow-up and other postoperative outcomes were collected up to 5 years postoperatively. If univariate analysis revealed a significant difference between cohorts, multivariable analysis was performed.

RESULTS

Two hundred and fifty three patients were red-flagged from 2012 to 2013, of which 79 underwent surgery. After excluding 21 revisions, 3 non-adult patients, and 6 band patients, 55 red-flagged patients were analyzed in addition to 273 control patients. Patient age, sex, initial BMI, ASA, and co-morbidities were similar between groups, though flagged patients underwent RYGB more frequently than control patients. Notably, percent excess BMI loss and percent follow-up (6 months-5 years) were similar. In multivariable analysis, minor complications were more common in flagged patients; and marginal ulcers, endoscopy, and dilation for stenosis were more common in flagged versus control patients who underwent RYGB. Perforation, reoperation, revision, incisional hernia, and internal hernia were statistically similar in both groups, though reoperation was significantly more common in patients with multiple reasons to be flagged compared to controls.

CONCLUSION

Bariatric patients deemed high risk for various psychosocial issues have similar follow-up, BMI loss, and major complications compared to controls. High-risk RYGB patients have greater minor complications, warranting additional counseling of high-risk patients.

Patience is a virtue: Multiple preoperative visits are associated with decreased recurrence in pediatric pilonidal disease

BACKGROUND/PURPOSE

This study aimed to compare preoperative management strategies for patients undergoing trephination for pilonidal disease and evaluate risk factors for recurrence.

METHODS

A retrospective review was performed of children undergoing index surgical treatment with trephination for pilonidal disease between September 2017 and April 2019. Intraoperative and postoperative management were standardized. Demographic and perioperative data were collected and analyzed.

RESULTS

One-hundred twenty patients were identified with a median follow-up time of 7.5 months (interquartile range 4.1-13.2 months). Overall, 24 (20%) patients had a postoperative recurrence of pilonidal disease. Patients with multiple preoperative surgery clinic visits were less likely to have recurrent disease compared to those seen only once preoperatively (11% vs 26%, p = 0.040). Compared to patients without recurrence, those who recurred went to the operating room sooner from the time of initial surgical consultation (32 days vs 54 days, p < 0.001). Perioperative antibiotics, history of acute infection, and prior drainage procedures were not risk factors for recurrence.

CONCLUSIONS

Multiple preoperative clinic visits are associated with a lower recurrence rate in children undergoing trephination for pilonidal disease. An increased duration of preoperative medical management may be responsible for this finding. Prospective study is needed to confirm these findings and identify additional factors that influence recurrence.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

III (Retrospective Comparative).

Validity and efficacy of diets used for preoperative weight reduction among patients qualified for bariatric surgery

INTRODUCTION

Bariatric surgery is the most effective method of weight reduction among patients suffering from morbid obesity. Reduction of body weight before surgery is an important element. The aim of the study was to present the current knowledge on preoperative weight reduction and diet for this purpose.

MATERIAL AND METHODS

To achieve the aims of the paper, articles available in the PubMed / MEDLINE database published in 2005-2020 were used, as well as the guidelines of societies such as Metabolic and Bariatric Surgery Chapter of the Association of Polish Surgeons, American Association of Clinical Endocrinologists, The Obesity Society and American Society for Metabolic &amp; Bariatric Surgery, International Federation for Surgery of Obesity and Metabolic Disorders-European Chapter and European Association for the Study of Obesity.

RESULTS

Studies show that even a modest reduction in weight in the early preoperative period facilitates surgery and reduces the number of complications. The available data do not support the effect of preoperative weight loss on increased postoperative weight loss. The use of balanced, energy-restricted diet in the preoperative period prepares the patient for changes in the way of nutrition, which improves the nutritional status of patient. Low calorie (LCD) or very low calorie (VLCD) diet can be an effective method of weight loss before surgery, however, this approach does not allow to modify eating habits. The use of a very low calorie ketogenic diet (VLCKD) remains under discussion.

CONCLUSIONS

There is a need for large randomized trials to assess short and long term benefits of preoperative weight loss and methods of weight loss among patients qualified for bariatric surgery, also the standardization of nutritional management in the preoperative period.

Factors Affecting Metabolic Outcomes Post Bariatric Surgery: Role of Adipose Tissue

Obesity is an ever-growing public health crisis, and bariatric surgery (BS) has become a valuable tool in ameliorating obesity, along with comorbid conditions such as diabetes, dyslipidemia and hypertension. BS techniques have come a long way, leading to impressive improvements in the health of the majority of patients. Unfortunately, not every patient responds optimally to BS and there is no method that is sufficient to pre-operatively predict who will receive maximum benefit from this surgical intervention. This review focuses on the adipose tissue characteristics and related parameters that may affect outcomes, as well as the potential influences of insulin resistance, BMI, age, psychologic and genetic factors. Understanding the role of these factors may help predict who will benefit the most from BS.

Pre-specified Weight Loss Before Bariatric Surgery and Postoperative Outcomes

Bariatric surgery is increasing exponentially to address the steep rise in the prevalence of severe obesity. Most centers require pre-specified preoperative weight loss before allowing patients to receive surgery. We examined the current evidence surrounding the potential benefits of this requirement on postoperative outcomes. We reviewed the current literature by conducting a multistage advance electronic search in Ovid®/MEDLINE® and PubMed for publications indexed after 2008 reporting preoperative weight loss and postoperative outcomes. Thirteen original publications, three randomized control trials (RCT), and five systematic reviews that met inclusion criteria were included. These were analyzed with regards to weight loss before surgery and postoperative outcomes. There were varied reports regarding the significant effect of preoperative weight loss. Six of the original articles (50%) did not identify a significant difference in the outcome while two of the RCT (essentially the same patient population, started in 2007 and reanalyzed in 2009) demonstrated some advantage. A later RCT (2012) did not show any advantage, albeit in the short term. The results of the systematic reviews, some with heterogenic designs, show no conclusive evidence that weight loss before surgery conferred improved postoperative outcomes. There is not enough high-quality evidence to back up the requirement of pre-specified preoperative weight loss before receiving surgery. Further validation of the possible benefits of pre-specified preoperative weight loss may need to be carried out.

Influence of dynamic preoperative body mass index changes on patient-reported outcomes after surgery for degenerative lumbar spine disease

Psychological factors demonstrably and often massively influence outcomes of degenerative spine surgery, and one could hypothesize that preoperative weight loss may correlate with motivation and lifestyle adjustment, thus leading to potentially enhanced outcomes. We aimed to evaluate the effect of preoperative weight loss or gain, respectively, on patient-reported outcomes after lumbar spine surgery. Weight loss was defined as a BMI decrease of ≤ − 0.5 kg/m² over a period of at least 1 month, and weight gain as a BMI increase of ≥ 0.5 kg/m² in the same time period, respectively. The primary endpoint was set as the achievement of the minimum clinically important difference (MCID) in the ODI at 1 or 2 years postoperatively. A total of 154 patients were included. Weight loss (odds ratio (OR): 1.18, 95% confidence interval (CI): 0.52 to 2.80) and weight gain (OR: 1.03, 95% CI: 0.43 to 2.55) showed no significant influence on MCID achievement for ODI compared to a stable BMI. The same results were observed when analysing long-term NRS-BP and NRS-LP. Regression analysis showed no correlation between BMI change and PROM change scores for any of the three PROMs. Adjustment for age and gender did not alter results. Our findings suggest that both preoperative weight loss and weight gain may have no measurable effect on long-term postoperative outcome compared to a stable BMI. Weight loss preoperatively—as a potential surrogate sign of patient motivation and lifestyle change—may thus not influence postoperative outcomes.

Post-operative intensive care unit admission after elective non-cardiac surgery: A single-center analysis of the NSQIP database

BACKGROUND

Admission to the intensive care unit (ICU) after surgery can be associated with significant morbidity and mortality. This observational cohort study aims to identify perioperative factors associated with post-operative ICU admission in patients undergoing elective non-cardiac surgery.

METHODS

Data from the ACS NSQIP^® database at a tertiary care academic medical center were analyzed from January 2011 to September 2016. Univariable and multivariable logistic regression of patient and surgery-specific characteristics was performed to assess association with post-operative ICU admission. The Current Procedural Terminology (CPT) and International Classification of Diseases (ICD-9) billing codes, as well as associated outcomes, were reviewed.

RESULTS

Of 5254 database patient records, 1150 met our inclusion criteria. Elevated body mass index (BMI), longer procedure duration and a diagnosis of disseminated cancer were associated with post-operative ICU admission. Prostatectomy and morbid obesity were the most common CPT and ICD-9 codes identified. Patients who were admitted to the ICU after surgery had a longer hospital length of stay (LOS), had a higher frequency of readmission, re-operation, and in-hospital mortality.

CONCLUSION

Admission to the ICU after elective non-cardiac surgery is common. Our analysis of the ACS NSQIP^® database identified elevated BMI, longer duration of surgery and disseminated cancer as predictors of post-operative ICU admissions in patients undergoing elective non-cardiac 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.

Perioperative and Postoperative Effects of Preoperative Low-Calorie Restrictive Diets on Patients Undergoing Laparoscopic Sleeve Gastrectomy

OBJECTIVE

A restrictive diet applied before bariatric surgery can be required to reduce the liver volume or as a necessity imposed by insurance companies. However, the benefits of preoperative weight loss remain controversial. The present study aimed to investigate the perioperative and postoperative outcomes of a restrictive diet applied before laparoscopic sleeve gastrectomy.

MATERIALS AND METHODS

The data of 128 patients who received surgery in 2015 and 2016 were retrospectively analyzed. All patients were advised to follow a 4-week low-calorie (1000 cal) restrictive diet. Nevertheless, approximately 50% of patients did not accept the diet plan. We divided the patients into two groups as dieters (group 1) and non-dieters (group 2).

RESULTS

In group 1, changes in after-diet BMI and liver size were statistically significant (p < 0.001). In group 2, mean operation duration, mean hospitalization duration values, mean BMI values, and mean body weight at postoperative 1, 3, 6, and 12 months were statistically significantly higher than in group 1. No statistically significant difference was found between early complication rates of the groups (p = 0.844).

CONCLUSION

Low-calorie restrictive diet applied before laparoscopic sleeve gastrectomy has reduced liver volume and shortens surgery and hospitalization time but does not have any significance concerning early complications and weight loss after operation in 1 year. Also, non-adherence of the bariatric surgery candidate patients to the diet seems to be a challenge.

Management of Diabetes in Patients Undergoing Bariatric Surgery

PURPOSE OF REVIEW

The number of bariatric surgeries for patients with type 1 or type 2 diabetes continues to grow. Clinicians are challenged to choose therapies that reach glycemic targets without inducing adverse effects in post-bariatric patients without published guidelines. This review evaluates data supporting the best strategies for diabetes management in patients undergoing bariatric surgery.

RECENT FINDINGS

Though few clinical trials have evaluated the safety and effectiveness of different glucose-lowering therapies following bariatric surgery, remission of diabetes or reduced medications is an established benefit of bariatric surgery. Adverse events including diabetic ketoacidosis in post-bariatric patients on sodium-glucose co-transporter 2 (SGLT2) inhibitors or inadequate insulin have been reported in patient's with both type 1 and type 2 diabetes. Metformin, glucagon-like peptide-1 (GLP-1) agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, SGLT2 inhibitors, insulin, and sulfonylureas have been used successfully in the perioperative period for other surgeries and guidelines recommend adjusting the doses of these medications especially in the perioperative period. Clinicians should favor weight-neutral or weight-loss promoting therapies in post-bariatric surgery patients such as medical nutrition therapy, metformin, GLP-1 agonists, SGLT2 inhibitors, and DPP-4 inhibitors.

Does Preoperative Weight Loss Predict Significant Postoperative Weight Loss Among Patients who Underwent Laparoscopic Sleeve Gastrectomy?

Background Some bariatric practices, mainly those conducted under public-funded services, have adopted achieving a target preoperative weight loss (PrWL) before offering surgery. There are varied opinions on the correlation between preoperative and postoperative weight loss (PoWL) for the different surgical options. This study investigated the impact of target PrWL on PoWL for patients who underwent laparoscopic sleeve gastrectomy (LSG). Materials and methods A longitudinal retrospective cohort study was carried out on patients who had documented preoperative weight before LSG (n=155) from the authors' institution between February 2008 to October 2017. Patients were grouped into two cohorts based on meeting the 5% target PrWL or not. The endpoint included percent postoperative weight loss (% PoWL) at one year and two to three years. Results A total of 155 individuals were identified and analysed. Of these patients, 78.7% of them (n=122) achieved the 5% target PrWL (target group) while 21.3% (n= 33) did not (non-target group). At one year, there was no statistical significant difference in the mean % PoWL between the non-target and target groups (22.3 ± 8.1% versus 19.4 ± 11.8% p value= 0.08). A similar observation was made at two-three years, where the mean % PoWL in the non-target group was 14.7 ± 10.7% versus 16.3 ± 14.4% in the target group (p value= 0.07). Our further analysis highlighted a statistically significant weak inversely proportional correlation between % PrWL and % PoWL at one year and two to three years. Conclusion Meeting target PrWL does not significantly impact on PoWL after LSG. Therefore, it should not serve as exclusion criteria for eligible patients who are in need of surgery.

Impact of a preoperative low-calorie diet on liver histology in patients with fatty liver disease undergoing bariatric surgery

BACKGROUND

A low-calorie diet (LCD) before bariatric surgery has been shown to reduce liver volume and facilitate ease of operation. It is estimated that 75%-100% of individuals undergoing bariatric surgery have nonalcoholic fatty liver disease (NAFLD).

OBJECTIVES

We aimed to investigate how an LCD affects liver histology in the setting of NAFLD.

SETTING

University Hospital, United States.

METHODS

Forty intraoperative liver specimens were analyzed histologically as follows: 20 with and 20 without a preoperative 2-week, 1200 kcal/d LCD. Weight was measured prediet, at surgery, and 6 months after surgery. NAFLD activity score was used to grade liver histology at surgery. The NAFLD activity score scores steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis.

RESULTS

The non-LCD group (n = 20) had mean weight at surgery of 136.1 ± 24.1 kg. The LCD group (n = 20) had initial mean weight of 128.6 ± 25.4 kg, with presurgical weight loss of 3.43 kg (range, 0-9.3 kg), mean change in body mass index 1.24 kg/m² (2.66% total weight loss) on an LCD. The LCD group had significantly less steatosis (P = .02), fewer foci of lobular inflammation (P = .01), and less hepatocellular ballooning (P = .04) compared with the non-LCD group; with no difference in degree of fibrosis. Fewer patients in the LCD group had nonalcoholic steatohepatitis with ballooning (P = .04). Weight loss on an LCD before bariatric surgery was predictive of weight loss 6 months after surgery (P = .026).

CONCLUSIONS

A 2-week LCD before bariatric surgery is associated with significant improvement in steatosis, inflammation, and hepatocellular ballooning in NAFLD. Among LCD patients, preoperative weight loss was associated with improved 6-month weight loss and liver function.

Body composition changes after left gastric artery embolization in overweight and obese individuals

PURPOSE

To determine the effects of left gastric artery embolization (LGAE) on computed tomography (CT) body composition change.

MATERIALS AND METHODS

Sixteen overweight or obese patients who had abdominal CT scans before and after LGAE for gastric bleeding were retrospectively reviewed. Body composition analysis was performed with semiautomated imaging processing algorithms (MATLAB 13.0, Math Works, MA). Adipose tissue and lean skeletal muscle were measured using threshold attenuation values. Total body fat index (BFI), subcutaneous fat index (SFI), visceral fat index (VFI), intramuscular fat index (IMFI), and skeletal muscle index (SMI) were determined ([tissue area (cm)]²/[height (m)]²). Excess body weight (EBW) was determined based on the Lorentz formula for ideal body weight.

RESULTS

Mean follow-up was 1.5 ± 0.8 months. Following LGAE, patients experienced significantly decreased body weight (p = 0.003), BMI (p = 0.005), EBW (p = 0.003), BFI (p = 0.03), SFI (p = 0.03), and SMI (p < 0.001). Changes in VFI and IMFI did not significantly change (p = 0.13 and p = 0.83, respectively).

CONCLUSIONS

Patients who underwent LGAE had significant unintended weight loss as a result of decreased body fat and skeletal muscle. Body composition analysis can readily assess the extent of fat loss and identify muscle wasting.