Standard versus distal Roux-en-Y gastric bypass in patients with BMI 50-60 kg/m2: 5-year outcomes of a double-blind, randomized clinical trial

Long-term changes in lipid indices following Roux-en-Y gastric bypass: a meta-analysis

INTRODUCTION

Bariatric surgery yields clinically significant long-term weight loss accompanied by marked improvements in numerous weight-related comorbidities including type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea, and fatty liver disease.

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the effect of (RYGB) surgery on lipid profile.

DATA SOURCE

We searched PubMed, Scopus, Web of Science and Scholar from inception to May 20th, 2024.

STUDIES SELECTION

Clinical studies that reported lipid profile data with a follow-up of at least 5 years after RYGB were eligible.

DATA EXTRACTION

Two independent reviewers extracted data and assessed the risk of bias.

RESULTS

Of the 4922 articles identified from our database search, 38 studies that measured lipid profile following RYGB were identified and selected for the analysis. Compared to pre-surgery, at post-surgery follow-up of ≥ 5 years, RYGB was associated with significant reductions in mean total cholesterol (TC) (WMD: - 17.95 mg/dl, 95% CI: - 22.68, - 13.22, 95% PI: - 46.18, 10.27 p < 0.001; I2:92.3), LDL-cholesterol (WMD: - 18.55 mg/dl, 95% CI: -21.85, -15.25, 95% PI: - 39.01, 1.92 p < 0.001; I2:91.8), and triglycerides (WMD: - 60.76 mg/dl, 95% CI: - 66.29, - 55.22, 95% PI: - 91.24, - 30.27 p < 0.001; I2:83.7), and increase in HDL-cholesterol (WMD: 13.75 mg/dl, 95% CI: 12.38, 15.13, 95% PI: 5.32, 22.19 p < 0.001; I2:91.4).

CONCLUSION

RYBG is associated with clinically significant large improvements in serum lipids at a post-operative follow-up of 5 years or more.

Total Alimentary Limb Length Is Not Associated with Weight Loss Following Proximal Roux-en-Y Gastric Bypass

BACKGROUND

Standard Roux-en-Y gastric bypass (RYGB) typically manipulates the proximal portion of the small intestine, leaving a variable and unknown common channel and total alimentary limb length (TALL). Despite high variability in postoperative weight loss, the factors contributing to this variability remain unknown. Given the known variability in small intestinal length, this unmeasured variability in TALL may be associated with weight loss responses.

OBJECTIVE

To test the hypothesis that TALL is associated with postoperative weight loss following primary laparoscopic Roux-en-Y gastric bypass (RYGB).

SETTING

Vanderbilt University Medical Center; Nashville, Tennessee, USA.

METHODS

A total of 329 patients were recruited for this observational study and consented to laparoscopic measurement of the entire small intestinal length at the time of primary RYGB. Of these patients, 208 had successful measurement of the small bowel length (SBL) and underwent RYGB with a fixed biliopancreatic limb length (BPL, 50 cm). Common channel length (CCL) was allowed to vary normally to test the association between TALL and postoperative weight loss.

RESULTS

Follow-up rates were 77% at 6 months and 41% at 24 months. Average SBL was 592 cm (min = 390 cm, max = 910 cm), with a standard deviation of 107 cm that led to significant variation in CCL (shortest 190 cm, longest 730 cm). Regression was used to model weight loss and body mass index, as well as percent change from baseline, for each patient given the measured TALL and CCL. Despite significant variation in TALL, there were no clinically significant effects of TALL or CCL on weight loss up to 24 months.

CONCLUSIONS

With a fixed BPL, normal variation in TALL does not significantly contribute to weight loss variability following RYGB. Future studies are needed to better understand the importance of intestinal limb lengths in primary and revisional RYGB surgery.

The One Anastomosis Gastric Bypass Is a Suitable Alternative to Roux-en-Y Gastric Bypass in Patients with Body Mass Index ≥50 kg/m2: A Propensity Score-Matched Analysis

INTRODUCTION

Body mass index (BMI) ≥50 kg/m2 is more challenging for the metabolic bariatric surgeon because of a thicker abdominal wall, more visceral fat, and hepatomegaly by liver steatosis. This study aimed to give an overview of 5-year outcomes after one anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) in these patients in terms of weight loss, remission of comorbidities, and complications.

METHODS

This retrospective single-center cohort study focused on patients with BMI ≥50 kg/m2 undergoing OAGB or RYGB between 2015 and 2017 at a nonacademic teaching hospital in the Netherlands. A 1:1 propensity score-matched (PSM) comparison was conducted.

RESULTS

In total, 158 patients underwent OAGB and 32 patients RYGB. After performing a 1:1 PSM, we obtained two nearly identical cohorts of 28 patients. Follow-up data after 5 years were available in 79% of the patients after OAGB and 82% of the patients after RYGB. Both procedures resulted in equal weight loss, remission of comorbidities, and short-term complications. More minor midterm complications were seen after OAGB (50% versus 18%; p = 0.011) due to reflux complaints (50% versus 7%; p < 0.001). The number of patients with major midterm complications did not differ (7% after OAGB versus 14% after RYGB; p = 0.388). The only major complication after OAGB was conversion to RYGB due to reflux in 7.1% of the patients. In contrast, major complications following RYGB were more diverse.

CONCLUSION

Both procedures resulted in similar weight loss, remission of comorbidities, short-term and major midterm complications, making OAGB a suitable alternative to RYGB for patients with a BMI ≥50 kg/m2.

Long-term weight loss of distal gastric bypass is moderately superior compared to proximal gastric bypass in patients with a BMI of 37-44 Kg/m2

PURPOSE

The laparoscopic Roux-en-Y gastric bypass (LRYGB) is one of the standard procedures in metabolic surgery. Different limb lengths have been proposed in the past to maximize weight loss (WL) and reduce metabolic complications. Distal gastric bypass surgery with a very short common channel (CC) (up to 100 cm) has been often criticized due to frequent side effects such as malnutrition, bone weakening and short-bowel syndrome. We introduced a modified version of a distal LRYGB with a 50-70 cm long biliopancreatic limb (BPL) and an intermediate short CC (120-150 cm). Our primary goal was to compare the long-term WL between distal and proximal LRYGB in two cohorts of patients. Secondary outcomes were weight regain (WR), insufficient weight loss (IWL), postoperative complications and metabolic changes 5 years after surgery.

METHODS

In this retrospective study we collected data from 160 patients operated between 2014 and 2015, with a BMI of 37-44 Kg/m2. 101 patients underwent a distal and 59 patients a proximal LRYGB in two bariatric centers. WL was calculated as percent of excess of BMI loss (%EBMIL), loss of body mass index (Delta-BMI), percent of excess weight loss (%EWL) and percent of total weight loss (%TWL). Data were collected 3, 6, 9, 12, 24, 48 and 60 months after surgery.

RESULTS

The distal LRYGB resulted in significantly better 5-year-WL compared to the proximal bypass in terms of %EBMIL (median at 5 years: 83% vs. 65%, p = 0.001), %TWL (median at 5 years: 32% vs. 26%, p = 0.017) and %EWL (median at 5 years: 65% vs. 51%, p = 0.029), with equal major complications and metabolic alterations. In addition, WR was significantly lower in patients with distal bypass (18% vs. 35%, p = 0.032).

CONCLUSIONS

Distal LYRGB with a 120-150 long CC results in better WL and WL-maintenance compared to proximal LRYGB without major side effects after five years.

Prevalence and associated factors of vitamin D deficiency after Roux-en-Y gastric bypass: a systematic review and meta-analysis

OBJECTS

To estimate the prevalence and associated factors of vitamin D deficiency (VDD) after Roux-en-Y gastric bypass (RYGB).

METHODS

PubMed, EMBASE, and CENTRAL were searched for relevant records from inception to 17 March 2023, using search terms: vitamin D, vitamin D3, vitamin D deficiency, hypovitaminosis D, gastric bypass, and RYGB. Studies were eligible for inclusion if they provided related data on VDD prevalence after RYGB.

RESULTS

Of the 1119 screened studies, 72 studies involving 7688 individuals were enrolled in the final analysis. The prevalence estimates of VDD after RYGB were 42%. Subgroup analyses suggested the pooled prevalence of postoperative VDD was 35% for follow-up duration less than or equal to 1 year, 43% for greater than 1 and less than or equal to 5 years, and 54% for greater than 5 years. Meta-regression showed that VDD prevalence was positively correlated with follow-up time. Also, the prevalence was higher in studies with inadequate vitamin D supplementation than in those with adequate supplementation and in Asia population than in those from South America, Europe, and North America. Other factors associated with high VDD prevalence after RYGB included high presurgical VDD prevalence, noncompliant patients, and black populations. No significant association existed between VDD and alimentary length.

CONCLUSION

VDD presented a high prevalence in patients following RYGB. It occurred more frequently with longer postoperative follow-up time. Population-specific vitamin D supplementation measures, targeted treatment for presurgical VDD, improved patient compliance, and periodical follow-ups were necessary to reduce VDD and other adverse outcomes.

Gastric Bypass Mortality Trends in Racial Cohorts: Are We Improving?

INTRODUCTION

Roux-en-Y gastric bypass (RYGB) continues to be safely performed in racial cohorts. However, studies continue to report differences in complications, with non-Hispanic black (NHB) patients having a higher rate of adverse outcomes, including mortality. It is unclear how these disparate outcomes have evolved over time. Our objective was to determine RYGB procedure and mortality trends in racial cohorts.

METHODS

Using the 2015 to 2019 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Project (MBSAQIP) database, we identified primary RYGB cases performed laparoscopically or robotically. Non-Hispanic white (NHW) and non-Hispanic black (NHB) patient cohorts were matched based on patient and surgical characteristics. Conditional logistic regression analysis was conducted on the matched pairs. Primary outcomes of interest included year-to-year all-cause and procedure-related mortality. Stata/MP 16.1 was utilized for analysis, and a p-value of < 0.05 and a 95% confidence interval that excluded 1 were considered significant.

RESULTS

A total of 148,829 RYGB cases in NHW (82.8%) and Black (17.2%) patients were analyzed. RYGB trends remain similar for NHB and NHW patients over 5 years. In matched cohorts, all-cause mortality (OR 2.23; 95% CI: 1.16-4.29), aggregate related readmission (OR 1.39; 95% CI: 1.27-1.51), related reintervention (OR 1.36; 95% CI: 1.19-1.56), and VTE (OR 1.86; 95% CI: 1.40-2.45) were more likely in NHB patients. During the study period, year-to-year mortality was higher in NHB patients compared to NHW patients.

CONCLUSION

Over a 5-year period, year-to-year mortality remains higher in NHB patients after RYGB. While bariatric outcomes continue to improve, outcome gaps between racial cohorts seem to persist.

[Current evidence on loop length in intestinal bypass procedures]

BACKGROUND

Intestinal bypass procedures are well recognized for their long-term weight reduction and control of metabolic comorbidities. The selection of the length of the small bowel loop has a significant influence on the positive and also negative effects of the chosen procedure but national and international standardization are missing.

OBJECTIVE

The aim of this article is to give an overview of the current evidence on the various intestinal bypass procedures and the influence of the chosen small bowel loop length on the desired and adverse postoperative outcomes. The IFSO 2019 consensus recommendations on the standardization of bariatric surgery and metabolic procedures form the basis of these considerations.

MATERIAL AND METHODS

The current literature was searched for comparative studies addressing the question of different small bowel loop lengths in a Roux-en‑Y gastric bypass, one anastomosis gastric bypass, single anastomosis duodenoileal bypass with sleeve gastrectomy and biliopancreatic diversion (with duodenal switch).

RESULTS

Due to the heterogeneity of currently available studies and interindividual differences in total small bowel lengths in humans, it is difficult to give definitive recommendations for the choice of small bowel loop lengths. The longer the biliopancreatic loop (BPL) or the shorter the common channel (CC), the higher is the risk of (severe) malnutrition. To prevent malnutrition, the BPL should not be longer than 200 cm and the CC should have a length of at least 200 cm.

CONCLUSION

The intestinal bypass procedures recommended in the German S3 guidelines are safe and show good long-term outcomes. As part of the postbariatric follow-up, the nutritional status of patients following an intestinal bypass has to be followed-up on the long term in order to avoid malnutrition preferably prior to a clinical manifestation.