very long Roux limb Roux-en-Y gastric bypass on nutrient status: a 1-year follow-up report from the Dutch Common Channel Trial (DUCATI) Study

Randomized controlled trials comparing gastric bypass, gastric band, and sleeve gastrectomy: A systematic review examining validity and applicability to wider clinical practice

Consideration of how applicable the results of surgical trials are to clinical practice is important to inform decision-making. Randomized controlled trials comparing at least two surgical interventions (of gastric bypass, gastric band, and sleeve gastrectomy) for severe and complex obesity were examined using the PRagmatic Explanatory Continuum Indicator Summary-2 tool, to consider how applicable the trial results are to clinical practice, and the Risk of Bias 2 tool, to examine validity. MEDLINE, Embase, and CENTRAL databases were searched for studies published between November 2013 and June 2021, and 15 were identified. Using the PRagmatic Explanatory Continuum Indicator Summary-2 tool, three were classified as pragmatic, with good applicability to clinical practice. Ten had more explanatory domains but did include some pragmatic characteristics, and two were predominantly explanatory. This was due to some trial design features that would not be considered applicable to the wider clinical setting, including being single-centered, having prescribed intervention delivery methods, and intensive follow-up regimens. Only two trials had low risk of bias, of which one was considered pragmatic. Three had high risk of bias. Overall, few trials in bariatric surgery are pragmatic with low risk of bias. Well-designed pragmatic trials are needed to inform practice and reduce research waste.

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.

American Society for Metabolic and Bariatric Surgery literature review on the effect of Roux-en-Y gastric bypass limb lengths on outcomes

This literature review is issued by the American Society for Metabolic and Bariatric Surgery regarding limb lengths in Roux-en-Y gastric bypass (RYGB) and their effect on metabolic and bariatric outcomes. Limbs in RYGB consist of the alimentary and biliopancreatic limbs and the common channel. Variation of limb lengths in primary RYGB and as a revisional option for weight recurrence after RYGB are described in this review.

Standard Biliopancreatic Limb (50 cm) Roux-en-Y Gastric Bypass Versus Long Biliopancreatic Limb (100 cm) Roux-en-Y Gastric Bypass in Patients with Body Mass Index 40-50 kg/m2: a Randomized Prospective Study

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is a widely performed procedure worldwide especially with the presence of associated medical conditions. Patients with body mass index (BMI) 40-50 kg/m² are at more risk of weight regain and relapse of comorbidities. There is a controversy on the optimum alimentary (AL) and biliopancreatic (BPL) limb lengths to be used in RYGB to achieve weight loss and remission of comorbidities without causing nutritional deficiencies in those patients.

STUDY DESIGN

hundred-and-fifty patients with BMI between 40 and 50 kg/m² were divided equally into 2 groups undergoing standard RYGB (S-RYGB) with AL:150 cm and BPL: 50 cm and long biliopancreatic RYGB (L-RYGB) with AL: 100 cm and BPL: 100 cm. BMI, % of total weight loss (%TWL), effect on diabetes (DM), hypertension (HTN), dyslipidemia, and nutritional statuses were recorded at 1, 2, and 3 years.

RESULTS

Only 64/75 patients in S-RYGB and 57/75 patients in L-RYGB completed the study. L-RYGB had faster weight loss, higher %TWL, and less BMI than S-RYGB with the maintenance of achieved weight. L-RYGB had better control of DM and dyslipidemia than S-RYGB. There were no significant differences in nutritional status between S-RYGB and L-RYGB rather than lower levels of calcium and Hb and higher levels of PTH in L-RYGB yet they remain within the normal range.

CONCLUSION

The application of L-RYGB helps in achieving faster weight loss for a longer period with better remission of associated comorbidities as DM, HTN, and dyslipidemia in patients with BMI 40-50 kg/m² but with effects on the nutritional status.

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

Background

The optimal surgical weight loss procedure for patients with a BMI of 50 kg/m² or more is uncertain. This study compared distal Roux-en-Y gastric bypass (RYGB) with standard RYGB.

Methods

In this double-blind RCT, patients aged 18–60 years with a BMI of 50–60 kg/m² were allocated randomly to receive standard (150 cm alimentary, 50 cm biliopancreatic limb) or distal (150 cm common channel, 50 cm biliopancreatic limb) RYGB. The primary outcome (change in BMI at 2 years) has been reported previously. Secondary outcomes 5 years after surgery, such as weight loss, health-related quality of life, and nutritional outcomes are reported.

Results

Between May 2011 and April 2013, 123 patients were randomized, 113 received an intervention, and 92 attended 5-year follow-up. Mean age was 40 (95 per cent c.i. 38 to 41) years and 73 patients (65 per cent) were women; 57 underwent standard RYGB and 56 distal RYGB. BMI was reduced by 15.1 (95 per cent c.i. 13.9 to 16.2) kg/m² after standard and 15.7 (14.5 to 16.9) kg/m² after distal RYGB; the between-group difference was −0.64 (−2.3 to 1.0) kg/m² (P = 0.447). Total cholesterol, low-density lipoprotein cholesterol, and haemoglobin A1c levels declined more after distal than after standard RYGB. High-density lipoprotein cholesterol levels increased more after standard RYGB. Vitamin A and vitamin D levels were lower after distal RYGB. Changes in bone mineral density, resting metabolic rate, and total energy intake were comparable.

Conclusion

Distal RYGB did not enable greater weight loss than standard RYGB. Differences in other outcomes favouring distal RYGB may not justify routine use of this procedure in patients with a BMI of 50–60 kg/m². Registration number: NCT00821197 (http://www.clinicaltrials.gov).

Presented in part as abstract to the IFSO (International Federation for the Surgery of Obesity and Metabolic disorders) conference, Madrid, Spain, August 2019.

Midterm Results from the Dutch Common Channel Trial (DUCATI): Superior Weight Loss Results of the Long Roux Limb Gastric Bypass in Comparison to the Standard Bypass at 3-Year Follow-Up

In the multi-center Dutch Common Channel Trial (DUCATI), a very long Roux limb Roux-en-Y gastric bypass (VLRL-RYGB: BP-limb 60 cm, Roux limb variable, and common channel 100 cm) was compared to a standard Roux-en-Y gastric bypass (S-LRYGB: BP-limb 60 cm, Roux limb 150 cm, and common channel variable) in the treatment of morbidly obese patients. As all trial patients are beyond 3-year follow-up a midterm analysis was performed to investigate the effect of the VLRL-RYGB.

METHODS

A total of 444 patients were randomized (1:1) to receive either a VLRL-RYGB or a S-LRYGB. Follow-up results for weight loss, effect on obesity-related comorbid conditions, complications, reoperation, and malnutrition are investigated.

RESULTS

At 3-year follow-up a significant difference in %TWL (34.0% vs. 31.4%, p = 0.017) and %EWL (84.7% vs. 76.6%, p = 0.043) was observed in favor of VLRL-LRYGB group. Overall complication rate 3-years after surgery was 15.8% in the VLRL-LRYGB group vs. 9% in the S-LRYGB group (p = 0.031). Eight (3.6%) patients in the VLRL-LRYGB group versus 2 (0.9%) in the S-LRYGB group (p = 0.055) required revisional surgery for malabsorption. In the VLRL-LRYGB group 71.9% of patients had resolution of T2DM versus 48.9% in the S-LRYGB group (p = 0.044).

CONCLUSION

At midterm FU a considerable, significantly increased effect on weight loss of the VLRL-LRYGB was observed compared to the S-LRYGB, with a higher risk of overall complications, but no significant nutritional side effects. These results might impact the current view on the value of the Roux limb in the discussion on optimum limb lengths in Roux-en-Y gastric bypass surgery.

Comparing a Short Biliopancreatic Limb to a Long Biliopancreatic Limb in Patients with a Roux-en-Y Gastric Bypass with 4 Years Follow-up

INTRODUCTION

In order to design the most effective weight loss procedure, the ideal biliopancreatic limb (BPL) and alimentary limb (AL) length in Roux-en-Y gastric bypass (RYGB) have been discussed extensively. Yet, no consensus has been reached. The aim of this study was to compare weight loss after a short and long BPL in patients who underwent a RYGB with a minimum of 4 years follow-up.

METHODS

This retrospective cohort study consisted of 574 patients who underwent a primary RYGB procedure between March 2015 and January 2017. Patients were divided in two groups based on the surgical procedure performed: a short BPL group (BPL of 50 cm with an AL of 150 cm) and long BPL group (BPL of 150 cm with an AL of 75 cm). The percentage total weight loss (%TWL) between groups was compared up to 4 years after surgery. Secondary outcomes were 30-day postoperative complications and health-related quality of life (RAND-36).

RESULTS

The short BPL group consisted of 286 patient and the long BPL group of 288 patients. Follow-up rates of both groups at the first, second, third, and fourth year after surgery were comparable. The long BPL group showed significantly more %TWL compared to the short BP limb group starting at 6 months (p = 0.004) until 4 years after surgery (p < 0.001). Thirty-day complications and health-related quality of life did not differ.

CONCLUSION

The results showed significantly more %TWL in patients receiving a long BPL compared to the short BPL up to 4 years after surgery.

Long-Term Outcome of Proximal Versus Very-Very Long Limb Roux-en-Y Gastric Bypass: the Roux-Limb to Common Channel Ratio Determines the Long-Term Weight Loss

BACKGROUND

The influence of the Roux limb (RL) length on weight loss in Roux-en-Y (RYGB)-type gastric bypass procedures is still unclear. This study analyzes the true impact of RL length by comparing the long-term outcomes of proximal RYGB (PRYGB) and very-very long limb RYGB (VVLL-RYGB).

METHODS

RL length in PRYGB was 150 cm. In VVLL-RYGB, common channel length was 100 cm. In both groups, biliopancreatic limbs measured 50-60 cm, resulting in equal total alimentary limb lengths. To adjust for pre-operative differences between groups, and to predict the long-term outcome, a mixed model analysis was performed.

RESULTS

Two hundred thirty-two patients with VVLL-RYGB (73.7% female, mean age 41.1 ± 10 years, initial BMI 45.8 ± 6.3 kg/m²) and 223 with PRYGB (83.9% female, mean age 38.5 ± 11 years, initial BMI 42.9 ± 4.9 kg/m²) were included. Mean follow-up was 9.4 ± 4 years in VVLL-RYGB and 5.3 ± 1.9 years in PRYGB. After 5 years, mean BMI reduction was 15.7 ± 5.9 kg/m² in VVLL-RYGB and 11.9 ± 4.1 kg/m² in PRYGB (p < 0.001), and mean %EWL was 78.3 ± 23.1% and 70.2 ± 23.7% (p = 0.002) with a follow-up rate of 78% and 75.9%, respectively. The mixed model analysis showed a significantly higher weight rebound after PRYGB. Frequency of revisional surgery (i.e., limb length alteration, pouch banding) was similar between VVLL-RYGB and PRYGB (25 vs. 29 revisions, p = 0.463).

CONCLUSION

The VVLL-RYGB has a significantly higher long-term BMI reduction and a significantly lower weight rebound. The length of the Roux limb significantly influences long-term outcome.

The effect of a duodenal-jejunal bypass liner on lipid profile and blood concentrations of long chain polyunsaturated fatty acids

BACKGROUND & AIMS

Duodenal-jejunal bypass liners (DJBLs) prevent absorption in the proximal small intestine, the site of fatty acid absorption. We sought to investigate the effects of a DJBL on blood concentrations of essential fatty acids (EFAs) and bioactive polyunsaturated fatty acids (PUFAs).

METHODS

Sub-study of a multicentre, randomised, controlled trial with two treatment groups. Patients aged 18-65 years with type-2 diabetes mellitus and body mass index 30-50 kg/m² were randomised to receive a DJBL for 12 months or best medical therapy, diet and exercise. Whole plasma PUFA concentrations were determined at baseline, 10 days, 6 and 11.5 months; data were available for n = 70 patients per group.

RESULTS

Weight loss was significantly greater in the DJBL group compared to controls after 11.5 months: total body weight loss 11.3 ± 5.3% versus 6.0 ± 5.7% (mean difference [95% CI] = 5.27% [3.75, 6.80], p < 0.001). Absolute concentrations of both EFAs, linoleic acid and α-linolenic acid, and their bioactive derivatives, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, were significantly lower in the DJBL group than in the control group at 6 and 11.5 months follow-up. Total serum cholesterol, LDL-cholesterol and HDL-cholesterol were also significantly lower in the DJBL group.

CONCLUSION

One year of DJBL therapy is associated with superior weight loss and greater reductions in total serum cholesterol and LDL-cholesterol, but also depletion of EFAs and their longer chain derivatives. DJBL therapy may need to be offset by maintaining an adequate dietary intake of PUFAs or by supplementation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02459561.

Dietary Recommendations for Bariatric Patients to Prevent Kidney Stone Formation

Bariatric surgery (BS) is one of the most common and efficient surgical procedures for sustained weight loss but is associated with long-term complications such as nutritional deficiencies, biliary lithiasis, disturbances in bone and mineral metabolism and an increased risk of nephrolithiasis, attributed to urinary metabolic changes resultant from low urinary volume, hypocitraturia and hyperoxaluria. The underlying mechanisms responsible for hyperoxaluria, the most common among all metabolic disturbances, may comprise increased intestinal oxalate absorption consequent to decreased calcium intake or increased dietary oxalate, changes in the gut microbiota, fat malabsorption and altered intestinal oxalate transport. In the current review, the authors present a mechanistic overview of changes found after BS and propose dietary recommendations to prevent the risk of urinary stone formation, focusing on the role of dietary oxalate, calcium, citrate, potassium, protein, fat, sodium, probiotics, vitamins D, C, B6 and the consumption of fluids.