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 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.