Gastric bypass shows slight edge over sleeve gastrectomy in long-term study

By Dr. Sushama R. Chaphalkar, PhD.Jan 25 2024Reviewed by Lily Ramsey, LLM

In a recent phase III randomized controlled trial (RCT) published in The Lancet Regional Health – Europe, researchers from the Netherlands investigated and compared the long-term weight loss effects of sleeve gastrectomy and Roux-en-Y gastric bypass in people with obesity.

They found that the two procedures had clinically comparable excess loss of body mass index (BMI) in individuals with obesity in grades 2 and 3.

Further, they found that Roux-en-Y gastric bypass resulted in significantly higher total weight loss (TWL) and showed benefits in outcomes such as dyslipidemia and gastroesophageal reflux disease (GERD).

Study: Long-term effect of sleeve gastrectomy vs Roux-en-Y gastric bypass in people living with severe obesity: a phase III multicentre randomised controlled trial (SleeveBypass). Image Credit: Shidlovski/Shutterstock.com

Background

Obesity, a global health concern, has seen an alarming rise, emphasizing the need for effective treatments. Metabolic surgeries such as Roux-en-Y gastric bypass and sleeve gastrectomy have emerged as highly effective interventions.

Previous trials and reviews compared the two procedures but showed conflicting results, with potential advantages for Roux-en-Y gastric bypass in terms of weight loss and remission of type 2 diabetes (T2D).

Sleeve gastrectomy is less challenging and more commonly performed among the two procedures. While it may be advantageous in terms of health-related quality of life (HRQoL), there remain concerns about its irreversibility and potential risk of GERD.

Given the current lack of clarity in this regard, researchers in the present study aimed to assess the clinical comparability between sleeve gastrectomy and Roux-en-Y gastric bypass, thereby contributing further evidence in the field.

About the study

The present study (SleeveBypass) was conducted as a phase III RCT in two Dutch hospitals. Patients eligible for metabolic surgery (n = 628) were randomized 1:1 to undergo either sleeve gastrectomy (n = 312) or Roux-en-Y gastric bypass (n = 316).

During the study, a crossover occurred wherein procedures were swapped for 13 and 16 patients initially assigned to sleeve gastrectomy and Roux-en-Y gastric bypass, respectively. While the mean age of the patients was 43 years, their baseline BMI was 43.5 kg/m², and 81.8% of them were female.

Patients with severe GERD, hiatal hernia, prior metabolic or major abdominal surgery, and inability to provide informed consent were excluded.

Stratification of the patients was based on gender, T2D, and BMI. Surgical procedures followed specific protocols, and patients adhered to the Enhanced Recovery After Bariatric Surgery protocol.

The study's primary outcome was weight loss by percentage excess BMI loss after five years of surgery. The secondary outcomes included total weight loss, comorbidity resolution, surgical duration, hospital stay, additional clinical visits, morbidity and mortality within 30 days, the need for revision surgery, and HRQoL.

Measurements were collected up to five years postoperatively. Statistical analysis included the use of linear mixed models, Chi-squared test, Fisher exact test, multivariable logistic regression, unpaired Student’s t-test, non-parametric Mann–Whitney U Test, and multiple imputation methods.

Results and discussion

About 34.1% of the participants had hypertension, 18.5% had T2D, 21.7% had dyslipidemia, 15.4% had obstructive sleep apnea (OSA), and 23.1% had severe joint pain at the baseline.

The mean excess BMI loss was higher after Roux-en-Y gastric bypass (67.1%) than sleeve gastrectomy (58.8%). However, the difference between the two groups (8.3%) was found to be within the equivalence margin.

Five years post-surgery, sleeve gastrectomy resulted in a TWL of 22.5%, while Roux-en-Y gastric bypass led to a higher TWL of 26%. Both the procedures showed significant improvement in obesity-related comorbidities after five years.

However, dyslipidemia was observed to improve more with Roux-en-Y gastric bypass (83%) than with sleeve gastrectomy (62%, P = 0.006). Additionally, sleeve gastrectomy had a higher occurrence of de novo gastro-esophageal reflux disease (16%) as compared to Roux-en-Y gastric bypass (4%, P < 0.001).

Although minor complications were more frequent with Roux-en-Y gastric bypass than with sleeve gastrectomy, the differences among the two groups in terms of major complications, hypertension, T2D, OSA, joint pain, and HRQoL were not found to be statistically significant among the two groups.

This is the largest trial comparing Roux-en-Y gastric bypass and sleeve gastrectomy for obesity treatment. However, it is limited using a relatively larger equivalence margin, a lack of accounting for baseline BMI's effect on BMI loss, and a potential selection bias.

Conclusion

In conclusion, the findings of the SleeveBypass trial support the use of metabolic surgery for the management of obesity, providing clearer insights into the pros and cons of sleeve gastrectomy and Roux-en-Y gastric bypass.

The study provides valuable evidence that could potentially aid clinicians and policymakers for informed decision-making, leading to improved public health outcomes.