Comparing Weight Loss and Health Outcomes: Sleeve Gastrectomy vs. Gastric Bypass

When it comes to bariatric surgery, two of the most common procedures are laparoscopic sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). However, there’s been a lack of long-term data comparing the outcomes of these surgeries, particularly beyond the five-year mark. That’s where the SM-BOSS study comes in.

Dr. Alexander Abkin, a New Jersey-based bariatric surgeon, explains: “While both procedures can lead to significant weight loss, patients often wonder which procedure provides the best long-term outcomes. The SM-BOSS study sheds important light on this question.”

The Study Design

The SM-BOSS trial, which ran from January 2007 to November 2011, included 3,971 patients with severe obesity. Of those, 217 were enrolled and randomly assigned to undergo either SG or RYGB at four bariatric centers in Switzerland. With a decade of follow-up data now available, this study provides crucial insights into the long-term weight loss, metabolic improvements, and quality of life for both groups of patients.

Dr. Abkin shares: “This study is particularly valuable because it gives us insight into the effects of these surgeries a decade after the procedures, which is rare in the field of bariatrics.”

Key Findings

The primary goal of the study was to compare the percentage of excess body mass index loss (%EBMIL) at the 5-year mark. However, the latest data includes outcomes at 10 years and beyond, providing a deeper understanding of how patients fared long term.

Weight Loss:

After 10 years, patients who underwent RYGB experienced a higher %EBMIL compared to those who had SG, though the difference wasn’t statistically significant across the whole study group. On average, RYGB patients had a %EBMIL of 65.2%, while SG patients had 60.6%. However, when looking at patients who followed the study’s protocol, RYGB patients had a notably higher %EBMIL than those who had SG (65.9% vs. 56.1%, respectively).

Dr. Abkin notes: “The difference in weight loss between RYGB and SG becomes more apparent in patients who adhere to their surgical protocol, though both procedures are effective for the majority of patients.”

Reoperation Rates:

One of the most important findings from this study is the higher conversion rates for SG. That is, patients who underwent SG were more likely to require additional surgery due to insufficient weight loss or complications like gastroesophageal reflux disease (GERD). Specifically, 29.9% of SG patients required a conversion, compared to just 5.5% of RYGB patients. This is a significant difference and speaks to the reliability of RYGB for long-term outcomes.

“For patients looking for a more stable long-term solution, RYGB seems to offer an edge in terms of reducing the need for reoperation,” says Dr. Abkin. “SG, while effective initially, may lead to more issues down the line, such as GERD or suboptimal weight loss.”

GERD and Quality of Life:

A key point in the study was the difference in the incidence of gastroesophageal reflux disease (GERD). SG patients were found to have a significantly higher rate of GERD compared to RYGB patients. This underscores a common issue with sleeve gastrectomy: it can lead to a worsening of reflux symptoms over time.

“GERD is a major concern for many of my patients undergoing SG, and the data here highlights why some patients may experience discomfort years after surgery,” Dr. Abkin comments.

Long-Term Health:

The study also looked at metabolic outcomes, showing that both procedures led to improvements in obesity-related diseases, like diabetes and hypertension. However, the long-term benefits were more pronounced in the RYGB group.

RYGB Shows Stronger Long-Term Results

While both SG and RYGB are effective weight loss surgeries, the SM-BOSS study reveals that RYGB provides better long-term weight loss results and fewer complications, particularly when it comes to GERD and the need for reoperations.

Dr. Abkin concludes: “Both SG and RYGB can help patients achieve significant weight loss, but the findings of this study suggest that RYGB might offer a more reliable, long-term solution for those struggling with obesity. However, it’s important to note that the choice of surgery depends on individual health conditions and goals.”

Ultimately, patients considering bariatric surgery should work closely with a skilled bariatric surgeon to choose the procedure that best aligns with their long-term health and weight loss goals.