Bariatric surgery has become an increasingly common and effective treatment option for long-term weight loss and improving obesity-related diseases like type 2 diabetes, heart disease, and certain cancers. As these procedures have advanced technologically and surgical teams have gained more expertise, bariatric surgery has also become very safe, with risks comparable or lower than some common operations like gallbladder removal . However, there are still differences in safety profiles between the various types of weight loss surgery. Two of the most popular bariatric procedures are sleeve gastrectomy and gastric bypass. Recent large studies provide insight into their long-term safety and effectiveness.
Sleeve gastrectomy, also called vertical sleeve gastrectomy (VSG), is now the most commonly performed bariatric procedure worldwide . It involves surgically removing a large portion of the stomach along the greater curvature, creating a smaller stomach "sleeve". This smaller stomach pouch restricts food intake, leading to weight loss. Sleeve gastrectomy is simpler to perform than gastric bypass since it only requires one intestinal connection. It also does not lead to malabsorption issues that can occur with bypass procedures.
The Roux-en-Y gastric bypass (RYGB) is considered the gold standard bariatric procedure. It involves creating a small stomach pouch and then connecting it directly to the small intestine, bypassing part of the stomach and upper small intestine. This alters gut hormone signals and nutrient absorption, also leading to weight loss. Gastric bypass typically results in greater and more sustainable weight loss than sleeve gastrectomy, but does carry higher risk for nutritional deficiencies and requires more complex intestinal connections.
Several recent large studies have compared the safety profiles of sleeve gastrectomy and gastric bypass:
A 2022 study published in JAMA Surgery looked at over 95,000 Medicare patients who underwent either sleeve gastrectomy or gastric bypass . After 5 years follow-up, there were no significant differences between procedures for risk of death, hospital readmissions, or need for subsequent bariatric procedures.
Another 2022 study published in JAMA Network Open examined outcomes in over 25 healthcare systems and nearly 60,000 patients aged 12-79 years . They found gastric bypass had higher rates of serious complications compared to sleeve gastrectomy during the first 30 days after surgery.
A 2021 study in over 38,000 commercially insured bariatric surgery patients found sleeve gastrectomy was associated with fewer re-interventions, complications, and lower healthcare spending in the first 2 years after surgery compared to gastric bypass . However, sleeve gastrectomy patients did have a slightly higher rate of surgical revisions.
Recent large studies consistently show sleeve gastrectomy has an overall better safety profile compared to gastric bypass, at least in the first few years after surgery. Serious complications like leaks and bleeding are less common with sleeve procedures. Longer-term risks for sleeve gastrectomy may include increased use of gastric acid medications and need for surgical revisions. Overall though, both gastric bypass and sleeve gastrectomy are very safe when performed by an experienced bariatric surgery team. Patients should discuss these procedures and their unique benefits, risks, and lifestyle impacts with their surgeon to determine which is the best personal choice.
When deciding between sleeve gastrectomy and gastric bypass, there are a few key factors patients should consider:
Weight Loss Differences
For most patients, gastric bypass results in greater total weight loss - around 28-35% of total body weight on average, compared to 20-25% with sleeve procedures . Gastric bypass also seems to have better outcomes for resolving type 2 diabetes and metabolic disease. However, for some patients, the difference in weight loss between procedures may not be significant enough to justify higher risks.
A major advantage of sleeve gastrectomy is that it's reversible if necessary. Gastric bypass involves permanent changes to the digestive tract that cannot be easily reversed. Patients who may become pregnant or have other health changes in the future should consider reversibility.
As discussed above, sleeve gastrectomy has been associated with fewer complications like leaks and bleeding, lower mortality risk, and less need for additional surgeries compared to gastric bypass. However, sleeve procedures may have increased gastroesophageal reflux symptoms.
The experience and training of the bariatric surgery team is one of the most important factors for safety and effectiveness. Patients should choose a facility that specializes in bariatric procedures and ask about the surgeon's background with their preferred technique.
Recent large studies show both sleeve gastrectomy and gastric bypass are very safe and effective procedures for long-term weight loss and resolving obesity-related diseases. Sleeve gastrectomy seems to have a lower risk profile in the first few years after surgery. Gastric bypass may lead to greater total weight loss for some patients. When choosing between these options, patients should consider differences in reversibility, complication risks, and expected weight loss results, in addition to the expertise of their surgical team. With an experienced surgeon, both sleeve and bypass procedures are excellent options for treating severe obesity.
Writer: Carrie H.
Carrie is a dedicated health and nutrition writer with a strong background in medical and scientific research. She is driven by a passion for helping others lead healthier lives, diving into the latest scientific research. Combining evidence-based knowledge with practical advice, Carrie strives to provide accurate and valuable information on health, nutrition, and wellness. Her ultimate aim is to empower readers, enabling them to make informed choices about their well-being.
Reviewed By: Dr. Kevin Huffman
Dr. Kevin D. Huffman, D.O., is a leading board-certified bariatric physician with extensive expertise in treating obesity. He has trained countless healthcare providers and founded American Bariatric Consultants to develop protocols and training materials sought by medical societies, pharmaceutical companies, patients, and hospitals. Dr. Huffman's impact extends beyond patient care as he prepares physicians for board certification, expanding access to this vital treatment.