Gastric sleeve to bypass conversion usually does not lead to substantial additional weight loss if the original gastric sleeve surgery was done properly. Both sleeve gastrectomy and gastric bypass are metabolic surgeries with similar mechanisms of action. They mainly alter gut hormone secretion in response to food intake by increasing gastric emptying and food passage through small intestines.  Gut hormones like GLP-1 (better known under its pharmaceutical name of Ozempic, Mounjaro, Zepbound…) are secreted by the intestines in response to food intake. These hormones increase satiety, decrease appetite and cravings, as well as improve blood sugar level, leading to weight loss. Major studies such as SLEEVEPASS, SM_BOSS and STAMPEDE trials have shown comparable weight loss and health improvement between gastric sleeve and gastric bypass surgery.

Therefore, if the original gastric sleeve was performed correctly, converting to gastric bypass changes the anatomy but does not significantly enhance the metabolic weight loss effect.

For this reason, when weight loss stalls or weight is regained after an initial properly performed gastric sleeve surgery, conversion to gastric bypass may not be the best option for you to lose weight. An experienced bariatric surgeon may offer you one of two options in this case:

1. Pharmacotherapy with GLP-1/GIP agonist medications (like Ozempic and Zepbound) along with behavioral changes is a great first line treatment. These medications are effective and safe with limited side effects.
2. If GLP-1 therapy is not enough, Single Anastomosis Duodeno-Ileal Bypass (SADI) is increasingly considered the procedure of choice in many cases after failed gastric sleeve surgery. SADI is a malabsorptive procedure that consists of bypassing a long segment of the small bowel to limit the absorption of calories and nutrients. The risk of diarrhea, vitamin deficiency and malnutrition is around 10%. Nutritional supplementation and adequate protein intake are needed. SADI is a newer bariatric operation and long-term outcome data are still not available.

If the initial gastric sleeve surgery was not properly performed resulting in poor weight loss or severe acid reflux, then three options are available depending on gastric sleeve anatomy:

1. For a retained gastric fundus (upper part of the sleeve was not completely resected), a re-sleeve is indicated
2. For a neo-fundus formation (dilated upper part of sleeve) resulting in acid reflux but adequate weight loss, hiatal hernia repair is all what you need to stop reflux. This condition typically occurs secondary to functional obstruction at the stomach angulation due to improper staple line alignment during surgery. https://houstonsleevesurgeon.com/the-perfect-sleeve-gastrectomy-to-prevent-gerd
3. For a narrowed sleeve lumen (Stomach was aggressively resected over a small calibration tube) resulting in severe acid reflux, conversion to gastric bypass is indicated to bypass the narrowing.

For additional information and in-depth evaluation for weight regain or limited weight loss following gastric sleeve surgery, give us a call at 832-963-1803. At Houston Weight Loss Surgery Center, we offer individualized, safe and reliable weight loss solutions that best fit your condition.

References:

• Salminen P, Helmiö M, Ovaska J, et al. Effect of laparoscopic sleeve gastrectomy vs laparoscopic Roux-en-Y gastric bypass on weight loss at 5 years among patients with morbid obesity: the SLEEVEPASS randomized clinical trial. JAMA 2018;319:241-54. 10.1001/jama.2017.20313
• Peterli R, Wolnerhanssen BK, Peters T, et al. Effect of laparoscopic sleeve gastrectomy vs laparoscopic Roux-en-Y gastric bypass on weight loss in patients with morbid obesity: the SM-BOSS randomized clinical trial. JAMA 2018;319:255-65. 10.1001/jama.2017.20897
• Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes — 5-year outcomes. N Engl J Med 2017;376:641-51. 10.1056/NEJMoa1600869