Both are common ways to replace a Lap-Band. A sleeve removes most of the stomach and leaves a narrow tube; a gastric bypass makes a small stomach pouch and connects it to the small intestine. In large US data, conversion to bypass had somewhat more early complications. Weight results were similar in the short term and sometimes better with bypass later, and reflux often decides the choice.
How the two operations differ
In a sleeve gastrectomy, the surgeon removes a large part of the stomach, leaving a tube-shaped stomach. The intestine is not changed. In a Roux-en-Y gastric bypass, the surgeon creates a small pouch from the upper part of the stomach and connects it directly to the small intestine, so food skips most of the stomach and the first part of the intestine.
When either one follows a band, the band, tubing and port are removed, and the surgeon works through scar tissue left by the band. The practice's pages on the gastric sleeve and gastric bypass describe each operation in more detail.
Early safety: what national data show
Two analyses used the national quality database run by the American College of Surgeons and the American Society for Metabolic and Bariatric Surgery (ASMBS), looking at band removal and conversion done in one operation. Patients in the two groups were matched so they were comparable in age, weight and health conditions.
| Within 30 days | Band to sleeve | Band to bypass |
|---|
| Readmission, 2015 data (1,354 matched pairs) | 3.69% | 7.46% |
| Readmission, 2015-2017 data (4,987 matched pairs) | 3.77% | 6.16% |
| Reoperation, 2015-2017 data | 1.36% | 2.15% |
| Death, 2015-2017 data | 0.06% | 0.02% |
The bypass conversions also took longer in the operating room, an average of 151 minutes against 113. The difference in deaths was not statistically significant, and both studies concluded that both conversions were reasonably safe in the first 30 days, with more complications after conversion to bypass.
Weight loss after conversion
A 2017 review pooled eight studies with 635 patients. Weight loss at 6 and 12 months was similar after both conversions, while bypass produced more excess weight loss and a larger drop in body mass index after 24 months. An Italian study of 51 patients followed to five years found no significant difference between the two groups at one, three or five years.
Most of these studies are small and not randomized, so they cannot tell you how you personally will do. They do suggest that neither option is clearly worse for weight, and that the decision usually turns on other factors.
Reflux, diabetes and vitamins
- Reflux. ASMBS says a sleeve "may worsen or cause new onset reflux and heart burn," while it says a gastric bypass "also helps patients with reflux (heart burn) and often the symptoms quickly improve." Many band patients already have reflux, which often points toward bypass.
- Diabetes. ASMBS says a gastric bypass "often results in improvement of adult onset diabetes even before any weight loss occurs," and describes the sleeve as having less impact on metabolism than bypass procedures.
- Vitamins and minerals. ASMBS lists more vitamin and mineral deficiencies after a bypass than after a sleeve. Bypass can also cause "dumping syndrome," a sick feeling after eating, especially sweets. The 2019 guidelines published with ASMBS recommend two multivitamin-mineral doses a day after either operation, plus calcium, vitamin D and B12 as needed, with lifelong lab checks.
- Reversibility. ASMBS lists the sleeve as a non-reversible procedure. A bypass is also a permanent change in anatomy and is not something to plan on undoing.
How the choice is usually made
The decision rests on your evaluation, not a preference chart. Expect questions about reflux and heartburn medication, diabetes, regular use of anti-inflammatory pain relievers, smoking, pregnancy plans, and why the band is coming out. Expect tests that look at the esophagus, stomach and any hiatal hernia, usually an upper GI X-ray and an endoscopy; see tests for Lap-Band problems.
Whether the conversion is done in the same operation as band removal is a separate question, covered in one-stage vs two-stage conversion. For what to expect locally, see Lap-Band to sleeve conversion in Rancho Cucamonga.
Frequently asked questions
Is a sleeve after a band the same as a first-time sleeve?
The finished shape is similar, but the operation is not. The surgeon has to remove the band and work through scar tissue around the upper stomach, where the band sat. That is part of why conversions are studied separately from first-time operations. Ask your surgeon how the band area will be handled in your case.
Which conversion is better if I already have bad heartburn?
Reflux usually favors bypass. ASMBS notes that a sleeve may worsen reflux or cause it for the first time, while reflux symptoms often improve after a bypass. Severe reflux with a band can also come from a band that is too tight or has slipped, so your surgeon will want to see test results before deciding.
Why would anyone choose the sleeve if bypass may give more weight loss?
Because the trade-offs are real. In national data, band-to-sleeve conversion had fewer readmissions and reoperations in the first month. A sleeve also leaves the intestine unchanged and carries fewer vitamin and mineral deficiencies than a bypass, according to ASMBS. For someone without significant reflux, those points can outweigh a possible weight advantage.
Will I need vitamins for life after either conversion?
Yes. After a band, the guidelines list one daily multivitamin; after a sleeve or bypass they list two, plus calcium and vitamin D, with B12 as needed. Regular blood tests check for deficiencies. Lifelong supplements and labs are part of either choice, slightly more so after bypass.
Talk with Dr. Davtyan in Rancho Cucamonga
Dr. David G. Davtyan, MD, FACS, FICS, FASMBS, performs gastric sleeve, gastric bypass and revision surgery and can review your history and test results with you. The Rancho Cucamonga office is at 8330 Red Oak Street, Suite 201, Rancho Cucamonga, CA 91730; call 909-355-2525 or toll free 877-9-BE-SLIM (877-923-7546). The first consultation is complimentary and Spanish is spoken; use the contact page or browse the Lap-Band in Rancho Cucamonga guide.
Sources
More in the Lap-Band in Rancho Cucamonga guide
Start at the Lap-Band in Rancho Cucamonga page, or go straight to a topic.
Understanding your band
Weighing your options
Getting care in Rancho Cucamonga
