Converting a gastric sleeve to a gastric bypass

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Converting a gastric sleeve to a gastric bypass

A gastric sleeve can be converted to a Roux-en-Y gastric bypass when the sleeve is causing a problem that a bypass is better suited to treat. The two main reasons are acid reflux that medicine does not control and weight that was not lost or has come back. Conversion is a second major operation with somewhat higher risk than a first bypass, so it follows testing, not symptoms alone.

Why sleeves are converted

A large study of the question is an analysis of the MBSAQIP national registry by Dang and colleagues, published in Obesity Surgery in 2023. It covered 13,432 sleeve-to-bypass conversions done in 2020 and 2021. The recorded reason was reflux (GERD) in 55.3 percent, weight recurrence in 24.4 percent and inadequate weight loss in 12.7 percent.

Reflux after a sleeve is well documented. In the SLEEVEPASS randomized trial, which followed patients for 10 years (Salminen and colleagues, JAMA Surgery, 2022), 31 percent of sleeve patients had esophagitis (inflammation of the esophagus seen on endoscopy) compared with 7 percent of bypass patients, and 64 percent of sleeve patients were taking acid-reducing medicine compared with 36 percent. Of the 19 sleeve patients who needed a reoperation during the trial, 14 had it for reflux.

The sleeve is a narrow, higher-pressure tube, which can push acid upward. A bypass leaves only a very small stomach pouch, which makes little acid, and routes food and digestive juices away from the esophagus. Our pages on acid reflux after a gastric sleeve and weight regain after a gastric sleeve cover those problems and the steps that come before surgery.

What changes in the operation

A sleeve cannot be undone, because the removed part of the stomach is gone. Conversion works with what remains. The surgeon divides the sleeve near its upper end to form a small pouch, then brings up a loop of small intestine and joins it to the pouch. The rest of the sleeve stays in the body but no longer receives food. It is commonly done through small incisions, and scar tissue from the first operation may have to be freed first. If a hiatal hernia is present, ask your surgeon whether it would be repaired at the same time.

The gastric bypass page describes the operation itself.

What the evidence says about risk and results

In the MBSAQIP analysis, outcomes in the first 30 days were compared with 84,543 first-time bypasses:

Within 30 days	Sleeve converted to bypass	First-time bypass
Serious complications	7.2%	5.0%
Leak at the new connection	0.5%	0.4%
Bleeding	2.0%	1.6%
Reoperation	3.0%	1.9%
Readmission	7.3%	4.8%
Death	0.1%	0.1%

After adjusting for age, BMI and other conditions, the authors found conversion was linked to a higher chance of a serious complication than a first-time bypass, with no significant difference in deaths.

On results, a 2021 systematic review and meta-analysis by Matar and colleagues in Obesity Surgery pooled 17 studies with 556 patients. Average total body weight loss one year after conversion was 22.8 percent, with BMI falling from about 38.5 to 32.1. The pooled complication rate was 16.4 percent within 30 days and 11.4 percent after 30 days. The authors described potential resolution of reflux symptoms and called for more studies sorted by the reason for conversion. The 2022 ASMBS/IFSO guidelines say revisional surgery is more complex than a first operation and is linked to longer hospital stays and higher complication rates, and that it is effective in achieving additional weight loss in selected patients.

A bypass brings its own long-term considerations: dumping syndrome after sugary foods, ulcers at the new connection (smoking and anti-inflammatory painkillers raise that risk), a greater need for vitamin and mineral supplements, and internal hernias. In SLEEVEPASS, 18 of the 22 reoperations in the bypass group were for internal herniation.

Tests before a conversion

Conversion is planned from findings, not from symptoms alone. Ask which tests apply to you and where they are done. The work-up commonly includes:

Upper endoscopy, a camera exam that shows esophagitis, a hiatal hernia, or a narrowed or twisted sleeve
Upper GI X-ray (a contrast swallow), which shows the sleeve's shape and how it empties
pH monitoring, in some cases, to measure acid in the esophagus over 24 hours
Blood tests and a nutrition review, since deficiencies should be corrected first
A review of weight history, eating pattern and medicines when the reason is weight

Non-surgical steps are commonly tried first: acid-reducing medicine and meal changes for reflux, and dietitian support or weight-loss medication for regain. The page on GLP-1 medications after bariatric surgery covers the medication route.

How insurers look at a conversion

Published policies treat reflux and weight differently. Aetna's policy considers conversion of a sleeve to a bypass medically necessary for reflux when the reflux is documented by an upper GI study, abnormal 24-hour pH monitoring or esophagitis on endoscopy, and a severity test is met, such as symptoms not controlled after at least one month of twice-daily proton pump inhibitor medicine with lifestyle changes. Done mainly for qualifying reflux, Aetna does not count it as repeat bariatric surgery.

Cigna's policy covers conversion when there is a major complication of the first operation, and it names reflux refractory to medical therapy. Without a complication, it requires weight loss failure at least two years after the first surgery and that the patient again meets the initial criteria, and it does not cover revision for inadequate weight loss due to not following postoperative nutrition and exercise recommendations. Plans differ; see bariatric revision cost and insurance.

When to call

Call your surgeon's office for heartburn that breaks through your medicine, regurgitation at night, a new cough or hoarseness, food sticking, or steady weight regain. Go to an emergency room or call 911 if you cannot keep liquids down, vomit blood, have black stools, or have severe chest or abdominal pain. Chest pain should never be assumed to be reflux.

Frequently asked questions

Will converting to a bypass stop my reflux?

It can help, but no one can promise it. In the 10-year SLEEVEPASS results, fewer bypass patients than sleeve patients had esophagitis or took acid medicine, though those were first operations, not conversions. The 2021 meta-analysis by Matar and colleagues described potential resolution of reflux symptoms after conversion. Some people still need medication afterward. Testing beforehand helps show whether acid is the cause.

How long after a sleeve can a conversion be done?

The Aetna and Cigna policies above set no waiting period for reflux that meets their criteria; timing depends on test results and how you are doing. For weight alone, insurers may set one. Cigna's policy, for example, requires weight loss failure at least two years after the first operation, and Aetna's measures excess weight loss at two years.

Is a re-sleeve an alternative to converting to a bypass?

Sometimes, when tests show a part of the stomach was left wide or has stretched and reflux is not the problem. A re-sleeve is not a treatment for reflux and may worsen it. The choice depends on your anatomy and your reason for revision. See the gastric sleeve revision page, and ask a surgeon which options apply to you.

Will I need different vitamins after a conversion?

Probably. A bypass routes food past the first part of the small intestine, where iron, calcium and some other nutrients are absorbed, so supplement doses and blood test schedules are usually stepped up compared with a sleeve. Ask your surgeon for a new plan. Do not change doses on your own before then.

Talk with Dr. Davtyan in Rancho Cucamonga

Dr. David G. Davtyan, MD, FACS, FICS, FASMBS, is a bariatric surgeon. Whether a sleeve can be converted depends on the case, including who did the first operation, so call and ask the office whether a conversion is available for you. Surgery is done at a hospital where Dr. Davtyan has surgical privileges; ask which one and what stay to expect. Call Davtyan Medical Weight Loss & Wellness at 909-355-2525 or use the contact page; the office is at 8330 Red Oak Street, Suite 201, Rancho Cucamonga, CA 91730. More topics are in the Rancho Cucamonga gastric sleeve guide.

Converting a gastric sleeve to a gastric bypass

Converting a gastric sleeve to a gastric bypass

Why sleeves are converted

What changes in the operation

What the evidence says about risk and results

Tests before a conversion

How insurers look at a conversion

When to call

Frequently asked questions

Will converting to a bypass stop my reflux?

How long after a sleeve can a conversion be done?

Is a re-sleeve an alternative to converting to a bypass?

Will I need different vitamins after a conversion?

Talk with Dr. Davtyan in Rancho Cucamonga

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More in the Gastric Sleeve in Rancho Cucamonga guide

Understanding the sleeve

Weighing your options

Getting care in Rancho Cucamonga

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