Gastric Sleeve: A Complete Guide

You have probably been told the sleeve is the simple one. That is half true. It is technically simpler than the bypass and it asks less of you afterward. It is also permanent, and it has one weakness that gets glossed over in consultations more often than it should.

What is removed and what is left

In a sleeve gastrectomy, the surgeon removes roughly 80 percent of your stomach along the greater curvature and leaves a narrow tube, often described as banana shaped, running from your esophagus down to the pylorus. NIDDK describes it as removing most of the stomach and closing the remainder with staples. The pylorus, the valve at the bottom of the stomach, stays. So does the whole of your intestine. Nothing is rerouted.

That last point matters more than it sounds. Because food still travels the normal path, you do not get the intestinal malabsorption that comes with a bypass, and you are less likely to run into the specific problems that rerouting causes.

Why your hunger changes, not just your capacity

The part of the stomach that gets removed includes the fundus, which is where most of your ghrelin is produced. Ghrelin is a 28 amino acid peptide, discovered in 1999, that drives appetite. Plasma ghrelin falls significantly after sleeve gastrectomy, and in one series that fall tracked with weight loss over the first three months before plateauing at six months while weight loss continued.

Three mechanisms are usually described for the sleeve: reduced capacity, loss of the fundus so the stomach no longer relaxes to accommodate a large meal, and the hormonal shift involving lower ghrelin along with changes in GLP-1 and PYY. This is why most people report that they are not just physically limited but genuinely less interested in food, at least for the first year or two.

The operation itself

The sleeve is done laparoscopically or robotically through several small incisions. A calibrating tube, called a bougie and typically sized between 32 and 40 French, is passed into the stomach to size the sleeve. The surgeon separates the stomach from the omentum, exposes the angle of His, and staples along the bougie starting 2 to 6 cm above the pylorus, depending on the surgeon. An international consensus recommended starting at least 3 cm from the pylorus and using a larger bougie, since a 2013 meta-analysis found a 66 percent reduction in leak rate with a bougie of 40 French or larger without a meaningful loss of weight loss effect.

Before stapling, your surgeon should look at your diaphragm to see whether you have a hiatal hernia, and repair it if you do. Ask whether this is part of the plan. It is one of the few things that changes your reflux outlook and it is easier to do at the time of your sleeve than later.

Most people stay overnight. How long you stay varies by program and by whether your center uses an enhanced recovery protocol. Ask yours what to expect.

How much weight, and how fast

ASMBS states that people having metabolic and bariatric surgery may lose as much as 77 percent of their excess weight in the first year, depending on the procedure. That is a figure for surgery in general, not a sleeve specific forecast. Treat it as a ceiling.

The honest long term picture:

• In the SLEEVEPASS randomized trial at 10 years, median excess weight loss after sleeve was 43.5 percent, compared with 50.7 percent after gastric bypass, a difference of 8.4 percentage points.
• In a review of 11 studies covering 1,020 patients followed 10 years or more, mean total weight loss was 24.4 percent, with individual studies ranging from 17 percent to 36.9 percent. Eighty percent of those studies reported more than 20 percent total weight loss maintained.

Total weight loss of roughly a quarter of your starting body weight, held for a decade, is a real and useful result. If you started at 300 pounds that is around 75 pounds still gone at 10 years. It is also not the number most people picture when they book surgery. The spread between studies, 17 percent to nearly 37 percent, is wide enough that anyone quoting you a single figure is guessing.

In the same long term review, remission rates were 45.6 percent for type 2 diabetes, ranging from zero to 94.7 percent across studies, and 41.4 percent for hypertension, ranging from 14 to 78.4 percent. The variation is genuine and reflects different populations and different definitions of remission.

Regain and revision

In that 10 year review, 19.2 percent of sleeve patients went on to a further operation, with individual study rates from 1 percent to 49.5 percent. Of those revisions, 67.2 percent were conversions to Roux-en-Y gastric bypass, 19.7 percent to duodenal switch, 6.6 percent to one anastomosis gastric bypass and 5.5 percent to SADI-S. In the SLEEVEPASS trial the overall 10 year reoperation rate was 15.7 percent after sleeve, which was not significantly different from the 18.5 percent seen after bypass.

So roughly one in five sleeve patients has another operation within a decade. That is not a failure of the procedure and it is not a failure of yours if it happens to you. It is a known part of the arc.

The reflux problem

This is the sleeve's specific weakness and the evidence is genuinely contested. Reported rates of new reflux after sleeve range from roughly a third of patients to more than half, depending on how it is measured and for how long.

• A meta-analysis of nine studies found the odds of GERD were 3.61 times higher after sleeve, and pooled the rate of new onset GERD at 50.8 percent. Pooled erosive esophagitis was 23.1 percent for Los Angeles class A, 14.6 percent for class B, 4.3 percent for class C and 3.3 percent for class D. Pooled Barrett's esophagus was 7.3 percent.
• The 10 year review put new onset GERD at 32.3 percent, with a range of 21.4 to 58.4 percent, and Barrett's at 0.5 percent.
• In SLEEVEPASS at 10 years, 31 percent of sleeve patients had esophagitis on endoscopy compared with 7 percent after bypass, and 64 percent were on proton pump inhibitors compared with 36 percent. Barrett's esophagus was found in 4 percent of both groups, with no statistically significant difference.

The spread is explained by how the studies defined reflux. Symptom questionnaires and endoscopic findings do not agree with each other, and studies that scoped everyone find more disease than studies that waited for complaints. What is not in dispute is that reflux after sleeve is common, that it is more common than after bypass, and that it is now the leading reason sleeve patients get converted to a bypass later.

If you already have significant reflux, a hiatal hernia, esophagitis or Barrett's, raise it before you consent to a sleeve. That conversation belongs with your surgeon.

The other thing to be clear about

The sleeve cannot be reversed. The removed portion of your stomach is gone. It can be converted to a bypass or a duodenal switch, but you cannot be put back the way you were. If reversibility is important to you, say so out loud during your consultation rather than assuming it is on the table.

Nutrition after a sleeve

You still need supplements. ASMBS nutritional guidance recommends at least 12 mg of thiamine daily, 45 to 60 mg of elemental iron daily for sleeve patients and menstruating women, 1,200 to 1,500 mg of calcium daily, and 3,000 IU of vitamin D3 daily until blood levels are sufficient. Nutrient labs should be checked every 3 to 6 months in the first year and annually after that. Your program will set your specific regimen.

Who the sleeve suits

It is a reasonable default for most people who want a durable operation without intestinal rerouting, who do not have significant reflux, and who want a lower supplementation burden than the bypass carries. It is a poor fit if reflux is already part of your life. Bring your heartburn history to the table honestly, even the part where you have been quietly taking antacids for years.