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Choosing a Type of Weight Loss Surgery

Reviewed by Brunilda Nazario, MD on December 09, 2022

Do You Qualify for Weight Loss Surgery?

Obesity is a medical term for a chronic disease that threatens your health and requires long-term management. There are several medications, devices, and surgeries to help you achieve weight loss. Weight loss surgery, also called bariatric surgery or metabolic surgery, refers to operations that help you lose weight by altering your digestive system and/or appetite.

You may be a candidate for weight loss surgery if:

  • You're obese (with a body mass index or BMI of 30 or above) and have a weight-related health condition, such as type 2 diabetes with uncontrolled blood sugar despite the best treatments
  • Your BMI is higher than 35, even if you don’t have other weight-related conditions 
  • You know the risks and benefits.
  • You're ready to adjust how you eat after the surgery.
  • You're committed to making lifestyle changes to keep the weight off.

Bariatric surgery is usually only for adults. It’s not generally recommended for teens unless they're extremely obese (with a BMI of at least 35) and have a weight-related medical condition.

Bariatric surgery is not just about losing weight. It can help you live longer, with a better quality of life, in part by treating or preventing obesity-related conditions like: 

  • Heart disease
  • High blood pressure
  • Diabetes
  • Arthritis
  • Some cancers

Before you get weight loss surgery, you'll go through a thorough screening process. Your doctor will consider your physical and emotional health and whether you’re ready to make permanent lifestyle changes. 

You’ll have a nutritional assessment to look at any nutrition deficiencies as well as unhelpful eating patterns. You’ll likely be screened for eating disorders, depression, and substance use disorder.

If you're thinking about metabolic/bariatric weight loss surgery, talk to your doctor about whether it's a good option for you.

Types of Weight Loss Surgeries

Bariatric surgeries are done with small cuts, using minimally invasive techniques or with robotic surgery. Different procedures help with weight loss in different ways.

Restrictive surgeries work by shrinking the size of your stomach and slowing digestion. A normal stomach can hold about 3 pints of food. After surgery, your stomach may at first hold as little as an ounce, although later that could stretch to 2 or 3 ounces. The smaller your stomach, the less you can eat. The less you eat, the more weight you lose.

Malabsorptive/restrictive surgeries change how you take in food. They give you a smaller stomach and also remove or bypass part of your digestive tract, which makes it harder for your body to absorb calories. Doctors rarely do purely malabsorptive surgeries anymore because of the side effects.

Implanting an electrical device, the newest of the three techniques, prompts weight loss by interrupting nerve signals between the stomach and the brain.

Adjustable Gastric Banding

What it is: Gastric banding is a type of restrictive weight loss surgery.

How it works: The surgeon uses an inflatable band to squeeze the stomach into two sections: a smaller upper pouch and a larger lower section. The two sections remain connected by a very small channel, which slows down the emptying of the upper pouch. Most people can only eat a half-cup to 1 cup of food before feeling too full or sick. The food also needs to be soft or well-chewed.

Pros: This operation is simpler to do and safer than gastric bypass and other operations. You get a smaller scar, recovery is usually faster, and you can have surgery to remove the band.

You can also get the band adjusted in a doctor's office. To tighten the band and further restrict your stomach size, the doctor injects more saline solution into the band. To loosen it, the doctor uses a needle to remove liquid from the band.

Cons: People who get gastric banding often have less dramatic and slower weight loss than those who get other surgeries. They may also be more likely to regain some of the weight over the years.

Risks:  One of the most common side effects of gastric banding is vomiting after you eat too much too quickly. The band might slip out of place, become too loose, or leak. Some people need more surgeries. As with any operation, infection is a risk. Although unlikely, some complications can be life-threatening.

Sleeve Gastrectomy

What it is: Also called vertical gastric sleeve surgery (VSG surgery), this is another form of restrictive weight loss surgery. In the operation, the surgeon removes about 80% of your stomach. What remains is a narrow tube or sleeve, which connects to your intestines. By removing a part of the stomach that makes hormones that drive hunger, this procedure also decreases your appetite.  

Pros: A sleeve gastrectomy is a simple, safe operation that gives you a lower-risk way to lose weight. If needed, once you’ve lost weight and your health has improved – usually after 12-18 months – you can have a second surgery, such as gastric bypass.

Because it doesn’t affect your intestines, a sleeve gastrectomy doesn't change how your body absorbs food, so you're not likely to fall short on nutrients.

Cons: Unlike gastric banding, a sleeve gastrectomy can’t be reversed.

Risks: Typical risks include infection, leaking of the sleeve, and heartburn or reflux.

Gastric Bypass Surgery (Roux-en-Y Gastric Bypass)

What it is: Gastric bypass combines both restrictive and malabsorptive approaches.

In the operation, the surgeon divides the stomach into two parts, sealing off the upper section from the lower. The surgeon then connects the upper stomach directly to the lower section of the small intestine.

Basically, the surgeon is creating a shortcut for the food, bypassing part of the stomach and the small intestine. Skipping these parts of the digestive tract means your body absorbs fewer calories.

Pros: Weight loss tends to be swift and dramatic. About 50% of it happens in the first 6 months. It may continue for up to 2 years after the operation. Because of the rapid weight loss, conditions affected by obesity – such as diabetes, high blood pressure, high cholesterol, arthritis, sleep apnea, and heartburn – often get better quickly.

Gastric bypass also has good long-term results. Studies have found that many people keep most of the weight off for 10 years or longer.

Cons: You won't absorb food the way you used to, and that puts you at risk for not getting enough nutrientswhich could lead to vitamin and mineral deficiencies. The loss of calcium and iron could lead to osteoporosis and anemia. You'll have to be very careful with your diet, and take supplements, for the rest of your life.

Another risk of gastric bypass is dumping syndrome, in which food dumps from the stomach into the intestines too quickly, before it's been properly digested. About 85% of people who get a gastric bypass have some dumping. Symptoms include nausea, bloating, pain, sweating, weakness, and diarrhea. Dumping is often triggered by eating sugary or high-carbohydrate foods. Adjusting your diet can often help.

Unlike adjustable gastric banding, gastric bypass is generally considered irreversible. It has been reversed in rare cases.

Risks: Because gastric bypass is more complicated, it's riskier. Infection and blood clots are risks, as they are with most surgeries. Also, you may get gallstones because of the rapid weight loss.

Biliopancreatic Diversion

What it is: This is a more drastic version of a gastric bypass. The surgeon removes as much as 70% of your stomach and bypasses 75% of your small intestine.

A somewhat less extreme version is biliopancreatic diversion with a duodenal switch, sometimes just called “the duodenal switch.” It's still more involved than a gastric bypass, but this procedure removes less of your stomach and bypasses less of your small intestine than biliopancreatic diversion without the switch. It also makes dumping syndrome, malnutrition, and ulcers less common than with a standard biliopancreatic diversion.

Pros: Biliopancreatic diversion can result in even greater and faster weight loss than a gastric bypass. Although much of your stomach is removed, what's left is still larger than the pouches formed during gastric bypass or banding procedures. So you may be able to eat larger meals with this surgery than with others. This procedure also affects your intestinal hormones in a way that reduces hunger, helps you feel full, and improves blood sugar control. 

Cons: Biliopancreatic diversion is less common than gastric bypass. One of the reasons is that your risk of not getting enough nutrients is much more serious. It also poses many of the same risks as gastric bypass, including vitamin and mineral deficiencies and dumping syndrome. But the duodenal switch may lower some of these risks.

Risks: This is one of the most complicated and riskiest weight loss surgeries. As with gastric bypass, it poses a fairly high risk of hernias, which will need more surgery to correct. But this risk is lower when your doctor uses minimally invasive procedures (called laparoscopy).

Single Anastomosis Duodeno-Ileal Bypass With Sleeve Gastrectomy (SADI-S)

What it is: This is a simpler form of the duodenal switch. Basically, it’s a sleeve gastrectomy followed by a bypass of your small intestine. It has elements of both restrictive and malabsorptive techniques.

Your surgeon first creates a narrow gastric sleeve by removing about 80% of your stomach. They then reroute part of your small intestine, creating two pathways. One carries food from your stomach to the bowel. The other carries bile from your liver into the small intestine. 

A smaller stomach means you feel full with less food. And because the food you eat has less time to mix with digestive acids, you absorb fewer calories. 

Pros. SADI-S is simpler and safer than the duodenal switch procedure. It has fewer complications than traditional bypass surgeries, but it results in greater weight loss and better control of diabetes. Because it removes less of your intestine than some other types of bariatric surgery, your body doesn’t lose as many nutrients. You can have this procedure if you’ve already had a sleeve gastrectomy and aren’t happy with the results.

Cons. You’ll need diet monitoring and nutritional supplements for the rest of your life. You may have bowel movements more often and notice more flatulence. 

Risks. Your risk of complications like bleeding, nausea, and leaks at the surgical connection sites are similar to those of other weight loss procedures. The sleeve gastrectomy can’t be reversed. Since this is a newer procedure, we don’t have much information on long-term outcomes. 

Weight Loss Devices

The gastric balloon and vagal blockade aren’t technically considered weight loss surgery. But a doctor implants or places one of these devices in your body to help you lose weight. 

Gastric balloon/intragastric balloon system. An intragastric balloon is a type of restrictive procedure in which a deflated balloon is placed in your stomach through your mouth. It’s then filled with saline solution that provides a sense of fullness and reduces hunger. The intragastric balloon is not meant for people who’ve had previous weight loss surgery or who have bowel disease or liver failure.

Pros: There’s no real surgery involved and no hospital stay is needed. The balloon is temporary; it stays in place for 6 months. You can lose about 10% of your excess body weight during that time.

Cons: Possible stomachache, nausea, and vomiting a few days after placement of the balloon.

Risks: The FDA in 2017 reported five deaths that may have been caused by the intragastric balloons (such as by perforation of the stomach or esophagus, or by intestinal blockage).The FDA also received some reports of spontaneous balloon overinflation, either with air or fluid, and pancreatitis that was caused by the balloon pressing on surrounding organs.  

Vagal Blockade, or vBloc. An implanted pacemaker-like device sends regular electrical impulses to the vagus nerve, which signals your brain that your stomach is full. The vagus nerve extends from your brain to your stomach. The blockade device is placed under your rib cage and is operated by remote control that can be adjusted outside your body. 

Pros: Implanting this device is noninvasive. The outpatient procedure may take up to an hour and a half while you’re under general anesthesia.

Cons:  If the battery completely drains, a doctor has to reprogram it. Side effects can include nausea, vomiting, heartburn, problems swallowing, belching, mild nausea, and chest pain

Risks: Infection or pain at the implantation site. The device has a low rate of serious complications.  

NOTE: The vagal blockade is not endorsed by the American Society of Metabolic and Bariatric Surgery (ASMBS). Because of this, centers accredited by the American College of Surgeons Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) must get institutional review board (IRB) approval before implanting these devices.

Which Weight Loss Surgery Is Best?

The ideal weight loss surgery for you depends on your health and body type.

For instance, if you are very obese, or if you have had abdominal surgery before, simpler surgeries might not be possible. Talk with your doctor about the pros and cons of each procedure.

If possible, go to a medical center that specializes in weight loss surgery. Complications are less likely when weight loss surgery is done by experts. Always make sure that your surgeon has had plenty of experience doing the procedure you need.

Show Sources

SOURCES:

News release, Allergan.

ACP Medicine: "Endocrinology Chapter X: Obesity."

American Society for Bariatric Surgery: "Brief History and Summary of Bariatric Surgery."

American Society for Metabolic and Bariatric Surgery: "Bariatric Surgery: Postoperative Concerns," "Vagal Blocking Therapy for Obesity," “Benefits of Weight Loss Surgery.”

American Family Physician: "Complications of Adjustable Gastric Banding Surgery for Obesity."

National Institute of Diabetes and Digestive Kidney Diseases: "Gastrointestinal Surgery for Severe Obesity."

Obesity Action Coalition: "Gastrointestinal Surgery (Bariatric Surgery)," "Laparoscopic Sleeve Gastrectomy."

News release, FDA.

Letter to Health Care Providers: FDA.

UCSan Diego Health: "Weight Loss Surgery Summaries."

Shikora, SA. J Obese, 2015.

BMC Obesity: "Aspiration therapy for obesity; a safe and effective treatment."

Mayo Clinic: “Bariatric Surgery.”

Cleveland Clinic: “Department of Nutrition Therapy,” “5 Tips to Help You Mentally Prepare for Bariatric Surgery.”

International Federation for the Surgery of Obesity and Metabolic Disorders: “Single Anastomosis Duodenal-Ileal Bypass With Sleeve (SADI-S).”

Obesity Surgery: “Long-Term Results of Single-Anastomosis Duodeno-ileal Bypass with Sleeve Gastrectomy (SADI-S).”

Darebin Weight Loss Surgery: “SADI-S.”

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