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The Roux-en-Y gastric bypass

The Roux-en-Y gastric bypass is a surgical procedure that limits both the size of the stomach and the amount of calories and nutrients absorbed into the body. The digestive tract is surgically adjusted so that the lower portion of the stomach and first segment of the small intestine (called the duodenum) are bypassed.

How does gastric bypass work?

Food entering the small top portion of the stomach causes a sensation of fullness, and then slowly empties into the jejunum (the middle segment of the small intestine) through a small outlet. Digestive juices from the lower stomach and duodenum flow to mix with food lower down the intestinal tract, allowing less time for absorption of calories.

How much weight can you expect to lose with gastric bypass?

On average, gastric bypass produces significant long-term weight loss—up to 60-80 percent of excess weight.

Advantages of gastric bypass:

  • Gastric bypass causes favorable changes in gut hormones that reduce and satisfy hunger.
  • Over time, patients generally maintain excess weight loss of more than 50 percent.
  • Gastric bypass has been shown to produce faster remission of type 2 diabetes than restrictive banding (Lap-Band) procedures.

Restrictive banding

The laparoscopic adjustable gastric band procedure, commonly called Lap-Band, is the least invasive way of surgically reducing the amount of food your stomach can hold. Through small incisions, an adjustable silicone elastomer ring is placed around the stomach.

How does the Lap-Band work? 

The Lap-Band serves as a belt, creating a small pouch at the top of the stomach, that restricts the amount of food you can consume during a meal. The size of the opening between the upper pouch and the lower stomach controls how fast food moves down the digestive tract. After surgery, your doctor can adjust the size of the opening as needed. With the Lap-Band adequately adjusted, your new small stomach will reduce your hunger. You’ll feel full sooner and stay satisfied longer after each meal.

How much weight can you expect to lose with the Lap-Band?

The average recorded weight loss through Lap-Band in the United States is approximately 36-38 percent of excess weight in two to three years after surgery. A few patients have been able to lose up to 50 percent of their excess weight.

Advantages of the Lap-Band: 

  • The band can be adjusted to fit individual needs.
  • The process can usually be reversed, if necessary.

Sleeve gastrectomy

Sleeve gastrectomy, often called the gastric sleeve, is a restrictive procedure, meaning it reduces the amount of food your stomach can hold. With the gastric sleeve, about 80 percent of your stomach is surgically removed, leaving a stomach with a size and shape similar to a banana.

How does the gastric sleeve work?

With a smaller stomach, you will feel full faster when eating, reducing the amount of food you consume. In addition, the smaller stomach causes hormonal changes that help decrease hunger.

How much weight can you expect to lose with the gastric sleeve?

The average loss of excess body weight in the first year is 50 to 60 percent.

Advantages of the gastric sleeve:

  • It is a simpler operation than the gastric bypass, with fewer potential risks.
  • It can be performed using minimally invasive techniques.
  • Weight loss is generally better than with restrictive banding (Lap-Band).
  • There is no device left in the body and no need for adjustments.
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