Understanding Metabolic and Bariatric surgery
Kaiser Permanente offers two types of metabolic and bariatric surgery: gastric sleeve (sleeve gastrectomy) and gastric bypass (also called Roux-en-Y). There are other types of surgeries, but Kaiser Permanente focuses on the gastric sleeve and gastric bypass because they are the safest and most effective.
How does surgery change the digestive system?
Hormone changes
The main way surgery works is through hormonal changes that reduce hunger, decrease desire for food, and increase the feeling of fullness after eating.
Restriction
Surgery makes your stomach smaller. While this is a change, it’s not a significant contributor for keeping weight off.
Malabsorption
Surgery changes how your digestive system absorbs food. However, it is not the primary driver of weight loss—the hormonal changes are.
How is surgery done?
The two main ways that surgery is done are laparoscopic and open surgery. The results from laparoscopic and open surgery are the same, but people typically recover faster from laparoscopic surgery and have fewer complications.
Laparoscopic procedure (most common)
The surgeon starts with a small cut near the belly button. The belly is then filled with a gas to create space so it’s easier for the surgeon to operate. A thin tool called a laparoscope is inserted through the cut. It has a light and a tiny camera that sends a picture to a TV screen. A few other small cuts are made nearby so other tools can be inserted. The surgeon then performs the whole procedure using those tools.
Open procedure (less common)
The surgeon makes one long cut and the operation is done through that opening.
Gastric Sleeve
Sleeve gastrectomy surgery makes the stomach smaller by permanently removing most of it. Once you’re under anesthesia, the surgeon will place a small tube in your mouth and guide it down to your stomach. This tube is about the size and shape your stomach will be after surgery. The surgeon cuts the stomach around the tube’s outline. The part that’s left behind is closed with permanent staples. The tube is then carefully pulled back out.
The final result is a reduction in the stomach’s size by 60 to 80%. The size of the new stomach is not permanent. It’s normal for the size of the stomach to grow over time, depending on eating patterns after surgery. Therefore, you must be committed to changing the way you eat, including taking vitamin and mineral supplements for the rest of your life.
Gastric Bypass
With gastric bypass surgery, the stomach is separated into two parts. Each part is stapled shut. This leaves a small stomach pouch about the size of an egg. Like gastric sleeve, this small pouch limits (restricts) how much food you can comfortably eat.
Next, the small intestine is cut and reattached to the stomach pouch. This is the “bypass.” The other part of the intestine is reattached to your new digestive system so digestive juices can flow easily. Food now moves from the new stomach pouch directly to the lower part of the small intestine. In gastric bypass surgery, nothing is removed.
The final result is a stomach that can hold about 2 tablespoons of food (restriction) and a rerouting of the intestines to bypass the first 10 inches of small intestine (malabsorption). The size of the stomach after surgery is not permanent. It’s normal for the size of the stomach pouch and its connection to the intestine to grow over time, depending on eating patterns after surgery. Therefore, you must be committed to changing the way you eat, including taking vitamin and mineral supplements for the rest of your life.
What can I expect from each surgery?
Gastric Sleeve
Gastric Bypass
Patients often have a goal weight that may or may not be realistic. Expected weight loss after surgery depends on many factors, including nutrition, physical activity, sleep, and mental health and wellness. A successful surgery gets you to a weight you can maintain with realistic lifelong lifestyle changes.
Metabolic and Bariatric Surgery: Overview and Research Summary
Together, you and your surgeon will discuss all your options and make a shared decision on the type of surgery you would like to have. Review some of the recent Kaiser Permanente data to help inform your decision, including information on expected weight loss and health condition improvement.