Indication: No studies evaluate the commonly used indications for bariatric surgery. Consensus guidelines suggest that the surgical treatment of obesity should be reserved for patients with a body-mass index (BMI) >40 kg/m(2) or with BMI >35 kg/m(2) and 1 or more significant co morbid conditions, when less invasive methods of weight loss have failed and the patient is at high risk for obesity-associated morbidity and mortality (strength of recommendation: C, based on consensus guidelines). Types: There are two basic types of weight loss surgery — restrictive surgeries and malabsorptive/restrictive surgeries.
They help with weight loss in different ways. Restrictive surgeries: work by physically restricting the size of the stomach and slowing down digestion. A normal stomach can hold about 3 pints of food. After surgery, the stomach may at first hold as little as an ounce, although later that could stretch to 2 or 3 ounces. The smaller the stomach, the less you can eat. The less you eat the more weight you lose. Malabsorptive/restrictive surgeries: are more invasive surgeries that work by changing how you take in food.
In addition to restricting the size of the stomach, these surgeries physically remove or bypass parts of your digestive tract, which makes it harder for your body to absorb calories. Purely malabsorptive surgeries — also called intestinal bypasses — are no longer done because of the side effects. Specific Types of Weight Loss Surgery There are many different surgical procedures for weight loss, and each has several variations. Adjustable Gastric Banding Gastric banding is among the least invasive weight loss treatments.
This surgery uses an inflatable band to squeeze the stomach into two sections: a smaller upper pouch and a larger lower section. The two sections are still connected; it’s just the channel between them is very small, which slows down the emptying of the upper pouch. Gastric banding physically restricts the amount of food you can take in at a meal. Most people can only eat a ? to 1 cup of food before feeling too full or sick. The food also needs to be soft or well-chewed. There are several brands of adjustable gastric bands available. They include LAP-BAND and REALIZE. Pros.
The advantage to gastric banding is that it’s simpler to do and safer than gastric bypass and other operations. It’s routinely done as minimally invasive surgery, using small incisions, special instruments, and a tiny camera called a laparoscope. Recovery is usually faster. You can also have it reversed by surgically removing the band. Because the band is connected to an opening just beneath the skin in the abdomen, it can be easily loosened or tightened in the doctor’s office. To tighten the band and further restrict the stomach size, more saline solution is injected into the band.
To loosen it, the liquid is removed with a needle. The Cons. People who get gastric banding often have less dramatic weight loss than those who get more invasive surgeries. They may also be more likely to regain some of the weight over the years. The Risks. The most common side effect of gastric banding is vomiting, a result of eating too much too quickly. Complications with the band aren’t uncommon. It might slip out of place, or become too loose, or leak. Sometimes, further surgeries are necessary. As with any surgery, infection is always a risk. Although unlikely, some complications can be life-threatening.
Sleeve Gastrectomy This is another form of restrictive weight loss surgery. In the operation, which is usually done with a laparoscope, about 75% of the stomach is removed. What remains of the stomach is a narrow tube or sleeve, which connects to the intestines. Sometimes, a sleeve gastrectomy is a first step in a sequence of weight loss surgeries. It can be followed up by gastric bypass or biliopancreatic diversion, if more weight loss is needed. However, in other cases, it might be the only surgery you need. The Pros. For people who are very obese or sick, standard gastric bypass or biliopancreatic diversion may be too risky.
A sleeve gastrectomy is a simpler operation that allows them a lower-risk way to lose weight. If needed, once they’ve lost weight and their health has improved — usually after 12 months to 18 months — they can go on to have a second surgery, such as gastric bypass. In people with high BMIs, sleeve gastrectomies result in an average weight loss of greater than 50% of excess weight. Because the intestines aren’t affected, a sleeve gastrectomy doesn’t affect the absorption of food, so nutritional deficiencies are not a problem. The Cons. Unlike gastric banding procedures, a sleeve gastrectomy is irreversible.
Most importantly, since it’s relatively new, the long-term benefits and risks are still being evaluated. The Risks. Typical surgical risks include infection, leaking of the sleeve, and blood clots. Gastric Bypass Surgery (Roux-en-Y Gastric Bypass) Gastric bypass is the most common type of weight loss surgery. It combines both restrictive and malabsorptive approaches. It can be done as either a minimally invasive or open surgery. 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.
Essentially, the surgeon is creating a shortcut for the food, bypassing a section of the stomach and the small intestine. Skipping these parts of the digestive tract means that fewer calories get absorbed into the body. The Pros. Weight loss tends to be swift and dramatic. About 50% of it happens in the first six months. It may continue for up to two years after the operation. Because of the rapid weight loss, health conditions affected by obesity – such as diabetes, high blood pressure, high cholesterol, arthritis, sleep apnea, heartburn, and other conditions — often improve quickly.
You’ll probably also feel a dramatic improvement in your quality of life. 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. The Cons. By design, surgeries like this impair the body’s ability to absorb food. While that can cause rapid weight loss, it also puts you at risk of serious nutritional 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 is “dumped” 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 sugary or high-carbohydrate foods, and adjusting the diet helps. However, some experts actually see dumping syndrome as beneficial, in that it encourages people to avoid foods that could lead to weight gain. Unlike adjustable gastric banding, gastric bypass is generally considered irreversible.
It has been reversed in rare cases. Therefore, getting this surgery means that you’re permanently changing how your body digests food. The Risks. Because these weight loss surgeries are more complicated, the risks are higher. The risk of death from these procedures is low — about 1% — but they are more dangerous than gastric banding. Infection and blood clots are risks, as they are with most surgeries. Gastric bypass also increases the risk of hernias, which can develop later and may need further surgery to fix. Also, a side effect of rapid weight loss can be the formation of gallstones.
Biliopancreatic Diversion This is essentially a more drastic version of a gastric bypass, in which part of the stomach — as much as 70% — is removed, and even more of the small intestine is bypassed. A somewhat less extreme version of this weight loss surgery is called biliopancreatic diversion with a duodenal switch or “the duodenal switch. ” While still more involved than a gastric bypass, this procedure removes less of the stomach and bypasses less of the small intestine. It also reduces the risk of dumping syndrome, malnutrition, and ulcers, which are more common with a standard biliopancreatic diversion.
The Pros. Biliopancreatic diversion can result in even greater and faster weight loss than a gastric bypass. Studies show an average long-term loss of 70% to 80% of excess weight. Although much of the stomach is removed, the remainder is still larger than the pouches formed during gastric bypass or banding procedures. So you may actually be able to eat larger meals with this surgery than with others. The Cons. Biliopancreatic diversion is less common than gastric bypass. One of the reasons is that the risk of nutritional deficiencies is much more serious.
It also poses many of the same risks as gastric bypass, including dumping syndrome. However, the duodenal switch may lower some of these risks. The Risks. This is one of the most complicated and high-risk weight loss surgeries. According to National Institutes of Health, the risk of death from the duodenal switch ranges between 2. 5% and 5%. As with gastric bypass, this surgery poses a fairly high risk of hernia, which will need further surgery to correct. However, this risk is lower when the procedure is done laparoscopically. Reference: News release Allegran.
ACP Medicine: “Endocrinology Chapter X: Obesity. ” American Society for Bariatric Surgery web site: “Brief History and Summary of Bariatric Surgery. ” American Society for Metabolic and Bariatric Surgery web site: “Bariatric Surgery: Postoperative Concerns. ” National Institute of Diabetes and Digestive Kidney Diseases: “Gastrointestinal Surgery for Severe Obesity. ” Obesity Action Coalition web site: “Gastrointestinal Surgery (Bariatric Surgery),” Laparoscopic Sleeve Gastrectomy. ” Reviewed by Melinda Ratini, DO, MS on May 29, 2012 © 2012 WebMD, LLC. All rights reserved.