Weight Loss Surgery

How does Surgery Promote Weight Loss?

• Gastrointestinal surgery is the best option for people who are severely obese and cannot lose weight by traditional means or who suffer from serious obesity-related health problems.
• The surgery promotes weight loss by restricting food intake and, in some operations, interrupting the digestive process.
• However, the best results are achieved with healthy eating behaviors and regular physical activity.

Who can consider Weight Loss Surgery (WLS) ?

• People who may consider gastrointestinal surgery include those with a body mass index (BMI) above 40-about 100 pounds of overweight for men and 80 pounds for women.
• People with a BMI between 35 and 40 who suffer from type 2 diabetes or life-threatening cardiopulmonary problems such as severe sleep apnea or obesity-related heart disease may also be candidates for surgery.

Choose the surgery option best suited to you:

• The most important step in weight loss surgery is to know about the various surgical options.
• The best source of information will be your bariatric surgeon and other physicians who will recommend the best option to you for weight loss.
• Make sure you understand well about the option being recommended.
• The decision to have a weight loss surgical procedure may take several visits to their office and consultation with more than one doctor.
• Ask your doctor for names of other patients who have had similar weight loss surgeries and who are willing to discuss their experiences, good and bad, with you.
• Although the results of weight loss surgery can be drastic, there are potential risks and complications. Before making your decision, you should be well informed.
• Before you sign a consent form, you should have a solid understanding of what the complications involved.

What are options of Weight Loss Surgery?
Gastrointestinal surgery for obesity is also called bariatric surgery. It alters the digestive process. The operations promote weight loss by closing off parts of the stomach to make it smaller. Operations that only reduce stomach size are known as "restrictive operations" because they restrict the amount of food the stomach can hold.

Some operations combine stomach restriction with a partial bypass of the small intestine. These procedures create a direct connection from the stomach to the lower segment of the small intestine, literally bypassing portions of the digestive tract that absorb calories and nutrients. These are known as malabsorptive operations.

Weight Loss Surgery is an expensive option to lose weight.
There are several types of restrictive and malabsorptive operations. Each one carries its own benefits and risks.

Benefits

• Right after surgery, most patients lose weight quickly and continue to lose for 18 to 24 months after the procedure. Although most patients regain 5 to 10 percent of the weight they lost, many maintain a long-term weight loss of about 100 pounds.
• Surgery improves most obesity-related conditions. For example, in one study blood sugar levels of 83 percent of obese patients with diabetes returned to normal after surgery.

Risks

• Patients who have weight-loss surgery require follow-up operations to correct complications.
• Abdominal hernia is the most common complication requiring follow-up surgery
• Less common complications include breakdown of the staple line and stretched stomach outlets.
• During rapid or substantial weight loss, a person's risk of developing gallstones increases.
• Nearly 30 percent of patients who have weight-loss surgery develop nutritional deficiencies such as anemia, osteoporosis, and metabolic bone disease. These deficiencies usually can be avoided if vitamin and mineral intakes are high enough.
• Women of childbearing age should avoid pregnancy until their weight becomes stable because rapid weight loss and nutritional deficiencies can harm a developing fetus.

Restrictive Operations
Restrictive operations serve only to restrict food intake and do not interfere with the normal digestive process. To perform the surgery, doctors create a small pouch at the top of the stomach where food enters from the esophagus. Initially, the pouch holds about 1 ounce of food and later expands to 2-3 ounces. The lower outlet of the pouch usually has a diameter of only about ¾ inch. This small outlet delays the emptying of food from the pouch and causes a feeling of fullness.

As a result of this surgery, most people lose the ability to eat large amounts of food at one time. After an operation, the person usually can eat only ¾ to 1 cup of food without discomfort or nausea. Also, food has to be well chewed. Restrictive operations for obesity include adjustable gastric banding (AGB) and vertical banded gastroplasty (VBG).

• Adjustable gastric banding (AGB). In this procedure, a hollow band made of special material is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the larger remainder of the stomach. The band is then inflated with a salt solution. It can be tightened or loosened over time to change the size of the passage by increasing or decreasing the amount of salt solution.
• Vertical banded gastroplasty( VBG) This has been the most common restrictive operation for weight control. In this, both a band and staples are used to create a small stomach pouch.

Risks Involved

• Successful results depend on the patient's willingness to adopt a long-term plan of healthy eating and regular physical activity
• Restrictive operations are less successful than malabsorptive operations in achieving substantial, long-term weight loss.
• However, some patients regain weight.
• Others are unable to adjust their eating habits and fail to lose the desired weight.
• A common risk of restrictive operations is vomiting, which is caused when the small stomach is overly stretched by food particles that have not been chewed well.
• Band slippage and saline leakage have been reported after AGB.
• Risks of VBG include wearing away of the band and breakdown of the staple line.
• In a small number of cases, stomach juices may leak into the abdomen, requiring an emergency operation.
• In less than 1 percent of all cases, infection or death from complications may occur.

Malabsorptive Operations

Malabsorptive operations are the most common gastrointestinal surgeries for weight loss. They restrict both food intake and the amount of calories and nutrients the body absorbs.

• Roux-en-Y gastric bypass (RGB). This operation, is the most common and successful malabsorptive surgery. First, a small stomach pouch is created to restrict food intake. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the lower stomach, the duodenum (the first segment of the small intestine), and the first portion of the jejunum (the second segment of the small intestine). This bypass reduces the amount of calories and nutrients the body absorbs.
• Biliopancreatic diversion (BPD). In this more complicated malabsorptive operation, portions of the stomach are removed. The small pouch that remains is connected directly to the final segment of the small intestine, completely bypassing the duodenum and the jejunum. Although this procedure successfully promotes weight loss, it is less frequently used than other types of surgery because of the high risk for nutritional deficiencies. A variation of BPD includes a "duodenal switch" which leaves a larger portion of the stomach intact, including the pyloric valve that regulates the release of stomach contents into the small intestine. It also keeps a small part of the duodenum in the digestive pathway.

Benefits:

• Malabsorptive operations produce more weight loss than restrictive operations.
• They are more effective in reversing the health problems associated with severe obesity.

• Patients who have malabsorptive operations generally lose two-thirds of their excess weight within 2 years.

Risks

• In addition to the risks of restrictive surgeries, malabsorptive operations also carry greater risk for nutritional deficiencies. This is because the procedure causes food to bypass the duodenum and jejunum, where most iron and calcium are absorbed.
• Menstruating women may develop anemia because not enough vitamin B12 and iron are absorbed.
• Decreased absorption of calcium may also bring on osteoporosis and metabolic bone disease.
• RGB and BPD operations may also cause "dumping syndrome." This means that stomach contents move too rapidly through the small intestine. Symptoms include nausea, weakness, sweating, faintness, and sometimes diarrhea after eating.

Source :   http://www.nlm.nih.gov