ADAM Health Encyclopedia

Weight-loss surgeries

Definition

Weight-loss surgeries are procedures that can be used to cause significant weight loss if you are very obese.

Alternative Names

Bariatric surgery - gastric bypass; Roux-en-Y gastric bypass; Gastric bypass; Laparoscopic adjustable gastric banding; LAGB; Vertical banded gastroplasty

Description

Weight-loss surgeries lower the body's intake of calories, which help you lose weight. Calorie reduction occurs in two ways:

• After the surgery, your stomach is smaller. You feel full or satisfied faster and learn to reduce the amount that you eat at any given time. (This is called a restrictive procedure)
• When you eat, the food skips over part of your stomach and small intestines so that they absorb fewer calories. Unfortunately, sometimes nutrients are lost as well. (This is called a bypass or malabsorptive procedure.)

Some surgeries use both of these techniques.

Before any weight-loss operation, your doctor will give you a complete medical examination and evaluate your overall health.

You also will have a psychological evaluation. This will determine whether you are ready to stick to a healthier lifestyle. If you are not ready to make lifestyle changes (and have not tried hard to do so already), you will not be considered eligible for the procedure. Without changing your lifestyle, the surgery will not be a success.

You will also receive nutritional counseling before and after your surgery.

GASTRIC BYPASS

Roux-en-Y gastric bypass is the most common surgery of this type.

The surgery is performed under pain-killing medicine (anesthesia). There are two basic steps:

• STEP 1 -- The first step in the surgical procedure makes your stomach smaller. The surgeon divides the stomach into a small upper section and a larger bottom section using staples that are similar to stitches. The top section of the stomach (called the pouch) will hold your food.
• STEP 2 -- After the stomach has been divided, the surgeon connects a section of the small intestine to the pouch. When you eat, the food will now travel from the pouch through this new connection ("Roux limb"), bypassing the lower part of the stomach. The surgeon will then reconnect the base of the Roux limb with the rest of the small intestines from the bottom of the stomach, forming a y-shape.

This "y-connection" allows food to mix with pancreatic fluid and bile, helping to absorb important vitamins and minerals. You still may have poor absorption of certain nutrients.

The risk of poor absorption is of greater concern in gastric surgeries that skip over a larger portion of the small intestines. These are performed much less often than the Roux-en-Y gastric bypass described here.

Gastric bypass can be performed as open surgery with a larger surgical cut in the abdomen.

It may also be done using a camera placed in the abdomen (laparoscopy). This less-invasive technique allows the surgeon to make smaller surgical cuts, which lowers the risk of large scars and hernias after the procedure.

First, small surgical cuts are made in your abdomen. The surgeon passes thin surgical instruments through these narrow openings. The surgeon also passes a camera (laparoscope) through one of these small openings and watches through a lens and video monitor to do the surgery.

Not everyone is a candidate for the laparoscopic approach. Your surgeon will determine the best and safest approach for you.

You may NOT be a good candidate for laparoscopy if you:

• Have had past abdominal surgery, due to scar tissue
• Have significant heart and lung disease
• Weigh more than 350 pounds

Gastric bypass tends to work better for weight loss than purely restrictive surgeries. However, your body may not absorb vitamins and minerals properly.

LAPAROSCOPIC ADJUSTABLE GASTRIC BANDING (Lap-Band, LAGB)

A newer procedure, called the Lap-Band, places a band around the upper part of the stomach, creating a small pouch to hold food. The band limits the amount of food you can eat, and increases the time it takes the intestines to digest the food.

Your doctor can later adjust the band to allow food to pass more slowly or quickly through your digestive system. Possible complications include nausea, vomiting, and gastroesophageal reflux.

Final weight loss with gastric banding is not as much as with gastric bypass. However, it may be enough for many patients. You should talk to your physician about which procedure is best for you.

Why the Procedure is Performed

Weight-loss surgery may be an option if you are very obese and have tried unsuccessfully to lose weight on diet and exercise programs and are unlikely to lose weight successfully with nonsurgical methods.

Gastric bypass surgery is not a "quick fix" for obesity. The surgery can take several hours and has risks and possible complications. For example, people can vomit after the surgery if they eat more than the new, small stomach can hold.

Your commitment to diet and exercise must be very strong because even after the surgery, you must stick to these lifestyle changes. Otherwise, you are likely to have complications from the surgery.

The procedure may be considered for obese individuals who have:

• A Body Mass Index (BMI) of 40 or more. BMI is a calculation based on height and weight that is used to determine whether you are of normal weight or are overweight. Someone with a BMI of 40 or more is at least 100 pounds over their recommended weight. A normal BMI is between 18.5 and 25.
• A BMI of 35 or more along with a life-threatening illness that can be made better with weight loss, such as sleep apnea, type 2 diabetes, and heart disease.

Outlook (Prognosis)

The weight loss results of gastric bypass surgery are generally good. Most patients lose an average of 10 pounds per month and reach a stable weight 18 - 24 months after surgery. Often, the greatest rate of weight loss occurs in the very beginning (just after the surgery when you are still on a liquid diet).

Losing enough weight as a result of surgery can improve or even relieve many medical problems, such as:

• Asthma
• High blood pressure (hypertension)
• Obstructive sleep apnea
• Stress incontinence

After the surgery, you will need to follow up with your doctor fairly often during the first year. During those visits, your physician will be checking your physical and mental health, including any change in weight and your nutritional needs. You will likely see a dietitian during those visits as well.

The surgery is not a solution by itself. Although it can train you to eat smaller amounts of food and feel full more quickly, you still have to do much of the work. To lose weight and avoid complications from the procedure, you must exercise and eat properly -- according to important, healthy guidelines that your doctor and nutritionist will teach you.

Risks

The risks of weight-loss surgery include:

• Anemia from iron or vitamin B12 deficiencies
• Bleeding
• Breakdown of the pouch needing repair
• Calcium deficiency, which can contribute to the development of early osteoporosis or other bone disorders
• Death from breathing (respiratory) failure, blood clots to the lungs, or problems with the bypass procedure
• Follow-up surgeries to correct complications, or to remove extra skin
• Gallstones and gallbladder attacks
• Gastritis and heartburn
• Infections
• Malnourishment
• Vomiting from eating more than the stomach pouch can hold

Follow-up surgeries may be less likely if gastric bypass is done with a laparoscope.

Another common complication from weight-loss surgery is "dumping syndrome." The symptoms often include:

• Bloated feeling
• Diarrhea
• Dizziness
• Nausea and vomiting
• Sweating