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Gastric bypass

• Overview
• Recovery
• Risks

Alternative Names:

Bariatric surgery - gastric bypass; Roux-en-Y gastric bypass

Definition:

Gastric bypass surgery is one type of procedure that can be used to cause significant weight loss if you are very obese. The surgery reduces your body's intake of calories. Calorie reduction is accomplished in two ways:

1. After the surgery, your stomach is smaller. You feel full faster and learn to reduce the amount that you eat at any given time.
2. Part of your stomach and small intestines are literally bypassed (skipped over) so that fewer calories are absorbed. Unfortunately, sometimes nutrients are lost as well.

The surgery is only right for you if you meet certain strict criteria described later in this article.

Description:

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

A psychological evaluation will be given to you. This will determine whether you are ready to adhere 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 extensive nutritional counseling before (and after) your surgery.

The surgery is performed under 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 portion of the stomach. The surgeon will then reconnect the base of the Roux limb with the remaining portion 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, aiding the absorption of important vitamins and minerals. You still may experience poor absorption of certain nutrients.

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

LAPAROSCOPY

Gastric bypass can be performed using a laparoscope. This less-invasive technique allows the surgeon to make smaller incisions, which lowers the risk of large scars and hernias after the procedure.

First, small incisions are made in your abdomen. The surgeon passes slender 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.

TYPES OF WEIGHT LOSS SURGERIES

Weight loss surgery can be divided into three types:

• Restrictive procedures reduce the size of your stomach.
• Malabsorptive procedures alter the flow from your stomach to your intestine, causing poor absorption of calories, vitamins, and minerals in the intestine.
• Combination procedures involve characteristics of both restrictive and malabsorptive procedures.

Gastric bypass surgeries are combination procedures that use both restriction and malabsorption to achieve weight loss.

Because it is a combination approach, it tends to be more successful for weight loss than purely restrictive surgeries. However, your body may not absorb vitamins and minerals properly.

Restrictive-only procedures are not as successful. It is easy to "cheat" and eat too much food, over-stretching the newly created stomach pouch.

A newer procedure, called the Lap-Band, uses 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.

Indications:

Gastric bypass surgery may be an option if you are significantly obese and have tried unsuccessfully to lose weight on diet and exercise programs and are unlikely to lose weight successfully with non-surgical 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, vomiting following the surgery is not uncommon because of eating more than the new, small stomach can accommodate.

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

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 .

LAPAROSCOPY

Not everyone is a candidate for the laparoscopic (minimally invasive) approach. You are probably NOT a good candidate for laparoscopy if you weigh more than 350 pounds. Others who have had past abdominal surgery may also not be candidates, due to scar tissue. Your surgeon will determine the best and safest approach for you.

• Review Date: 5/15/2006
• Reviewed By: Eugene A. Trowers, Jr., MD, MPH, FACP, Department of Gastroenterology, Florida State University College of Medicine, Assistant Dean, Tallahassee Regional Campus, Tallahassee, FL. Review provided by VeriMed Healthcare Network.

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