Learn more about how gastric bypass surgery works and what kind of patients make good candidates.
According to the New England Journal of Medicine, gastric bypass surgery accounts for 80 percent of all bariatric, or weight loss, surgeries performed in the United States. Originally developed in the 1960s by Drs. Mason and Ito, gastric bypass surgery was conceived after observing that patients who had undergone partial stomach removal for ulcers had also lost weight. Gastric bypass surgery has evolved to its current form, known as the Roux-en-Y gastric bypass.
It is important to note that gastric bypass surgery isn't for everyone. Patients who may be suited for gastric bypass have a body mass index (BMI) greater than 40 percent, which is the equivalent of about 100 pounds of excess body fat for men and 80 pounds for women. The surgery is also suitable for patients who have a BMI from 35 to 39.9 percent, but also suffer from obesity-related health problems.
According to the U.S. Department of Health and Human Services Weight-control Information Network, Roux-en-Y gastric bypass surgery limits food intake and decreases the body's ability to absorb calories. This type of gastric bypass surgery, which is performed under general anesthesia, involves two distinct steps.
The first step of gastric bypass surgery makes the stomach smaller. To accomplish this, the surgeon uses staples to section off a large lower section and a small upper section. After the surgery, only the small upper section of the stomach is able to hold food. According to the Mayo Clinic, the resulting stomach pouch is the approximate size of a walnut and can hold only an ounce of food.
During the second part of the procedure, the surgeon reroutes the intestine. In order for food to bypass the large lower section of the stomach, the surgeon connects part of the small intestine directly to the small upper section of the stomach. This new connection is referred to as a "Roux limb." The other end of this section of small intestine is then connected with the rest of the small intestine as it exits the now defunct lower portion of the stomach. As a result of this procedure, not only is most of the stomach bypassed, but the duodenum (part of the lower intestine) and upper intestine are bypassed, as well.
The main benefit of gastric bypass surgery is weight loss. During the first two years after gastric bypass, most patients will lose 50 to 60 percent of their excess weight. It is important to note, however, that the weight loss will remain long-term only if the patient adheres closely to the diet and nutritional guidelines provided by their physician. Below is a list of healthy habits that are necessary in order to manage weight successfully, according to the Mayo Clinic:
• Snack/graze less throughout the day, which will lower calorie intake.
• Exercise regularly.
• Avoid foods that are high in sugar and fat.
• Be sure to follow up with a doctor regularly in order to review progress.
By changing lifestyle and eating habits after gastric bypass surgery, patients can ensure they are receiving the nutrients they need to stay healthy and avoid any problems.
There are also conditions associated with obesity that can benefit from gastric bypass surgery, including:
• High blood pressure
• High blood cholesterol
• Gastroesophageal reflux disease (GERD)
• Type 2 (adult-onset) diabetes
• Obstructive sleep apnea
In addition to increasing mobility and improving quality of life for obese people, gastric bypass also decreases the risk of dying from diabetes, heart disease and cancer.
Like any major surgical procedure, gastric bypass surgery has possible risks and complications. The most severe risk associated with this surgery is death. According to the Mayo Clinic, one death occurs for every 200 to 300 gastric bypass surgeries performed. The risk varies depending on the age, health and medical conditions of the patient before surgery.
Dangerous blood clots are another possible risk of gastric bypass surgery. Blood clots in the legs are more likely to develop in overweight people. If the clot travels to the lungs, it can cause a pulmonary embolism, a serious and sometimes deadly condition. Walking and using intermittent pressurized leg wraps can help reduce this risk.
Other postoperative complications can include infection, bleeding, leaking where the intestines are sewn together or around the line of staples in the stomach, hernia at the incision site, narrowing of the opening where the stomach connects to the small intestine, pneumonia and development of gallstones. Some of these complications, including narrowing of the opening between stomach and small intestine, and leakage around the staples in the stomach, are serious enough to warrant surgical correction.
Another complication of gastric bypass surgery is known as "dumping syndrome." This group of symptoms includes nausea, vomiting, dizziness, excessive sweating and diarrhea, and occurs when food moves too quickly through the small intestine. Dumping syndrome is exacerbated by consumption of high-sugar or high-fat food.
A significant long-term complication of gastric bypass surgery is malnutrition. After the surgery, the shorter intestinal tract causes food to move through the digestive system more quickly, which may prevent nutrients from having enough time to be absorbed into the body. Also, because the stomach is able to hold only a minimal quantity of food, fewer nutrients are available for absorption in the first place.
Patients who undergo gastric bypass surgery may suffer from deficiencies in iron, calcium and vitamins A, B12, D, E, K and others. If the malnutrition is not immediately addressed by a doctor during a follow-up examination, the problems can progress and lead to such diseases as pellagra, beriberi, kwashiorkor, anemia, metabolic bone disease and osteoporosis.
Gastric bypass surgery is certainly not an easy fix to an overweight problem. People considering gastric bypass should consult a doctor to find out if the surgery is right for them.