Bariatric surgery promotes weight loss by changing the digestive system's anatomy, limiting the amount of food that can be eaten and digested.
Obesity normally is defined through the use of body mass index (BMI) measurement. Physician offices, obesity associations, nutritionists, and others offer methods for calculating BMI, which is a comparison of height to weight. Those with a BMI of 30 or higher are considered obese. However, at 40 or higher, they are considered severely obese—approximately about 100 pounds overweight for men and 80 pounds overweight for women.
Many people who are obese struggle to lose weight through diet and exercise but fail. Only after they have tried other methods of losing weight will they be candidates for bariatric surgery, which today is considered a "last resort" for weight loss. In general, guidelines agree that those with a BMI of 40 or more, or a BMI of 35 to 39.9 and a serious obesity-related health problem, qualify for bariatric surgery. More than 23 million Americans are candidates for bariatric surgery. More than 100,000 of the procedures were performed in 2003 and the number of surgeries performed will probably continue to rise for many years.
Bariatric surgery is not for everyone and the surgeon and other physicians will evaluate all medical conditions before allowing a patient to proceed. As a major surgery, there are associated risks and side effects. Women of childbearing age should be aware that rapid weight loss and nutritional deficiency associated with bariatric surgery may be harmful to a developing fetus. It is important that a patient reveal all current medications and conditions during any pre-operative discussions or examinations. Also, the physician will carefully evaluate the patient to ensure that he or she is prepared to make a lifelong commitment to the changes in eating and lifestyle required to make the surgery successful.
Though many studies have shown general safety associated with the major surgeries, they are relatively new and research on long-term effects are not as widespread as they are for many other surgeries and procedures. When choosing a surgeon to perform the operation, patients should check with organizations such as the American Society for Bariatric Surgery for certification. A patient also should ask about the surgeon's experience in performing the particular operation.
Although the number of obese teenagers and resulting bariatric surgeries has increased, some experts are questioning the decision to perform bariatric surgery on teens. There are no specific clinical guidelines for determining a safe age for the procedure, but some physicians agree that bariatric surgery is not appropriate for children younger than age 15, since they are still growing and forming bones.
When food is chewed and swallowed, it moves along the digestive tract. In the stomach, a strong acid helps break down food so it can be digested and the body can absorb the food's nutrients and calories. The stomach can hold about three pints of food at one time. As digestion continues, food particles become smaller and move from the stomach into the intestine. The various parts of the small intestine are nearly 20 feet long if laid out straight. Those food particles not digested in the small intestine are stored in the large intestine until they are eliminated as waste.
When a patient has bariatric surgery, this digestive process is altered to help the patient lose weight. There are three main types of bariatric surgery, but only two types are commonly used today. The types are restrictive, malabsorptive, and combined restrictive/malabsorptive.
Restrictive surgery, often referred to as "stomach stapling" uses bands or staples to create a small pouch at the top of the stomach where food enters from the esophagus. This smaller pouch may hold only about 1 ounce of food at first and may stretch to hold about 2-3 ounces. The pouch's lower opening is made small, so that food moves slowly to the lower part of the stomach, adding to the feeling of fullness. The most frequently performed types of restrictive surgeries are vertical banded gastroplasty (VBG), gastric banding, and laparoscopic gastric banding. VBG is used less today in favor of gastric banding, which involves an adjustable hollow band made of silicone rubber.
Laparoscopic gastric banding, or Lap-band, was approved by the U.S. Food and Drug Administration (FDA) in 2001. Sometimes referred to as "minimally invasive" bariatric surgery, the surgeon uses small incisions and a laparoscope, or a small, tubular instrument with a camera attached, to see inside the abdomen and apply the band.
Malabsorptive procedures help patients lose weight by limiting the amount of nutrients and calories the intestine can absorb. Sometimes called intestinal bypasses, they are no longer used in the United States because they have often resulted in severe nutritional deficiencies.
Digestive tract— The organs that perform digestion, or changing of food into a form that can be absorbed by the body. They are the esophagus, stomach, small intestine, and large instestine.
Esophagus— A muscular tube about nine inches long that carries food from the throat (pharynx) to the stomach.
Combined restrictive/malabsorptive operations are the most common bariatric surgeries. They work by restricting both the amount of food the stomach can hold and the amount of calories and nutrients the body absorbs. The most common and successful combined surgery in recent years is called the Roux-en-Y gastric bypass (RGB). In this operation, the surgeon first creates a small pouch at the top of the stomach. Next, a Y-shaped section of the small intestine is connected to the small pouch, allowing food to bypass the lower stomach, the first part of the small intestine (duodenum), and the first portion of the next section of the small intestine (jejunum). It connects into the second half of the jejunum, reducing the amount of calories and nutrients the body absorbs. RGB may be performed with a laparoscope and a series of tiny incisions or with a large abdominal incision.
Procedure times vary, depending on the type of bariatric surgery chosen. However, most patients are in surgery for about one to two hours. Though costs can be as high as $35,000, more insurance companies are beginning to pay for the procedures if they are proven medically necessary. In 2004, the agency that pays for Medicare costs recognized obesity and many of its treatments as a medical cost for the first time, recognizing that obesity leads to many other medical problems.
The physician will first make sure that a patient is mentally prepared for the surgery and the commitment to follow-up care that will be required. Patients should have a consultation appointment with the surgeon prior to the procedure to discuss risks and benefits. Pre-operative instructions will be given that will tell the patient specific preparations prior to the surgery. These may include instructions about avoiding food or liquids, certain medications, and other instructions on the day before or the day of the procedure. Patients also may have several laboratory or other diagnostic tests prior to the surgery.
Depending on the type of procedure and any possible complications, patients can expect to stay at the hospital or surgery center for about two to four days following the surgery. Those who have laparoscopic operations typically have shorter hospital stays and speedier recovery times. The physician and nurses will provide instructions for wound care and other follow-up when the patient is discharged from the hospital. Usually, bariatric surgery patients can resume normal activity within about six weeks following surgery, and as little as two weeks after laparoscopic procedures. It is important for bariatric surgery patients to lose weight at the recommended pace, take nutritional supplements as recommended, and attend follow-up visits with physicians and nutritionists.
How a patient complies with instructions from physicians following bariatric surgery is important. Most patients will require lifelong use of nutritional supplements such as multivitamins, calcium, and other vitamin supplements to prevent nutritional deficiencies. Because the stomach is smaller, patients will have to eat small portions of food and often must avoid certain types of food such as sugar.
The surgeon performing the procedure should discuss its specific risks prior to surgery. Risks for bariatric surgery include infection, blood clots, abdominal hernia, gallstones, nutritional deficiencies, possible nerve complications, and death. Death rates have been reported lowest for RGB and VBG, at less than 1% of patients.
Weight loss will occur gradually, as patients can eat less food and absorb fewer calories. When patients follow post-operative instructions, they can lead normal lives, eating less food and being careful to limit certain foods that may irritate their new stomach pouches. Most patients will lose 50-60% of their excess weight in the first year or two. With gastric bypass surgery, many can lose up to two-thirds of excess weight by the second postoperative year.
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MacNeil, Jane Saladoff. "Gastric Bypass Beat Medical Care for Moderate Obesity." Family Practice News (Jan. 15, 2005):60-61.
Santora, Marc. "Teenagers Turn to Surgery to Shrink Their Stomachs." The New York Times (Nov. 26, 2004):B1.
American Obesity Association. 1250 12th St. NW, Suite 300, Washington, DC 20037. 202-776-7711. http://www.obesity.org.
Gastrointestinal Surgery for Severe Obesity Weight-control Information Network, National Institutes of Health, 2004. http://win.niddk.nih.gov/publications/gastric.htm.
"Bariatric Surgery." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. (October 20, 2017). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/bariatric-surgery
"Bariatric Surgery." Gale Encyclopedia of Medicine, 3rd ed.. . Retrieved October 20, 2017 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/bariatric-surgery
Obesity surgery is an operation that reduces or bypasses the stomach or small intestine so that severely overweight people can achieve significant and permanent weight loss.
Obesity surgery, also called bariatric surgery, is performed only on severely overweight people who are more than twice their ideal weight. This level of obesity often is referred to as morbid obesity since it can result in many serious, and potentially deadly, health problems, including hypertension, Type II diabetes mellitus (non-insulin dependent diabetes), increased risk for coronary disease, increased unexplained heart attack, hyperlipidemia, and a higher prevalence of colon, prostate, endometrial, and, possibly, breast cancer. In 2003, researchers concluded that obesity surgery could cure Type II diabetes in many people who were not yet morbidly obese. Therefore, this surgery is performed on people whose risk of complications of surgery is outweighed by the need to lose weight to prevent health complications, and for whom supervised weight loss and exercise programs have repeatedly failed. Obesity surgery, however, does not make people thin. Most people lose about 60% of their excess weight through this treatment. Changes in diet and exercise still are required to maintain a normal weight.
The theory behind obesity surgery is that if the volume the stomach holds is reduced and the entrance into the intestine is made smaller to slow stomach emptying, or part of the small intestine is bypassed or shortened, people will not be able to consume and/or absorb as many calories. With obesity surgery the volume of food the stomach can hold is reduced from about four cups to about 1/2 cup.
Insurers may consider obesity surgery elective surgery and not cover it under their policies. Documentation of the necessity for surgery and approval from the insurer should be sought before this operation is performed.
Obesity surgery should not be performed on people who are less than twice their ideal weight. It also is not appropriate for people who have substance addictions or who have psychological disorders. Other considerations in choosing candidates for obesity surgery include the general health of the person and his or her willingness to comply with follow-up treatment.
Obesity surgery is usually performed in a hospital by a surgeon who has experience with obesity surgery or at a center that specializes in the procedure. General anesthesia is used, and the operation takes 2-3 hours. The hospital stay lasts about a week.
Three procedures are currently used for obesity surgery:
- Gastric bypass surgery. Probably the most common type of obesity surgery, gastric bypass surgery has been performed in the United States for about 25 years. In this procedure, the volume of the stomach is reduced by four rows of stainless steel staples that separate the main body of the stomach from a small, newly created pouch. The pouch is attached at one end to the esophagus. At the other end is a very small opening into the small intestine. Food flows through this pouch, bypassing the main portion of the stomach and emptying slowly into the small intestine where it is absorbed.
- Vertical banding gastroplasty. In this procedure, an artificial pouch is created using staples in a different section of the stomach. Plastic mesh is sutured into part of the pouch to prevent it from dilating. In both surgeries the food enters the small intestine farther along that it would enter if exiting the stomach normally. This reduces the time available for absorption of nutrients. The procedure is normally done laparoscopically, meaning that the surgeon makes one or more small incisions in the abdomen and inserts the necessary tools and instruments through the tiny holes. He or she can view the patient's organs via an inserted camera that displays pictures on a monitor. This method makes for a faster and easier recovery than a large incision.
- Jejunoileal bypass. Now a rarely performed procedure, jejunoileal bypass involves shortening the small intestine. Because of the high occurance of serious complications involving chronic diarrhea and liver disease, it has largely been abandoned for the other, safer procedures
After patients are carefully selected as appropriate for obesity surgery, they receive standard preoperative blood and urine tests and meet with an anesthesiologist to discuss how their health may affect the administration of anesthesia. Pre-surgery counseling is done to help patients anticipate what to expect after the operation.
Immediately after the operation, most patients are restricted to a liquid diet for 2-3 weeks; however, some may remain on it for up to 12 weeks. Patients then move on to a diet of pureed food for about a month, and, after about two months, most can tolerate solid food. High fat food is restricted because it is hard to digest and causes diarrhea. Patients are expected to work on changing their eating and exercise habits to assist in weight loss. Most people eat 3-4 small meals a day once they return to solid food. Eating too quickly or too much after obesity surgery can cause nausea and vomiting as well as intestinal "dumping," a condition in which undigested food is shunted too quickly into the small intestine, causing pain, diarrhea, weakness, and dizziness.
As in any abdominal surgery, there is always a risk of excessive bleeding, infection, and allergic reaction to anesthesia. Specific risks associated with obesity surgery include leaking or stretching of the pouch and loosening of the gastric staples. Although the average death rate associated with this procedure is less than one percent, the rate varies from center to center, ranging from 0-4%. Long-term failure rates can reach 50%, sometimes making additional surgery necessary. Other complications of obesity surgery include an intolerance to foods high in fats, lactose intolerance, bouts of vomiting, diarrhea, and intestinal discomfort
Studies on the risks of these surgeries continue. A 2003 report showed that gastric bypass surgery risk increases with age, weight and male gender. Patients age 55 and older experienced more complications than did younger patients and male patients had more life-threatening complications than female patients, particularly those who were more severely obese.
Many people lose about 60% of the weight they need to reach their ideal weight through obesity surgery. However, surgery is not a magic weight-loss operation, and success also depends on the patient's willingness to exercise and eat low-calorie foods. A 2003 report showed that super obese patients had a lower success rate with laparoscopic vertical banding gastroplasty than those considered morbidly obese. However, the overall success rate was nearly 77% of patients carrying less than 50% excess weight four years after the procedure.
"Gastric Bypass Surgery Risk Increases with Age, Weight, and Male Gender." Medical Devices and Surgical Technology Week January 19, 2003: 29.
"Laparoscopic Vertical Banding Gastroplasty Safe and Effective for Morbid Obesity." Medical Devices and Surgical Technology Week January 19, 2003: 2.
Sadovsky, Richard. "Obesity Surgery May Cure Diabetes in Nonobese Patients." American Family Physician 56 (February 15, 2003): 866.
"Obesity Surgery." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. (October 20, 2017). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/obesity-surgery
"Obesity Surgery." Gale Encyclopedia of Medicine, 3rd ed.. . Retrieved October 20, 2017 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/obesity-surgery
"bariatric surgery." A Dictionary of Nursing. . Encyclopedia.com. (October 20, 2017). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/bariatric-surgery
"bariatric surgery." A Dictionary of Nursing. . Retrieved October 20, 2017 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/bariatric-surgery