Obesity Surgery

Surgery is a treatment option suitable for some persons with obesity.  You and your doctor must work together to determine if you would benefit from obesity surgery, which is a major operation that can change your life in many ways. 

You must know about the risks and benefits of the surgery and the commitment you will have to make to lifestyle change and life-long follow-up with your medical team.¹  You must also take into account the health risks of being severely obese, and the health benefits you can gain from losing excess weight. 

This fact sheet is intended to help you better understand obesity surgery and does not take the place of medical advice from your doctor.

Being obese or severely obese puts you at a higher risk for developing or worsening many serious medical conditions.  There are more than 30 obesity-related medical conditions that can damage your quality of life and cause early death.  Some obesity-related medical conditions include arthritis, several cancers, carpal tunnel syndrome, cardiovascular disease, gallbladder disease, gout, hypertension, infertility, liver disease, low back pain, obstetric and gynecologic complications, sleep apnea, stroke, type 2 diabetes, and urinary stress incontinence.

Obesity is commonly measured by using the Body Mass Index (BMI). You can find out what your BMI is simply by knowing your height and weight and using a BMI chart (see Table 1) or BMI calculator.

Table 1 - BMI CHART

 To use this chart: Find your height in the left column.  Move across that row toward the right to find your approximate weight.  Then follow the weight column up to find your BMI in the bar at the top.

You are considered obese if you have a BMI of 30 or more.²  The number of adult Americans (age 20 or older) who are obese has increased significantly in less than 20 years - from 15% to 26%.  Severe obesity is defined as having a BMI of 40 or more.³  Approximately 2.9% of US adults (age 20 or older) today are severely obese.

Weight loss is recommended for persons with obesity or severe obesity.  Losing excess weight can improve your health by lowering risks from obesity-related medical conditions.  Methods of weight loss include dietary therapy, increased physical activity, behavior therapy, drug therapy, surgery or a combination of therapies. Surgery is a well-established method of long-term weight control for persons with severe obesity.  Several studies have reported patient weight loss of 60% of excess weight after five years.³

The benefits of obesity surgery appear to outweigh the risks.²  Each person’s medical situation is different, however, and you should discuss with your doctor whether the benefits of obesity surgery outweigh the risks in your specific case.⁴

You may qualify for obesity surgery:

• If you are severely obese (BMI of 40 or more) or have a BMI of 35 to 39.9 with serious medical conditions (such as high blood cholesterol and triglycerides, hypertension, sleep apnea, type 2 diabetes and other serious cardiopulmonary disorders).
• If you have tried other methods of weight loss (changes in eating, behavior, increased physical activity and/or drug therapy) and are still severely obese.
• If you are unable to physically perform routine daily activities (work-related and family functions) and your quality of life is seriously impaired due to the severity of your obesity.
• If you understand the procedure, risks of surgery and effects after surgery.
• If you are motivated to making a lifelong behavioral commitment that includes well-balanced eating and physical activity habits which are needed to achieve the best results.

Patient Profile

• The International Bariatric Surgery Registry (IBSR) has put together a database with information on 14,641 people who have had obesity surgery.⁵  The patients had the following characteristics:
• Average Weight at Time of Operation: 279.4 pounds (+/- 60.3*)
• Average BMI at Time of Operation: 46 (+/- 8.3*)
• A BMI between 35 and 39.9: 19.7%
• A BMI of 40 or more: 76.1%

*add (+) or subtract (-) the number in parenthesis from the average number to find a range.

Surgery and Weight Loss

Obesity surgery helps you lose weight by changing the way your body digests and absorbs food.  Your body digests food to break down what you eat into small pieces of nutrients (carbohydrates, proteins, fats, vitamins and minerals).  When the pieces are small enough, the cells of your body absorbthe nutrients to give you energy to live.

Digestion and absorption begin in the stomach, continue through the small intestine and end in the large intestine, which digests and absorbs what it can and eliminates the rest as waste.  Obesity surgery involves making changes to the stomach and/or small intestine.

The Stomach - is made smaller in size with surgery.  A section of your stomach is removed or closed which limits the amount of food it can hold and causes you to feel full.  This is called food intake restriction.^{6, 7}

The Small Intestine - is where most of digestion and absorption take place.  It has three parts: the duodenum (upper part connected to the stomach), the jejunum (middle part) and the ileum (lower part connected to the large intestine).  Surgery shortens the length of the small intestine and/or changes where it connects to the stomach. This limits the amount of food that is completely digested or absorbed and is called malabsorption.^{6, 7}

Through food intake restriction, malabsorption or both,  you can lose weight since less food either goes into your stomach or stays in your small intestine long enough to be digested and absorbed.

Types of Obesity Surgery

There are two types of obesity surgery: 1) restrictive and 2) combined restrictive and malabsorptive.  Different ways of performing each surgery, called operative procedures, have been developed.  Each type of surgery and operative procedure has its own risks and side-effects.  Your doctor can help you decide which is best for you.

1.     Restrictive Surgery - uses bands or staples to create food intake restriction. The bands or staples are surgically placed near the top of the stomach to section off a small portion that is often called a stomach pouch.  A small outlet, about the size of a pencil eraser, is left at the bottom of the stomach pouch.  Since the outlet is small, food stays in the pouch longer and you also feel full for a longer time.

• Vertical Banded Gastroplasty (VBG) - is a “pure” restrictive surgery since it only involves surgically creating a stomach pouch.  VBG uses bands and staples and is the most frequently performed procedure for obesity surgery.³
• Gastric Banding – involves the use of a band to create the stomach pouch. 
• Laparoscopic Gastric Banding (Lap-Band), approved by the FDA in June 2001, is a less invasive procedure in which smaller incisions are made to apply the band.  The band is inflatable and can be adjusted over time. ^7,8,9

Benefits and Risks

Success rate:  About 80% of patients lose some weight and 30% reach normal weight category with VBG.⁸ The long-term weight loss success rate with VBG is 40 to 63% of excess body weight over a three year period¹ and 50 to 60% after five years.³  A three year study with Lap-Band resulted in 62% of patients who lost at least 25% of their excess weight; 52% lost at least 33%; 22% lost at least 50% and 10% lost at least 75%.⁹

• Side-effects:  The stomach pouch holds about a half of a cup to one cup of food.  Eating too much at once or not chewing enough to break down food can cause nausea, stomach discomfort and vomiting.^3,8  Protein and vitamin deficiency have been reported in few cases, due to continual vomiting. Other side effects are heartburn and abdominal pain. ⁹
• Complications: Possible complications include leaking of stomach juices into the abdomen, injury to the spleen, band slippage, erosion of the band, breakdown of the staple line, and stomach pouch stretching from overeating.  Infection or death has been reported in less than 1 percent of patients. ^7,8

After Surgery

• Lifestyle Adjustments:  Patients must learn to eat smaller amounts of food at one time,⁸ to chew their food well and to eat slowly.³   Failure to adjust eating habits may inhibit weight loss.⁸
• Surgical Follow-up:  Follow-up, especially in the first three months after surgery, is necessary to maintain the proper intake of protein, calories, minerals and vitamins. With proper follow-up care and patient compliance, protein deficiency which typically occurs in the first three months after surgery, can be corrected within 18 months after surgery.³

Operative Procedures

• Roux-en-Y Gastric Bypass (RGB) - is the most commonly performed gastric bypass procedure,⁸ and the second most frequently performed surgery for obesity after VBG.³  RGB involves a stomach pouch for food intake restriction.  A direct connection, which is Y-shaped, is made from the ileum or jejunum to the stomach pouch for malabsorption.  The longer the segment of small intestine bypassed, the greater the malabsorption component and the greater the weight loss.  Gastric bypass with an extensive segment of small bowel bypassed is termed “Long Limb Gastric Bypass.”
• Biliopancreatic Diversion (BPD) - is one of the most complicated of the current operative procedures in obesity surgery,⁷ sometimes involving the removal of a portion of the stomach.  The remaining section of the stomach is connected to the ileum.⁸  BPD successfully promotes weight loss,⁸ but this procedure is typically used for persons with severe obesity who have a BMI of 50 or more.⁷

Benefits and Risks

• Success Rate: Researchers have found greater weight loss in gastric bypass (93.3 pounds) compared to gastroplasty (67 pounds) after one year.²  Over two years, gastric bypass surgery patients have been shown to lose two-thirds of excess weight.⁸  The success rate for weight loss for RGB is 68 to 72% of excess body weight over a three year period, and 75% for BPD.¹  After five years, the average excess weight loss from gastric bypass surgery ranges from 48 to 74%.³
• Side Effects: The “dumping syndrome” in which food moves too quickly through the small intestine can cause nausea, weakness, sweating, faintness, and sometimes diarrhea after eating.  There can also be an inability to eat sweets without severe weakness and sweating causing patients to lie down to let the symptoms pass.  Dairy intolerance, constipation, headache, hair loss and depression are other possible side effects.^{7, 8}
• Complications: There is a risk for nutritional deficiencies due to the bypass of the duodenum and part of the jejunum where many nutrients are absorbed.  Nutritional deficiencies include malabsorption of vitamin B12, leading to anemia and iron deficiency.  The reduction in vitamin D and calcium absorption can cause osteoporosis and other bone disease.^3,8  Other complications are similar to those of restrictive surgery and are due to creating a stomach pouch.

After Surgery

• Lifestyle Adjustments: Lifelong use of nutritional supplements such as multivitamins, vitamin B12, vitamin D and calcium is necessary.^3,4
• Surgical Follow-up: Physical, nutritional and metabolic counseling are needed to prevent nutritional deficiencies. ³

3.     Other Procedures
Restrictive and gastric bypass surgery are safe and effective over the long-term.⁷ Other procedures for weight loss which are usually not recommended include the following:

• Intestinal Bypass - These operations involved reducing or bypassing parts of the small intestine, and were more common in past years.  Some clinics have expertise in managing the typical complications of this surgery and  continue to offer it as an option.⁷
• Jaw Wiring - This is a form of food intake restriction for temporary use in patients without respiratory problems.  It can be effective for short-term weight loss.  However, weight regain occurs soon after the wires are removed.⁷
• Liposuction - This is the most frequent cosmetic operation in the United States in which fat tissue is removed.  Relatively small amounts of total body fat can be removed safely, however, and little weight is lost.⁷

General Benefits of Obesity Surgery

• Improvements in surgical techniques have resulted in considerable progress in safety, effectiveness and long-term integrity for promoting weight loss.^2,3
• Within 30 days of surgery, 93.4% of patients from a national registry reported no complications from surgery.³
• Weight loss usually occurs soon after obesity surgery and continues for 18 months to two years.  Most patients regain some weight after this time, however few regain it all. ^3,8
• After five years, patients have reported maintaining a weight loss of 60% of excess weight.³
• Patients will often see improvements in obesity-related medical conditions that they had before surgery such as diabetes mellitus, glucose intolerance, high cholesterol/triglycerides, hypertension,  and sleep apnea.^3,4,8  In general, 60% of patients with obesity-related medical conditions are no longer on medication for these conditions three years after surgery.²
• Patients have reported an enhanced quality of life, improved mobility and stamina, better mood, self-esteem and interpersonal effectiveness, and lessened self-consciousness.^3,7

General Risks of Obesity Surgery

• Complications caused by the surgery may be as high as 10 percent or more.⁴
• Complications requiring a hospital stay of seven or more days were reported in 1.35% of patients from the IBSR database.  Some of the complications involve the heart or liver, rupture of blood vessels in the lungs, infection surrounding the diaphragm area, leaking and bleeding of the stomach and intestines, blood clotting of veins, and blockage of the small intestine.³ 
• Complications requiring a hospital stay of less than seven days were reported in 5.28% of patients from the IBSR database.  These complications include breathing difficulties, wound infections, and  injury to the spleen.³
• Ten to 20% of patients have been reported to need follow-up operations to correct complications such as abdominal hernias. ⁸
• Gallstones develop in more than one-third of patients as a result of losing a large amount of weight or from losing weight quickly.⁸  Gallstones can be prevented by taking medication.
• Anemia, osteoporosis and other bone disease are nutritional deficiencies that develop after the surgery due to long-term loss of absorptive function.² Nutritional deficiencies, which occur in almost 30% of patients, can be prevented with proper attention to vitamin and mineral intake, especially vitamins B12 and D, calcium, folate and iron.^2,7
• Women of childbearing age should be aware that quick weight loss and nutritional deficiencies can harm a developing fetus.⁸
• The VBG and RGB death rate is relatively low.⁴  Within 30 days of surgery, death occurred in less than a quarter of one percent (0.17%) of patients in the IBSR database.  Pulmonary embolism was the most frequent cause of death.³

Bariatric Surgeons

Bariatrics is the medical treatment of obesity and obesity-related conditions.  Bariatric surgeons specialize in the surgical procedures used to treat obesity.  A medical team that includes a bariatric surgeon, as well as behavioral and nutritional specialists should be consulted before and after surgery.

Your Right to Know

Your surgeon must inform you about all you need to know to decide if you want to have the surgery.⁶  Before you have surgery, ask your surgeon to review a copy of an informed consent form specific to obesity surgery.

Things to look for on an informed consent form:

• Changes in anatomy and function from the surgery.
• Risk and complications from the surgery.
• For surgery that creates a stomach pouch, determine the size of the pouch and how the outlet will be stabilized.  The larger the pouch, the less the food intake restriction.

Become well-informed.  Ask your doctor about:

• How obesity surgery can benefit you specifically. How the risks and complications of obesity surgery effect you specifically and any other medical conditions you may have.
• How the surgery is different from other methods of weight loss.
• How you can get the name of patients who have already had obesity surgery, so that you can hear about their experiences.

The American Society for Bariatric Surgeons (ASBS) can help you locate a surgical obesity center or clinic in your area.  Contact ASBS at:

140 NW 75th Drive, Suite C
Gainesville, FL 32607
(352) 331-4900
www.asbs.org

Other AOA Obesity Educational Materials

The American Obesity Association (AOA) is a national, non-profit organization.  This fact sheet is a product of AOA’s National Campaign of Obesity Education, instituted to provide current information on obesity based on scientific evidence.  For additional information on obesity, contact AOA at:

1250 24th Street, N.W., Suite 300
Washington, DC 20037
(202) 776-7711
Toll Free: 1-800-98-OBESE
Fax: (202) 776-7712
www.obesity.org

References

1. Shape Up America!, American Obesity Association.  Guidance for the Treatment of Adult Obesity. Bethesda, MD, revised 1998.
2. National Heart, Lung, and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Obesity in Adults: The Evidence Report. NHLBI Obesity Education Initiative Expert Panel on the Identification, Evaluation, and Treatment of Obesity in Adults. Washington, DC: U.S. Department of Health and Human Services, 1998
3. American Society for Bariatric Surgery.  Rationale for the Surgical Treatment of Obesity. Updated April 6, 1998.
4. National Institutes of Health Consensus Development Conference Statement Online.  Gastrointestinal Surgery for Severe Obesity. March 25-27, 19919(1):1-20.
5. Renquist, K, Obesity Classification. Obesity Surgery 1998;8:480.
6. Mason EE, Heeson WW, Informed consent for obesity surgery.  Obes Surg  1998;8(4):419-428.
7. Kral, J.G.  Surgical Treatment of Obesity.  In Handbook of Obesity, ed. Bray, G.A., Bouchard, C., James, W.P.T.  New York. Marcel Dekker, Inc., 1998.
8. Gastric Surgery for Severe Obesity.  National Institute of Diabetes and Digestive and Kidney Diseases.  NIH Publication No. 96-4006, April 1996.
9. FDA Talk Paper. FDA Approves Implanted Stomach Band to Treat Severe Obesity. June 5, 2001.