 |
|||||||||
 |
|||||||||
 |
|||||||||
 |
|||||||||
|
|
About Bariatric Surgery |
||||||||
Bariatric Surgery is a weight loss procedure that has helped thousands of severely overweight people return to their normal body weight. The procedure may be appropriate for people with over 100 pounds to lose or a Body Mass Index (BMI) greater than 40. Patients can lose over 100 pounds in the first year after surgery.
It is a chronic
disease with multiple and complex causes, not just a problem of overeating.
The ultimate causes of severe obesity are unknown, and specific therapy
directed to it is not yet available. Until such treatment becomes
available, the control of overweight is a lifetime enterprise. It
is very important to understand that medical interventions, including
surgery, are not the cure for obesity, but a way of controlling this
disease. |
 |
||||||||
|
Why Morbid Obesity is Treated by Surgery The Anatomy and Functions Involved Operations for Obesity are Designed to Change the Energy Balance Mechanisms of Weight Control by Surgery Gastric Restriction Operations I. Gastric Restriction Operations |
|||||||||
 |
|||||||||
This obesity is called morbid because it is associated with progressive, serious and debilitating disease. It is a major contributor to diabetes, high blood pressure, cardiovascular disease, osteoarthritis of weight-bearing joints, respiratory problems, gallstones, urinary incontinence, swollen legs that may develop ulcers, gastro-esophageal reflux (with "heartburn"), stroke, infertility, certain types of cancer, depression, and many other serious disorders. The social, psychological and economic consequences of morbid obesity are devastating. Prejudice against the obese is common in our society. Unfortunately, the conservative management of morbid obesity (diet, exercise, drugs, behavioral modification, etc.) has been found to be ineffective in the long-term. More than 95% of subjects regain their lost weight within a few years after conservative treatment. Surgery for morbid obesity is the only method that has resulted in long term maintenance of weight loss and reduction in the associated diseases, with marked improvement in quality of life, social interaction, psychological well-being, work opportunities, and economic conditions. Morbid obesity is usually defined as being 100 pounds (45 kg) over "ideal weight". Listed in the Appendix section at the back of this booklet are Tables for Ideal Weighs that were developed by the life insurance company, based on survival statistics for both sexes, according to height and medium body frame. A better way of defining obesity is by using the Body Mass index (BMI), a ratio calculated by dividing the weight in kilograms by the height in meters squared (BMI=kg/height in m2). You can also find your BMI in table 3 of the Appendix. Candidates for surgery are persons with a BMI=40 or higher, and those with a BMI=35 or greater who suffer from serious diseases related to obesity. Why Morbid Obesity is Treated by Surgery Morbid obesity is treated by surgery because of the serious risks related to this degree of obesity, the relative low risk of operative treatment, and the ineffectiveness of medical & dietary interventions. Besides the danger serious diseases caused by excessive weight, there is a potential risk from a continuing increase in weight, towards what is called end-stage obesity. Variations in weight as a result of ineffective conservative treatment (yo-yo dieting) may be damaging. A patient should be at least 100 pounds (45 kg) above estimated ideal body weight before considering an obesity operation. At that point and beyond, surgery should be viewed as alleviation of a debilitating disease. Sometimes an operation may be considered at a lower weight if the patient's physician determines that there is sufficient medical need for weight reduction and surgery seems to be the only way to accomplish this. Weight loss following surgery for morbid obesity varies, depending on many factors. A patient's age, initial weight, ability to exercise and the type of operation used are examples of some of these factors. on average, patients lose about one-third of their initial weight in 12-18 months. Heavier patients tend to lose more weight, but initially lighter patients are more likely to lose a greater percentage of their excess weight and come closer to their ideal weight. The Anatomy and Functions Involved In order to
understand how operations aid weight loss, it is important to review
how our gastrointestinal tract functions (Figures 1A ans 1B). The
digestive tract is a marvelous assembly line in which food, digestive
juices and enzymes come together at the optimum place and time, to
allow for appropriate digestion and absorption of nutrients. The small bowel is about 15-20 feet (4.5-6 meters) long, which allows sufficient time for digestion and absorption to occur. The first part of the small bowel is called the duodenum. As food enters it is mixed with bile produced by the liver and juices from the pancreas, which are necessary to increase digestion. This area of bowel also accounts for the absorption of much of our body's iron and calcium. The last segment of the small intestine, called ileum, is also very important in the absorption of nutrients and fat-soluble vitamins (A,D,E and K). Once the intestinal contents reach the colon (large bowel), excess fluid is absorbed and a firmer stool is formed. Another valve separates the small intestine from the colon, to keep the bacteria-laden colon contents from coming back into the small bowel. This description is simplified. You and your surgeon should consider how much disruption to the digestive system's anatomy and function is necessary for you in your effort to achieve weight control.
Operations for Obesity are Designed to Change the Energy Balance Energy balance is related to the amount of food absorbed and the amount of energy is stored as fat, and from these reserves energy is drawn as needed. Body weight represents a sum of structural material (especially muscle and bone), body water and stored fat. Excess fat can be reduced by reducing caloric intake to a level below the energy cost of all work performed and/or increasing physical activity. Reduction in food intake or absorption, and increase in physical activity, will cause weight loss. Mechanisms of Weight Control by Surgery There are two
ways in which surgery may control obesity by changing energy balance: These procedures for weight control were indicated to surgeons by irreversible operations required for cancer or other diseases, which resulted in loss of large segments of stomach or small bowel. Failure to maintain weight after the surgery suggested that modifications of these operations might be used to produce weight loss in morbid obesity. Today, several variations of these surgical techniques are available for weight control. It is important to understand several basic principles for this surgery. Over the last 40 years we have learned that to control weight with an operation that restricts intake, surgeons need to help patients in eating less. this requires a "meal-sized" upper stomach pouch with an initial 1 1/2 ounce (15-30 ml) capacity. the pouch connects to the rest of the stomach or the small intestine through an outlet (stoma), about the width of your little finger. The stoma may be reinforced by using synthetic surgical materials, to prevent stretching. The small pouch and the narrow outlet produce early satiation ( a feeling of fullness) that in a cooperative, compliant patient, induces behavioral changes leading to less caloric intake and, therefore, weight loss. After adaptation occurs, the average patient can soon eat half to more that a cup of well-chewed food without discomfort. inadequate chewing can result in pain, reflux or vomiting. Patients must eat slowly, reduce meal size, and avoid overeating or drinking excessive fluids and carbonated drinking excessive fluids and carbonated drinks. Failure to follow these guidelines can defeat the purpose of the surgery, by stretching the pouch and/or the outlet. Snacking throughout the day and consuming high-calorie liquids should be avoided. lack of patients' compliance is one of the most common reasons for failure! The simpler and safer restrictive operations do not always produce the weight loss that surgeons and patients would like. For this reason, malabsorption techniques were added to the procedures, some of which include extensive bypass of the small intestine. the disadvantage is that the risks of complications and side-effects grow with the lengthening of bypassed bowel. You and your surgeon must balance the risks and the benefits over your lifetime with the operation you choose for control of your excess weight. Remember that the greater the operation to produce weight loss, the higher the risks and side-effects! Your surgeon will provide information about the operation recommended for you. Ask questions. Understand the answers. Be aware of the changes made the stomach and intestine, and the effects of the treatment. It may take several tips to the doctor's office, and consultation with more than one physician and possibly with some patients who have had similar operations. This is the correct path to informed consent. When the time comes to sign a permission form for your surgery, you should feel that you know what will be done, what you will need to do to live well with the operation, and any signs or symptoms of complications that may occur later. Above all, remember that surgery is not the cure for obesity and only well-informed, compliant patients make these operations succeed! Many sources, including the Internet, are available to aid the patient in choosing an operation. Theoretically, the patient should be able to make the choice. This, however, is usually impractical because many patients have neither the time nor the training to understand more than the major differences. If you need more information before making your decision, contact the American Society for Bariatric Surgery or visit our website at the addresses listed in the cover. I. Gastric Restriction Operations A. Gastric Banding (GB) Gastric banding is the simplest restrictive operation used for weight loss (Figure 2). A band made of synthetic material is placed around the stomach near the upper end, creating a small upper pouch and a narrow passage into the larger lower portion of the stomach. This technique leaves the digestive tract in normal sequence for digestion and absorption. The only intended effect is a reduction in capacity for a meal. Small pouch volume and correct outlet diameter are very important for the success of this operation. One advantage of gastric banding is that the stomach is not cut, stapled, or entered. thus, the risk of infection is less and there is no possibility of staple-line disruption. However, there is always a risk of injuring the esophagus or stomach when placing the band. Other important advantages are that the operation is easy to revise and is the only completely reversible technique if a need arises. In such a case, the band is removed and the stomach recovers its normal anatomy, without sequelae.
Some of the gastric bandings are done with an adjustable silicone band connected through a tube to a port (reservoir), which is placed under the skin of the upper abdomen. The collar around the stomach outlet is adjusted by adding or removing small amounts of saline solution by inserting a needle into the injection port. The adjustment is performed under x-ray control or in the physician's office. The functional integrity of the implanted parts is uncertain, but they can be surgically replaced. After gastric banding, the stomach can slip under the band, causing distention of the pouch and poor emptying. The band can cause scar tissue to build up and reduce the outlet, or it can loosen and no longer restrict eating, or it may rarely penetrate into the stomach. These problems can result in repeated vomiting or failure to lose weight, and may require another operation for correction.
In these procedures the upper stomach near the esophagus
is stapled vertically for about 2 1/2 inches (6m) to create the pouch.
The outlet is reinforced in the Vertical Banded Gastroplasty (VBG)
by a strip of plastic mesh, placed through a window made in the stomach
walls. This requires the use of another type of stapler, circular,
to cut out the window and seal the edges to prevent leaks (Figure
3). The pouch may be separated (divided) from the stomach body to
reduce staple-line disruption. However, this increases the risk of
leak and bleeding.
The advantage of these procedures is
that it is easy to construct a 15-20 ml pouch and a non-stretchable
outlet. These are commonly performed restrictive operations and have
extensive long-term Restrictive operations in general depend on a small pouch and outlet to reduce food intake, but over time the pouch can stretch and allow patients to eat too much. As is the case with all other operations for morbid obesity, readmission to the hospital may be required for fluid replacement or nutritional support, if there is excessive vomiting and adequate intake cannot be maintained.
The primary advantage of the restrictive procedures is that well-chewed food still enters and passes through the digestive tract in proper order so that iron, calcium, vitamin and nutrient absorption is maintained. however, a balanced diet providing appropriate nutrition, life-long monitoring and vitamin supplements is still required to ensure proper health. II. Combined Restrictive and Malabsorption Operations This type of operation maintains the principles of a small pouch and a narrow outlet to produce restriction of food intake, the main cause of weight loss.In addition, most of the stomach and the duodenum are bypassed, and malabsorption occurs. this results in additional weight loss, because food is delayed in mixing with stomach secretions, bile and pancreatic juice which are needed for the digestion of nutrients.
Roux-en-Y gastric bypass provides gastric restriction combined with some malabsorption. It is one of the most frequently performed operations for morbid obesity in the USA (Figure 5). The stapling may be positioned horizontally at the top of the stomach, but is more often done vertically, as in the gastroplasties, creating apouch the same as other restrictive operations. The stomach, however, is completely stapled shut and the outlet of the pouch opens into intestine rather than into the rest of the stomach. This is done by dividing the small bowel just beyond the duodenum and bringing it up to the pouch to construct a connection. The other open end of the bowel is sewn back into the side of the Roux limb of intestine, completing a Y-shaped arrangement that gives the technique its name. the length of either segment of bowel can be increased to produce more malabsorption, but this also increases the risks and side-effects.
Although the average weight loss is higher than pure restriction operations, poor absorption of iron and calcium results because the duodenum is bypassed. A lowering of total body iron and predisposition to iron deficiency anemia may occur when a patient experiences chronic blood loss (for instance, from excessive menstrual blood-flow or bleeding hemorrhoids). Women should be especially concerned about bone calcium loss, a risk of osteoporosis that occurs in women after menopause even with normal digestive tracts. operations that bypass the duodenum have caused metabolic bone disease in some patients. This may cause bone pain, loss of height, humped back and fractures of the ribs and hip bones. Iron and calcium should be replaced through diet and pills. A steady
reduction in Vitamin B12 also may occur because food does not reach
the part of the stomach below, where an "intrinsic factor" Gastric bypass may cause other side-effects. As we mentioned before, one of them is dumping syndrome, which can include nausea, weakness, sweating, faintness and sometimes diarrhea after eating. Some patients with this syndrome cannot eat sweets without becoming weak and sweaty to the point that they must lie down until the symptoms pass. This can be a great incentive for a sweet-a-holics to stay away from sweets. Pouch distention abd staple-line disruption may also occur, with the same consequences of compromised weight loss in gastroplasties. Double stapling or division (separation) of the pouch from the rest of the stomach have reduced the chances of disruption, although this increases the risk of postoperative leakage and bleeding. Another disadvantage of this operation is that the bypassed portion of the stomach, duodenum and segment of small bowel cannot be easily visualized by x-rays or endoscopy if a problem, such as ulcers, bleeding or malignancy occurs.
Silastic Ring vertical gastric bypass is a variant of the Roux-en-Y gastric bypass pouch is divided from the rest of the stomach, to remove the chance of staple-line disruption. The lower pouch is encircled by a Silastic ring or polypropylene (plastic) mesh band, which provides some restriction.
The pouch outlet connects to the small bowel the same way as in RYGBP, but the upper end of the Roux limb is interposed between the pouch and bypassed stomach. Weight loss and risks of metabolic side-effects are the same as for the RYGBP. Uncommonly, the ring or band may erode into the pouch. These operations also reduce the size of the stomach to restrict meal size and produce initial weight loss, by removing a large part of the stomach or stapling it to create small pouch. the difference is that the anatomy of the small bowel is changed, to decrease intestinal absorption and thus achieve greater weight reduction. This is done by diversion of bile and pancreatic juice, which are necessary for the absorption of fats, through a bypassed segment of small intestine. The ingested food meets the bile and pancreatic juice near the end of the small intestine; therefore, absorption of nutrients and calories is reduced. Since food bypasses the duodenum, all the considerations discussed in the gastric bypass section regarding the malabsorption of some minerals and vitamins apply to these techniques. The changed intestinal pathways increase the risk of gallstone formation. thus, removal of the gallbladder is recommended at the time of these operations. Re-routing bile and pancreatic juice from their normal entry just beyond the stomach also removes the buffer action of these fluids on stomach acid, which can cause irritation and ulcers. To prevent this, acid output needs to be reduced by some means when the operation is performed.
The original technique entails removing approximately 3/4 of the stomach to produce both restriction of food intake and reduction of acid output (Figure 6A). Leaving enough upper stomach is important to maintain protein intake and proper nutrition. The small bowel is then divided and one end is attached to the stomach pouch, creating what is called the alimentary limb. All of the food is moved through this segment of intestine, but not much of it is absorbed. the bile and pancreatic juice move through the biliopancreatic limb, which connects to the side of the intestine near its end.
These juices finally join the food in the bowel segment called the common limb. The length of this common limb is critical in the absorption of sufficient protein, fat and fat-soluble vitamins.
An alternative means of reducing acid output is to create a stapled or divided small gastric pouch, as in gastric bypass, leaving the remainder of the stomach in place (Figure 6B). A long limb of small bowel is attached to the stomach, in the same way as described above, to divert the bile and pancreatic juice and produce malabsorption.
This procedure carries fewer operative risks by avoiding removal of the lower 3/4 of the stomach, which results in permanent and irreversible changes in the gastrointestinal tract. Your surgeon can tell you the risks of ulcer, malnutrition, and other anticipated effects which depend on gastric pouch size and lengths of bypassed intestine.
Another form of biliopancreatic diversion is the "duodenal switch" procedure (Figure 6C). As with the original BPD, this operation includes stomach resection but only the outer margin is removed, leaving a sleeve of stomach with the pylorus and beginning of the duodenum at its end. The duodenum is divided so that pancreatic and bile drainage is bypassed. The near-end of the "alimentary limb" is then attached to the beginning of the duodenum, while the "common limb" is created in the same way as described before. For all of the malabsorption operations, there is a period of intestinal adaptation, after which bowel movements usually decrease to an average of about 3 per day. Annoying side-effects are abdominal bloating malodorous stool or flatus. In spite of these, the operations result in a substantial degree of patient satisfaction, mainly because patients can eat larger meals than patients with pure gastric restriction procedures or standard RYGBP.
These three types of malabsorptive operations create a similar short length of "common intestinal limb". The size of the stomach pouch and the length of the bypassed bowel are very important in preventing excessive malnutrition. The different constructions cause varying difficulties with iron, calcium, vitamins A and D, and protein absorption. Longer "common limbs" diminish these complications and reduce the need for hospitalization to treat metabolic problems, but weight loss is decreased. Close monitoring for protein malnutrition, anemia and bone disease is required after these operations. Nutritional supplements and vitamins, and life-long follow-up are critical to maintain health and well-being. A laparoscopic operation is performed with the aid of a laparoscope, a fiberoptic tube and light source connected to a small video camera, which allows the visualization of the abdominal organs on a TV monitor. Surgical instruments are inserted through small incisions in the abdominal wall. this is less invasive and reduces pain and the risk of wound complications. Recovery is usually more rapid, shortening the hospitalization. Laparoscopic operations have been used in general surgery for over a decade, and the technique is not experimental. Laparoscopic procedures for morbid obesity employ the same surgical principles as in "open" gastric banding, vertical gastroplasties and gastric bypass. The laparoscopic technique must be precise and should vary from open operations only in the size of the abdominal incision. However, these techniques are not free of complications and require special surgical expertise to reduce operative time and other risks. Not all patients are candidates for this procedure. Accordingly, the American Society for Bariatic Surgery recommends that laparoscopic operations for obesity should be performed only by surgeons who are experienced in both laparoscopic and open bariatic surgery and who understand the complexities of surgical treatment of morbid obesity. Risks and Complications
of Surgery for Morbid Obesity Final considerations need to be taken into account, because the cost of the surgery and follow-up differ widely according to the complexity of the operation. Some insurance companies approve benefits for the surgery if certain conditions are met, depending on different coverage policies. Other companies, however, have exclusion clauses for the treatment of obesity. be sure to consider all the options before committing yourself. if you decide to pay for the operation with your own funds, keep in mind that additional expenses may be necessary to treat complications after the surgery. It is advisable to discuss the chances of having to be hospitalized due to complications or metabolic problems, and the risk of needing further operations either to solve these problems or for failure to lose satisfactory weight. Finally, remember to ask about how the operation can be "undone", how your digestive system would function thereafter, and the consequences for the future if reversing the operation becomes necessary. Although the more complicated operations may produce more weight loss in a greater number of patients, any of the procedures previously described may occasionally fail to maintain weight loss in the long-term. Compensatory changes occur over time. These changes are necessary for health and survival, but overcompenstion may result in uncontrolled regain of weigh. Complex operations require more specialized medical supervision and treatment in ensuing years. The choice of operation must balance the greater potential weight loss of the more complex procedures with the increased risk and need for more extensive medical monitoring.
What has been described regarding the risks of these operations is what usually happens. There can be unexpected outcomes or complications. Sometimes these undesirable events may be later explained by findings from studies and may be corrected by medication, change in behavior or further surgery to modify or reverse the original operation. The outcome depends upon the patient's response in terms of healing and complications, and motivation to follow instructions after the surgery. Patient compliance impacts on the outcome and success of obesity surgery. One way of increasing patient compliance is through support groups conducted by a facilitator who has experience in the subject. Peer support groups can provide the patient with the security of ongoing postoperative care and education regarding their life-changing procedure. Because compliance with postoperative dietary guidelines is so important, a multi-disciplinary team is often utilized by your bariatric surgeon. this may include, among others, a dietician and a psychologist. The dietician can help you learn how and what foods and fluids to eat and drink following the operation. the bariatic surgery psychologist can help educate and prepare both you and your family for the changes that accompany weight loss, and assist you in following the postoperative guidelines. Remember, once you are in a bariatric surgery program, you and the specialists form a team with the purpose of achieving your sustained weight loss, improvement or resolution of serious medical conditions, and increase in your quality of life. The patient as well as the surgeon, in cooperation with his/her staff, must contribute actively to accomplish success. Because obesity is a chronic disease, frequent and long-term contact with your surgeon and regular follow-up visits are very important for a good outcome. In spite of all efforts, sometimes a patient simply does not respond to the operation in a manner acceptable to the patient or surgeon. if it becomes necessary, most of these procedures can be reversed, although this usually requires another operation of equal or greater risk than the initial surgery.
What you have read so far in this booklet may frighten you. "Why do this if it is so risky?" is a good question to ask yourself. Deciding to undergo an operation, especially for obesity, is one of the biggest decisions of your life. think about it very carefully. Surgery for morbid obesity is major surgery, not cosmetic. Although most patients improve their image and self-esteem, this should not be the only reason to have the operation. the goal is to live better, healthier and longer. The results of obesity surgery can be measured in terms of weight loss, resolution or improvement of the medical problems related to obesity, and quality of life. This generally occurs over a 6-18 month period after surgery. Many studies have shown that most patients lose a satisfactory amount of weight, although some weight regain is common. Even in such cases, keep in mind that surgery also prevents the weight gain that most of the population, especially women, experience with increasing age. More importantly, the operation can be cure or control many of the serious diseases that accompany morbid obesity. Most diabetic patients improve dramatically , many of them not needing medication after the surgery. high blood pressure is also resolved in more than half of the patients. Sleep apnea and other sleep disturbances improve or disappear, sometimes even before a great amount of weight is lost. The same may happen with urinary incontinence, acid reflux or menstrual problems. Swelling of the legs and joint pain also diminish, preventing later problems. Many infertile women become pregnant and have a safer pregnancy and delivery. The changes in cholesterol and other blood lipids reduce the risk of heart attacks and strokes, hopefully prolonging life. There are many health benefits of losing weight, but it is also important to consider the improvement in quality of life that most patients experience after surgery, even if not all excess weight has been lost. one of the most important benefits is feeling good about yourself. Improved image and confidence help in fighting the depression that so often accompanies obesity. Because of the prejudice against the obese in our society, losing weight increases social acceptance and opens doors for better work opportunities, friendships and even sexual relations. It is not infrequent for patients on welfare to become employed, or for singles to marry. However, keep in mind that strained relationships and even divorce may occur. Obesity surgery changes patients' lives! Your relationship to family, friends or co-workers may change, sometimes not ass positively as you wish.
A patient may have only one choice to make if the surgeon performs only one type of operation, and believes that this operation is the best one for all patients. however, the patient should understand what is involved in choosing to have that particular operation. the choice is not just between more or less weight loss. It involves many other differences that are dependent upon the choice of operation. Patients considering surgery must decide if the benefits outweigh the side-effects and possible complications. No operation will
automatically succeed without the patient's cooperation; nor chosen
operation works and complying with its requirements will help a patient
make that operation a success!
Last updated June 15, 2005. [MCM] Copyright © American Society for Bariatric Surgery. All rights reserved. |
|||||||||
