Gastric bypass surgery

Gastric bypass surgery
ICD-9-CM 44.31-44.39
MeSH D015390
MedlinePlus 007199

Gastric bypass surgery refers to a surgical procedure in which the stomach is divided into a small upper pouch and a much larger lower "remnant" pouch and then the small intestine is rearranged to connect to both. Surgeons have developed several different ways to reconnect the intestine, thus leading to several different gastric bypass (GBP) procedures. Any GBP leads to a marked reduction in the functional volume of the stomach, accompanied by an altered physiological and physical response to food.

The operation is prescribed to treat morbid obesity (defined as a body mass index greater than 40), type 2 diabetes, hypertension, sleep apnea, and other comorbid conditions. Bariatric surgery is the term encompassing all of the surgical treatments for morbid obesity, not just gastric bypasses, which make up only one class of such operations. The resulting weight loss, typically dramatic, markedly reduces comorbidities. The long-term mortality rate of gastric bypass patients has been shown to be reduced by up to 40%.[1][2] As with all surgery, complications may occur. A study from 2005 to 2006 revealed that 15% of patients experience complications as a result of gastric bypass, and 0.5% of patients died within six months of surgery due to complications.[3]

Uses

Gastric bypass is indicated for the surgical treatment of morbid obesity, a diagnosis which is made when the patient is seriously obese, has been unable to achieve satisfactory and sustained weight loss by dietary efforts, and suffers from comorbid conditions which are either life-threatening or a serious impairment to the quality of life.

Prior to 1991, clinicians interpreted serious obesity as weighing at least 100 pounds (45 kg) more than the "ideal body weight", an actuarially-determined body-weight at which one was estimated to be likely to live the longest, as determined by the life-insurance industry. This criterion failed for persons of short stature.

In 1991, the National Institutes of Health (NIH) sponsored a consensus panel whose recommendations have set the current standard for consideration of surgical treatment, the body mass index (BMI). The BMI is defined as the body weight (in kilograms), divided by the square of the height (in meters). The result is expressed as a number in units of kilograms per square meter. In healthy adults, BMI ranges from 18.5 to 24.9, with a BMI above 30 being considered obese, and a BMI less than 18.5 considered underweight.[4] (BMI is by itself not a reliable index of obesity: serious bodybuilders or strength athletes have BMIs in the obesity range while having relatively little body fat.)

The Consensus Panel of the National Institutes of Health (NIH) recommended the following criteria for consideration of bariatric surgery, including gastric bypass procedures:

The Consensus Panel also emphasized the necessity of multidisciplinary care of the bariatric surgical patient by a team of physicians and therapists to manage associated comorbidities and nutrition, physical activity, behavior, and psychological needs. The surgical procedure is best regarded as a tool which enables the patient to alter lifestyle and eating habits, and to achieve effective and permanent management of obesity and eating behavior.

Since 1991, major developments in the field of bariatric surgery, particularly laparoscopy, have outdated some of the conclusions of the NIH panel. In 2004 the American Society for Bariatric Surgery (ASBS) sponsored a consensus conference which updated the evidence and the conclusions of the NIH panel. This conference, composed of physicians and scientists of both surgical and non-surgical disciplines, reached several conclusions, including:

Surgical techniques

The gastric bypass, in its various forms, accounts for a large majority of the bariatric surgical procedures performed. It is estimated that 200,000 such operations were performed in the United States in 2008.[6] An increasing number of these operations are now performed by limited access techniques, termed "laparoscopy".

Laparoscopic surgery is performed using several small incisions, or ports: one to insert a surgical telescope connected to a video camera, and others to permit access of specialized operating instruments. The surgeon views his operation on a video screen. Laparoscopy is also called limited access surgery, reflecting the limitation on handling and feeling tissues and also the limited resolution and two-dimensionality of the video image. With experience, a skilled laparoscopic surgeon can perform most procedures as expeditiously as with an open incision—with the option of using an incision should the need arise.

The Roux-en-Y laparoscopic gastric bypass, first performed in 1993, is regarded as one of the most difficult procedures to perform by limited access techniques, but use of this method has greatly popularized the operation due to associated benefits such as a shortened hospital stay, reduced discomfort, shorter recovery time, less scarring, and minimal risk of incisional hernia.

Essential features

The gastric bypass procedure consists of:

Variations

Gastric bypass, Roux en-Y (RYGB, proximal)

Illustration of Roux-en-Y gastric bypass surgery

This variant is the most commonly employed gastric bypass technique, and is by far the most commonly performed bariatric procedure in the United States. The small intestine is divided approximately 45 cm (18 in) below the lower stomach outlet and is re-arranged into a Y-configuration, enabling outflow of food from the small upper stomach pouch via a "Roux limb". In the proximal version, the Y-intersection is formed near the upper (proximal) end of the small intestine. The Roux limb is constructed using 80–150 cm (31–59 in) of the small intestine, preserving the rest (and the majority) of it from absorbing nutrients. The patient will experience very rapid onset of the stomach feeling full, followed by a growing satiety (or "indifference" to food) shortly after the start of a meal.

Gastric bypass, Roux en-Y (RYGB, distal)

The small intestine is normally 6–10 m (20–33 ft) in length. As the Y-connection is moved further down the gastrointestinal tract, the amount available to fully absorb nutrients is progressively reduced, traded for greater effectiveness of the operation. The Y-connection is formed much closer to the lower (distal) end of the small intestine, usually 100–150 cm (39–59 in) from the lower end, causing reduced absorption (malabsorption) of food: primarily of fats and starches, but also of various minerals and the fat-soluble vitamins. The unabsorbed fats and starches pass into the large intestine, where bacterial actions may act on them to produce irritants and malodorous gases. These larger effects on nutrition are traded for a relatively modest increase in total weight loss.

"Mini-gastric bypass" (MGB)

The mini gastric bypass procedure was first developed by Robert Rutledge from the US in 1997, as a modification of the standard Billroth II procedure. A mini gastric bypass creates a long narrow tube of the stomach along its right border (the lesser curvature). A loop of the small gut is brought up and hooked to this tube at about 180 cm from the start of the intestine

Numerous studies show that the loop reconstruction (Billroth II gastrojejunostomy) works more safely when placed low on the stomach, but can be a disaster when placed adjacent to the esophagus. Today thousands of "loops" are used for surgical procedures to treat gastric problems such as ulcers, stomach cancer, and injury to the stomach. The mini gastric bypass uses the low set loop reconstruction and thus has rare chances of bile reflux.

The MGB has been suggested as an alternative to the Roux en-Y procedure due to the simplicity of its construction, and is becoming more and more popular because of low risk of complications and good sustained weight loss. It has been estimated that 15.4% of weight loss surgery in Asia is now performed via the MGB technique.[7]

Endoscopic duodenal-jejunal bypass

This technique has been clinically researched since the mid-2000s. It involves the implantation of a duodenal-jejunal bypass liner between the beginning of the duodenum (first portion of the small intestine from the stomach) and the mid-jejunum (the secondary stage of the small intestine). This prevents the partially digested food from entering the first and initial part of the secondary stage of the small intestine, mimicking the effects of the biliopancreatic portion of Roux en-Y gastric bypass (RYGB) surgery. Despite a handful of serious adverse events such as gastrointestinal bleeding, abdominal pain, and device migration — all resolved with device removal — initial clinical trials have produced promising results in the treatment's ability to improve weight loss and glucose homeostasis outcomes.[8][9][10]

Physiology

The gastric bypass reduces the size of the stomach by well over 90%. A normal stomach can stretch, sometimes to over 1000 mL, while the pouch of the gastric bypass may be 15 mL in size. The gastric bypass pouch is usually formed from the part of the stomach which is least susceptible to stretching. That, and its small original size, prevents any significant long-term change in pouch volume. What does change, over time, is the size of the connection between the stomach and intestine and the ability of the small intestine to hold a greater volume of food. Over time, the functional capacity of the pouch increases; by that time, weight loss has occurred, and the increased capacity should serve to allow maintenance of a lower body weight.

When the patient ingests just a small amount of food, the first response is a stretching of the wall of the stomach pouch, stimulating nerves which tell the brain that the stomach is full. The patient feels a sensation of fullness, as if they had just eaten a large meal—but with just a thimble-full of food. Most people do not stop eating simply in response to a feeling of fullness, but the patient rapidly learns that subsequent bites must be eaten very slowly and carefully, to avoid increasing discomfort or vomiting.

Food is first churned in the stomach before passing into the small intestine. When the lumen of the small intestine comes into contact with nutrients, a number of hormones are released, including cholecystokinin from the duodenum and PYY and GLP-1 from the ileum. These hormones inhibit further food intake and have thus been dubbed "satiety factors". Ghrelin is a hormone that is released in the stomach that stimulates hunger and food intake. Changes in circulating hormone levels after gastric bypass have been hypothesized to produce reductions in food intake and body weight in obese patients. However, these findings remain controversial, and the exact mechanisms by which gastric bypass surgery reduces food intake and body weight have yet to be elucidated.

For example, it is still widely perceived that gastric bypass works by mechanical means, i.e. food restriction and/or malabsorption. Recent clinical and animal studies, however, have indicated that these long-held inferences about the mechanisms of Roux en-Y gastric bypass (RYGB) may not be correct. A growing body of evidence suggests that profound changes in body weight and metabolism resulting from RYGB cannot be explained by simple mechanical restriction or malabsorption. One study in rats found that RYGB induced a 19% increase in total and a 31% increase in resting energy expenditure, an effect not exhibited in vertical sleeve gastrectomy rats. In addition, pair-fed rats lost only 47% as much weight as their RYGB counterparts. Changes in food intake after RYGB only partially account for the RYGB-induced weight loss, and there is no evidence of clinically significant malabsorption of calories contributing to weight loss. Thus, it appears RYGB affects weight loss by altering the physiology of weight regulation and eating behavior rather than by simple mechanical restriction or malabsorption.[11]

To gain the maximum benefit from this physiology, it is important that the patient eat only at mealtimes, 5 to 6 small meals daily, and not graze between meals. Concentration on obtaining 80–100 g of daily protein is necessary. Meals after surgery are 1/4–1/2 cup, slowly getting to 1 cup by one year. This requires a change in eating behavior and alteration of long-acquired habits for finding food. In almost every case where weight gain occurs late after surgery, capacity for a meal has not greatly increased. Some assume the cause of regaining weight must be the patient's fault, e.g. eating between meals with high-caloric snack foods, though this has been debated. Others believe it is an unpredictable failure or limitation of the surgery for certain patients (e.g. reactive hypoglycemia).

Complications

Any major surgery involves the potential for complications—adverse events which increase risk, hospital stay, and mortality. Some complications are common to all abdominal operations, while some are specific to bariatric surgery.

Mortality and complication rates

The overall rate of complications during the 30 days following surgery ranges from 7% for laparoscopic procedures to 14.5% for operations through open incisions. One study on mortality revealed a 0% mortality rate out of 401 laparoscopic cases, and 0.6% out of 955 open procedures (6 Deaths). Similar mortality rates—30-day mortality of 0.11% (364 deaths), and 90-day mortality of 0.3%—have been recorded in the U.S. Centers of Excellence program, the results being from 33,117 operations at 106 centers.[12]

Mortality and complications are affected by pre-existing risk factors such as degree of obesity, heart disease, obstructive sleep apnea, diabetes mellitus, and history of prior pulmonary embolism. It is also affected by the experience of the operating surgeon: the learning curve for laparoscopic bariatric surgery is estimated to be about 100 cases. Supervision and experience is important when selecting a surgeon, as the way a surgeon becomes experienced in dealing with problems is by encountering and solving them.

Complications of abdominal surgery

Infection

Infection of the incisions or of the inside of the abdomen (peritonitis, abscess) may occur due to release of bacteria from the bowel during the operation. Nosocomial infections, such as pneumonia, bladder or kidney infections, and sepsis (blood-borne infection) are also possible. Effective short-term use of antibiotics, diligent respiratory therapy, and encouragement of activity within a few hours after surgery can reduce the risks of infections.

Venous thromboembolism

Any injury, such as a surgical operation, causes the body to increase the coagulation of the blood. Simultaneously, activity may be reduced. There is an increased probability of formation of clots in the veins of the legs, or sometimes the pelvis, particularly in the morbidly obese patient. A clot which breaks free and floats to the lungs is called a pulmonary embolus, a very dangerous occurrence. Blood thinners are commonly administered before surgery to reduce the probability of this type of complication.

Hemorrhage

Many blood vessels must be cut in order to divide the stomach and to move the bowel. Any of these may later begin bleeding, either into the abdomen (intra-abdominal hemorrhage), or into the bowel itself (gastrointestinal hemorrhage). Transfusions may be needed, and re-operation is sometimes necessary. Use of blood thinners to prevent venous thromboembolic disease may actually increase the risk of hemorrhage slightly.

Hernia

A hernia is an abnormal opening, either within the abdomen or through the abdominal wall muscles. An internal hernia may result from surgery and re-arrangement of the bowel, and is a cause of bowel obstruction. Antecolic antegastric Roux-en-Y gastric bypass surgery has been estimated to result in internal hernia in 0.2% of cases, mainly through Petersen's defect.[13] An incisional hernia occurs when a surgical incision does not heal well; the muscles of the abdomen separate and allow protrusion of a sac-like membrane, which may contain bowel or other abdominal contents, and which can be painful and unsightly. The risk of abdominal-wall hernia is markedly decreased in laparoscopic surgery.

Bowel obstruction

Abdominal surgery always results in some scarring of the bowel, called adhesions. A hernia, either internal or through the abdominal wall, may also result. When bowel becomes trapped by adhesions or a hernia, it may become kinked and obstructed, sometimes many years after the original procedure. An operation is usually necessary to correct this problem.

Complications of gastric bypass

Anastomotic leakage

An anastomosis is a surgical connection between the stomach and bowel, or between two parts of the bowel. The surgeon attempts to create a water-tight connection by connecting the two organs with either staples or sutures, either of which actually makes a hole in the bowel wall. The surgeon will rely on the body's natural healing abilities and its ability to create a seal, like a self-sealing tire, to succeed with the surgery. If that seal fails to form for any reason, fluid from within the gastrointestinal tract can leak into the sterile abdominal cavity and give rise to infection and abscess formation. Leakage of an anastomosis can occur in about 2% of Roux-en-Y gastric bypass and less than 1% in mini gastric bypass. Leaks usually occur at the stomach-intestine connection (gastro-jejunostomy). There is a change in the drain fluid contents from serous (before the leak) to fecal/bilious (after the leak). Usually significant leaks need urgent re-operation. Sometimes a minor leakage can be treated with antibiotics only. It is usually safer to re-operate if an infection cannot be definitely controlled immediately.

Anastomotic stricture

As the anastomosis heals, it forms scar tissue, which naturally tends to shrink ("contract") over time, making the opening smaller. This is called a "stricture". Usually, the passage of food through an anastomosis will keep it stretched open, but if the inflammation and healing process outpaces the stretching process, scarring may make the opening so small that even liquids can no longer pass through it. The solution is a procedure called gastroendoscopy, and stretching of the connection by inflating a balloon inside it. Sometimes this manipulation may have to be performed more than once to achieve lasting correction.

Anastomotic ulcer

Ulceration of the anastomosis occurs in 1–16% of patients.[14] Possible causes of such ulcers are:

This condition can be treated with:

Dumping syndrome

Normally, the pyloric valve at the lower end of the stomach regulates the release of food into the bowel. When the gastric bypass patient eats a sugary food, the sugar passes rapidly into the intestine, where it gives rise to a physiological reaction called dumping syndrome. The body will flood the intestines with gastric content in an attempt to dilute the sugars. An affected person may feel their heart beating rapidly and forcefully, break into a cold sweat, get a feeling of butterflies in the stomach, and may have an anxiety attack. The person usually has to lie down, and could be very uncomfortable for 30–45 minutes. Diarrhea may then follow.

Nutritional deficiencies

Nutritional deficiencies are common after gastric bypass surgery, and are often not recognized. They include:[15]

Nutritional effects

After surgery, patients feel fullness after ingesting only a small volume of food, followed soon thereafter by a sense of satiety and loss of appetite. Total food intake is markedly reduced. Due to the reduced size of the newly created stomach pouch, and reduced food intake, adequate nutrition demands that the patient follow the surgeon's instructions for food consumption, including the number of meals to be taken daily, adequate protein intake, and the use of vitamin and mineral supplements. Calcium supplements, iron supplements, protein supplements, multi-vitamins (sometimes pre-natal vitamins are best), and vitamin B12 (cyanocobalamin) supplements are all very important to the post-operative bypass patient.

Total food intake and absorbance rate of food will rapidly decline after gastric bypass surgery, and the number of acid-producing cells lining the stomach increases. Doctors often prescribe acid-lowering medications to counteract the high acidity levels. Many patients then experience a condition known as achlorhydria, where there is not enough acid in the stomach. As a result of the low acidity levels, patients can develop an overgrowth of bacteria. A study conducted on 43 post-operative patients revealed that almost all of the patients tested positive for a hydrogen breath test, which indicated an overgrowth of bacteria in the small intestine.[19] Bacterial overgrowth causes the gut ecology to change and induces nausea and vomiting. Recurring nausea and vomiting eventually change the absorbance rate of food, contributing to the vitamin and nutrition deficiencies common in post-operative gastric bypass patients.

Protein nutrition

Proteins are essential food substances, contained in foods such as vegetables, fruits, legumes, nuts, meat, fish, poultry, dairy products and eggs. With reduced ability to eat a large volume of food, gastric bypass patients must focus on eating their protein requirements first, and with each meal. In some cases, surgeons may recommend use of a liquid protein supplement. Powdered protein supplements added to smoothies or any food can be an important part of the post-op diet.

Calorie nutrition

The profound weight loss which occurs after bariatric surgery is due to taking in much less energy (calories) than the body needs to use every day. Fat tissue must be burned to offset the deficit, and weight loss results. Eventually, as the body becomes smaller, its energy requirements are decreased, while the patient simultaneously finds it possible to eat somewhat more food. When the energy consumed is equal to the calories eaten, weight loss will stop. Proximal GBP typically results in loss of 60–80% of excess body weight, and very rarely leads to excessive weight loss. The risk of excessive weight loss is slightly greater with distal GBP.

Vitamins

Vitamins are normally contained in foods and supplements. The amount of food eaten after GBP is severely reduced, and vitamin content is correspondingly lowered. Supplements should therefore be taken to complete minimum daily requirements of all vitamins and minerals. Pre-natal vitamins are sometimes suggested by doctors, as they contain more of certain vitamins than most multi-vitamins. Absorption of most vitamins is not seriously affected after proximal GBP, although vitamin B12 may not be well-absorbed in some persons: sublingual preparations of B12 provide adequate absorption. Some studies suggest that GBP patients who took probiotics after surgery are able to absorb and retain higher amounts of B12 than patients who did not take probiotics after surgery. After a distal GBP, fat-soluble vitamins A, D, and E may not be well-absorbed, particularly if fat intake is large. Water-dispersed forms of these vitamins may be indicated on specific physician recommendation. For some patients, sublingual B12 is not enough, and patients may require B12 injections.

Minerals

All versions of the GBP bypass the duodenum, which is the primary site of absorption of both iron and calcium. Iron replacement is essential in menstruating females, and supplementation of iron and calcium is preferable in all patients. Ferrous sulfate is poorly tolerated. Alternative forms of iron (fumarate, gluconate, chelates) are less irritating and probably better absorbed. Calcium carbonate preparations should also be avoided; calcium as citrate or gluconate (with 1200 mg as calcium) has greater bioavailability independent of acid in the stomach, and will likely be better absorbed. Chewable calcium supplements that include vitamin K are sometimes recommended by doctors as a good way to get calcium.

Alcohol metabolism

Post-operative gastric bypass patients develop a lowered tolerance for alcoholic beverages because their altered digestive tract absorbs alcohol at a faster rate than people who have not undergone the surgery. It also takes a post-operative patient longer to reach sober levels after consuming alcohol. In a study conducted on 36 post-operative patients and a control group of 36 subjects (who had not undergone surgery), each subject drank a 5 oz. glass of red wine and had the alcohol in their breath measured to evaluate alcohol metabolism. The gastric bypass group had an average peak alcohol breath level at 0.08%, whereas the control group had an average peak alcohol breath level of 0.05%. It took on average 108 minutes for the gastric bypass patients group to return to an alcohol breath of zero, while it took the control group an average of 72 minutes.[20]

Pica

There have been reported cases in which pica recurs after gastric bypass in patients with a pre-operative history of the disorder, which are possibly due to iron deficiency. Pica is a compulsive tendency to eat substances other than normal food. Some examples would be people eating paper, clay, plaster, ashes, or ice. Low levels of iron and hemoglobin are common in patients who have undergone gastric bypass.[21] One study reported on a female post-operative gastric bypass patient who was consuming eight to ten 32 oz. glasses of ice a day. The patient's blood test revealed iron levels of 2.3 mmol/L and hemoglobin level of 5.83 mmol/L. Normal iron blood levels of adult women are 30 to 126 µg/dL and normal hemoglobin levels are 12.1 to 15.1 g/dl. This deficiency in the patient's iron levels may have led to the increase Pica activity. The patient was then given iron supplements that brought her hemoglobin and iron blood levels to normal levels. After one month, the patient's eating diminished to two to three glasses of ice per day. After one year of taking iron supplements the patient's iron and hemoglobin levels remained in a normal range and the patient reported that she did not have any further cravings for ice.[22]

Results and health benefits of gastric bypass

Weight loss of 65–80% of excess body weight is typical of most large series of gastric bypass operations reported. The medically more significant effects include a dramatic reduction in comorbid conditions:

A study in a large prospective study of 2010 obese patients showed an 29% reduction in mortality up to 15 years following surgery (hazard ratio 0.71 when adjusted for sex, age, and risk factors), compared to a non-surgically treated group of 2037 patients.[27]

Concurrently, most patients are able to enjoy greater participation in family and social activities.

Cost of gastric bypass

The patient's out of pocket cost for Roux-en-Y gastric bypass surgery varies widely depending on method of payment, region, surgical practice and hospital in which the procedure is performed.

Methods of payment in the United States include private insurance (Individual & Family coverage, Small Group coverage through an employer (Under 50 full-time employees) and Large Group coverage through an employer (50 or more full-time employees), public insurance (Medicare and Medicaid) and self-pay. Out of pocket costs for a patient with private or public insurance that specifically list bariatric surgery as a covered benefit include several insurance-policy-specific parameters such as deductible levels, coinsurance percentages, copay amounts and out of pocket limits.

Patients without insurance must pay for surgery directly (or through a third party lender), and total out of pocket costs will depend on the surgical practice they choose and the hospital in which the surgical practice performs the procedure. On average, the total cost of gastric bypass surgery is about $24,000 in the United States, although on a state-specific level it ranges from an average of $15,000 (Arkansas) to an average of $57,000 (Alaska).[28]

Living with gastric bypass

Gastric bypass surgery has an emotional and physiological impact on the individual. Many who have undergone the surgery suffer from depression in the following months as a result of a change in the role food plays in their emotional well-being.[29] Strict limitations on the diet can place great emotional strain on the patient. Energy levels in the period following the surgery can be low, both due to the restriction of food intake and negative changes in emotional state.[30] It may take as long as three months for emotional levels to rebound. Muscular weakness in the months following surgery is also common. This is caused by a number of factors, including a restriction on protein intake, a resulting loss in muscle mass and decline in energy levels. Muscle weakness may result in balance problems, difficulty climbing stairs or lifting heavy objects, and increased fatigue following simple physical tasks. Many of these issues pass over time as food intake gradually increases. However, the first months following the surgery can be very difficult, an issue not often mentioned by physicians suggesting the surgery. The benefits and risks of this surgery are well established; however, the psychological effects are not well understood.

Even if physical activity is increased patients may still harbor long term psychological effects due to excess skin and fat. Often bypass surgery is followed up with "body lifts" of skin and liposuction of fatty deposits. These extra surgeries have their own inherent risks but are even more dangerous when coupled with the typical nutritional deficiences that accompany convalescing gastric bypass patients.

Surgeon accreditation

The American Society for Metabolic & Bariatric Surgery lists bariatric programs and surgeons in its "Centers of Excellence" network,[31] while the American College of Surgeons accredits providers through its Bariatric Surgery Center Network.[32] For listings of surgeons and centers in other countries, the International Federation for the Surgery of Obesity and Metabolic Disorders lists medical associations by country.[33]

See also

References

  1. ↑ Adams TD, Gress RE, Smith SC, et al. (August 2007), "Long-term mortality after gastric bypass surgery", N. Engl. J. Med., 357 (8): 753–61, PMID 17715409, doi:10.1056/NEJMoa066603.
  2. ↑ Sjöström L, Narbro K, Sjöström CD, et al. (August 2007), "Effects of bariatric surgery on mortality in Swedish obese subjects", N. Engl. J. Med., 357 (8): 741–52, PMID 17715408, doi:10.1056/NEJMoa066254.
  3. ↑ "Complications and Costs for Obesity Surgery Declining". Agency for Healthcare Research and Quality. 29 April 2009. Retrieved 24 August 2011.
  4. ↑ Body mass index for adults. [www.webmd.com/a-to-z-guides/body-mass-index-bmi-for-adults]
  5. ↑ "Gastric Bypass Surgery Roux En-Y". bariatricguide.org. BSIG. Retrieved 10 August 2013.
  6. ↑ Claire Ainsworth, 2009, Full without Food, New Scientist, 5 September 2009, No 2724
  7. ↑ Lomanto, Davide; Lee, Wei-Jei; Goel, Rajat; Lee, Jeannette Jen-Mai; Shabbir, Asim; So, Jimmy BY; Huang, Chih-Kun; Chowbey, Pradeep; Lakdawala, Muffazal (2011), "Bariatric Surgery in Asia in the Last 5 Years (2005–2009)", Obesity Surgery, 22 (3): 502–6, PMID 22033767, doi:10.1007/s11695-011-0547-2
  8. ↑ Sullivan, S. (2015). "Endoscopic Treatment of Obesity". In Jonnalagadda, S.S. Gastrointestinal Endoscopy: New Technologies and Changing Paradigms. Springer. pp. 61–82. ISBN 9781493920327. Retrieved 18 March 2016.
  9. ↑ Muñoz, R.; Escalona, A. (2015). "Chapter 51: Endoscopic Duodenal-Jejunal Bypass Sleeve Treatment for Obesity". In Agrawal, S. Obesity, Bariatric and Metabolic Surgery: A Practical Guide. Springer. pp. 493–498. ISBN 9783319043432. Retrieved 18 March 2016.
  10. ↑ ASMBS (January 2004). "Story of Obesity Surgery". American Society for Metabolic and Bariatric Surgery. Retrieved 18 March 2016.
  11. ↑ Stylopoulos Nicholas; Nicholas Hoppin; Alison G.; Kaplan Lee M (2009). "Roux-en-Y Gastric Bypass Enhances Energy Expenditure and Extends Lifespan in Diet-induced Obese Rats". Obesity. 17 (10): 1839–1847. doi:10.1038/oby.2009.207.
  12. ↑ "Know the possible risks of bariatric surgery". Retrieved 6 January 2014.
  13. ↑ "Frequency and management of internal hernias after laparoscopic antecolic antegastric Roux-en-Y gastric bypass without division of the small bowel mesentery or closure of mesenteric defects: review of 1400 consecutive cases", Surg Obes Relat Dis, 2: 87–91, PMID 16925328, doi:10.1016/j.soard.2005.11.004
  14. ↑ Sacks, M.D., Bethany C.; Samer G. Mattar, M.D., F.A.C.S., Faisal G. Qureshi, M.D., George M. Eid, M.D., Joy L. Collins, M.D., Emma J. Barinas-Mitchell, Ph.D., Philip R. Schauer, M.D., Ramesh C. Ramanathan, M.D. (2006), "Incidence of marginal ulcers and the use of absorbable anastomotic sutures in laparoscopic Roux-en-Y gastric bypass" (PDF), Surgery for Obesity and Related Diseases, Gainesville, Florida: American Society for Bariatric Surgery, 2 (1): 11–16, PMID 16925306, doi:10.1016/j.soard.2005.10.013, retrieved 25 January 2009, Marginal ulceration is a known complication of both open and laparoscopic Roux-en-Y gastric bypass, with an incidence of approximately 1% to 16%; most recent studies cite an incidence of approximately 2%.
  15. ↑ John, S; Hoegerl, C (2009), "Nutritional deficiencies after gastric bypass surgery", The Journal of the American Osteopathic Association, 109 (11): 601–604, PMID 19948694
  16. 1 2 Poitou Bernert, C., Ciangura, C., Coupaye, M., Czernichow, S., Bouillot, J.L., & Basdevant, A. (2007), "Nutritional deficiency after gastric bypass: diagnosis, prevention and treatment", Diabetes & Metabolism, 33 (1): 13–24, doi:10.1016/j.diabet.2006.11.004.
  17. ↑ Madan, A. K., Orth, W. S., Tichansky, D. S., & Ternovits, C. A. (2006), "Vitamin and trace mineral levels after laparoscopic gastric bypass", Obesity Surgery, 16 (5): 603–606, PMID 16687029, doi:10.1381/096089206776945057.
  18. ↑ Paluszkiewicz, Rafał; Kalinowski, Piotr; Wróblewski, Tadeusz; Bartoszewicz, Zbigniew; Białobrzeska-Paluszkiewicz, Janina; Ziarkiewicz-Wróblewska, Bogna; Remiszewski, Piotr; Grodzicki, Mariusz; Krawczyk, Marek (2012), "Prospective randomized clinical trial of laparoscopic sleeve gastrectomy versus open Roux-en-Y gastric bypass for the management of patients with morbid obesity.", Videosurgery and Other Miniinvasive Techniques, 7 (4): 225–32, PMC 3557743 Freely accessible, PMID 23362420, doi:10.5114/wiitm.2012.32384
  19. ↑ Adams, T., Avelar, E., Cloward, T., R., Farney, R.G., Halverson, C.R., Hopkin, P.N.,...& Hunt, S. (2005), "Design and rationale of the Utah obesity study. A study to assess morbidity following gastric bypass surgery", Contemporary Clinical Trials, 26 (5): 534–551, PMID 16046191, doi:10.1016/J.CCT.2005.05.003.
  20. ↑ , Hagedorn, J., Encarnancion, B., Brat, G., & Morton, J., "Does gastric bypass alter alcohol metabolism?", Surgery for Obesity and Related Diseases, 3: 543–548, doi:10.101616/j.jpedsurg.2004.09.034.
  21. ↑ News-Medical.net, Gastric Bypass Complications. Retrieved 2013-05-24.
  22. ↑ Kushner, R.; Gleason, B.; Shanta-Retelny, V. "Reemergence of pica following gastric bypass surgery for obesity: a new presentation of an old problem". Journal of the American Dietetic Association. 104: 1393–97. doi:10.101616/j.jada.2004.06.026.
  23. ↑ "Magee pilot study probes further into weight-loss methods". March 3, 2010. Retrieved 6 January 2014.
  24. ↑ Pories, WJ; Caro, JF; Flickinger, EG; Meelheim, HD; Swanson, MS (September 1987). "The control of diabetes mellitus (NIDDM) in the morbidly obese with the Greenville Gastric Bypass". Annals of Surgery. 206 (3): 316–23. PMC 1493167 Freely accessible. PMID 3632094. doi:10.1097/00000658-198709000-00009.
  25. ↑ Pories WJ, Swanson MS, MacDonald KG, et al. (September 1995), "Who would have thought it? An operation proves to be the most effective therapy for adult-onset diabetes mellitus", Ann. Surg., 222 (3): 339–50; discussion 350–2, PMC 1234815 Freely accessible, PMID 7677463, doi:10.1097/00000658-199509000-00011.
  26. ↑ Long, SD; O'Brien, K; MacDonald KG, Jr; Leggett-Frazier, N; Swanson, MS; Pories, WJ; Caro, JF (May 1994). "Weight loss in severely obese subjects prevents the progression of impaired glucose tolerance to type II diabetes. A longitudinal interventional study". Diabetes Care. 17 (5): 372–5. PMID 8062602. doi:10.2337/diacare.17.5.372.
  27. ↑ Sjöström L, Narbro K, Sjöström CD, et al. (August 2007), "Effects of bariatric surgery on mortality in Swedish obese subjects", N. Engl. J. Med., 357 (8): 741–52, doi:10.1056/NEJMoa066254, PMID 17715408
  28. ↑ Quinlan, J, Average Cost of Gastric Bypass Surgery by Region, Bariatric Surgery Source, retrieved 24 October 2014
  29. ↑ Elkins, G; Whitfield, P; Marcus, J; Symmonds, R; Rodriguez, J; Cook, T (2005), "Noncompliance with behavioral recommendations following bariatric surgery", Obesity Surgery, 15 (4): 546–51, PMID 15946436, doi:10.1381/0960892053723385
  30. ↑ Delin, CR; Watts, JM; Saebel, JL; Anderson, PG (1997), "Eating behavior and the experience of hunger following gastric bypass surgery for morbid obesity", Obesity Surgery, 7 (5): 405–13, PMID 9730494, doi:10.1381/096089297765555386
  31. ↑ Surgical Review Corporation Centers of Excellence
  32. ↑ ACS Bariatric Surgery Center Network
  33. ↑ IFSO National Councils

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