Bariatric surgery, or weight loss surgery, is a type of procedure performed on people who are dangerously obese, for the purpose of losing weight. This weight loss is usually achieved by reducing the size of the stomach with an implanted medical device (gastric banding) or through removal of a portion of the stomach (gastric bypass surgery).

Long-term studies show the procedures cause significant long-term loss of weight, recovery from diabetes, improvement in cardiovascular risk factors, and a reduction in mortality of 23% to 40%.^[1]

The U.S. National Institutes of Health recommends bariatric surgery for obese people with a body mass index (BMI) of at least 40, and for people with BMI 35 and serious coexisting medical conditions such as diabetes.^[1]

Contents 1 Indications 2 Classification of surgical procedures 2.1 Predominantly malabsorptive procedures 2.1.1 Biliopancreatic diversion 2.1.2 Jejunoileal bypass 2.1.3 Endoluminal sleeve 2.2 Predominantly restrictive procedures 2.2.1 Vertical Banded Gastroplasty 2.2.2 Adjustable gastric band 2.2.3 Sleeve gastrectomy 2.2.4 Intragastric balloon 2.3 Mixed procedures 2.3.1 Gastric Bypass Surgery 2.3.2 Sleeve gastrectomy with duodenal switch 2.3.3 Implantable Gastric Stimulation 3 Eating after bariatric surgery 4 Effectiveness of surgery 4.1 Weight loss 4.2 Reduced mortality and morbidity 5 Adverse effects 6 See also 7 References

[edit] Indications

A medical guideline by the American College of Physicians concluded^[2][3]:

• "Surgery should be considered as a treatment option for patients with a BMI of 40 kg/m² or greater who instituted but failed an adequate exercise and diet program (with or without adjunctive drug therapy) and who present with obesity-related comorbid conditions, such as hypertension, impaired glucose tolerance, diabetes mellitus, hyperlipidemia, and obstructive sleep apnea. A doctor–patient discussion of surgical options should include the long-term side effects, such as possible need for reoperation, gallbladder disease, and malabsorption."
• "Patients should be referred to high-volume centers with surgeons experienced in bariatric surgery."

[edit] Classification of surgical procedures

Procedures can be grouped in three main categories:^[4]

[edit] Predominantly malabsorptive procedures

Predominantly malabsorptive procedures, although they also reduce stomach size, these operations are based mainly on creating malabsorption.

[edit] Biliopancreatic diversion

This complex operation is also known as biliopancreatic diversion (BPD), or Scopinaro procedure. This surgery is rare now because of problems with malnourishment. It has been replaced with the Duodenal switch, also known as the BPD/DS. Part of the stomach is resected, creating a smaller stomach (however after a few months the patient can eat a completely free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum.^{[citation needed]}

In around 2% of patients there is severe malabsorption and nutritional deficiency that requires restoration of the normal absorption. The malabsorptive effect of BPD is so potent that those who undergo the procedure must take vitamin and dietary minerals above and beyond that of the normal population. Without these supplements, there is risk of serious deficiency diseases such as anemia and osteoporosis.^{[citation needed]}

Because gallstones are a common complication of the rapid weight loss following any type of bariatric surgery, some surgeons remove the gallbladder as a preventative measure during BPD. Others prefer to prescribe medications to reduce the risk of post-operative gallstones.^{[citation needed]}

Far fewer surgeons perform BPD compared to other weight loss surgeries, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients.^{[citation needed]}

[edit] Jejunoileal bypass

This procedure is no longer performed.^{[citation needed]}

[edit] Endoluminal sleeve

Although only performed on mice at present, this surgery involved placing a 10cm long impermeable sleeve into the intestine to block absorption of food in the duodenum and upper jejunum. A study at Massachusetts General Hospital Weight Center and Gastrointestinal Unit found that mice who had the surgery ate 30% less food and lost 20% more weight than counterpart mice, while blood glucose levels returned to normal levels in all mice who had the surgery.^[5]

[edit] Predominantly restrictive procedures

Predominantly restrictive procedures primarily reduce stomach size.^{[citation needed]}

[edit] Vertical Banded Gastroplasty

In the vertical banded gastroplasty, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach.^{[citation needed]}

[edit] Adjustable gastric band

The restriction of the stomach also can be created using a silicone band, which can be adjusted by addition or removal of saline through a port placed just under the skin. This operation can be performed laparoscopically, and is commonly referred to as a "lap band." The first gastric band was patented in 1979^[6] and successfully applied in animal experiments. An American company, INAMED Health, later designed the BioEnterics LAP-BAND Adjustable Gastric Banding System, which was introduced in Europe in 1993. Neither of these bands was initially designed for use with laparoscopic surgery. The LAP-BAND System received U.S. Food and Drug Administration (FDA) approval in June 2001. In 2000, a lower pressure, wider, one-piece adjustable gastric band called the MIDband was introduced by Medical Innovation Development of Lyon France.^[7] In 2002, a lower pressure, wider, one-piece adjustable gastric band called the Bioring designed specifically for laparoscopic insertion was introduced in France by Cousin-Biotech,^[8] and swiftly become one of the leading bands in that country. There are now a number of band manufacturers.^{[citation needed]}

[edit] Sleeve gastrectomy

Sleeve gastrectomy is a surgical weight-loss procedure in which the stomach is reduced to about 15% of its original size, by surgical removal of a large portion of the stomach, following the major curve. The open edges are then attached together (often with surgical staples) to form a sleeve or tube with a banana shape. The procedure permanently reduces the size of the stomach. The procedure is performed laparoscopically and is not reversible.

[edit] Intragastric balloon

This surgery involves endoscopic placing a deflated balloon into the stomach, and then filling it to decrease the amount of gastric space. The balloon can be left in the stomach for a maximum of 6 months^[9] and results in an average weight loss of 5-9BMI over half a year.^[10] While not yet approved by the FDA the Intragastric balloon is approved in Australia, Canada, Mexico, India and several European and South American countries.^[11][12]

[edit] Mixed procedures

Mixed procedures apply both techniques simultaneously.

[edit] Gastric Bypass Surgery

The most common form of gastric bypass surgery is the Roux-en-Y gastric bypass. Here, a small stomach pouch is created with a stapler device, and connected to the distal small intestine. The upper part of the small intestine is then reattached in a Y-shaped configuration.^{[citation needed]}

The gastric bypass is the most commonly performed operation for weight loss in the United States, and approximately 140,000 gastric bypass procedures were performed in 2005, dwarfing the number of Lap-Band, duodenal switch and vertical banded gastroplasty procedures. Since the gastric bypass has been performed for almost 50 years, surgeons have become very comfortable with, and aware of, the risks and benefits of the procedure. The gastric bypass operation has become the "gold standard" in the U.S. for comparison with new procedures. A factor in the success of gastric bypass surgery is strict post-surgical adherence to a gastric bypass diet.^{[citation needed]}

[edit] Sleeve gastrectomy with duodenal switch

A variation of the biliopancreatic diversion includes a Duodenal switch. The part of the stomach along its greater curve is resected. The stomach is "tubulized" with a residual volume of about 150 ml. This volume reduction provides the food intake restriction component of this operation. This type of gastric resection is anatomically and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine. The duodenum and the upper part of the small intestine are reattached to the rest at about 75-100 cm from the colon.^{[citation needed]}

[edit] Implantable Gastric Stimulation

This procedure where a device similar to a heart pacemaker is implanted by a surgeon, with the electrical leads stimulating the external surface of the stomach, is being studied in the USA. Electrical stimulation is thought to modify the activity of the enteric nervous system of the stomach, which is interpreted by the brain to give a sense of satiety, or fullness. Early evidence suggests that it is less effective than other forms of Bariatric Surgery.^{[citation needed][citation needed]}

[edit] Eating after bariatric surgery

Immediately after bariatric surgery, the patient is restricted to a clear liquid diet, which includes foods such as clear broth, diluted fruit juices or sugar-free gelatin desserts. This diet is continued until the gastrointenstinal tract has recovered somewhat from the surgery. The next stage provides a blended or pureed sugar-free diet for at least two weeks. This may consist of skimmed milk, cream of wheat, a small pat of margarine, protein drinks, cream soup, pureed fruit and mashed potatoes with gravy.^[13]

Post-surgery, overeating is curbed because exceeding the capacity of the stomach causes nausea and vomiting. Diet restrictions after recovery from surgery depend in part on the type of surgery. Many patients will need to take a daily multivitamin pill for life to compensate for reduced absorption of essential nutrients ^[14]. Because patients cannot eat a large quantity of food, physicians typically recommend a diet that is relatively high in protein and low in carbohydrates and alcohol.

[edit] Effectiveness of surgery

[edit] Weight loss

In general, the malabsorptive procedures lead to more weight loss than the restrictive procedures. A meta-analysis from University of California, Los Angeles reports the following weight loss at 36 months:^[3]

• Biliopancreatic diversion - 53 kg
• Roux-en-Y gastric bypass (RYGB) - 41 kg
  • Open - 42 kg
  • Laparoscopic - 38 kg
• Adjustable gastric banding - 35 kg
• Vertical banded gastroplasty - 32 kg

[edit] Reduced mortality and morbidity

Several recent studies report decrease in mortality and severity of medical conditions after bariatric surgery.^[15][16][17] But long term effects are not clear.^[18] In the Swedish prospective matched controlled trial, patients with a body mass index (BMI) of 34 or more for men and 38 or more for women underwent various types of bariatric surgery and were followed for an average of 11 years. Surgery patients had a 23.7% reduction in mortality (5.0% vs. 6.3% control, adjusted hazard ratio 0.71). This means 75 patients must be treated to avoid one death after 11 years (number needed to treat is 77).^[15]

In a Utah retrospective cohort study that followed patients for an average of 7 years after various types of gastric bypass, surgery patients had 0.4% mortality while control patients had 0.6% mortality.^[16] Death rates were lower in the gastric bypass patients for all diseases combined, as well as for diabetes, heart disease and cancer. Deaths from accident and suicide were 58% higher in the surgery group.

A randomized, controlled trial in Australia compared laparoscopic adjustable gastric banding ("lap banding") with non-surgical therapy in 80 moderately obese adults (BMI 30-35). At 2 years, the surgically-treated group lost more weight (21.6% of initial weight vs. 5.5%) and had statistically significant improvement in blood pressure, measures of diabetic control, and high-density lipoprotein cholesterol.^[17] Post surgical complications included 1 patient with an infected surgical site, 4 with lap band malpositioning requiring laparoscopic revision, and 1 patient with cholecystitis. In the non-surgical group, 12 patients declined or did not tolerate orlistat or diet restrictions, and 4 patients developed acute cholecystitis.^{[citation needed]}

Bariatric surgery in older patients has also been a topic of debate, centered on concerns for safety in this population. One study of elderly patients undergoing laparoscopic bariatric surgery at Mount Sinai Medical Center, however, reported 0% conversion to open surgery, 0% 30-day mortality, 7.3% complication rate, and average hospital stay of 2.8 days.^[19] post operative mortality from 0.1 - 2 %

Laparoscopic bariatric surgery requires a hospital stay of only one or two days. Short-term complications from laparoscopic adjustable gastric banding are reported to be lower than laparoscopic Roux-en-Y surgery, and complications from laparoscopic Roux-en-Y surgery are lower than conventional (open) Roux-en-Y surgery.^[1][20][21]

[edit] Adverse effects

Complications from weight loss surgery are frequent. A study of insurance claims of 2522 who had undergone bariatric surgery showed 21.9% complications during the initial hospital stay and a total of 40% risk of complications in the subsequent six months. This was more common in those over 40 and led to increased health care expenditure. Common problems were gastric dumping syndrome in about 20% (bloatedness and diarrhoea after eating, necessitating small meals or medication), leaks at the surgical site (12%), incisional hernia (7%), infections (6%) and pneumonia (4%). Mortality was 0.2%.^[22] As the rate of complications appears to be reduced when the procedure is performed by an experienced surgeon, guidelines recommend that surgery is performed in dedicated or experienced units.^[2]

[edit] See also

• Revision weight loss surgery

[edit] References

v • d • e Digestive system surgical and other procedures (ICD-9-CM V3 42-54) Digestive tract Upper GI tract SGs/Esophagus Sialography · Esophagectomy Stomach Gastrostomy (Percutaneous endoscopic gastrostomy) · Gastrectomy (Billroth I, Billroth II, Roux-en-Y) · Bariatric surgery (Gastric bypass surgery, Adjustable gastric band, Sleeve gastrectomy, Vertical banded gastroplasty surgery) · Gastroenterostomy · Hill repair · Nissen fundoplication · Gastropexy Imaging Endoscopy: Esophagogastroduodenoscopy Upper gastrointestinal series Lower GI tract Small bowel Bariatric surgery (Duodenal switch, Jejunoileal bypass) · Jejunostomy · Ileostomy · Partial ileal bypass surgery Large bowel Colectomy · Colostomy · Appendicectomy · Hartmann's operation Rectum Lower anterior resection · Abdominoperineal resection Anus Anal sphincterotomy · Lateral internal sphincterotomy Imaging Endoscopy: Colonoscopy (Virtual) · Proctoscopy · Sigmoidoscopy · Enteroscopy · Capsule endoscopy Transrectal ultrasonography · Enteroclysis · Small bowel follow-through · Abdominal ultrasonography · Lower gastrointestinal series Accessory Liver Hepatectomy · Liver transplantation · Artificial extracorporeal liver support (Liver dialysis, Bioartificial liver devices) Gallbladder, bile duct Cholangiography (Endoscopic retrograde cholangiopancreatography, Percutaneous transhepatic cholangiography, Magnetic resonance cholangiopancreatography) · Cholecystectomy · Cholecystography · HIDA scan Pancreas Pancreatectomy · Pancreaticoduodenectomy · Pancreas transplantation · Puestow procedure · Frey's procedure Abdominopelvic Peritoneum Paracentesis · Intraperitoneal injection Hernia Herniorrhaphy · MacEwen's operation Other Laparotomy digestive system navs: anat of tract,glands,perit,diaphragm/physio/dev, noncongen/congen/congen of d+w/neoplasia, symptoms+signs/eponymous, proc