Treatment
Medical Therapy
A preoperative trial of weight loss is beneficial to ensure patient compliance with the postoperative diet protocol. Also, a preoperative liquid diet can shrink the liver, thus facilitating the surgical procedure.
Surgical Therapy
Types of bariatric surgery include the following:
- Restrictive procedures (eg, adjustable gastric banding, sleeve gastrectomy)
- Restrictive procedures with some malabsorption (eg, Roux-en-Y gastric bypass)
- Malabsorptive procedures with some restriction (eg, biliopancreatic diversion with duodenal switch)
Bariatric surgery can be performed by an open technique and by a laparoscopic technique. The laparoscopic approach has currently become the more popular approach.
Gastric bypass
Laparoscopic Roux-en-Y gastric bypass.
Gastric bypass is currently the most popular procedure performed in the United States. (See image above and Image 1.) This procedure has earned the reputation of being the gold standard, against which other procedures are compared. The procedure has a restrictive and a malabsorptive component.
The gastric bypass provides a substantial amount of dietary restriction. The restriction is created by the small stomach pouch, which gives the patient a feeling of satiety after eating a small meal. The restrictive element of the operation consists of the creation of a small gastric pouch (approximately 20 mL in volume) and probably a small outlet that, on distention by food, causes the sensation of satiety.
In addition, the gastric bypass provides a small-to-moderate degree of intentional malabsorption due to the separation of food, which passes through the alimentary limb of the Y, from the biliopancreatic secretions, which pass through the biliopancreatic limb of the Y. The degree of malabsorption can be adjusted by modifying the length of the alimentary and biliopancreatic limbs.
The malabsorptive element is a result of bypassing the distal stomach, the entire duodenum, and varying the length of the jejunum. The extent of the bypass of the intestine determines the degree of macronutrient malabsorption. The standard Roux limb is about 75 cm. More extensive malabsorptive variations consist of gastric bypasses with a 150-cm Roux limb (long-limb) or with a very long-limb (distal gastric bypass). In addition to restricting food intake, causing some degree of malabsorption, it also causes dumping syndrome in response to a high-sugar liquid meal.
Weight loss after a standard 75-cm Roux gastric bypass usually exceeds 100 lb or about 65-70% of excess body weight and about 35% of BMI. The longer-limb bypasses are used to obtain comparable weight reductions in patients who are super obese (BMI >50 kg/m2). Weight loss generally levels off in 1-2 years, and a regain of up to 20 lb from the weight loss nadir to a long-term plateau is common.
Reversal
For all bariatric procedures, pure reversal without conversion to another bariatric procedure is almost certainly followed by a return to morbid obesity. Gastric bypass can be reversed, though this is rarely required.
Revision
Long Roux-en-Y gastric bypass.
A standard Roux gastric bypass with failed weight loss can be revised to a very long-limb Roux-en-Y procedure or the dilated gastric pouch can be revised. (See image above and Image 4.)
After gastric bypass surgery, some patients may experience dumping syndrome upon ingestion of sweets. This is caused by the rapid passage of gastric pouch contents directly into the small bowel, unimpeded by a pyloric valve. The presence of concentrated simple sugars in the Roux limb presents a substantial osmotic load that may result in cramping and abdominal discomfort; additionally, the ensuing rapid release of insulin by the pancreas may cause symptomatic hypoglycemia. This unpleasant reaction to sugar is considered to be a desired effect of gastric bypass surgery, and it has been referred to by patients as the postoperative police officer.
Weight loss after gastric bypass has been shown to be greater than that obtained by dietary, medical, behavioral, or combined approaches to weight loss.
A long-term follow-up study performed by MacLean et al defined postoperative success as a reduction in weight to a BMI of less than 35 kg/m2.1 By this criterion, a successful outcome was achieved in 93% of patients with an initial BMI of less than 50 kg/m2 and in 57% of patients with an initial BMI of greater than 50 kg/m2.
Since its initial description in 1994 by Wittgrove and others, the laparoscopic gastric bypass approach has been shown to combine the efficacy of the open approach with the decreased pain, lower wound morbidity, and shorter convalescence of a minimally invasive procedure.2 Results of several laparoscopic gastric bypass series have paralleled or improved upon those of open surgery. In Higa's series of 400 laparoscopic procedures, patients lost an average of 69% of their initial excess weight by 12 months after their operations.3 Schauer's group reported even better weight loss; in a group of 275 patients undergoing laparoscopic gastric bypass, there was an average loss of excess weight of 83% at 24 months after surgery.
A prospective, randomized trial was completed that compared the results of laparoscopic gastric bypass to the results of open gastric bypass. Patients who had undergone laparoscopic gastric bypass were found to have substantially less impairment of pulmonary function after surgery and decreased postoperative pain.
In the author's experience, the convalescence after laparoscopic gastric bypass is substantially reduced relative to open procedures, with some patients returning to work in 2 weeks or less.
Laparoscopic adjustable gastric banding
Adjustable gastric banding.
Laparoscopic adjustable gastric banding is the most common bariatric procedure and is performed in Europe, Australia, and South America. (See image above and Image 2.) In June 2001, the US Food and Drug Administration (FDA) approved it for use in the United States. Lap-Band (Inamed) is the only device approved for this use in the United States.
The device consists of an adjustable inflatable band placed around the proximal part of the stomach. This creates a small gastric pouch (approximately 15 mL in volume) and a small stoma. Band restriction is adjustable by adding or removing saline from the inflatable band by a reservoir system of saline attached to the band and accessible through a port, which is attached by a catheter to the band. The port is placed subcutaneously in the anterior abdominal wall after the band is secured around the stomach.
Adjustment of the band through the access port is an essential part of laparoscopic adjustable gastric banding therapy. Appropriate adjustments, performed up to 6 times annually, are critical for successful outcomes. Patients must chew food thoroughly to allow food to pass through the band. Adjusting the inflation of the cuff changes the size of the opening through which food passes but does not change the size of the gastric pouch; deflation of the cuff is useful when the outlet is obstructed.
Weight loss after laparoscopic adjustable gastric banding is about 50-60% of excess body weight in approximately 2 years.
Laparoscopic adjustable gastric banding can be completely reversed with removal of the band, tubing, and port.
Biliopancreatic diversion with duodenal switch
Biliopancreatic diversion with duodenal switch.
The procedure (see image above and Image 5) includes the following:
- Lateral 75% gastrectomy, resulting in a tubular stomach
- Duodenum divided past the pyloric valve
- Ileum divided
- Distal end anastomosed to proximal duodenum
- Common channel created distally with Y-anastomosis
- Optional appendectomy and cholecystectomy
Malabsorption is achieved by separating food from biliopancreatic digestive fluids. More weight loss results from fat malabsorption. Protein absorption is also reduced. This has the best weight loss with the least regain. There is less disruption of eating patterns. Early weight loss is from restriction and malabsorption, and, later, it is mostly from malabsorption; 75-85% of excess body weight loss is at 18 months. Pyloric preservation protects against marginal ulceration and dumping syndrome.
The procedure is technically challenging and difficult to reverse. Insurance companies may not cover this procedure because it is still considered investigational.
Sleeve gastrectomy.
Sleeve gastrectomy, a type of unbanded gastroplasty, employs subtotal gastric resection to create a long lesser curve – based gastric conduit. (See image above and Image 3.) In this procedure, the stomach is reduced to about 15-20% of its original size by the surgical removal of a large portion of the stomach, following the greater curve. The mechanism of weight loss and resultant comorbidity improvement that follows sleeve gastrectomy may be related to gastric restriction or to neurohumoral changes observed following the procedure (due to the gastric resection). Sleeve gastrectomy has been used as the first of a 2-stage procedure for high-risk patients,4 but owing to its simplicity and favorable outcomes,5 it is currently being offered as a primary, stand-alone procedure. In the first decade of the 21st century, many hundreds of sleeve gastrectomies were performed in the United States.Based on follow-up periods of 6 months to 3 years, patients were found to have lost 33-83% of their excess weight.6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
Compared with other bariatric procedures, sleeve gastrectomy is the more physiologic treatment, because it does not involve malabsorption, abnormal tracts, blind tracts, or the placement of a foreign body. This procedure is widely performed laparoscopically.18
Incision reduction strategies
Progression of surgical techniques, with open surgery in the first image and single-incision, transumbilical laparoscopic surgery in the third illustration.
There has been a growing trend in bariatric surgery toward reduction of abdominal incisions, a change offering much-improved cosmetic outcomes and, potentially, shorter patient hospital stays. (See image above and Image 6.) Such minimally invasive surgery also provides, as a result of decreased abdominal trauma, reductions in pain, scarring, and tissue injury. Saber and colleagues developed a single-incision, transumbilical laparoscopic approach for sleeve gastrectomies, in which the procedure is performed mainly through the umbilicus; the sleeve is extracted through the umbilicus without extending the incision.18
In addition, Saber and colleagues developed a single-incision, transumbilical laparoscopic technique for the placement of an adjustable gastric band; in addition to offering the aforementioned benefits of such an approach, this technique facilitates later outpatient adjustment of the band.
Preoperative Details
The diversity of clinical and occult obesity-related comorbidities necessitates a multidisciplinary team approach in the preoperative evaluation of the patient who is morbidly obese. This evaluation will enhance the postoperative outcome. Preoperative cardiac, pulmonary, psychiatric, and endocrine evaluations may be necessary. These evaluations help to exclude patients who may not benefit from surgery; at the same time, they optimize those considered being potential good candidates for surgery. Preoperative nutritional consultation helps in obtaining a detailed diet history and in explaining preoperative and postoperative diet protocol.
Intraoperative Details
See Surgical Therapy.
Postoperative Details
After surgery, patients must remain on a high-protein, low-fat diet, and they must supplement their diet with multivitamins, iron, and calcium, usually on a twice-a-day basis. Ursodiol (Actigall) may be given to minimize the risk of developing gallstones during the period of acute weight loss. Patients must modify their eating habits by avoiding chewy meats and other foods that may inhibit normal emptying of their stomach pouch. Nutritional and metabolic blood tests need to be performed on a frequent basis; in the author's practice, these tests are performed at 6 months after surgery, 12 months after surgery, and then annually thereafter.
Postbariatric surgery body contouring
Massive weight loss is associated with negative consequences for the body, such as flabby skin, abdominal skin overhang, and pendulous breasts. The excess skin does not contract back to its preweight gain tightness. Redundant rolls of tissue may also be associated with intertrigo and significant hygiene problems. Surgical correction of these body deformities can significantly enhance physical and physiological changes. The usual time lapse between gastric bypass and plastic surgery procedures is 12-18 months.
Treatment alternatives for body contouring procedures include lipoplasty, conventional surgery, or a combination of the 2 procedures. Conventional contouring procedures include abdominoplasty, buttock lift, lower body lift, thigh lift, upper arm lift, facelift, breast reduction, mastopexy, and/or augmentation. Multiple procedures are usually required, and a staged approach to body contouring surgery following bariatric surgery seems to improve safety and outcomes.
Complications of body contouring procedures include hematomas and seromas, as well as fat necrosis, skin slough, infection, and deep vein thrombosis. In addition, the patient should be involved with a team that assesses nutritional and psychological issues as needed.
Follow-up
For excellent patient education resources, visit eMedicine's Public Health Center. Also, see eMedicine's patient education articles Obesity and Surgery in the Treatment of Obesity.
Complications
Complications of Roux-en-Y gastric bypass are as follows:
- Early complications
- Anastomotic leak (1-3%)
- Pulmonary embolism, deep vein thrombosis (<1%)
- Wound infection (more common with open approach)
- Gastrointestinal hemorrhage, bleeding (0.5-2%)
- Respiratory insufficiency, pneumonia
- Acute distention of the distal stomach
- Late complications (less frequent and less dramatic than with gastric banding)
- Stomal stenosis, most common (20%)
- Bowel obstruction, small bowel obstruction (1%)
- Internal hernia
- Cholelithiasis
- Micronutrient deficiencies
- Marginal ulcer
- Staple line disruption
- Ventral hernia formation (more prevalent after open approach)
Operative (30-day) mortality for gastric bypass when performed by skilled surgeons is about 0.5%. The risk of dying in the first month after a Roux-en-Y gastric bypass from complications of the operation is about 0.2-0.5% in expert centers. Studies have demonstrated that the mortality rate from hospitals with less experience with the procedure is far higher than that reported by expert centers. Compared with open procedures, laparoscopic gastric bypass has a higher rate of intra-abdominal complications, whereas the duration of hospitalization is shorter, wound complications are lower, and the postoperative patient comfort is higher.
Lifelong oral or intramuscular vitamin B-12 supplementation and iron, vitamin B, folate, and calcium supplementation are recommended to avoid specific nutrient deficiency conditions, such as anemia.
Complications of the adjustable gastric band procedure are as follows:
- Early complications
- Injury of the stomach or esophagus
- Bleeding
- Food intolerance (most common immediate postoperative complication)
- Wound infection
- Pneumonia
- Late complications
- Food intolerance or noncompliance to band (13%)
- Band slippage (stomach prolapse) (2.2-8%)
- Pouch dilatation
- Band erosion into the stomach
- Port complications
- Reoperation rate (2-41%)
- Esophageal dilatation
- Failure to lose weight
- Port infection, band infection
- Leakage of the balloon or tubing
- Mortality rate (0.5%; 0% in some series)
Because the biliopancreatic diversion with duodenal switch procedure is less well known, the complications are potentially more problematic if the surgeon is unfamiliar with the procedure.
- Fat malabsorption results in diarrhea and foul-smelling gas in approximately 30% of patients.
- The potential nutritional deficiencies mandate frequent follow-up visits, with close monitoring and supplementation of multivitamins and minerals.
- Malabsorption of fat soluble vitamins (vitamins A, D, E, and K)
- Vitamin A deficiency, which causes night blindness
- Vitamin D deficiency, which causes osteoporosis
- Iron deficiency (similar incidence to Roux-en-Y gastric bypass procedure)
- Protein-energy malnutrition (may require a second operation to lengthen the common channel)
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Further Reading
Related eMedicine topics:
Body Contouring, Abdominoplasty
Laparoscopic Gastric Bypass
Laparoscopic Lap Band Placement
Obesity [Endocrinology]
Obesity [Pediatrics: General Medicine]
Clinical guidelines:
American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient. American Association of Clinical Endocrinologists - Medical Specialty Society
American Society for Metabolic and Bariatric Surgery - Professional Association
The Obesity Society - Disease Specific Society. 2008 Jul-Aug. 83 pages. NGC:006716
Expert panel on weight loss surgery. Massachusetts Department of Public Health - State/Local Government Agency [U.S.]. 2004 Aug 4 (revised 2007 Dec 12). 106 pages. NGC:006638
Role of endoscopy in the bariatric surgery patient. American Society for Gastrointestinal Endoscopy - Medical Specialty Society. 2008 Jul. 10 pages. NGC:006609
SAGES guideline for clinical application of laparoscopic bariatric surgery. Society of American Gastrointestinal and Endoscopic Surgeons - Medical Specialty Society. 2003 Jul (revised 2008 Oct). 20 pages. NGC:006413
Clinical trials:
Energy Expenditure and Gastric Bypass Surgery Study
Hepatic Effects of Gastric Bypass Surgery
Impact of GBS on CVD in Type 2 Diabetes Mellitus
Randomized Controlled Trial of Laparoscopic Gastric Bypass Plus Omentectomy Versus Laparoscopic Gastric Bypass Alone in Improving Diabetic Indices
Trial of Leptin Administration After Roux-en-Y Gastric Bypass
Keywords
bariatric surgery, gastric bypass, stomac h, obesity, gastric, bariatric, weight loss surgery, weight surgery, stomach surgery, gastric banding, gastrectomy, Roux-en-Y, gastric sleeve, gastric bypass surgery, body mass index, BMI, laparoscopic gastric bypass, duodenal switch, gastric bypass complications, adjustable gastric banding, Roux-en-Y gastric bypass, sleeve gastrectomy, biliopancreatic diversion with duodenal switch
