Bariatric 
Surgery 
for Weight Loss

Thursday, December 13, 2012

Obesity is a major health problem worldwide, and it has reached epidemic proportion in Western society. Evidence that obesity is a major risk factor for many diseases and is associated with significant morbidity and mortality continues to accumulate.

The estimated number of overweight individuals in the world is 1.7 billion. In the United States, the problem is at epidemic proportions. As much as two-thirds of the U.S. population is overweight, and half of the people in this group can be classified as obese.

Bariatric surgery is currently the only modality that provides significant, sustained weight loss for the patient who is morbidly obese, with resultant improvement in obesity-related comorbidities. A prospective, controlled Swedish study involving 4,047 obese patients, half of whom had undergone bariatric procedures, followed these patients over 14.7 years. The study found that, when comparing bariatic surgery to usual care, this type of surgery showed a significantly reduced number of cardiovascular deaths (P =.002) and lower incidence of cardiovascular events (P < .001) in obese adults.1

Surgery for obesity should be considered a treatment of last resort after dieting, exercise, psychotherapy and drug treatments have failed.

Developed at the 1991 National Institutes of Health (NIH) Consensus Development Conference Panel, the generally accepted criteria for surgical treatment include a BMI of greater than 40 kg/m2 or a BMI of greater than 35 kg/m2 in combination with high-risk comorbid conditions, such as sleep apnea, pickwickian syndrome, diabetes mellitus or degenerative joint disease.

In 1954, Kremen and Linner introduced jejunoileal bypass, the first effective surgery for obesity in the United States. In this procedure, the proximal jejunum was connected directly to the distal ileum, bypassing 90% of the small intestine out of the intestinal stream of ingested nutrients (blind loop). The procedure induced a state of malabsorption, which led to significant weight loss. However, many patients developed complications secondary to malabsorption (e.g., steatorrhea, diarrhea, vitamin deficiencies, oxalosis) or due to the toxic overgrowth of bacteria in the bypassed intestine (e.g., liver failure, severe arthritis, skin problems). Consequently, many patients have required reversal of the procedure, and the procedure has been abandoned. This led to a search for better operations.

Modifications in the original procedures and the development of new techniques have led to three basic concepts for bariatric surgery:

  • gastric restriction (adjustable gastric banding, sleeve gastrectomy)
  • gastric restriction with mild malabsorption (Roux-en-Y gastric bypass)
  • a combination of mild gastric restriction and malabsorption (duodenal switch)

Contraindications to bariatric surgery include illnesses that greatly reduce life expectancy and are unlikely to be improved with weight reduction, including advanced cancer and end-stage renal, hepatic and cardiopulmonary disease.

The inability to understand the nature of bariatric surgery or the behavioral changes required afterward, untreated schizophrenia, active substance abuse, and noncompliance with previous medical care are also considered contraindications to bariatric surgery.

To learn more about the various types of bariatric surgery and receive CME credit, please visit cme.dannemiller.com/mdnews/dec.

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References

Sjöström L, Peltonen M, Jacobson P, Sjöström CD, Karason K, Wedel H, et al. Bariatric surgery and long-term cardiovascular events. JAMA. Jan 4 2012;307(1):56-65. 
Saber, A. Bariatric Surgery and Treatment and Management. www.medscape.com. Accessed 10/31/2012.