GASTRIC BYPASS SURGERY OVERVIEW

There is considerable misinformation concerning the validity of bariatric surgery in the management of morbid obesity. Bariatric surgery is a recognized sub-interest in the field of General Surgery. It has been endorsed by the National Institutes of Health Consensus Conference, 1992. The American Society for Bariatric Surgery is recognized by the American College of Surgeons and a specialty surgical society in the Specialty & Service Society section of the American Medical Association. It must be emphasized that these procedures are in no way to be considered as cosmetic surgery.

The American Society for Bariatric Surgery reports surgical treatment is medically necessary because it is the only proven method of achieving long term weight control for the morbidly obese. Surgical treatment is not a cosmetic procedure. Surgical treatment of morbid obesity does not involve the removal of adipose tissue (fat) by suction or excision. Bariatric surgery involves reducing the size of the gastric reservoir, with or without a degree of associated malabsorption. Eating behavior improves dramatically. (1) This reduces caloric intake and ensures that the patient practices behavior modification by eating small amounts slowly, and chews each mouthful well. Success of surgical treatment must begin with realistic goals and progress through the best possible use of well-designed and tested operations. These have been worked out over the last thirty years, and are now standardized, clearly defined procedures, with well-recognized and documented outcome results.

The American Society for Bariatric Surgery re-enforces that prevention of secondary complications of morbid obesity is an important goal of medical management. Therefore, the option of surgical treatment is a rational one supported by the time-honored principle that diseases that harm call for therapeutic intervention that is less harmful than the disease being treated. The biological basis for morbid obesity is unknown, though recent work has demonstrated a genetic component of between 25 and 50%, and several studies confirm the influence of genetically determined proteins produced by the fat cell which have a place in the control of satiety. This confirms that morbid obesity is a disease, not a disorder of willpower, as sometimes implied. The physiologic, biochemical and genetic evidence is overwhelming that clinically morbid obesity is a complex disorder. Contributing causes are inheritance, environmental, cultural, socioeconomic and psychological.

Current medical standards suggest that patients whose BMI exceeds 40 (or 35-39 with life threatening co-morbidities) are potential candidates for surgery if they strongly desire substantial weight loss, because obesity morbidly impairs the quality of their lives. They must clearly and realistically understand how their lives may change after operation.

Some candidates for surgical treatment of morbid obesity have such impaired health that they must be hospitalized pre-operatively and undergo treatment to improve their operative risk. The American Society for Bariatric Surgery reports that weight loss usually reaches a maximum between 18 and 24 months postoperatively. Mean percent excess weight loss at five years ranged from 48 to 74% after gastric bypass and from 50 to 60% after vertical banded gastroplasty. In a study of over 600 patients following gastric bypass, with 96% follow-up, mean percent excess weight loss still exceeds 50% after fourteen years. Another 10-year follow-up series from the University of Virginia reports weight loss of 60% of excess weight at 5 years and in the mid 50's between years 6 and 10. Multiple other authors have reported 5 and 6-year follow-up of their patient series with similar weight loss results.

The American Society for Bariatric Surgery reports weight reduction surgery has been reported to improve several co morbid conditions such as glucose intolerance and frank diabetes mellitus, sleep apnea and obesity associated hypoventilation, hypertension, and serum lipid abnormalities. A recent study showed that Type II diabetics treated medically had a mortality rate three times that of a comparable group who underwent gastric bypass surgery. Also preliminary data indicate improved heart function with decreased ventricular wall thickness and decreased chamber size with sustained weight loss. Other benefits observed in some patients after surgical treatment include improved mobility and stamina. Many patients note a better mood, self-esteem, interpersonal effectiveness, and an enhanced quality of life. They have lessened self-consciousness. They are able to explore social and vocational activities formerly inaccessible to them. Self body image disparagement decreases.

 

1. Rand CS, Macgregor AM, Hankins GC. Eating behavior after gastric bypass surgery for obesity. South Med J 1987; 80(8): 961-4.