الفهرس 
Anatomy of the StomachOnly 14 pages are availabe for public view
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Abstract
Obesity is a major public health challenge; it is widespread, highly prevalent and has clinical implications with potential negative effects on almost every organ system, as well as being a psychosocial and economic burden.
Bariatric surgery remains the most effective and durable treatment option for obese patients. Available procedures include laparoscopic and open Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy, adjustable gastric band, vertical banded gastroplasty, duodenal switch, and biliopancreatic diversion. Despite its proven efficacy, it is estimated that less than 1% of obese subjects who qualify for bariatric surgery will undergo this intervention. The explanation for this is likely multifactorial, including high surgical costs, patient preference, access to care, and the morbidity and mortality associated with surgical interventions. Although mortality rates associated with bariatric surgery have decreased significantly and are now comparable to those of cholecystectomy or appendectomy in bariatric centers with high surgical volumes, early and late rates of adverse events associated with bariatric surgery remain problematically high at 17%.
Roux-en-Y gastric bypass (RYGB) is a recognized treatment for patients with class III obesity, especially in the presence of type 2 diabetes. The popularity of this surgical intervention relates to the extent and consistency of weight loss achieved and to its beneficial effects on co- morbid conditions.
Resolution of hyperglycemia after bariatric surgery occurs within days of the surgery, pointing to immediate, weight loss–independent mechanisms possibly related to surgery-induced changes in food intake (caloric restriction), gastrointestinal (GI) anatomy, or transit of nutrients. The predominant hypotheses on the physiological background for the metabolic advantages (specifically, the glucose-lowering effects) after bariatric surgery include changed release of GI hormones (increased secretion of hormones with antidiabetes properties and reduced secretion of “diabetogenic” hormones) and surgery-induced restriction of food intake.
Bariatric surgery not only causes weight loss, it also leads to normalization of blood sugars in over 80% of his diabetic patients. Initially, the normalization of blood sugars was thought to be directly caused by the weight loss. However, it has subsequently been noted that blood glucose control improves immediately following the surgery, prior to any significant weight loss. Most remarkably, many obese diabetic patients who undergo bariatric surgeries are relieved of their anti-diabetic medications in a matter of days.
The observed remission of type 2 diabetes before any significant weight loss has taken place suggests that the operation itself, including rerouting of ingested food (bypassing significant parts of the small intestine) and digestive fluids, changes handling of nutrients. In support of this theory, the purely restrictive procedure of gastric banding, which gives rise to long-term metabolic advantages associated with weight loss , has no acute effect on postprandial glucose metabolism (or gut hormones) .