الفهرس 
ANATOMY OF THE STOMACH AND SMALL INTESTINEOnly 14 pages are availabe for public view
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Abstract
O
besity is defined as, a body mass index (BMI) of 30 kg/m2 or more. Morbid obesity is defined as a body mass index (BMI) of > 40 kg/m2 or BMI > 35 kg/m2 together with obesity-related disease.
Obesity is a worldwide epidemic, and is rapidly becoming one of the most serious chronic health problems world-wide. In the developed countries, a large proportion of the population are overweight, with approximately up 30 % of the population are affected by morbid obesity.
Clear understanding of the pathophysiology of morbid obesity is essential for management and prevention of this disease. The exact cause of obesity is unclear. However, there are many factors that contribute to the development of morbid obesity including personal, like age and gender, genetic, environmental, dietary, socioeconomic, behavioral, and drug-induced obesity.
Obesity is a chronic disease that causes serious medical co-morbidities. Such co-morbidities are associated with reduction of life expectancy, and quality of life. These co-morbidities include: cardiovascular dysfunction, hypertension, respiratory system dysfunction, osteoarthritis, diabetes mellitus, gastroesophageal reflux disease, renal dysfunction, neurological disability, and hernia. There is also an increased risk for the development of certain types of cancer associated with overweight. In addition, obesity is associated with an increased risk of mortality at all ages. Therefore, it is considered as one of the leading preventable cause of death worldwide.
Non-surgical approaches to treatment of clinically severe obesity include various combinations of low- or very low-calorie diets, behavioral modification, exercise, and pharmacologic agents. In addition to weight reduction regimens, co-morbid factors such as diabetes mellitus, hypertension and dyslipidemia, can be treated by usual medical methods.
Non-surgical treatment of clinically severe obesity aims to create a caloric deficit sufficient to result in both permanent weight loss and reduction of weight-related risk factors or co-morbidity. These methods have limited success in achieving sustained weight loss. Therefore the National Institutes of Health established guidelines for the surgical therapy of morbid obesity, now referred to as bariatric surgery.
Bariatric surgery is the only effective means of achieving long-term weight loss in the morbidly obese. A burgeoning medical and surgical literature supports its rapid adoption.
Bariatric surgical procedures reduce caloric intake by modifying the anatomy of the gastrointestinal tract. These operations are classified as either restrictive or malabsorptive. Restrictive procedures (e.g. vertical banded gastroplasty, or vertical sleeve gastrectomy) limit intake by creating a small gastric reservoir with a narrow outlet to delay emptying. Malabsorptive procedures (e.g. biliopancreatic diversion with duodenal switch) bypass varying portions of the small intestine where nutrient absorption occurs. Roux-en-Y gastric bypass is often referred to as a combination restriction–malabsorption procedure. Open and laparoscopic techniques, have been described.
The debate about which operation is best will continue for some years and other operations are likely to evolve.
Minimally invasive bariatric surgeries are now among the most commonly performed elective surgeries worldwide. Choice of procedure seems to be driven by local culture, surgeon and patient preference and knowledge of risk versus benefit.
A decision for surgical therapy should be reached only after assessment of the probability that the patient will be able to tolerate surgery without excessive risk and to comply adequately with the postoperative regimen. The operation should be carried out by a surgeon substantially experienced with the appropriate procedures and working in a clinical setting with adequate support for all aspects of perioperative management and assessment to have a reasonable chance of being both safe and successful.
The mortality rate associated with bariatric surgery is about 0.1% to 2.0%. Nonfatal perioperative complications include venous thromboembolism, anastomotic leaks, wound infections, bleeding, incidental splenectomy, incisional and internal hernias, and early small-bowel obstruction occure in both LSG and RYGB but in a different ratio.
Postoperative gastrointestinal complications of surgery are common. Nausea and vomiting occur in more than 50% of patients undergoing restrestrictive procedure LSG. Dumping syndrome, Deficiencies of iron, calcium, folate, vitamin B12, electrolyte imbalance and other nutrients occur after procedures with a component of malabsorption procedure RYGB.