الفهرس 
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Abstract
Obesity is simply defined as ”excessive amount of body fat”; it is considered a great problem in both developed & developing nations.
Obesity is a disease, and as such is in many respects not preventable. The components of this disease likely include a combination of environmental and genetic factors. The recent rapid rise in the incidence of obesity in less than a generation’s time suggests that genetic causes alone cannot be responsible for the disease. Nevertheless, the multifactorial contributions to the disease increase the difficulty in understanding its causes.
The degrees of obesity are defined by body mass index, or BMI (calculated as weight in kilograms divided by height in meters squared), which correlates body weight with height. Patients are classified as overweight, obese, or severely obese (sometimes referred to as morbidly obese)
Significant comorbidities, defined as medical problems associated with or caused by obesity, are numerous.
Diet, physical exercise or medical therapy has not proved to be efficient in treating morbid obesity in the long term.
Surgical therapy is the only effective and proven therapy for patients with severe obesity (body mass index of ≥35 kg/m2). Bariatric operations prolong survival and resolve comorbid medical conditions associated with severe obesity.
Bariatric surgery is also metabolic surgery, treating the varied metabolic consequences of the comorbid diseases arising from severe obesity.
Bariatric operations involve either restriction of caloric intake or malabsorption of nutrients, or both. Long-term follow-up is essential before the merits of an operation can be confirmed.
Malabsorptive operations are highly effective in producing durable weight loss but have considerable nutritional side effects. Patients undergoing such procedures require close follow-up and must take appropriate nutritional supplements.
Malabsorptive bariatric techniques were initially derived from the metabolic outcomes of massive intestinal resection (usually following mesenteric infarction). The first bariatric procedures were the jejuno-ileal bypass and jejuno-colic bypass, techniques which gave good weight loss and improvement/remission of the metabolic conditions accompanying obesity.
Unfortunately, these procedures were associated with severe late nutritional complications that caused them to be abandoned. In an attempt to deal with these nutritional complications, Nicola Scopinaro developed the biliopancreatic diversion with the intention of maintaining malabsorption but avoiding major uncontrolled malabsorption, disruption of the enterohepatic cycle, and the presence of a long blind loop.
One of the features of Scopinaro’s technique was the concept of “the three limbs”: the alimentary limb, biliopancreatic limb and the common channel. Over the years, a number of different groups have demonstrated different results based on the varying length of these limbs.
Hess then pioneered the biliopancreatic diversion with duodenal switch (BPD-DS). This technique offered two advantages over previous operations:
• The performance of a sleeve gastrectomy as a restrictive component, with preservation of the pylorus
• Anastomosis of the alimentary limb to the first part of the transected duodenum and a common channel of 100 cm.
Almost two decades after the description of Hess’ technique, a further modification of the BPD-DS—the single anastomosis duodeo-ileal bypass with sleeve gastrectomy, SADI-S was introduced . SADI-s was designed to simplify the BPD-DS while maintaining the principles of biliopancreatic diversion.
In SADI-S a sleeve gastrectomy over a large bore bougie (54 French) is initially performed and the duodenum is transected 2–4 cm from the pylorus. An ileal loop, 200–250 cm from the cecum, is ascended antecolically and anastomosed to the duodenum in an end-to-side fashion.
Advantages:
1-Excellent metabolic results (Anti-diabetic mechanisms): SADI-S comprises all the possible mechanisms involved in obesity related metabolic comorbidities improvement:
• Moderate gastric restrictions; as the stomach is calibrated with a large bore bougie.
• Moderate reduction in the caloric intake;
• A bypass of the duodeno-pancreas;
• A rapid entrance of undigested chymus into the distal intestine; selective fat malabsorption; while preserving the enterohepatic cycle.
• And in, the short run, maintained weight loss.
In this way it is easily explained why all diabetic patients have completely resolved their condition after the sixth postoperative month and with no need of specific therapy or diet they are able to maintain normal levels of glycosylated hemoglobin. The same arguments explain the improvement of the lipidic profile.
2- SADI-S is a versatile technique, and depending on the preferences of the surgeon or on the patient’s characteristics, it can be performed as a gastric bypass with a narrow gastric tube and a duodeno-jejunal bypass with more than 3 m of common channel, or stay as a malabsorptive operation with a short common limb (200–250 cm) and a wider gastric tube.
3-SADI-s is also proven to be a good option as a second-step operation in those patients who have undergone laparoscopic sleeve gastrectomy (LSG) and have experienced weight regain or unresolved comorbidities.
After a failed sleeve gastrectomy, SADI-s is prefered to gastric bypass as it is believed that the failure of an essentially restrictive procedure requires the addition of a malabsorptive component. Furthermore, it is easier for the surgeon to perform a one loop duodeno-ileal bypass in “virgin territory” than to revise a gastric pouch or gastrojeunal anastomosis in a potentially hostile area.
Advantages over other bariatric operations:
1- Advantages Over Scopinaro’s Procedure:
The sleeve gastrectomy and the pyloric preservation are potential major advantages of duodenal switch over classical biliopancreatic diversions: There is also a potentially decrease incidence of postoperative dumping, as there is a preserved (although reduced) gastric secretion with no defunctioned remanent stomach.
It has also the potential benefit of the preservation of the gastric antrum and the pylorus; in that acid and intrinsic factor secretion would be maintained and so iron, calcium, vitamin B12 and protein absorption would be better than after a classical BPD without jeopardizing weight loss.
The sleeve gastrectomy performed in this procedure results in fundal removal thereby reduces gherelin secretion which increases the metabolic potential of the operation. A possible limitation could be the presence of gastroesophageal reflux disease, but if the gastric tube is wider than the esophagus there should not be an increase in gastric pressure and a problem with esophageal emptying.
Nonetheless Barrett’s esophagus is considered a relative contraindication for the performance of this operation.
2- Advantages Over Duodenal Switch:
As SADI-s is a one-loop duodenal switch, the advantage of the technique is the elimination of one anastomosis.
Although Roux-en-Y diversion was introduced to avoid alkaline reflux.
After a post-pyloric division of the duodenum, there may not be a need to build up a Roux-en-Y reconstruction- indeed we have demonstrated using the Bilitec system that SADI-s does not cause dudenogastric reflux.
The reduction to one anastomosis has three direct advantages:
1-The operation is shortened and consequently less anaethetic derived complications
2-There is a lower risk of anastomotic leak or strictures.
3-and the mesentery is undisturbed which is expected to reduce the incidence of internal hernias.
3 -Advantages Over Gastric Bypass:
In mini gastric bypass, the anastomosis is performed between the intestine and the lesser curvature of the stomach, and this warrants the bathing of marginal ulcers, and reflux gastritis are surely related to this procedure. The preservation of the pylorus and the first 4 cm of the duodenum avoids this problem: pancreatobiliary secretions are the natural environment of the duodenum, so no damage is expected to happen. It is very important to assure that the anastomosis is performed on duodenal mucosa and that the pylorus is not damaged during the procedure.
The weight loss after SADI-s procedure is greater, as the rate of co-morbidity resolution is more pronounced than that seen in published series of gastric bypass surgery.
The reduction to one anastomosis simplifies the procedure, and the sleeve gastrectomy can be considered to be more physiological than the minimal pouch of gastric bypass.
Finally, we need to remember that there is always the right patient for the right surgery. It has not been determined so far how to “fit” the patient to the “right size” operation.
Compliance, however, is responsible many times for the success or bad results of a bariatric procedure.
The patient who does not understand the importance of, or cannot afford, having correct protein intake is prone to develop severe protein malnutrition. A similar situation is created by inadequate replacements of vitamins, minerals, and other nutrients. If a patient is to benefit from weight loss surgery, he or she has to realize that there will be a cost for it.
Tolerance and acceptance for some side effects is very important. The cost and benefit analysis needs to be perfectly understood preoperatively in order to guarantee good or at least acceptable results from a bariatric operation.
Compliance is a prime condition for a patient yet to undergo malabsorptive procedure.
The socioeconomic status and eating habits of the patient do interfere many times with the end results.
All bariatric operations are tools that serve to allow the patient to lose weight, become healthier, and improve quality of life. These changes are maintained long term especially if the patient permanently adopts the new eating patterns and exercise habits that are taught and expected in the early year(s) after surgery.