الفهرس 
PathophysiologyOnly 14 pages are availabe for public view
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Abstract
Obesity is considered a major health and socio economic problem. Over weight, obesity and morbid obesity are terms often used to describe individuals with and increased body fat. The most common definition of morbid obesity is a body mass index (BMI) of 40 Kg /m2 or more. More than 250 millions individuals are obese. The aetiology of this condition is multi factors including; familial and genetic predisposition, drug induced obesity, endocrinal causes, childhood over nutrition, intake of food in large quantities and many times in the day, psychological factors, environmental factors, special habits like alcohol consumption and smoking and personal factors like; age, gender, ethinity and parity.
Storage of excess calories as fat must ultimately result from a net positive energy balance (energy intake greater than energy expenditure) over time. Thus, the physiologic determinants of body composition are energy intake, energy output, and partitioning of energy stores as fat, carbohy¬drate, and protein. Many physiologic systems (endo¬crine, gastrointestinal, central nervous, peripheral nervous, and cardiovascular) affect these functions. Small changes in any of these determinants can, over time, result in substantial changes in body weight
Clear understanding of the pathophysiology of morbid obesity is essential for management and prevention of this disaster. There are several factors concerning the occurrence of obesity, the first one in this mechanism is the genetic control also central nervous system control, afferent signals, pattern of feeding, socioeconomic factors, exercise and pattern of distribution of excess adipose tissue, leptin also, have a role in the mechanism of this disease. Leptin is the best known of the afferent fat signals and the best candidate for primary signal communication of body fat information to the central controller.
There are many disastrous diseases associated with morbid obesity including; cardiovascular diseases, diabetes mellitus, respiratory problems, digestive diseases, arthritis, chronic abdominal compartmental syndrome, hernia, infectious problems, pseudotumour cerebri, endocrinal abnormalities, psychological problems, complications associated with pregnancy, cancer, neurological complications and other medical problems compounded by obesity.
The goal of weight-loss therapy is to improve health by modifying obesity-related diseases and the risk for future obesity-related medical complications
Treatment of morbid obesity may be conservative as medical treatment (behavior modification, diet regimen, exercise and drugs) and active physical interventions (as jaw wiring, gastric balloon, acupuncture and waist cord) or it may be surgical as which may be open as gastric by- pass, intestinal bypass and gastroplasty which divided in to Vertical banded gastroplasty, horizontal gasroplasty, gastric banding and gastric wrap or laparoscopic surgery as laparoscopic vertical banded gastroplasty, laparoscopic adjustable gastric banding, laparoscopic gastric bypass, laparoscopic malabsorpative procedure and laparoscopic bariatric pacing.
The key to therapy is to generate a negative energy balance by having the patient eat fewer calories than are expended so that endogenous fat stores will be consumed for fuel. Approximately 75% to 85% of weight that is lost by dieting is composed of fat, and 15% to 25% is fat free mass
Surgical treatment seems to be more effective in the management of morbid obesity with acceptable rate of complications. The surgical modalities used in the bariatric surgery initially used in treating other conditions, and these modalities was found to cause weight loss post- operatively as a side effect.
It is obvious from the number of procedures practiced that the ideal operation for morbid obesity has not been developed. This is because these producers are accompanied by significant morbidly and mortality that varies between 1 and 5 %. The most common and accepted procedure nowadays is gastric banding. This is because of the preservation of the normal anatomy of the upper gastrointestinal tract and the possibility of reverse of this procedure if the postoperative complications cannot be overcomed. The idea of this technique is the usage of a dacron tube or silicon bands to compartmentalize the stomach into small proximal and large distal segments. It is a pure restrictive technique with the ability to reverse it in any time with un avoided complications.
Also now Roux -en-Y gastric bypass (RYGBP) is currently one of the most frequently performed procedures for the surgical treatment of morbid obesity especially for severly morbid obesity, with high success of this procedure in weight loss.
Truncal vagotomv has been shown to reduce overweight by alteration of various mechanisms including gastrointestinal motility, digestion, hunger sensation and peptide release.
Gastric pacing involves the application of an electrical current to the stomach to influence or change gastic emptying. This may involve stimulating the stomach from proximal to distal (antegrade pacing) or from distal to proximal (retrograde pacing).
Laparoscopic bariatric surgery take place in the last few years strongly, due to the greatly diminished post-operative complications. It is indicated in severe obesity especially if it is associated with the severe comorbidities.
Laparoscopic Vertical Gastroplasty is a reduction in volume of the gastric pouch (remaining volume about 20-40cc of average stomach capacity about 2500cc) and a partial hindrance to its emptying.
LASGB is the least invasive surgical treatment of morbid obesity because it respects gastric wall integrity. The laparoscopic approach reduces invasiveness even further.
Laparoscopic sleeve gastrectomy has been gaining considerable popularity since its introduction as a stand-alone operation for the treatment of obesity. This procedure is commonly performed through multiple ports. However, since the advent of natural orifice transluminal endoscopic surgery, interest has been increasing in developing alternative access techniques for laparoscopic surgery that could result in decreased wound-related morbidity, improved pain, and superior cosmesis.
A new bariatric procedure, gastric myo-electrical stimulation, has been developed. The Implantable Gastric Stimulator (IGS) induces satiety while avoiding the morbidity and mortality of the common restrictive malabsorptive or combination restrictive or malabsorptive procedure
Single port laparoscopy has been proposed to as a less invasive alternative that might deliver these benefits. A single central point of access limits the instruments to in-line, parallel movements.
Patients undergoing bariatric surgery are considered to be at high risk for surgical complications regardless of whether their surgery is open or laparoscopic.