The American Society of Metabolic and Bariatric Surgery describes two basic approaches that weight loss surgery takes to achieve change:
Restrictive & Malabsorptive Procedure - Gastric Bypass Roux-en-Y
In recent years, better clinical understanding of procedures combining restrictive and malabsorptive approaches has increased the choices of effective weight loss surgery for thousands of patients. By adding malabsorption, food is delayed in mixing with bile and pancreatic juices that aid in the absorption of nutrients. The result is an early sense of fullness, combined with a sense of satisfaction that reduces the desire to eat.
According to the American Society of Metabolic and Bariatric Surgery and the National Institutes of Health, Roux-en-Y gastric bypass is the current gold standard procedure for weight loss surgery. It is one of the most frequently performed weight loss procedures in the United States. In this procedure, stapling creates a small (15 to 20cc) stomach pouch. The remainder of the stomach is not removed, but is completely stapled shut and divided from the stomach pouch. The outlet from this newly formed pouch empties directly into the lower portion of the jejunum, thus bypassing calorie absorption. This is done by dividing the small intestine just beyond the duodenum for the purpose of bringing it up and constructing a connection with the newly formed stomach pouch. The other end is connected into the side of the Roux limb of the intestine creating the "Y" shape that gives the technique its name. The length of either segment of the intestine can be increased to produce lower or higher levels of malabsorption.
or Minimally Invasive Surgery
For the last decade, laparoscopic procedures have been used in a variety of general surgeries. Many people mistakenly believe that these techniques are still "experimental." In fact, laparoscopy has become the predominant technique in some areas of surgery and has been used for weight loss surgery for several years. Although few bariatric surgeons perform laparoscopic weight loss surgeries, more are offering patients this less invasive surgical option whenever possible.
When a laparoscopic operation is performed, a small video camera is inserted into the abdomen. The surgeon views the procedure on a separate video monitor. Most laparoscopic surgeons believe this gives them better visualization and access to key anatomical structures.
The camera and surgical instruments are inserted through small incisions made in the abdominal wall. This approach is considered less invasive because it replaces the need for one long incision to open the abdomen. A recent study shows that patients having had laparoscopic weight loss surgery experience less pain after surgery resulting in easier breathing and lung function and higher overall oxygen levels. Other realized benefits with laparoscopy have been fewer wound complications such as infection or hernia, and patients returning more quickly to pre-surgical levels of activity.
Laparoscopic procedures for weight loss surgery employ the same principles as their "open" counterparts and produce similar excess weight loss. Not all patients are candidates for this approach, just as all bariatric surgeons are not trained in the advanced techniques required to perform this less invasive method. The American Society of Metabolic and Bariatric Surgery recommends that laparoscopic weight loss surgery should only be performed by surgeons who are experienced in both laparoscopic and open bariatric procedures.