|Gastric Bypass - The Digestive Process
To better understand how the gastric bypass weight-loss surgery works, it is helpful to know how the normal digestive process works. As food moves along the digestive tract, special digestive juices and enzymes arrive at the right place at the right time to digest food and absorb calories and nutrients. After we chew and swallow our food, it moves down the esophagus to the stomach, where a strong acid and powerful enzymes continue the digestive process. The stomach can hold about three pints of food at one time. Food is slowly released into the small intestine where absorption of the nutrients, vitamins and minerals takes place. The rate at which foods and fluids are released into the small intestines is controlled by a sphincter on the outlet of the stomach. Empty time can be over several hours.
Bariatric operations currently performed include gastric restriction (vertical banded gastroplasty; laparoscopic adjustable gastric banding), malabsorption (biliopancreatic diversion; biliopancreatic diversion with duodenal switch), or both (Roux-en-Y gastric bypass). Two of the most commonly performed bariatric surgeries are the laparoscopic adjustable gastric banding procedure and the Roux-en-Y gastric bypass.
Roux-en-Y Gastric Bypass Surgery
The most common bariatric surgery procedure performed in the United States, Roux-en-Y gastric bypass (RYGB) combines a restrictive and malabsorptive procedures. A small (15-30 cc) gastric pouch is created to restrict food intake and a Roux-en-Y gastrojejunostomy provides the mild malabsorptive component. Bariatric surgeons can perform the Roux-en-Y gastric bypass procedure using minimally invasive surgical techniques.
The advantages of Roux-en-Y gastric bypass include superior weight loss when compared to vertical banded gastroplasty, with excellent long-term weight reduction and resolution or elimination of co-morbidities (80 percent resolution of Type II diabetes after surgery). Early and late complication rates are reasonably low, and operative mortality ranges from 0.2 percent to 1 percent.
Disadvantages of Roux-en-Y gastric bypass include the potential for anastomotic leaks and strictures, severe dumping syndrome symptoms and procedure-specific complications, including distension of the excluded stomach and internal hernias. Roux-en-Y gastric bypass is technically more challenging to perform than the restrictive procedures, particularly when using the laparoscopic approach. In experienced hands, the conversion rate of laparoscopic Roux-en-Y gastric bypass to open is 5 percent.
Laparoscopic Adjustable Gastric Banding
A restrictive procedure, laparoscopic adjustable gastric banding (LAGB) involves placing a silicone band with an inflatable inner collar around the upper stomach. The band is connected to a port that is placed in the subcutaneous tissue of the abdominal wall. The inner diameter of the band can be adjusted according to weight loss by injecting saline through the port.
Laparoscopic adjustable gastric banding surgery is performed laparoscopically, offering less surgical trauma in the wound and to the viscera, improved postoperative pulmonary function and decreased incidence of wound-related complications such as hematomas, seromas, infections, hernias and dehiscence. LAGB is technically the simplest bariatric surgery to perform and requires less operating time than other procedures. No anastomoses are created, and the morbidity and mortality are low. The procedure is reversible and, if patients fail to lose adequate weight after laparoscopic adjustable gastric banding, it can be converted to a Roux-en-Y gastric bypass.
The disadvantages of laparoscopic adjustable gastric banding include the need for frequent postoperative visits for band adjustments and band slippage or gastric prolapse through the band (5 percent to 10 percent), which requires re-operation. Band erosion into the stomach, gastroesophageal reflux, esophageal dilation and dysmotility also can occur.
Laparoscopic technique helps reduce pain, shorten recovery
Traditional or "open" gastric bypass surgery requires a 6-to 8-inch incision and approximately four weeks of recuperation. Some surgeons can offer gastric bypass surgery patients the laparoscopic approach.
This procedure involves making five to six small openings (approximately ? to 1 inch in size) in the abdomen. These openings allow the bariatric surgeon to pass a light, camera and surgical instruments into the abdomen. The abdomen is inflated with gas (carbon dioxide) to allow the surgeon to get a better view of the stomach and internal structures. Surgical instruments about the width of a pencil are placed into the abdomen to complete the surgery.
In a Roux-en-Y gastric bypass surgery,most of the stomach is "bypassed" and a small portion (about the size of an egg) remains functional. In some cases, the bariatric surgeon may find it necessary to convert from laparoscopic to open surgery. The surgeon bases this decision on various factors, including the patient?s safety and the opportunity to achieve the best possible outcome.
The minimally invasive approach achieves results identical to those associated with open surgery, but with less post-operative pain and swifter recovery. Patients who undergo laparoscopic bypass surgery can return to work after two to four weeks. Laparoscopic surgery also reduces the risk of developing hernias, which are more common after traditional abdominal surgery.
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This information has been provided courtesy of the Cleveland Clinic Bariatric and Metabolic Institute. Please visit the Cleveland Clinic Bariatric and Metabolic Institute.