disorders of nutrition
Metabolic and Bariatric Surgery
Types of Metabolic and Bariatric Surgery
Metabolic and bariatric surgery is done using one of two methods: Minimally invasive surgery Open abdominal surgery Usually, minimally invasive techniques—laparoscopy or robotic-assisted procedures—are used. In laparoscopic procedures, a tube fitted with a camera (laparoscope) is inserted into a small incision (about 1/2 inch long) near the navel. Four to six other surgical instruments are then inserted into the abdomen through similar small incisions. In robotic-assisted procedures, the surgeon uses robotic arms to hold and manipulate the instruments threaded through the small incisions. Traditional open surgery uses a long incision up and down the middle of the abdomen, and is now performed only in certain cases. Minimally invasive techniques result in less pain and a shorter healing time than open surgery. Metabolic and bariatric surgery may involve Reducing the size of the stomach, sometimes bypassing part of the small intestine (for example, the Roux-en-Y gastric bypass) Endoscopic procedures (such as placement of a balloon in the stomach) Both of these procedures limit the amount of food people can eat. Also, they result in changes in metabolism and hormones that promote weight loss—for example, by making people feel full sooner. The most common procedures done in the United States include the following: Sleeve gastrectomy None Roux-en-Y gastric bypass None Revisional procedures (such as reducing the size of the stomach pouch) Biliopancreatic diversion with duodenal switch (BPD/DS) Single anastomosis duodeno-ileal bypass with sleeve gastrectomy Endoscopic procedures Adjustable gastric banding None Some procedures such as the vertical banded gastroplasty and Adjustable gastric banding are rarely done now. Sleeve gastrectomy is the most commonly used metabolic and bariatric surgical procedure in the United States. It causes substantial and sustained weight loss. Most of the stomach is removed, making the stomach into a narrow tube (sleeve) that resembles a banana. The small intestine is not altered. The resulting sleeve holds less food and thus reduces the number of calories consumed. People also feel less hungry, Sleeve gastrectomy results in certain hormonal changes, which may result in feeling full sooner and which may contribute to weight loss. These changes also improve how the body uses glucose, possibly helping reduce the severity of Diabetes Mellitus (DM) . Serious complications are rare. An infection can occur if the stomach contents leak outside of the sleeve. Gastroesophageal Reflux Disease (GERD) (GERD) may develop or worsen. People who have significant symptoms due to GERD before surgery may be advised against sleeve gastrectomy. Serious bleeding can occur with any surgical procedure. For Roux-en-Y gastric bypass, a small part of the stomach is detached from the rest, creating a small stomach pouch. As a result, the amount of food that can be eaten at one time is drastically reduced. The stomach pouch is connected to a lower part of the small intestine (called the jejunum). Thus, a large part of the stomach and small intestine is bypassed. This arrangement resembles a Y—hence the name. The opening between the pouch and the intestine is made narrow. As a result, food moves slowly out of the pouch into the intestine, and people may feel full for a longer time. Because food bypasses the lower, disconnected part of the stomach and the upper part of the small intestine (duodenum), where much of the digestion and absorption occurs, the amount of food and number of calories absorbed is reduced. The bypassed parts of the stomach and duodenum are then connected lower in the small intestine so that digestive juices (bile acids produced by the liver and pancreatic enzymes) can still mix with food and food can still be digested. Also nutrients, including vitamins and minerals, can still be absorbed, reducing the risk of nutritional deficiencies. Gastric bypass (and sleeve gastrectomy) results in certain hormonal changes. These changes may result in feeling full sooner and may contribute to weight loss. These changes also improve how the body uses glucose (a sugar), possibly helping reduce the severity of Diabetes Mellitus (DM) or causing it to resolve. Most people stay in the hospital overnight or longer. For many people who have had a gastric bypass, eating foods high in fat and refined sugar can cause dumping syndrome. Symptoms of dumping syndrome include indigestion, nausea, diarrhea, abdominal pain, sweating, light-headedness, and weakness. Dumping syndrome occurs when undigested food from the stomach moves into the small intestine too quickly. Similar to Sleeve gastrectomy , complications of gastric bypass can include infection if the stomach contents leak out of the stomach at the new connections and bleeding. Blockage of the intestine is a rare complication that can occur any time after surgery. For this procedure (called Roux-en-Y gastric bypass), part of the stomach is detached from the rest, creating a small pouch. The pouch is connected to a lower part of the small intestine —an arrangement that resembles a Y. As a result, parts of the stomach and small intestine are bypassed. However, digestive juices (bile acids and pancreatic enzymes) can still mix with food, enabling the body to absorb vitamins and minerals and reducing the risk of nutritional deficiencies. Sometimes a second (called revisional) procedure is needed when people have not reached their weight goal or have regained the weight they lost, or because a different complication has occurred. For example, if Gastroesophageal Reflux Disease (GERD) (GERD) develops after sleeve gastrectomy. GERD can be treated by doing a Roux-en-y gastric bypass. Revisional procedures can be more complicated and have a slightly higher risk of complications than the original surgery. However, these procedures are safe and effective when done by experienced bariatric surgeons, The type of revisional procedure depends on the original procedure and the reason for the revision. For example if gastric bypass was done, the stomach pouch may stretch and need to be made smaller. Or, surgeons may shorten the part of the small intestine that is attached to the stomach. These procedures reduce the absorption of calories and nutrients and the amount of food a person can eat. Before a revisional procedure, Endoscopy is usually done. A flexible viewing tube is passed through the mouth and down the throat to examine the upper part of the digestive tract. Biliopancreatic diversion with a duodenal switch accounts for fewer than 5% of bariatric procedures done in the United States. However, the number of procedures done each year is increasing. Biliopancreatic diversion with a duodenal switch is usually done only in people with very severe obesity. This procedure has three main steps: Sleeve gastrectomy None Division of the first portion of the small intestine (the duodenum) Connection between the lower part small intestine (ileum) and the duodenum An additional connection is made between two parts of the ileum to create a Y similar to that done in the Roux-en-Y gastric bypass . First, a sleeve gastrectomy is done to remove most of the stomach. The first part of the small intestine (the duodenum) is then divided just after the end of the stomach. The lower part of the intestine (the ileum) is attached to the duodenum so that food goes through the sleeve from the beginning of the duodenum to the ileum. Then, the second connection is made between two parts of the ileum. Thus, much of the middle part of the small intestine (jejunum) is bypassed. As a result, digestive juices (bile acids and pancreatic enzymes) cannot mix with food where they usually do, and absorption of nutrients and calories is reduced. Weight loss and is substantial, but nutritional deficiencies can result if supplements are not taken. After this procedure, doctors do tests to check for vitamin and mineral deficiencies. Biliopancreatic diversion with a duodenal switch may also help people with Metabolic Syndrome . Biliopancreatic diversion with a duodenal switch can be done as one or two procedures: first, sleeve gastrectomy alone, then biliopancreatic diversion with duodenal switch after initial weight loss. Single anastomosis duodeno-ileal bypass with sleeve gastrectomy is similar to biliopancreatic diversion with a duodenal switch but is slightly simpler and faster, and the risk of nutritional deficiencies is less because the part of the small intestine that absorbs nutrients is longer. The main difference is that single anastomosis duodeno-ileal bypass with sleeve gastrectomy involves only one connection. First, a Sleeve gastrectomy is done to remove a large part of the stomach, and the smaller banana-shaped stomach is formed. Then, the first part of the small intestine (duodenum) is cut just below the stomach. Another cut is made several feet from the lower end of the small intestine (ileum). The cut end of the duodenum attached to the stomach is then connected to the ileum. Because the length of this new segment of small intestine remains relatively long, more nutrients are absorbed. After this procedure, people must still take nutritional supplements and be monitored for deficiencies, although they less likely to occur than after the biliopancreatic diversion with duodenal switch. Weight loss is substantial and maintained, people feel less hungry, and blood sugar is controlled. This procedure may worsen or lead to Gastroesophageal Reflux Disease (GERD) symptoms. Bile reflux can also occur. New endoscopic procedures can help treat people who are not able to have surgery or who prefer not to have surgery. In one procedure, an uninflated balloon is passed down the throat into the stomach and is filled with saline. The balloon reduces the amount of food that the stomach can hold so that people feel full after eating a smaller amount of food. After 6 months, the balloon is removed. People lose weight initially, but over the long term, they may gain the weight back. Another procedure is endoscopic sleeve gastroplasty. A doctor inserts an endoscope through the mouth down the throat into the stomach and threads instruments through the endoscope and into the stomach. The doctor then stitches the stomach from within to make the stomach smaller. Complication rates are low. The most common complications include nausea, gastrointestinal bleeding, leaking of the stomach contents, and infections. Gastroesophageal Reflux Disease (GERD) is less likely to occur after endoscopic sleeve gastroplasty. Also, endoscopic sleeve gastroplasty may be reversible. Results after 5 years suggest weight loss is maintained, However, although some people require revisional procedures. Adjustable gastric banding is now rarely used in the United States. More often, people who have had this procedure have the bands removed and have a Sleeve gastrectomy or For adjustable gastric banding, a band is placed at the upper end of the stomach to divide the stomach into a small upper part and a large lower part. Food passes through the band on its way to the intestine, but the band slows the passage of food. Connected to the band is a piece of tubing with a device that allows access to the band at the other end of the tube (through a port). The port is placed just under the skin so that doctors can adjust the tightness of the band after surgery. Doctors can inject fluid through the port into the band to expand it and make the passageway between the upper and lower stomach smaller. Or they can remove fluid from the band to make the passageway larger if a problem occurs or the band is too restrictive. When the passageway is smaller, the upper part of the stomach fills more quickly, sending a message to the brain that the stomach is full. As a result, people eat smaller meals and lose substantial amounts of weight over time. Over the long term, complications include Gastroesophageal Reflux Disease (GERD) , esophagitis, slipped bands, and deterioration of tissue under the band. For this procedure, an adjustable band is placed around the upper part of the stomach. It enables doctors to adjust the size of the passageway for food through the stomach as needed. After a small incision is made in the abdomen, a viewing tube (laparoscope) is inserted. While looking through the laparoscope, the surgeon places the band around the upper part of the stomach. On the inside of the band is an inflatable ring, which is connected to tubing with a small port at the other end. The port is placed just under the skin. A special needle can be inserted into the port through the skin. The needle is used to insert a salt water (saline) solution into the band or to remove the saline. Thus, the passageway can be made smaller or larger. When the passageway is smaller, the upper part of the stomach fills faster, causing people to feel full more quickly and thus eat less. 