Restrictive Bariatric Procedures: Gastric Sleeve and Gastric Banding / Lap-Band Surgery
Restrictive procedures limit the stomach’s volume with a gastric band or gastric sleeve. With gastric banding, an inflatable silicone device is placed around the upper part of the stomach to create a small pouch. The new pouch holds ½ cup of food as opposed to 6 cups of food in a normal stomach. This laparoscopic approach requires a small incision in the abdominal wall to create a small tunnel behind the stomach for inserting, and locking in, a band. The gastric band, or lap-band, restricts food intake, reduces appetite, and slows digestion. Patients feel fuller faster and learn to eat smaller portions. Gastric banding is the least invasive procedure. Since no part of the stomach is removed and the intestines are not re- routed, patients continue to absorb foods normally after implementation. With gastric sleeving, more than half of the stomach is removed leaving a tube or banana-like shape. Surgical staples are used to close the new stomach. This irreversible surgery requires that patients make major lifelong changes to their diet habits including eating only smaller portions and healthy, vitamin-rich foods.
Malabsorptive Bariatric Procedures: Biliopancreatic Diversion / Duodenal Switch
Malabsorptive procedures change how food nutrients are absorbed during digestion. One type of malabsorptive surgery is biliopancreatic diversion with duodenal switch where approximately 70% of the stomach is removed along the greater curvature. A lengthy part of the small intestine is then rerouted, creating two separate paths that lead to one common channel. The shorter path takes food from the stomach to the common channel. The longer path takes bile from the liver to the common channel. In the common channel, the food contents mix with the bile before heading into the large intestine. This reduces the amount of time calories and fat are able to be captured and absorbed in the small intestine.
Mixed Bariatric Procedures: Gastric Bypass Surgery
Gastric bypass surgery combines malabsortive and restrictive techniques simultaneously. This type of surgery makes the stomach smaller and causes food to bypass part of the small intestine. In normal digestion, food passes through the stomach, enters the small intestine where nutrients are absorbed, before passing into the large intestine. In Roux-en-Y gastric bypass, a small stomach pouch is created in the upper portion of the stomach and is connected directly to the middle portion of the small intestine, bypassing the larger portion of the stomach and the first portion of the small intestine. This surgery reduces the amount of foods patients are able to eat and causes them to feel full more quickly. Total food intake and nutrient absorbance are dramatically reduced. Patients must follow doctors’ orders for what, when, and how often to eat. Calcium, iron, protein, and multi-vitamin supplements also become very important to maintain adequate nutrition.