Diagram of a biliopancreatic diversion.Bariatric procedures can be grouped in three main categories: blocking, restricting, and mixed, the latter understood to work by altering gut hormone levels responsible for hunger and satiety. A retrospective observational cohort study between 2005 to 2015 explored bariatric procedures for comparative effectiveness, and found that different procedures may help patients lose more weight, while others have increased chances of adverse events. Standard of care in the United States and most of the industrialized world in 2009 is for laparoscopic as opposed to open procedures. Future trends are attempting to achieve similar or better results via endoscopic procedures. Blocking procedures Some procedures block absorption of food, although they also reduce stomach size. Biliopancreatic diversion This operation is termed biliopancreatic diversion (BPD) or the Scopinaro procedure. The original form of this procedure is now rarely performed because of problems with it. It has been replaced with a modification known as duodenal switch (BPD/DS). Part of the stomach is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum. In around 2% of patients there is severe malabsorption and nutritional deficiency that requires restoration of the normal absorption. The malabsorptive effect of BPD is so potent that, as in most restrictive procedures, those who undergo the procedure must take vitamin and dietary minerals above and beyond that of the normal population. Without these supplements, there is risk of serious deficiency diseases such as anemia and osteoporosis. Because gallstones are a common complication of the rapid weight loss following any type of<unk> , some surgeons remove the gallbladder as a preventive measure during BPD. Others prefer to prescribe medications to reduce the risk of post-operative gallstones. Diagram of a vertical banded gastroplasty. Far fewer surgeons perform BPD compared to other weight loss<unk> es, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients. Jejunoileal bypass This procedure is no longer performed. It was a surgical weight-loss procedure performed for the relief of morbid obesity from the 1950s through the 1970s in which all but 30 cm (12 in) to 45 cm (18 in) of the small bowel was detached and set to the side. Endoluminal sleeve This is a flexible tube inserted, through the mouth and stomach, into the upper small intestine. The purpose is to block absorption of certain foods/calories. It does not involve actual cutting and so is designed to lower risks from infection etc. however the results were not conclusive and the device had issues with migration and slipping. A study recently done in the Netherlands found a decrease of 5.5 BMI points in 3 months with an endoluminal sleeve Restrictive procedures Procedures that are restrictive shrink the size of the stomach or take up space inside the stomach, making people feel more full when they eat less. Diagram of an adjustable gastric banding. Vertical banded gastroplasty In the vertical banded gastroplasty, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach. Adjustable gastric band The restriction of the stomach also can be created using a silicone band, which can be adjusted by addition or removal of saline through a port placed just under the skin. This operation can be performed laparoscopically, and is commonly referred to as a "lap band". Weight loss is predominantly due to the restriction of nutrient intake that is created by the small gastric pouch and the narrow outlet. It is considered somewhat of a safe surgical procedure, with a mortality rate of 0.05%. Sleeve gastrectomy Sleeve Gastrectomy. Sleeve gastrectomy, or gastric sleeve, is a surgical weight-loss procedure in which the stomach is reduced to about 15% of its original size, by the surgical removal of a large portion of the stomach, following the major curve. The open edges are then attached together (typically with surgical staples, sutures, or both) to leave the stomach shaped more like a tube, or a sleeve, with a banana shape. The procedure permanently reduces the size of the stomach. The procedure is performed laparoscopically and is not reversible. It has been found to be comparable in effectiveness to Roux-en-Y gastric bypass. Intragastric balloon Intragastric balloon involves placing a deflated balloon into the stomach, and then filling it to decrease the amount of gastric space. The balloon can be left in the stomach for a maximum of 6 months and results in an average weight loss of 5–9 BMI over half a year. The intragastric balloon is approved in Australia, Canada, Mexico, India, United States (received FDA approval in 2015) and several European and South American countries. The intragastric balloon may be used prior to another<unk>  in order to assist the patient to reach a weight which is suitable for<unk> , further it can also be used on several occasions if necessary. There are three cost categories for the intragastric balloon: pre-operative (e.g. professional fees, lab work and testing), the procedure itself (e.g. surgeon, surgical assistant, anesthesia and hospital fees) and post-operative (e.g. follow-up physician office visits, vitamins and supplements). Quoted costs for the intragastric balloon are surgeon-specific and vary by region. Average quoted costs by region are as follows (provided in United States Dollars for comparison): Australia: US$4,178; Canada: US$8,250; Mexico: US$5,800; United Kingdom: US$6,195; United States: US$8,150). Stomach folding Basically, the procedure can best be understood as a version of the more popular gastric sleeve or gastrectomy<unk>  where a sleeve is created by suturing rather than removing stomach tissue thus preserving its natural nutrient absorption capabilities. Gastric plication significantly reduces the volume of the patient's stomach, so smaller amounts of food provide a feeling of satiety. The procedure is producing some significant results that were published in a recent study in Bariatric Times and are based on post-operative outcomes for 66 patients (44 female) who had the gastric sleeve plication procedure between January 2007 and March 2010. Mean patient age was 34, with a mean BMI of 35. Follow-up visits for the assessment of safety and weight loss were scheduled at regular intervals in the postoperative period. No major complications were reported among the 66 patients. Weight loss outcomes are comparable to gastric bypass. The study describes gastric sleeve plication (also referred to as gastric imbrication or laparoscopic greater curvature plication) as a restrictive technique that eliminates the complications associated with adjustable gastric banding and vertical sleeve gastrectomy—it does this by creating restriction without the use of implants and without gastric resection (cutting) and staples. Mixed procedures Mixed procedures apply block and restrict at the same time. Roux-en-Y gastric bypass. Gastric bypass<unk>  A common form of gastric bypass<unk>  is the Roux-en-Y gastric bypass, designed to alter the gut hormones that control hunger and satiety. While the complete hormonal mechanisms are still being understood, it is now widely accepted that this is a hormonal procedure in addition to restriction and malabsorption properties. Gastric bypass is a permanent procedure that helps patients reset hunger and satiety and by altering stomach and small intestine handle the food that is eaten to achieve and maintain weight loss goals. After the<unk> , the stomach will be smaller and there will be an increase in baseline satiety hormones, to help the patient will feel full with less food. The gastric bypass had been the most commonly performed operation for weight loss in the United States, and approximately 140,000 gastric bypass procedures were performed in 2005. Its market share has decreased since then and by 2011, the frequency of gastric bypass was thought to be less than 50% of the weight loss<unk>  market. A factor in the success of any<unk>  is strict post-surgical adherence to a healthy pattern of eating. There are certain patients who cannot tolerate the malabsorption and dumping syndrome associated with gastric bypass. In such patients, although earlier considered to be an irreversible procedure, there are instances where gastric bypass procedure can be partially reversed. Diagram of a sleeve gastrectomy with duodenal switch. Sleeve gastrectomy with duodenal switch A variation of the biliopancreatic diversion includes a duodenal switch. The part of the stomach along its greater curve is resected. The stomach is "tubulized" with a residual volume of about 150 ml. This volume reduction provides the food intake restriction component of this operation. This type of gastric resection is anatomically and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine. The duodenum and the upper part of the small intestine are reattached to the rest at about 75–100 cm from the colon.. Like the Roux en Y Bypass, it is now understood that its results are largely due to a significant alteration in gut hormones that control hunger and satiety, in addition to its restriction and malabsorption properties.
Bariatric surgery
Gastric bypass surgery
Bariatrics
Endoscopic sleeve gastroplasty
Rosedale diet
Low-carbohydrate diet
Specific carbohydrate diet
Scarsdale diet