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NewYork-Presbyterian/Weill Cornell Medical Center - Center for Advanced Digestive Care

Gastrointestinal Metabolic Surgery for Obesity

Weight loss and metabolic surgery programs at the Center for Advanced Digestive Care at NewYork-Presbyterian/Weill Cornell Medical Center represent a new perspective in the treatment of severe obesity as a digestive disease. Our innovative program is based on science, recognizing that the gastrointestinal tract and the small bowel in particular, play a critical role in the regulation of blood sugar levels, insulin action and production as well as in the control of appetite and body weight.

Our comprehensive weight loss programs offer medical obesity screening, counseling, surgery and extensive follow-up.

Our multidisciplinary program provides long-term solutions for people who continually struggle with their weight and the associated metabolic conditions such as high blood pressure, high cholesterol, sleep apnea among others. We have a unique center where patients see a full range of specialists who work together as a team to evaluate their condition, provide counseling, determine the underlying metabolic cause of their weight, and develop an individual treatment plan. By tailoring procedures to the metabolic characteristics of each patient, surgery results in much more than loss of body weight - it also improves life expectancy and quality of life of severely obese patients.

The American College of Surgeons has accredited NewYork-Presbyterian Hospital as a Center of Excellence in bariatric surgery with the highest possible designation - one of only seven centers nationwide.

For more information on weight-loss surgery, including risks, and obesity treatment, visit our Health Library.

Procedures

Bariatric (weight-loss) surgery is performed because it is currently the best treatment option for producing lasting weight loss in obese patients for whom non-surgical methods of weight loss have failed.

Physicians at the Center for Advanced Digestive Care are leading international experts in bariatric surgery and have pioneered the modern concept of metabolic surgery. Their clinical and preclinical research has advanced the understanding of the mechanisms of action of surgical procedures and the recognition that certain operations can control appetite and body weight by influencing their hormonal regulation and not solely due to mechanical restriction of food intake and absorption as originally believed. Based on this new understanding, a multidisciplinary team of surgeons, physicians, and allied health care professionals at NewYork-Presbyterian/Weill Cornell Medical Center are working together to select the procedure that best suits a patient's need from a range of minimally invasive laparoscopic bariatric operations

Roux-en-Y Gastric Bypass (RYGB)

Gastric bypass is the most common and successful weight loss surgery in the US, with acceptable risks and side effects. Although originally considered a restrictive procedure that reduced food intake and body weight primarily due to the creation of a tiny stomach pouch, it has recently become clear that gastric bypass actually improves the hormonal regulation of appetite, energy expenditure and the action and production of insulin. These metabolic effects are responsible for the dramatic improvement of obesity, diabetes, and lipid metabolism.

Technically, the RYGB involves the use of a surgical stapler to create a small, vertically-oriented gastric pouch usually less than 30 cc in size. The gastric pouch, which is completely divided from the gastric remnant, is connected to the upper small bowel (jejunum). Bowel continuity is restored by a newly formed connection between the excluded small bowel limb (duodenum-jejunum, that carries bile and pancreatic juices) and the alimentary limb that receives the nutrients from the gastric pouch. After RYGB, ingested food bypasses approximately 90% of the stomach (the entire duodenum and a portion of the jejunum) but bile and ingested food mix in the mid portion of the small bowel so that nutrients can be absorbed through the remaining portion of the intestine.

Biliopancreatic Diversion (BPD)

Like gastric bypass, the BPD re-routes the passage of nutrients and bile throughout the intestine and reduces the size of the stomach available as a reservoir for nutrients. However, there are important technical differences that have implication for its mechanisms of action, efficacy and potential side effects. After a BPD, the stomach size is usually larger than with gastric bypass. However, unlike in gastric bypass where the excluded stomach is left in place, the BPD involves a removal of a variable volume of the organ. Further, the bypass of the small intestine is much longer than in a standard RYGB, leaving only a short segment of small bowel exposed to the mix of nutrients and bile. This significantly reduces absortion of nutrients and contributes to the profound weight loss effect of the procedure. On the other hand, it is associated with a greater risk of nutritional side effects. At our Center, the procedure is performed in its technical variant called BPD-Duodenal Switch (see below), to reduce some of the potential side effect of the classic BPD.

Duodenal Switch (or BPD-DS)

This surgical procedure is a variation of the BPD. More of the stomach is retained, including the valve that controls the release of food into the small intestine. A longer segment of small bowel is exposed to nutrients, thereby minimizing the postoperative nutritional side effects of BPD.

Technique: A large part of the stomach is removed along its greater curvature, leaving behind a vertically-oriented, sleeve-shaped pouch (for this reason this technical step is called "sleeve gastrectomy"). The small part of stomach that is left is connected directly to the last part of the small intestine (ileum), leaving only a short segment (100cm) of the small intestine exposed to the mix of digestive juices (bile or pancreatic enzymes). As a consequence, nutrients are not as easily absorbed. It should be noted that, when compared to the RYGB, the BPD-DS can cause more significant malabsorption of nutrients. This may be useful in a very severely obese person ("super obesity"); however, it does expose the person to a greater risk of postoperative nutritional side effects.

Sleeve Gastrectomy

Sleeve gastrectomy is a component of the BPD-DS operation described above but can be performed as a stand alone operation as well. This is done either as the first step of a two-staged BPD-DS (see below "Multistep operations") or as a primary bariatric procedure. The latter option has recently become increasingly popular as studies suggest that the sleeve gastrectomy is capable of inducing sufficient weight loss and metabolic control at least in the short-mid term.

In addition to reducing the capacity of the stomach, this procedure eliminates the ghrelin-rich gastric fundus (ghrelin is a hormone that is linked with increasing hunger), which may play a role in the mechanism of action of the procedure. Sleeve gastrectomy has also been shown to improve diabetes in severely obese patients. The long-term efficacy of the procedure continues to be investigated through clinical research.

Laparoscopic Adjustable Gastric Banding (LAGB)

This procedure is conceptually and technically easier than other procedures, because neither the stomach nor intestines is cut. Surgeons place an adjustable band-like saline tube around the upper part of the stomach to create a small pouch above the band. Typically, the resulting weight loss and metabolic effects that occur after this procedure are, on average, less dramatic than when compared to other options. Appropriately selected patients can witness satisfactory results making gastric banding a valuable option in such cases due to the limited operative risk and nutritional abnormalities.

Technique: The LAGB involves encircling the upper part of the stomach with a band-like, saline-filled tube. The band is wrapped around the superior portion of the stomach, just distal to the gastroesophageal junction. The amount of restriction may be adjusted by injecting or withdrawing saline solution from the hollow core of the band through a subcutaneous port similar to that used for long-term venous access in chemotherapy patients.

Multi-Step Operations (Laparoscopic Staged Procedures)

A two-stage approach, utilizing a laparoscopic procedure, may be performed on morbidly obese people who are also diagnosed with other medical illnesses that increase their risk of developing complications both during and after an operation. This approach is usually performed for BPD-Duodenal Switch (see above) but may also be done for gastric bypass (RYGB). Both stages are performed laparoscopically; in the first stage, either a sleeve gastrectomy or a small bowel bypass is performed. After an appropriate period of recovery, this is then followed by the second stage, where the remaining steps of the operation are performed to complete the intended procedure. Conducting two-stage procedures represents a valuable and relatively simple solution to help reduce the risk of surgery in appropriate candidates.

Revisional Procedures

Surgeons at the Center for Advanced Digestive Care are well-known for performing revisional procedures to correct failed bariatric surgery. Revisional surgery may be an option for patients who have already undergone a procedure and need another one to either repair the first one or for those who have gained weight or have not lost sufficient weight.

Many times, patients need a revisional surgery to convert an older weight loss procedure to a more modern, effective one such as the Roux-en-Y gastric bypass or a duodenal switch.

Clinical Trials

NewYork-Presbyterian is a leading international center for clinical investigation of the treatment of obesity and diabetes. Several clinical trials are currently underway.