What is Bariatric/Metabolic Surgery?


Bariatric surgery is defined as “surgical procedures performed on the stomach or intestines to induce weight loss”.

Historical perspective

Surgeons first began to recognize the potential for surgical weight loss while performing operations that required the removal of large segments of a patient’s stomach and intestine. After the surgery, doctors noticed that in many cases patients were unable to maintain their pre-surgical weight. With further study, surgeons were able to recommend similar modifications that could be safely used to produce weight loss in morbidly obese patients. Experiments were done in the last half of the 20th century to see if diseases like high blood lipids and cholesterol could be treated with surgical procedures such as intestinal bypass. In 1995, Dr. Walter Pories and his research team published an article titled “Who would have thought it? An operation proves to be the most effective therapy for adult-onset diabetes mellitus”. Since that landmark paper, much evidence has been accumulated showing that bariatric surgery can significantly improve, and even put into remission, several metabolic diseases, particularly adult onset or type 2 diabetes mellitus. The best-known metabolic surgery is the Gastric Bypass with over 50 years of experience with this procedure. Other established procedures are the Vertical Sleeve Gastrectomy and the Biliopancreatic Diversion with or without Duodenal Switch. These procedures have been continually refined in order to improve results and minimize the risks. Today’s bariatric surgeons have access to a substantial body of clinical data to help them determine which surgeries should be used and why.

How does bariatric/metabolic surgery help lose weight and keep it off?

In order for a person with morbid obesity to achieve significant long-term weight loss, the body’s weight regulation system must be reset so that the body will stop storing excess fat. Bariatric/metabolic surgery modifies your set point. By altering the complex relationship your body has with food and its metabolism, bariatric surgery helps reset your body’s ability to effectively manage weight. By altering the anatomy of the stomach and/or intestine, these surgeries affect hormonal signals, resulting in decreased appetite, increased feelings of fullness, increased metabolism, and healthier food preferences. These positive changes allow your body to lose weight without the internal fight to return to the higher set point. Without the hormonal changes and alteration of the “set point” that bariatric surgery provides, many patients with severe obesity are not successful in managing their weight and health conditions by diet alone.

Why “laparoscopic” surgery?

Bariatric surgery that was first started in the 1950’s was performed by open or conventional approach of a cut right down the middle of the belly as shown in the figure below (picture below). This often resulted in a debilitating infection in the cut, which took months to heal. One third of patients developed an incisional hernia, a medical term for a large defect in their abdominal wall, that allowed the intestines to leave the abdomen and emerge just under the skin, creating a very large and visible bulge in the abdomen. This hernia is very difficult to repair, even by the most experienced general surgeons. midline incision Laparoscopic surgery began in the 1990’s and is considered less invasive because it replaces the need for one long incision to open the abdomen. The patient is left with 5 small (less than 1 cm) cuts that heal quickly and minimize pain (picture below). When a laparoscopic operation is performed, a small video camera is inserted into the abdomen. The surgeon views the procedure on a separate video monitor. The camera and surgical instruments are inserted through small incisions made in the abdominal wall. Typically, by one year after surgery the 5 small scars nearly completely disappear and are not visible for most people. Our founding bariatric surgeon Dr. Nicolas Christou, performed the first elective laparoscopic gastric bypass in Canada at the McGill University Health Center in Montreal on February 8th 2002. Our first patient is shown here on the morning after her surgery (left), at 3 years after her surgery (center) and after 10 years (right).