• Mayo Clinic Q and A: What is bariatric surgery?

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DEAR MAYO CLINIC: I’ve struggled with obesity for many years and have tried to lose weight through a healthy diet and exercise. My doctor recently told me that I could be a good candidate for bariatric surgery. What is bariatric surgery? And are there different types of procedures available?

ANSWER: Obesity is a disease, and overcoming it often is not easy. The Centers for Disease Control and Prevention defines overweight or obesity as a "weight that is higher than what is considered healthy for a given height." We assess the severity of obesity by body mass index, or BMI, which is the weight divided by the square height. The higher the BMI, the more severe the case of obesity.

Obesity is a complex disease with many predisposing factors and causes. While eating unhealthy food and not doing enough physical activity contribute to obesity, other factors, including psychological, behavioral and genetic causes, play a significant role. Certain medications also can increase one's weight and lead to being overweight.

Since the reasons behind obesity are complex, managing this disease is not simple and requires a multidisciplinary team to treat and cure it. While healthy diet and exercise are encouraged, these often need to be supplemented with other treatments to reduce weight and treat severe obesity. For example, your health care team might incorporate weight loss medication into your treatment plan, which has recently shown significant promise in reducing weight. However, weight gain is fairly common after stopping weight loss medication. Endoscopic therapy is also an option for patients with BMIs that fall in the low-risk or moderate-risk obesity categories. While these options are effective for some patients, weight relapse is a concern, especially if utilized in high-risk patients with obesity.

The most effective therapy for obesity is bariatric surgery, also called weight loss surgery. Bariatric surgery not only leads to significant weight loss, it also provides the most durable method for weight loss. Bariatric surgery can lead to 30% to 40% total body weight loss. Additionally, weight loss often is sustained for many years, and the risk of weight recurrence is lower. Bariatric surgery also can lead to the resolution or treatment of many other obesity-associated diseases. These include high blood pressure, increased cholesterol levels, sleep apnea and diabetes.

Bariatric surgery most often is recommended for patients whose BMI is at least 40 or above 35 if obesity is associated with other diseases, such as hypertension, reflux, diabetes, sleep apnea, joint issues or other medical conditions. Patients whose BMI is 30 to 35 may be eligible for surgery if they present with certain conditions.

The four most common types of bariatric procedures include sleeve gastrectomy; gastric bypass; modified duodenal switch, or SADI-S; and the traditional duodenal switch.

Sleeve gastrectomy involves removing or stapling off about 80% of the stomach and leaving a tube-shaped stomach about the size and shape of a banana. This surgery restricts the amount of food you can eat and also prompts hormonal changes that decrease the hunger sensation.

The second commonly performed surgery is gastric bypass, also called Roux-en-Y gastric bypass. Gastric bypass involves creating a small pouch from the stomach and connecting that pouch directly to the small intestine. The bypass also changes certain hormone levels that help you feel less hungry and induce weight loss.

Modified duodenal switch and biliopancreatic diversion with duodenal switch are recommended for patients with higher BMIs. Both operations are highly effective, especially for patients with diabetes. However, you must strictly follow nutritional recommendations.

At Mayo Clinic, bariatric procedures are performed using minimally invasive techniques, either laparoscopically or robotically. Patients will have only a few half-inch incisions and can walk and drink within hours after surgery. Usually, patients can return home after spending only one night in the hospital. The multidisciplinary team at Mayo Clinic, which includes endocrinologists, dieticians, psychologists and bariatric surgeons, tailors treatment plans to each patient's individual needs and characteristics, and provides support at all stages of the weight loss journey. Dr. Omar Ghanem, Surgery, Mayo Clinic, Rochester, Minnesota