COMMENTARY

Managing Obesity in Primary Care: When It's Time for Gastric Bypass Surgery

Charles P. Vega, MD; Caroline M. Apovian, MD

Disclosures

February 21, 2017

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Charles P. Vega, MD: Hello. I am Dr Chuck Vega. Welcome to Critical Issues in Obesity. I am a clinical professor of family medicine at the University of California at Irvine. For our three-part series, I am delighted to be joined by Dr Caroline Apovian. She is a professor of medicine and pediatrics at Boston University School of Medicine. She is also the director of nutrition and weight management at Boston Medical Center.

We are going to talk about bariatric surgery. We have had two great discussions on obesity thus far. First we assessed dietary interventions to promote weight loss. We also reviewed the new medications indicated for obesity.

Unfortunately, these interventions fail in many patients, and they remain obese. They may suffer from complications of obesity such as diabetes and cardiovascular disease and may be considered for a more dramatic intervention—bariatric surgery.

The increase in the application of bariatric surgery has been nothing short of remarkable in the past 15 years. In 2013, the American Society for Metabolic and Bariatric Surgery reported that more than 175,000 bariatric procedures were performed in the United States—a 15% increase from 2011. Sleeve gastrectomy, for the first time, emerged as the most common procedure.

The widespread use of bariatric surgery makes sense because it can be highly effective. A review of studies of bariatric surgery with 5 years of follow-up found that risks for type 2 diabetes and hyperlipidemia were reduced by two thirds after bariatric surgery. The risk for hypertension was nearly cut in half. Long-term quality of life generally appears to improve after bariatric surgery.

At the same time, bariatric surgery carries some risks. Approximately 2% of gastric bypass procedures leak, with similar rates regardless of whether patients received a Roux-en-Y or a gastric sleeve procedure. The risk for mortality in the perioperative period is not inconsequential.

From your perspective, as somebody who treats many patients with difficult-to-manage obesity, what patient best fits the profile for bariatric surgery?

Caroline M. Apovian, MD: That is a very good question. We go along with the guidelines.[1] First of all, you look at the body mass index (BMI). If a patient's BMI is over 40 kg/m2, or higher than 35 kg/m2 in a patient with a serious comorbidity, the patient is a candidate for bariatric surgery. The candidate needs to understand what bariatric surgery does and understand that it isn't a panacea. The gut hormonal milieu will change. Patients need to understand that the signals going from the gut to the hypothalamus are going to change. This will increase satiety with smaller amounts of food. There may be an additional factor involved in patients who resolve their type 2 diabetes pretty quickly after surgery. Those mechanisms still have not been elucidated completely. The patient needs to understand them as well.

Beyond that, patients who have struggled all their lives, who have been on diet and medication treatment programs or diet and lifestyle programs and have been able to lose weight but failed to maintain it, those are all good candidates for bariatric surgery. The main focus is still the BMI and comorbidities. The patient with early-onset diabetes or who has had diabetes for 7 or fewer years and has a BMI >35 kg/m2 is the perfect candidate.

Dr Vega: These patients have not suffered the complications associated with diabetes yet; peripheral neuropathy, nephropathy, and retinopathy have yet to set in. It can make a difference in terms of morbidity and mortality for them in the long run.

Dr Apovian: It is about the prediction of resolution. You want the best chance for the diabetes to be resolved. Patients who have had very severe diabetes or diabetes for longer than 7 years, for example, do not remit as often as those who had less severe diabetes for a shorter duration. Relapse often occurs after about 5 years. If you choose the patient wisely, you have at least the possibility of resolution for at least 5 years after surgery.

The Rebound Effect

Dr Vega: What are some of the factors that result in that rebound effect, in which patients gain weight again after 5 years? What have you seen in your clinical practice?

Dr Apovian: Most people do gain weight after surgery. A gain of less than 10% of their original weight loss is typical, and that outcome is still considered successful surgery. The body's set point changes because the gut hormones change, with reduced hunger hormones going to the brain. Satiety hormones are secreted earlier, and levels of these hormones are higher. The body is settling into a lower body set point. The environment has not changed. If you do not change the environment, eventually the original signals that cause us to eat more and exercise less in this environment are still there. You are basically changing your body, but you have not changed the environment. Obesity is an epigenetic phenomenon.

Eventually patients will regain some weight. If they gain a significant amount of weight, then it is important to intensify the lifestyle changes and maybe add a medication or two and not wait too long. Usually patients will hit the nadir of their weight loss at 12-18 months. After that, they start to regain some weight. It is part of any good program to reinstitute lifestyle changes after that time period.

Dr Vega: Is there a particular type of bariatric surgery that you prefer, or do you just leave it up to the patient?

Dr Apovian: We tell the patient which procedure we recommend. Typically, we try to steer patients with diabetes towards the Roux-en-Y gastric bypass because it has the best results in terms of resolution of diabetes. Patients who have a lot of reflux might want to stay away from the sleeve gastrectomy, which produces reflux.

Many patients are interested in the sleeve gastrectomy because they perceive it to be a less aggressive procedure. Surgeons find it easier. It has become the most common procedure in the United States, whereas before, the Roux-en-Y gastric bypass was most common.

Dr Vega: Laparoscopic banding was also very popular.

Dr Apovian: It was popular. It was considered to be a reversible procedure. However, results have not shown maintenance of sufficient weight loss for many surgeons and patients. Unfortunately, it has fallen out of favor. It is still a good procedure for a certain type of patient—not the patient who wants to lose 100 pounds because that would be hard to do with the lap band, which does not change the anatomy at all. It is a device that is placed around the stomach. You get satiety because you are creating a smaller pouch, so that not a lot of food can get through. You get satiety, but the procedure does not change the gut hormones in the way that they are changed after the Roux-en-Y bypass and even after the sleeve gastrectomy.

Quality of Life: Better or Not?

Dr Vega: You mentioned a great concept. You are changing the body set points. This is something that patients are not used to. There is no way they could have become accustomed to this because it is something new and different for them, in terms of feelings of satiety and some of the hormonal changes, particularly in the first 6-month period. Some of my patients struggle with that overall. Maybe it is the gastrointestinal side effects or the cultural issues, the social issues around food consumption.

I'm not sure that all of my patients would agree that the surgery has improved their quality of life, even if it has cured their diabetes or significantly improved their hypertension. What has been your clinical experience in terms of how patients feel about the surgery afterwards? I wonder particularly about gastric reduction procedures, a more permanent solution.

Dr Apovian: That is the reason why most centers of excellence have a preoperative program that lasts at least 5-6 months to prepare the patient for the drastic lifestyle change that they will undergo after having surgery. You are creating a small pouch and a bypass of the duodenum and jejunum, so you simply cannot eat the way you used to ever again. You cannot have certain high-sugar foods and regular soda anymore because of dumping syndrome. This is a screening process.

When patients do not seem to want to or are unable to change their habits, we generally do not recommend that they go through the procedure. That is why we have a very intensive preoperative program. Without that program, patients undergoing surgery are not expecting to have dumping syndrome or to feel sick after they eat or to have a lot of gastrointestinal upset, nausea, and vomiting. They will develop nutritional deficiencies that are emergencies and can become permanent if not picked up as soon as possible. The most notable is thiamine deficiency, which causes Wernicke-Korsakoff encephalopathy and can lead to permanent nerve damage.

We have seen several cases like this. The patients have a lot of nausea and vomiting after the procedure and either do not follow up, or the care team doesn't pick up on the classic signs and symptoms. The procedure has risks and benefits. It is similar to having a coronary artery bypass graft (CABG). You don't expect the patient to go out and run a marathon 2 weeks after they have surgery. You still have a lifestyle change that you have to get over. Patients who do well after a CABG, for example, undergo cardiac rehabilitation. The same is true of a gastric bypass. It is not a quick fix or a panacea. It's a major lifestyle change.

Dr Vega: You are right. The benefit is that with gastric bypass, you can preload all of the information, and patients can make a very informed choice about it. As they find out more, they might find out that it is not for them. Therefore, they want to think about other treatments, and they go back to lifestyle change and medications. That is perfectly reasonable.

It is interesting to be having this conversation with you in January, when a lot of people make resolutions. One resolution might be to have a gastric bypass procedure and finally lose all of the weight. They may have made a resolution to lose weight 5 years in a row, but now they are going to do it through surgery.

They sign up for a program, which schedules them for surgery in February. That is completely inappropriate. They need time to get educated and prepare. Just as important as the surgeon, the center, and the procedure itself is the follow-up in terms of monitoring for safety and tolerability. It is absolutely critical. It starts with a good relationship with their treating physician and with the practice so that they can get the education that they need. A center of excellence should take that role very seriously in prepping their patients for bariatric surgery.

Hopefully our audience feels fully prepared to take on the disease of obesity. Caroline, your insights were absolutely invaluable. Thank you so much. I look forward to talking to you again sometime.

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