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Melanie Cole (Host):  For many people, severe obesity is a matter of life and death. Many people who are seriously overweight have tried different diets, medications and professional weightloss services for years without long-term success. Today, Dr. Richard Stahl, Associate Professor and General and Bariatric Surgeon at UAB Medicine joins the show to compare and contrast the two most common types of bariatric surgery; gastric bypass and sleeve gastrectomy. Dr. Stahl, I’m so glad to have you joining us again today. Let’s set the stage a little bit for providers. What is defined as obese and what other comorbid conditions can come along with obesity that would require that discussion of bariatric surgery?

Richard Stahl, MD (Guest):  Morbid obesity is defined as a body mass index of 40 or above. Body mass index is basically a weight to height ratio, and we can also call this class 3 obesity. We would recommend bariatric surgery for people at that category, class 3 obesity or body mass index 40 or above. We’d also recommend it for patients with the body mass index of 35 to 39.9 if they had other comorbidities associated with their obesity. One of the most common ones being diabetes but there can be others also.

It’s a little bit less clear about patients with class 1 obesity which is defined as a body mass index between 30 and 34.9, though patients in that weight class that have diabetes that has been difficult to control medically; those are also patients that bariatric surgery should be considered in.

Host:  So, then let’s compare and contrast. Discuss for us the two types and for other providers, help them understand why you choose the one you do for a patient. What goes into that discussion?

Dr. Stahl:  The two main operations that are being done today are the Roux-en-Y gastric bypass or the sleeve gastrectomy. That’s not to say that there aren’t others. There are a few other operations out there but the vast majority of patients undergoing bariatric surgery are having one of these two. The gastric bypass we think of as the gold standard. It has been around the longest. We have the longest follow up with that. And the gastric bypass is basically an operation where the stomach is divided into two separate pieces with the upper part being very small, roughly one to two tablespoons in size or about the size of an egg say. And then the intestine is brought up and anastomosed to that in a looks like the letter Y fashion hence the name Roux-en-Y gastric bypass. And that makes it so the patients have less of an appetite, eat less and the food that they do eat bypasses the remainder of the stomach and the first part of the small intestine.

The other operation is the sleeve gastrectomy. The sleeve gastrectomy does not reroute any of the GI tract. Food still follows the normal route and touches all the surfaces of the GI tract. But what we have done with this operation is reduce the size of the stomach by approximately 80%. If conceptually we are making the stomach more of a narrow tube and we are preserving the very bottom part of the stomach called the antrum, but otherwise removing most of the body of the stomach. And this has become an even more popular operation in recent years and is currently done more commonly than the gastric bypass.

I will stress just because something is more common doesn’t necessarily mean it’s better. It has become more popular for a number of reasons and it is a good operation. But I don’t want to impart the suggestion that this is clearly a better operation. It’s a different operation and there are some pros and cons to each of those which I can touch on if you would like.

Host:  Well I would like you to, the pros and cons because when you are thinking about patient selection and which patients would benefit the most from either one of these; tell us why. Tell us those pros and cons and if you have some predictors of treatment response Dr. Stahl.

Dr. Stahl:  First of all, when patients come to see us; we discuss both of the operations with them and make sure they have a full understanding of the various procedures that are available. For the vast majority of patients, I’d say probably 80% of patients, we ultimately ask them to choose between the two operations once we have presented the information that we know about each of them. So, most patients actually end up making up their own mind about which ones they want to do. However, some of the things that we will point out to them, differences between the operations.

We think that the weightloss results with the gastric bypass seem to be marginally better than what they are with sleeve gastrectomy. That’s not in all studies and not 100% of the time. But in many studies, and in our own review of our data, we see a little bit better weightloss results with the bypass versus the sleeve. On the other hand, if you look at complication rates; the complication rate with a bypass is a little bit higher than what it is with the sleeve. Again, not a huge difference but there is some difference.

A bypass operation is a technically more difficult operation to do. It takes longer to do. It takes about twice as long to do the operation. And therefore, because it’s more technically challenging; it does have a somewhat higher rate of complications. So, in that sense, you would say well the sleeve gastrectomy is a little bit easier, it takes less time to do and has a little bit lower complication rate. But the trade off might be well the sleeve gastrectomy may have marginally less weightloss than the gastric bypass.

Other differences; the gastric bypass may yield some vitamin and micronutrient deficiencies. Again, these are usually not particularly severe and usually typically prevented with vitamins and such that we have the patients take. Which we also have them take for sleeve gastrectomy though the incidence of vitamin and micronutrient deficiencies for it is less. So, again, that’s another trade off between the two operations.

If we look at patients with diabetes. In the case a patient comes to us that has diabetes and that’s what they are really most interested in improving. Well, the data suggests that diabetes improvement occurs with both of these operations but there seems to be more improvement with the gastric bypass if you compare it with the sleeve gastrectomy. So, that might be a decision point for patients.

Patients that either because of their size, shape or perhaps previous surgery, we might decide it’s very difficult for us to do a gastric bypass on them because with the gastric bypass, you have to have access to and be able to mobilize quite a bit of the intestine. If they have had a number of previous operations, and therefore we would expect to see adhesions and scar tissue; then we might lean towards a sleeve gastrectomy on that patient because in a sleeve gastrectomy, we really only have to work on the stomach and not have to deal with the small intestine which might have a lot of adhesions with it. so, that might be a deciding factor for us.

On the other hand, let’s say a patient comes to see us and has really severe reflux. Now reflux is very common in the morbidly obese population. It’s usually fairly well controlled with medications so people that have just mild or well-controlled reflux we wouldn’t necessarily change their operation. But let’s say somebody comes to us who has severe reflux and their main goal with surgery is they would really like to be relieved of their reflux. Well sleeve gastrectomy may not bet the best choice for that patient because sleeve gastrectomy can sometimes yield reflux. So, that patient may be better served with a gastric bypass. So, these are all some of the issues that we consider when we ware operating on them.

Another issue that we would consider is medications that the patient either is on or has to take. If a certain medications may have dismissed absorption after a gastric bypass, and we don’t think we have that to the same degree with sleeve gastrectomy. So, a good example of that would be some patients who are perhaps undergoing weightloss surgery because they have kidney failure or liver disease or something that they feel like they might be in need of a liver transplant or kidney transplant in the future or honestly even a heart transplant in the future. Those patients we would in general, not 100% of the time, but in general, would lean more towards a sleeve gastrectomy because we know those patients will have to depend on medications to take for rejection in the future. So, that might be a deciding point for us also.

All of those are all the various considerations that we take into consideration when we are seeing patients and trying to decide and help the patients decide which operation to have.

Host:  How interesting and good points all. Not something that the patient would think about or even other providers that are counseling their patients on bariatric surgery and referring to you specialists at UAB. So, as we wrap up, what would you like other providers to know when their patients say I really think that I want to consider bariatric surgery, what you would like them to discuss with them, any technical considerations you’d like other providers to know about and just really give us your best advice as you compare and contrast these two.

Dr. Stahl:  Yeah, I think one of the messages that we would like to impart to providers and to patients alike is although we sometimes refer to bariatric surgery as being the therapy of last resort. And there’s a little bit of truth to that because we don’t think bariatric surgery is appropriate for all individuals all the time. In fact, we very much advocate if a patient is able to achieve the weightloss that they need to achieve without surgery; then absolutely do it without surgery. That’s the best way to do it.

This operation should be reserved for patients that have been unable to do that. Unfortunately, that is quite common that they are unable to do that. Patients aren’t alone when they are not able to lose that kind of weight without surgery. Most patients can’t. So, instead of us saying it’s a therapy of last resort; we usually say look try to lose weight without surgery. But if you are unsuccessful, don’t put it off forever. Don’t put it off until you are so sick that perhaps you are not even a candidate for surgery anymore.

In much the same way that diabetes or hypertension are chronic diseases and should be treated early and got under control early; we know that morbid obesity is a chronic disease and the longer somebody has it, the worse it is for them. So, it’s much better for us to intervene at an earlier stage than to wait until the patients have suffered all the ravages of the comorbidities that go along with morbid obesity. We would rather see them earlier in the process when they are somewhat healthier and can undergo an operation a little bit easier. I think that’s probably the best take home message I would like for patients and providers to have. Think about bariatric surgery earlier in the process.

Host:  Wow, great information. Dr. Stahl, as always, thank you so much for joining us and sharing your expertise. A community physician can refer a patient to UAB Medicine by calling the MIST line at 1-800-UAB-MIST. And that wraps up this episode of UAB Med Cast. For more information on resources available at UAB Medicine, head on over to our website at www.uabmedicine.org/physician. If you as a provider found this podcast as informative, as I did, please share with other providers, share with your patients, share on your social media and be sure to check out all the other incredibly fascinating podcasts in the UAB library. Until next time, I’m Melanie Cole.