State of the Union: Weight Loss Surgery in 2023


Edited January 2023 to maintain the latest information in treatment and research.

An interview with Marc Bessler, MD, Chief of the Division of Minimal Access/Bariatric Surgery and Director of the Center for Metabolic and Weight Loss Surgery.

What’s new in surgical care for weight loss?

Well, in the last five years sleeve gastrectomy has overtaken gastric bypass as the primary operation for weight loss. And a “sleeve” is just an operation where we create the stomach into the shape of a sleeve—some people call it the banana operation. Before that, lap band [laparoscopic gastric banding] was maybe the most common operation, but the lap band fell out of favor because of the increasing knowledge around higher long-term complications.

Gastric bypass has been the gold standard and maybe still is, but sleeve gastrectomy, being a simpler operation with almost as good results—for weight loss, anyway—has supplanted it. I'd say 60 to 70 percent of our primary operations are sleeves.

Wow, that’s a big shift.

It is. But because one of the more common side effects of the sleeve is acid reflux, we're doing a bunch of revisions of sleeves, both for acid reflux and for weight regain. The patients that we choose for gastric bypass upfront tend to either already have reflux or have significant diabetes. Gastric bypass gets rid of reflux and is better for diabetes control than a sleeve. So, we will often convert those with a sleeve who suffer from reflux to a gastric bypass, and especially if they need more weight loss.

What would be the benefit of getting sleeve gastrectomy, or starting with a sleeve gastrectomy? 

The sleeve is a little bit less risk upfront. It's a little bit less complex of an operation. One day less in the hospital. It is associated with fewer long-term complications, other than the reflux.  

Patients who have a gastric bypass have about a 5 percent chance of developing an ulcer, and you don't get that ulcer risk with sleeves. And patients with gastric bypass have about a 2 percent lifetime risk of a bowel obstruction. You don't have that risk with a sleeve either. There's a little bit more vitamin and mineral malabsorption, especially iron malabsorption and anemia with a gastric bypass than with a sleeve. So, for a patient that doesn't need a bypass, a sleeve is a simpler and better way to go.

Are there any other factors you should consider when deciding between gastric bypass and sleeve? 

There's about a 10 percent difference between the two as far as weight loss. The biggest difference is in diabetes resolution. Gastric bypass puts anywhere between 70 and 90 percent of diabetes into remission. It has a much better result than the sleeve, as far as that goes, which is about 35 percent. 

How do you start that process with each individual patient, determining the course of treatment?  

Well, you sit with your patient and you talk to them about their weight loss goals. You ask them about their presence of diabetes and acid reflux. And if the patient has very mild diabetes or no diabetes and no reflux, you'll recommend the sleeve. If the patient has severe reflux or severe diabetes, you'll push them towards a bypass.  

There's one other operation called a duodenal switch that's becoming a little bit more popular, as both a revision for a sleeve and an upfront operation for patients with bad diabetes who need to lose more weight. It's the most effective of all the operations for both weight loss and diabetes. 

What is the duodenal switch operation exactly? 

Good question. It’s a sleeve plus an intestinal bypass, basically. So, it's a more aggressive bypass than even a gastric bypass, plus the sleeve. And those patients lose about 80 percent of their excess weight and have a 95 percent resolution of diabetes. 

But it's a more complex operation with higher surgical risk upfront and higher risk of vitamin deficiency, and, if they overeat, some diarrhea associated with it. So, it's not for everyone.

Can you explain more about the revisions you’re doing? Why are revisions so common?  

We don't generally believe in redo sleeves. Usually, if a patient had a sleeve and didn't do well (unless the sleeve wasn't done well in the first place) we'll revise them to either do a duodenal switch or a gastric bypass. We also do revisions for gastric bypass or for any operation that the patient is experiencing a problem. About a third of our practice has become taking care of issues with operations that others have done. 

Does that have to do with the vast weight loss industry, perhaps a varying standard of care in services? 

A lot of surgeons don't like taking care of other people's surgical patients or complications or problems, number one. Number two, they're not all up to the skillsets or the other things that are necessary to take care of such patients. Frankly, it takes more time and it doesn't pay any better, so surgeons in private practice maybe want to stay away from it. And then there are a lot more bariatric surgeons doing patients out there. There are probably 250,000 weight loss operations in a year now. Just more patients out there create more potential to have trouble. 

That, being said, the operations have become a lot safer and complications are maybe less common than they were in the past—as we learn more and more about complication causes and how to prevent those things. And the weight loss is really important for patients’ lives.  

In fact, patients who have surgery for weight loss live longer than similar weight patients who don't have surgery. There's less cancer, there's less diabetes, there's less heart disease. Now, we have evidence that shows it's a pretty significant impact on patients' health and wellbeing, not only quality of life. 

Surgery is now the standard—the best treatment option for people with obesity and diabetes. Is that right? 

Oh, for sure. But even if they don't have diabetes. Patients who are significantly overweight, 100 pounds or more, have a shortened life span. They actually get back that shortened life, that life expectancy, in proportion to how much weight they lose. 

Really? Can you break that down a bit? 

There are a bunch of studies looking at the degree of weight loss and the improvement in mortality. So, long-term, say a band operation causes 25 percent of your weight loss, patients have about a 25 percent reduction in their mortality rates.  

The patients who have a gastric bypass, as I said, have a 70 percent reduction in their excess weight and there's a close to 70 percent reduction in mortality. So, there's a pretty linear relationship between the degree of the excess weight that you lose and the mortality—the decrease in obesity-related mortality and the diseases that cause it. As I mentioned, cancers are increased in obese patients, but after surgery is decreased. Heart disease, same thing. Diabetes, same thing. 

That sounds incredibly significant.

It really is. Though, the only thing that's shown an increase, as far as mortality, is accidental and suicidal death after gastric bypass. And that may be because of two things— One is called dumping syndrome, where the stomach rapidly dumps contents into the intestine. So, patients that ingest sugars can drop their sugars, and even pass out after a gastric bypass. If they have a Snickers bar and then get in a car, an hour later they might literally pass out and get in an accident. 

And then there are a fair number of patients who are addicted to the carbs and now they can’t eat them, maybe cross-addicting to other things, or finding themselves more depressed. It's not totally clear what the cause is, we haven't seen the same increase in mortality necessarily after a sleeve but it has been documented after a bypass. It may be present after a sleeve, just not yet documented because it's a newer operation. Without a doubt, psych support and nutrition support, support in general, is important for patients after these operations. 

Right. Is that type of support built into the program for every patient? How does that process work, the coaching aspects before and after surgery? 

First, yes. Psych and nutritional support are part of treatment for every single patient. Everybody gets a psych clearance. Everybody sees a nutritionist. Everybody meets with a nurse practitioner or a surgeon to learn about the operations and to prepare for them.  

We do a preoperative weight loss effort, as well as all that education. And then post-op we see them frequently: one week, four to five weeks, three months, six months, and more if needed. That’s all with nutrition and nurse practitioner education and support.  

We also have support groups that we run so there's a lot of help for patients after the surgery, as well. They have to avail themselves to it, of course. They've got to show up and participate, but our patients really get so much out of it. There are lots of online resources too. Someone was just telling me there's a sleeve support chat group. I think it's on Facebook. It has over 100,000 patients on it. 

That’s great. Have surgical approaches changed at all? Minimally invasive approaches, robotic, that kind of thing? 

We've been doing minimally invasive surgery for a long time. Use of robotics is increasing as some surgeons favor robotic for whatever reason, but the outcomes are about the same. The incisions and the recovery are about the same.  

We are doing more endoscopic procedures. There are several endoscopic options now that are nonsurgical. The problem is that unfortunately, they're generally not covered by insurance. But endoscopic balloon placement, endoscopic suturing of the stomach. There's an endoscopic gastrostomy called Aspire, where a tube is put into a stomach with a valve on it that lets you drain the stomach after a meal. It's very effective at weight loss. Obviously, some people would find that inappropriate for them but there are many endoscopic approaches that are being developed. 

Are these endoscopic options all temporary interventions? 

They are, generally. When we take out the balloon, it's temporary. The endoscopic suturing tends to be a year or so and then the sutures start to pull through. Aspire, the emptying device, could stay in potentially forever so that one doesn't have to be temporary. But obviously the patient has to want it and be willing to use it, whereas the surgery is definitely more permanent than those things. 

What about medical treatments? Anything new we should know about? 

There are some new drugs. Particularly, diabetes medications that mimic the effects of gastric bypass, called GLP-1 agonists. One of the ways gastric bypass helps diabetes is by the intestine producing this hormone that increases insulin production from the pancreas. So, based on that, some companies got these GLP-1 agonists for diabetes. It turns out they also cause weight loss, so a lot of doctors are using these for diabetic patients who are obese, to both control and help their diabetes as well as help them lose weight. It can be effective, but keep in mind that they're expensive medications, and they're injectable. There are also some other medicines out there, but not super effective or comparable. 

Are there situations where you're doing a medical/surgical combination treatment? 

Generally, surgery works so well we don't need to do medical management unless the patient is struggling and regaining weight afterward. So, certainly we add medications to patients who are struggling with their weight loss after surgery, but it's rare that we plan to do both because surgery is so effective you don't really need the others.  

Oftentimes patients will have come to us after failing therapies. They'll have had an operation and sometimes go back on medical management afterward. Usually, patients come off all their medications after surgery, or a lot of their medications, because the surgery is so effective at reducing diabetes. And the weight loss also helps with hypertension, high cholesterol, et cetera. 

What's the most important thing that you would want prospective patients to know before coming in? 

First of all, that this will add so much quality to their lives. They will be healthier and they'll live longer as a result. But also, that this is a disease that is lifelong, the operation is a tool to help them, and they've got to work with it.  

The most important rule I tell people is avoid carbs as much as possible, keep the meal size to six ounces as much as possible (even if it means more frequent meals), and exercise regularly. People who commit to those things do a lot better than people who can't maintain those aspects. 

Is part of the pre-op prep and support to try and implement these practices and kind of get in the habit? 

We certainly ask people to do that, but it can be difficult. It's hard to eat as many calories as most people need before surgery without having some carbs in it, although we ask them to try. Really, we get their commitment afterward. I don't think anybody has shown that the ability to do those things pre-op correlates with weight loss afterward. And lots of people have tried all kinds of diets, it's a temporary thing. It's incredibly hard to do. 

But even after surgery, not everybody is able to stay away from carbs. Some people are truly addicted. There are way fewer food choices when you take carbs out of the picture. That being said, patients who avoid it as much as possible, and certainly don't make it the main component of their meals, seem to do better. 

Briefly, what is it about carbs, scientifically? 

I’ll try to be brief! First of all, there are no bad foods besides carbs. There may be some, you know, things with unhealthy fats. But there are no essential carbs (there are essential fats, proteins, amino acids). You can live your entire life without a carb and be totally healthy. That being said, the reason carbs can cause weight gain is because they trigger the release of insulin. Insulin's job is to take carbohydrates and put them into cells as fat. Carbohydrates end up making you gain weight if you eat any more than your body needs for fuel.  

Second, after these operations, the body produces increased insulin in proportion to the amount of food you've eaten. Your body turns carbs into sugar pretty quickly, and after the sugar is disposed of into the cells, the insulin sticks around and sugar levels start to fall. That’s where you have a very potent hunger stimulus: falling sugar levels. 

After these weight-loss operations, if you eat carbs you end up hungry an hour and a half later, eating carbs again. And it's a vicious cycle of stimulating hunger. That's why it's really important to stay away from carbs. Now, if you have a meal with a few carbs in it, and a lot of protein and some fats, then the protein and fats are at least staying around keeping your blood sugar up and won't be as troublesome. But if your meal is all or mostly carbs, you're going to be hungry again. 

Fascinating. What’s new in research? 

We've done a little bit of work into carbohydrates and food addiction. We did a small study where we looked at patients' weight loss who scored positive on a food addiction scale before surgery— those patients who scored positive were three times as likely to gain back a significant amount of weight after surgery. So, we've been trying to push those patients towards a food addiction program, something like Overeaters Anonymous or Food Addicts Anonymous or something like that. Because dealing with that psychological/addiction component is really important, and it’s extremely difficult without a lot of support. 

Does food addiction generally work the same way chemically as, say, drug addiction? 

Absolutely. It's been shown that sugars in these patients' brains act much like cocaine and other drugs to release dopamine. People may be using food as a drug to medicate all sorts of feelings, nevermind other patients who use it as entertainment. When they're bored, they eat. For these patients, when they're sad, when they're happy, when they're whatever, to modulate emotions they're using food. That's why these things are called comfort foods. You don't hear chicken as a comfort food so much. Maybe fried chicken, but for the most part, you're eating mac and cheese and cake and cookies, not protein and vegetables. 

Is this research becoming more significant given our childhood obesity epidemic in the United States? 

Well, it's really been the push over the past 30, 40 years to use carbs as your main dietary food. If you look at the nutrition food pyramid, it was all based on grains and stuff like that, then the more processed foods, fast foods, the ease of not eating well. You eat carbs and fats, and insulin just makes you store all that stuff away. I think it’s that unhealthy dietary push based on crops farmed in the United States, industry agenda, and all else. 

We also can’t discount decreased exercise and portion sizes. Obesity has increased in kids and adults. I think environment plays a large role in why we have more of this. Unfortunately, it's very hard to change the environment. When Mayor Bloomberg tried to outlaw or tax sodas that were more than 16 ounces, there was an uproar. Who needs more than 16 ounces of sugary soda at one time? Nobody should be having that much cola. 

Is there anything new in treatments for adolescent weight loss and surgery? 

Well, we do weight loss surgery for adolescents. Mostly, those are the sleeve procedures, but occasionally a bypass. That's becoming more common in teens, and certainly accepted, because it’s extremely effective— It is the most effective option. Unfortunately, there isn't much else in the way of nonsurgical treatment that's really been new and effective. 

That being said, obese teens have a better chance of not becoming obese adults than obese adults have of staying non-obese without surgery. So, it’s imperative we help teenagers and younger people make those lifestyle changes when their habits are still not fully developed.  Their brain is still plastic, and making life changes is sometimes easier for teens and kids than for adults. The adolescent program here is really top-notch and that’s run by Dr. Zitsman

What is the weight gain threshold, or benchmark in which surgery is recommended? 

Listen, if somebody is 80 pounds or more overweight with serious medical problems like diabetes, hypertension, sleep apnea, or if they're 100 pounds or more overweight, they qualify for surgery. I think any patient that meets those criteria ought to at least be considered for weight loss surgery because we know their lives are shortened. The rate of mortality is increased 50 percent to 100 percent in those groups of patients.  

Their disease is putting their life at risk, and that risk can be mitigated with an operation. You wouldn't hesitate to have an operation for a cancer that was increasing your risk of death, and obesity increases cancer risk by 40 percent. Yet people wouldn't think about it, it’s not discussed in the same way. But they need to be thinking about it, and we need to be talking about it. 

What makes you most optimistic about the future? 

Two things, really. First, I think we can make surgery safer. We’ve gotten pretty good at decreasing complication rates in surgery, but the one thing that was standing still, as far as mortality, were blood clots and pulmonary emboli. So, a couple of years ago we started a program of putting patients on low-dose blood thinners for a month after their surgery, and we haven't seen a blood clot since. 


The other thing we've done is decrease significantly the admission rates to the hospital by changing our post-operative management. With both education, managing hydration at home, which nursing can do, and by seeing patients earlier post-op to intervene if there's any sort of difficulty. We have decreased admission rates, and the length of initial hospital stay has also come down significantly. Patients are going home faster. They're coming back less and having fewer problems. All of that has really been enhancing success.  

Most patients come in and they leave the hospital in a day if they're having a sleeve. The readmission rate is significantly less than 5 percent. And the number of patients who need to stay a second day after a sleeve has gone down significantly, by at least a third. 

Even some gastric bypass patients who we usually keep for two days are going home one day after surgery. And that's due to the use of some new drugs to decrease nausea after anesthesia and decrease the narcotic use by using all types of other non-narcotic medications. And I'd say about half of our patients take no narcotic after surgery. 

That’s great. Let’s close this out by continuing to look forward. What are your goals for the next five years, 10 years? 

We want to continue to improve the patient experience. I'd love to see a situation where we can actually do outpatient surgery and have the patient followed up at home by a nurse or nurse practitioner the day after or so to take care of whatever issues there might be, check labs if needed. You know, to make surgery even less of an impact on patients' lives. Less pain, less recovery time.  

And I'm very excited about the possibility of endoscopic procedures. I’m developing a device for an endoscopic sleeve procedure that’s in the testing phase. And that would be totally endoscopic, no surgery at all, but with the success of a gastric bypass.  

You know, that’s the goal—to do it without surgery. With fewer complications, without the scarring, with less recovery time. That's where endoscopic devices have the advantage. So, if we get something that can actually last endoscopically, it could revolutionize the whole field.  

Surgery lasts, but it includes general anesthesia, you need recovery time, there are incisions and pain, and all that risk. Some of them are not reversible. Whereas if you had a device that you could put in or some sort of reversible technology you could do endoscopically, you wouldn't have scars, you wouldn't have as much pain, you wouldn't have as much recovery time. Maybe lower complication rates. And if we could achieve success, then that is a revolution. So, that's what we're working on!

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