Treating obesity is among the PCP's everyday duties, but when does a patient's body composition put them at risk and which treatments are appropriate? In this discussion, bariatric surgeon Jonathan T. Carter, MD, goes deep on the use – and limitations – of body mass index, including how it correlates with mortality from chronic conditions and when aggressive therapy is needed. And while GLP-1 drugs are game changers, he says, bariatric surgery continues to have value for a large subset of patients, with advanced techniques – such as sleeve gastrectomy – reducing the risk of complications and showing evidence of supporting long-term wellness. Bonus: A rundown on recommended follow-up care for surgical patients, from vitamins to bone scans.
OK, everybody is excited about GOP ones and um we're gonna talk a little bit about GOP ones. Um, I think they're wonderful drugs, game changing, uh, revolutionary. I'm a huge proponent of them. Um, but, uh, they have changed the landscape of how we think about and treat obesity. And, um, and so I wanted to talk a little bit about obesity and where GOP ones fit in. And then for the few patients who, uh, really need more than GOP ones, um, and need to be looking at surgery, we'll talk a little bit about that as well. So I want to take a step back and just talk about obesity in general. And you might ask, um, what is obesity? How do we define it? Because obviously all of us as human beings have some degree of fat within our bodies, and fat is uh necessary. It's a it's a it's the way that we keep our bodies warm, it's the way that we Um, can store, uh, calories for when we need them in the future. It protects all of our internal organs. Um, it's very, you know, it's a very, uh, positive tissue to have inside of our bodies. And so, at what point does, um, adiposity or fat start to become a health issue for us? And, um, you know, there's been a lot of debate over the years, and if you look at the World Health Organization, they define obesity as a disease. Uh, defined by excessive fat that can impair health. Um, they note that obesity can lead to increased risk of type 2 diabetes and heart disease. It can affect bone health, it can affect reproductive health, and also can increase the risk of cancer, but it stops short of defining how much fat is excessive fat. And indeed, um, this continues to be a source of discussion amongst experts to this day. And so as uh clinicians, we uh we measure obesity with an index called the body mass index, and I think most of us are quite familiar with this. Um, to calculate the body mass index, you just take your mass in kilograms and you divide it by your height squared. And the World Health Organization, as well as essentially every professional society who is involved with obesity, um, as well as the American Medical Association, um, have all, uh, used the same these same categories to define obesity. Um, normal weight is defined by a BMI greater than, uh, from 18.5 to 25. Overweight is 25 to 30. And then obesity starts with a BMI greater than 30. Um, obesity is then subcategorized into class 12 or 3, where class 1 is 30 to 35, 2 is 35 to 40, and 3 is greater than 40. Now, um, I've just made a huge leap. We just walked from excess fat deposits or excess adiposity to an index, which has nothing to do with fat. You might say, OK, well, you know, body mass, sure, there's uh fat within our bodies, but there's also muscle and bone, and water, and liver and kidney and brain, and all those things have mass. And so we've sort of made a big leap when we've talked about Uh, excess adiposity to talking about the body mass index. So you might ask, how well does body mass index actually correlate with body mass when we measure it. The other thing is mathematically, it's kind of a funny index, right? Because it's the mass divided by your height squared. Well, Obviously that is an attempt to normalize weight by height so that we can compare people of two different statures um directly, and that's because obviously a taller person you would expect to weigh more than a shorter person. Um, but the squared is kind of a weird term. You would think, you know, as generally speaking, mathematically as objects scale, the mass increases with the cube of the linear dimension, right? And so why are we, you might think like naturally it should be mass divided by height cubed. If you were a mathematician, you would think that. So why do we use height squared? It seems odd. And the answer to that question is because if you compare the shape of a tall person and the shape of a short person, it's not like the tall person is just a scaled version of the shorter person. Um, as we get taller, our, uh, long bones get taller. And our extremities get longer, but our um trunk doesn't scale similarly out. And many, many years ago, 150 years ago, there was a uh statistician and mathematician who was looking at a population of human beings who didn't have obesity, just completely normal weight human beings. And he noticed that if you um across a population, if you take the mass divided by height squared, that that's constant across different heights. And so that was the fundamental observation where the body mass index came from. But when um you apply it to obesity, it can start to be uh problematic because um if you have excess mass in one of your other compartments, like for instance, the muscle compartment, it can give you a elevated BMI which is not, uh, doesn't represent excess adiposity. And a classic example of that is, uh, bodybuilders. Uh, this is Arnold Schwarzenegger when he was competing um as Mr. Olympian. And at that point, he had a body mass index of 31, which, according to the chart I just showed you would be obese, but clearly he's not obese. He only had about 8% body fat. And so his BMI was um elevated by virtue of uh muscles. Um, and he's quite an extreme outlier, but there are outliers that you and I will see in our day to day practice. So how, what is the relationship of BMI to body fat mass? And uh that's been pretty well studied. And here it is. Uh, this is a large population of uh people in Australia actually, and they were all studied with the DEXA scans, so we knew exactly how much body fat they had, and then, um, they were weighed and their height measured so that their body mass index could be. Uh, calculated, and in this chart, they, uh, separated men and women. So if you just look at this, obviously there's a very um high degree of correlation between body mass index and body fat, and it's a linear correlation. Um, and if you are a statistician, you calculate the correlation coefficient, it's something like 0.82 or 0.3 or something. So a statistician would say these are very highly correlated. So that's um part of the reason we use the body mass index. But if you look at this, um, a little more closely, you start to see uh some of the reasons that people criticize the body mass index. So for instance, obviously there's a, there's a difference between men and women. And women in general have a higher body fat percentage than men. And if you look like, for instance, at a BMI of 25, you can see the dis the average woman or the distribution of women will be have a slightly higher body fat uh in kilograms than men. Or another way to say that, if you look at uh body fat of let's say 30 kg here, you see that women will have a slightly lower BMI than men for a given level of body fat. So there are uh sex. Uh, specific differences when we talk about body weight, uh, and fat. Um, the other thing, look at the distribution, so you can see the regression lines, but you can, uh, say, OK, let's take someone with a body mass index of 25, which we might say is, um, an ideal or maybe a desired body mass index. Look at the variability in fat mass. Like in men, you can see there are some men with a body mass index of 25 that are down in the 8% range, but there are others up above 20%. And similarly for women, body mass index of 25, there are some women down with less than 20 kg of body fat, and then others um appear at 30 kg of body fat. So there's a lot of variability at a given BMI and body fat mass. So when we, when we go from BMI to body fat mass, we're making a little bit of a leap. Now, a lot of our patients, um, Uh, are familiar with or concerned about their body fat percentage. And this sort of in, you know, if you're in the gym working with a trainer or you're working with a nutritionist, you know, there's a lot of uh talk about using body fat percentage as our uh measure of fat. And the correlation between body mass index and body fat percentage um is a little more strained, um, and the reason is we lose that linear relationship. And so you can see in both men and women as the body mass index goes up, the body fat percentage starts to level off. And there's a lot more variability. So what this blue line, which is 22%, that is the body fat percentage for which men have the lowest all cause mortality. And if you say, OK, well, what BMI does that correlate to, you can see there's a huge range. It's a BMI of 20 to up to about 30. Um, really wide range. And similarly for women, uh, if you ask your question, at what body fat percentage do women have the lowest all-cause mortality, it's about 34 35%, so that's the pink line. And you can see for women that correlates to a body mass index of 20 up to 20, you know, 627, something like that. And so, I think body fat percentage, although it's commonly used in our society, I don't think it's a great uh measure of uh adiposity or excess adiposity, and it, um, it doesn't correlate uh as nicely with the body mass index. So that's kind of some of the limitations of body mass and it's so why do so many professional societies use it? And it really comes down to this relationship. If you, if you take a population of people. And you make a graph of their body mass index and their all cause mortality. So that's death for any reason, cancer, cardiovascular, car accidents, you know, suicides, death, like dying for any reason at all. You get kind of this J-shaped curve, and this has been reproduced, uh, essentially throughout the world. Anyone that's ever looked at it rigorously. Um, this, uh, paper that I'm quoting was 3.6 million adults in the United Kingdom, but it's true in the United States, Australia, Asia, uh, India, wherever people have looked, this is generally for human beings, the relationship of BMI and mortality. And I've plotted two different curves. The red curve is men and the blue curve is women. So let's look at this. Um, the lowest all cause mortality occurs around 20 BMI of around 25-ish. For men, the inflection point is about here-ish, so maybe 26. And then as the BMI goes up, the all cause mortality increases, and it's a pretty substantial increase. By the time you get to a BMI of 40, you're up to about twofold increased risk of dying. Uh, the patients I see in my clinic typically have BMI's 50 or 60, so they're really in the 3 to 4 time, uh, risk of dying by virtue of their body mass index. Now look at the curve for women. Um, for women, it's a little bit flatter, and so you really don't see any, the lowest again is in the 25-ish, but the inflection point isn't really till about a BMI of 30, and then beyond that, there is a linear increase in all cause mortality uh with body mass index. And so if we go back and we think about these categories with this new knowledge. Um, you'll realize that these categories are a little bit arbitrary, right? If we want to really look at disease risk, it's, um, there's no natural divisions here. Someone has just taken this curve and said, well, we'll just divide it up into categories of 5, but realize it's a linear risk once you get above about a BMI of 30. And that's um part of uh uh uh one thing you have to understand when you look at these uh classifications of obesity, there's not a natural biology that's driving these divisions between categories. The other thing, and I'll be, I, I'm gonna put my foot out a little bit, maybe make a, a politically charged statement and, um, feel free to, I, I would love your comments or conversation or questions about this. But if you say like, how low should we be driving the BMI when we're treating patients, I would make an argument like kind of 30 should be your goalpost, and anything less than 30, um, shouldn't be a major. Uh, driver, because if you look at the people in that BMI 25 to 30, which the WHO says is overweight, I would argue that if you don't have increased all cause mortality by virtue of BMI, why are we bothering treating you? So I think this, um, this category of overweight is also a little suspect because um there's actually not much all cause mortality attributable to this to this uh category of BMI. Um, and so I, I don't think we need to be really aggressive at diagnosing and treating patients in our practice who are overweight. I think where we really wanna focus is on this side. The last comment I wanted to make about the BMI is, um, This, you know, why is it when your BMI gets too low, your all cause mortality starts to go up. And mathematically, um, what we can do is we can take the body mass index, which is your total mass, and imagine we knew how much of it was fat, we'll call that the fat mass, and then we add everything else, muscle, bone, kidney, brain, all the non-fat, and we'll just call that the fat-free mass. But the dominant component of that will be muscle mass in your fat-free mass. Um, so we could divide total mass into fat mass and fat-free mass, and then, uh, mathematically we could just separate these um into two separate, and this fat mass over 1 m squared, we'll call that the fat index, and then your fat free mass over a 1 m squared, we'll call that the lean index, or we could call it the fat-free mass index. Now then we could look at the contribution to mortality of each of those individually, knowing that they're just summitative, and that's been done. So if, if you look at the fat mass index, you can see that, um, again, it's pretty flat for lower fat mass index, but once you get a fat mass index of about 8, there is an increase in all cause mortality, which is being shown on the Y axis, um, in a almost linear fashion. Similarly, if you look at the lean mask, it's the opposite curve. So basically, if you have uh lots of muscle or moderate muscle or, or, um, average muscle, um, your, uh, all cause mortality is pretty much the same across all those categories. But once you get down to a, you know, level around, I don't know, 1819, something like that, basically, the less Uh, the more lean you are, so the less muscle mass you have, the higher your all cause mortality. So then that familiar J-shave curve, which I just showed you, you can think of that as the sum of two competing effects. The first effect is what is the effect of of fat mass on our mortality, and that's the whole right side of the curve, and basically the higher the fat mass is above a certain threshold, the higher the all cause mortality. Similarly, the lower part of the curve, what's driving that, that's being being driven by low muscle mass, low lean mass. And basically the less muscle you have, the higher your all cause mortality. And so the sum of those two curves gives us this J shaped um pattern. Now I would argue that's the strength of the BMI because it is true that BMI is not just measuring fat, it's, it's measuring total mass. But um it gives us a useful information. If someone's BMI too low, that's just as worrisome as if their BMI is too high, because um it's that low muscle mass that's driving mortality, and that's something that, that when we're treating our geriatric uh frail, um, Uh, patients that maybe we should be focusing on more, um, looking at ways to improve uh lean muscle mass and strength, avoiding falls and so forth. OK, so what um what is it about obesity that uh causes excess mortality? And it really comes down to two things. It's, um, cardiovascular mortality and cancer. And so if you look at causes of death and you look at the relationship between body mass index and all cause mortality, you can see for cancer, once you get above a BMI of about 25, there starts to be an increased risk and that's a um It looks linear here, but this is a logarithmic scale, so it's actually an exponentially increased risk as BMI goes up. And then similarly, cardiovascular risk starts to go up. So when we're treating obesity, our goal of therapy is we really wanna be driving down cardiovascular risk and cancer risk. That's the whole purpose of uh treating obesity in the first place. And indeed, it's um a fairly striking effect on mortality. Uh, this was a paper that was published in JAMA, and they took a large population of Of Americans and um put them into uh body mass index bins, and then for each bin, they calculated how many years of life expectancy did you lose by virtue of your body mass index. And this is the curve, um, this was in women specifically. And you can see, um, you don't start to see appreciable uh changes in Uh, mortality, um, until about a BMI 30-ish, and then from that point forward it moves up. Um, it can be striking, and the patients I see in my clinic typically will have BMIs in the high 40s, 50s, 60s, and for those patients, they've really lost about, uh, 10 years of life expectancy by virtue of their obesity. That's a substantial percentage of their lifespan. And that is what motivates us to do aggressive, uh, interventions like surgery. But obesity affects um all systems of the body, not just uh the cardiovascular and the uh cell replication systems, um. You know, really, uh, uh, obesity can be causative or can correlate with a number of diseases affecting every organ system of the body. And some of these um are quite familiar to us. We all know about the associations of obesity, type 2 diabetes, hyperlipidemia, hypercholesterolemia, so-called metabolic syndrome. But some of these, um, may be less obvious to you, um. You know, uh, if you look at osteoarthritis, if you talk to the orthopedic surgeons who are doing total hips and total knees, their, their business is being completely driven by obesity, um, cause you get accelerated osteoarthritis by virtue of obesity. Uh, incisional hernia is something I do a lot of in my practice. Um, you know, most incisional hernias occur in people with obesity. Um, if you If you close up a laparotomy incision, and it's a non-obese patient, it generally will heal pretty good and the patient won't get a hernia. Um, if it's a patient with a high BMI, they're gonna get a hernia. It's 100%, and then that just sets up the downstream, you know, repeated hernia repairs. Um. And so it's really uh in some obesity turns out to be a uh huge burden for the patient to carry, but it's also a huge burden for uh us in healthcare to carry, because we are the ones managing really all of these obesity related issues. So how do we think about treating obesity um in the era of GOP ones? And um the idea is that it really comes down to assessing the severity of the disease and then matching our intervention to the severity. And if you go back and you think about that BMI curve, you know, someone who has a BMI of 50 is a much, much higher risk of cancer, cardiovascular mortality, metabolic disease, so forth, than someone who has a BMI of 32. So it kind of makes sense. We should be much more aggressive about treating people who have a BMI of 48 than we do have a BMI of 32, even though they both have obesity, um, as their diagnosis. And so how does that play out? Um, Patients, uh, who are candidates for surgery, people really at the higher end of obesity. The current indications are BMI 35+. But if you already have metabolic disease like diabetes, hypercholesterolemia, sleep apnea, uh, uh, hypertension, we will relax the cutoff down to BMI of 30. Um, obesity, anti-obesity medications are, uh, are used in conjunction with surgery at the higher ends of the BMI in a multimodal, um, fashion. Um, but the indications for anti-obesity medicine alone are a little bit lower, so it's a BMI 27 with metalbo disease or a BMI greater than 30. As far as like who should be treating obesity, I think we all need to treat obesity. It's so prevalent in our society. I think we all, um, we owe our patients, um. Uh, to, to get involved in treating them. And I would suspect every one of you is actively treating obesity within your practice. I think the role of primary care is um to screen for, uh, obesity in our patients. Simple as uh calculating a body mass index and having it in your note, um, with every visit, um, bringing it up with the patient, which needs to be done sensitively. Um, but definitely needs to be done. It's not something we should beat around the bush or uh avoid discussing with our patients because we really do them a big disservice when we do that. I think uh we all need to know what sort of community-based programs we have available. I mean, every single community, I don't care where you live, is gonna have a jazzercise or aqua aerobics or, um, you know, nutritional classes or some sort of program to treat obesity, um, that's community based. And we can really reinforce uh healthy eating in, you know, what we call intensive lifestyle intervention and exercise regimens, not just to treat obesity, but just for general health. And so, I think all those are critical in the management. Um, most, uh, Major cities and uh metropolitan areas will have specialty uh weight management programs at UCSF. We have a wonderful group um called UCSF Weight Management. Uh, it is a practice run by internists who are uh specifically uh certified in obesity uh uh obesity medicine, and um they are experts in helping our patients lose weight. Uh, through a number of things, um, anti-obesity medications is a big part of that, but they, um, they're also, they'll look through the patient's current medications, look and see which one of those are, uh, contributing to obesity, and, uh, recommend or suggest alternatives. Um, they also work with uh psychiatrists and nutritionists, um, uh, uh, to help the patient with an intensive lifestyle intervention to go along with, uh, medication management. And so they are a critical partner and uh one that um I hope you all feel uh comfortable referring and um hopefully or freely referring to. And in the world of eye surgery, we do the same thing. Um, our group, uh, we also have um nutritionists, psychologists, uh, pharmacists, and, uh, physician assistants who all help the surgeons, um, with the uh multimodal treatment of disease. And so I wanna share a um anecdote with you. Uh, this is a patient I had way back in 2013, so she's what, 13 years, um, been my patient now. And when she came, she was 33. Uh, she suffered from severe obesity. Her body mass index was 44, which put her at about 112 pounds overweight. Um, you might say how do we calculate ideal body weight? It's just the weight that gives you a BMI of 25, and it's just a totally arbitrary thing. Like there's nothing magic about a BMI of 25. Um, it's just used as an arbitrary measuring point to to calculate excess weight. And like uh many patients with obesity, she'd been on every diet, you name the diet, she'd been on it. Um, she'd done that since she was in grade school, really. And although she was 33, she already had a lot of metabolic disease burden. She had hypertension, migraines, diabetes, asthma, and trigo urinary stress incontinence, PCOS. Um, and she realized, God, I'm only 33, like I gotta get on this. And so she came to see us to talk about options. Um, I would argue if you look at her past medical history, every one of these was caused from her obesity. So we could treat any of these individually, but if we could just treat her obesity as the root cause, we might be able to. induce remission and these other issues. And so, what would you, if you had Patty in your clinic, what would you recommend for her? So, you know, GOP ones were FDA approved uh for obesity indication in 2021. Um, Wagovi, which is the Nova Nordis product, was the first. And then uh Lily was upbound, uh received its uh approval, what about a year afterwards. Um, if you look at the effect of these drugs, these are gamechanging drugs. For the first time ever, we had really effective medications for obesity, caused a huge amount of excitement, um, which has continued. And I am a huge proponent of these drugs. I think they are a major, major uh advance in our arsenal to treat this disease. But also we have to look at our goals, uh, and the you know, the patients, the patient has their goals, but as providers, I think we have to also look at, you know, what are our goals um when we're treating this disease and and sort of how, how low should we drive body weight or BMI. So if we put Patty on Ozempic, and we got her a max dose. And she uh was able to continue that, no discontinuation from side effects. And she got the average result. The average result is about 15%. Uh, total body weight loss, which for Patty would be about 40 pounds and that would put her at a BMI of 37. Still, uh, well within class 2 obesity. If we put her on ep bound, which is trazepatide, and again, um, put her on it for a year, uh, no side effects requiring discontinuation, good availability, no insurance hassles. She would lose, the average patient lose about 20% body weight. And so for her that would be 52 pounds and that would put her at a BMI of 35. Now there's no doubt that is way better than where she started at this treatment. But I would argue maybe surgery is a good option for her, because we know with bariatric surgery, people lose about 30 to 35% total body weight loss up front. And that's a 1 year. And we also have long term data. Like we don't really know at all what happens after 1 year with GOP ones because all the phase 3 trials ended at 1 year. Although we do have a few 18 month follow-up trials where we saw what could happen when we discontinue therapy. What do you, what happens? Everyone knows all the weight comes back. So we know that if you go on therapy, you need to stay on it uh for lifelong. But bariatric surgery, you get a uh very durable, we've been measuring patients out 20 years, and this is what happens, they have a little bit of weight regain and then they plateau, and if you look 1015 years out, they usually maintain around 25, 20-25% total body weight loss. And so, um, Patty, uh, we talked to her, and this was back in 2013, so this was kind of before sleeves were very popular, and so she went for the bypass, and here she is, um, at her two-year checkup, and she had a really amazing response. She, um, had lost 124 pounds. Uh, she sent me this picture as she just had run the San Francisco half marathon, I think, um. BMI gotten down to 22, which I think is exceptional, um, for her. But look at the metabo, uh, burden that she was carrying. She had complete remission of pretty much all of her metabolic disease. Her hypertension was gone. She was off meds. Her A1C had normalized. She was off meds completely. Um, her periods had, uh, uh, re had become more regular and frequency and Um, she, uh, had just, uh, gotten married and she was, uh, thinking about trying to get pregnant and her migraines went away, and her asthma was gone, she's running and her urinary stress continence was gone, so really a dramatic lifestyle intervention for her. So how do we do that? So, um, in bariatric surgery, you know, the focus of our practice is really uh multidisciplinary care. So we've got, um, 3 surgeons, we've got a gastroenterologist, we have a nutritionist, we have a psychiatrist, we've got 2 PAs, and we have a pharmacist, and we're all, uh, obesity focused in our practice. And unlike most surgical practices, we are committed to longitudinal care. So it's not like refer, surgery, post-op, done. It's, we, we'll actually um work with the patient for years. And I'll tell you, it's very common, uh, about 25% of our patients now come to us on a GOP 1. And um it's very common that we will prescribe or recommend a GOP one after surgery, maybe after a couple of years, if our goals, our collective goals are additional weight loss or avoidance of weight regain. So we really use GOP ones uh commonly in our practice, um, uh, even though we're a surgical practice. Um, So what do we do when you send a patient over? We do an H&P. We have a comprehensive lab panel. We, uh, importantly, we check all their micronutrients cause we're worried about micronutrient deficiencies, uh, after bariatric surgery. Uh, we do a cardiopulmonary assessment, we do nutritional and psych evaluations with counseling and training, um, as obesity is A disease that's strongly, uh, uh, linked to behavioral it, you know, to our behavior. We all have to eat, but, uh, often we have maladaptive eating patterns, and that can be really addressed with uh cognitive behavioral therapy or just good solid nutritional um education and advice. Um, we do pregnancy, contraception, uh, counseling and smoking cessation counseling. Um, and, uh, we really require all patients to have primary care. A lot of, a lot of patients come to see us that don't have primary care, but, uh, and, and when they do, we, um, are insistent that they establish primary care because we really want, um, in the initial workup, we want to make sure they're up to date on their cancer screenings. Um, and we also want a part, you know, make sure that we have a partner, um, in the longitudinal care of the patient. Typical outcomes after bariatric surgery, um, this was a nice paper, uh, out in the New England Journal, following a cohort of Americans, and it showed the results, uh, over time with uh gastric bypass specifically. And you can see the average patient initially loses about 35% total body weight loss. And um most patients maintain that over time. If you look at 12 years, it's about 30% total body weight loss um versus baseline, which is up here. What I liked about this paper, it actually showed each individual patient, so you get a sense of the distribution. And you can see there's a fair amount of variability. Um, there are some people who are just rocking it out, you know, lose 40, 50% of their body weight. These are patients that are getting down to near normal BMI's just like Patty did. And you can see for those patients, they tend to maintain their excellent result. But there is a subset of patients that have a less than, uh, uh, optimal or less than desired result with the intervention and experience significant weight regain. So, you know, you can see there's some patients that only lost, like this patient only lost 10% of their body weight with the bypass. And, you know, this patient, um, by 6 years out, had already regained and, um, was close to their baseline. So it doesn't work in every patient every time. I think we see a lot of variability and Um, that's why I think multidisciplinary and using GOP ones as an adjunct in the post- bariatric bypass, uh, baria surgery population can be such a powerful tool. It's not just about weight though. It's really about treatment of metabolic disease. And I think one of the success stories of the last 20 years has been characterizing the metabolic benefits of bariatric surgery. Um, take type 2 diabetes. You know, when we operate on a type 2 diabetic, um, if you look at all comers, about 60% will go into remission, meaning normal A1C off meds. Um, if you look over time, like 5 years out, maybe about 30% will have a sustained remission, which is pretty impressive if you think about it, given that we're talking about a 2 hour intervention and a night or two in the hospital, you know, it's really a dramatic improvement. But um it's not just about surrogate end points, you know, if our motivation to treat obesity is to reduce um that scary BMI J-shaped curve that I showed you at the beginning, you might ask, well, how well does uh bar eye does bar eye surgery actually affect mortality? And it indeed it does. Um, this was a study in JAMA that looked at Patients who had bariatric surgery compared to patients with obesity who did not and followed them out, and this is a Kaplan Meyer curve of all cause mortality, and you could see that um That basically, uh, having metabolic surgery uh conferred a very strong mortality benefit over time. Uh, the patients who had the surgery were 40% less likely to die over time. And why is that? Um, it's because there's a reduced risk of cancers. Uh, this was a trial that uh looked again. Uh, obese controls versus people have bariatric surgery and, and looked at all cause cancer incidents. It was published in The Lancet and again, there's about a 40% reduction in cancers when we do these surgeries. And so that's kind of what motivates it all. Now, there's a downside to bariatric surgery, and I think we've all met a patient who's had a complication. It might be an iron deficiency, it might be a marginal ulcer, it might be an intestinal obstruction. So there is a downside, um, to gastric bypass surgery. And if you look at the risks, uh, the short term risks are listed here. But one of the uh lingering concerns is long term risks. There's a risk of marginal ulcer and risk intestinal obstruction. It's pretty low, it's about 1% per year, but if you're doing the operation on someone who's 40 years old, their lifelong burden, it starts to be, uh, much more significant. And so, um, surgeons in the field kind of were looking at ways to reduce these risks even further, and came up with an operation called the sleeve gastrectomy. And the sleeve is very simple conceptually. We just take a stapler and we just remove the stomach, um, about 80% of the stomach, which is the greater curve, and that just leaves the, uh, the patient with a narrow, lesser curved base stomach. Um, Uh, for which to hold their food and eat, and the sleeve works really great. It works about as well as a bypass. Um, if you look at, uh, weight loss outcomes, this is a graph over 10 years of a prospective randomized trial of sleeve versus bypass, and on the y axis is total, um, Total body weight loss expresses a percentage of total body weight. And so, and the bypass is kind of the light blue and the sleeve is the dark blue. So you can see both operations at one year, um, patients lose kind of in the 25 to 30% body weight, and out 10 years, they maintain, you know, the sleeves were about 20% and the bypass were about 25% in this trial, um, but very similar statistically. You guys want to see how we do it? Just for fun? OK. I'm gonna show you a surgical video. And um if you have a queasy stomach, just close your eyes for a couple minutes and I'll let you know when the video is open or when done, um. OK, and I'll show you how we actually do this operation. OK. So we do it uh laparoscopically, um, the operation takes about an hour. Um, the patient spends one night in the hospital. Um, and then they go home the next day. The first week's a pretty rough week. Uh, most patients are struggling, uh, to maintain hydration, uh, nausea, uh, abdominal pain. By the end of the first week, they're like, OK, I, I can get through this. I'm gonna make it. Uh, most people take about 2 to 3 weeks off work. Um, and the way we actually do it is we put a, uh, bougie down to size the sleeve. Uh, the bougie is 40, uh, French, which is about the diameter of my thumb. And then what we're gonna do is we're gonna uh staple right along that, um, and so this is the human stomach. I've got the liver retracted up, and we're using a surgical stapler which basically fires 3 rows of staples and then cuts down the middle. And uh we reinforce that with a piece of fabric, and this fabric dissolves after about, oh, I don't know, maybe a couple weeks, um, and we just do that to distribute the tension from the metal staples, and that helps reduce bleeding along the staple line. And so, um, we've got this bougie, uh, off to the left side of the screen, and I can feel that bougie. And we're just gonna successively fire the stapler alongside that bougie and that ensures that we have the correct size sleeve. Now one thing that's kind of interesting and cool, there's um the, the patient still has an antrim, so we don't resect the Antrim. And you'll recall from medical school, the stomach has two parts. There's the body and there's the antrim. And the body's, uh, the body of the stomach, its job is to hold food. So it's like a reservoir. And it gets more and more food you eat it, it expands, so it, it can hold that food and eventually present it to the small intestines for digestion. But the Antrim doesn't hold food. The job of the Antrim is to churn up the food and then push it into the duodenum, and we don't want to mess that up when we do a sleep. So we actually preserve the antrim, and we just resect the body of the stomach. OK, keep those eyes closed. We're almost done with the video. I'll let you know when we're all done. So we just um we just continue to fire up the bougie. Here we are next to the gastroesophageal junction. So this is the diaphragmatic hiatus under the uh silver grasper here. You can see the very tip of the spleen off the end of the stapler, and here I'm making my final fire. With the sleeve, and so the sleeve is what's left and then we remove um that uh that gastric uh remnant out of the body, so we pull it out. Now we finished the operation with uh something called omentopexy, and and what we do is we take the sleeve staple line and we reattach it to where we divided the gastrocolic omentum at the start of the operation. And uh the reason we do that is we don't want the sleeve to be twisted or contorted in a funny way. We kind of want to straighten it out, and, um, by putting a row of sutures, um, that allows us to do it. And prevent that. There are some surgeons think that it reduces GERD after sleep. I'm not sure it does. But, OK. All right, you can open your eyes if you have a queasy stomach. We're done with the surgery video. We're back to the slides. So, um, if you look at, uh, my program today, about 85% of patients go for the sleeve operation. And about 15% do the bypass and and the and the reason why it really boils down to this slide. If you look at your risk of short term complication within 30 days, um, the sleeve has about half the risk of complication cause it's just a simpler operation. Uh, we don't have to mess with the intestines, we don't have to do anastomosis. And so, if you look at leak, it's about half the rate. If you look at bleeding, it's about half the rate. If you look at blood clots, it's actually not much difference for blood clots. Um, if you look at needing to come back to the hospital and get an intervention, it's about 50%. If you look at total readmissions, it's about 50%. So it's just a, it's an even safer operation for the patient to go. Um, I'll tell you, I do a lot of sleeves. I do a lot of bread and butter general surgery like gallbladder and uh big hernias and stuff. And I'll tell you. Um, I have less butterflies in my stomach going into a sleeve than I do going into a gallbladder, um, because the sleeves, uh, is very, uh, refined and, you know, it's, it's just not a big, big operation, you know, so I kind of feel like Uh, and if you look at the, if you look at the, the 30 day risk to the patient, actually the sleeve has a lower risk than gallbladder surgery. Most of us wouldn't be nervous about referring a patient to have their gallbladder out if needed. And so similarly, sleeve is just as a lower risk, not a big deal. Um, in the long term, uh, you know, we really, there's no risk of marginal ulcer, and since we don't touch the intestines, there's really no attributable risk of intestinal obstruction to the sleeve. And so that spares the patient these long term risks. The one downside we see with the sleeve is GERD, and we see that in about 30% of patients. And uh many of them, um, when they develop severe GERD, we may have to put them on a PPI. Um, if it's really severe, we might have to convert them to bypass, although that's a pretty rare situation. How should we follow patients after baria surgery? This is something that um you may need to address in your clinic, um, if you're seeing these patients, um, Uh, the way we see them, we like to see our patients, um, 3 months after surgery, 6 months after surgery, then annually. Um, and what do we do at each visit? Um, we ask how you're doing, how you're eating, how's your strength training, how's your sleep, uh, how's your, um, alcohol drug use, um, after surgery, there can be an uptick in alcohol use that we want to screen for. Community engagement, general health, well-being. Um, we wanna make sure that patients are taking their vitamins, so every bariatric patient needs to take a, uh, bariatric formulated vitamin. Um, you should know that there are companies that make vitamins specifically for bariatric surgery patients. Uh, the one that we use is called ProCare, and this is, uh, what the picture looks like, but there are other companies that also do it, and those, their products are fine too. Um, All all the bariatric patients should be taking calcium + D either 2 or 3 times a day. And um we'll review their meds and, you know, often we'll notice, oh well, your blood pressure seems to be pretty good. You were on 3 agents, go, you know, go talk to your primary care doctor. Go talk to your cardiologist, like maybe we can back off one of your blood pressure meds or maybe we can back off your diabetes meds. Um, and so that's something where we want to partner with you and back off patients' medications as their comorbidities go away. And then um we also uh want to screen for micronutrient deficiencies and so this is the uh labs that we specifically order. And if you want to take a screenshot of this and build a panel on your own, if you're seeing these patients, feel free to um uh copy this. So that's really it. If you look at what's in the vitamins, um, uh, this is what's in it, and if you just sort of look broadly, it's about twice as much as a normal adult multivitamin, with a couple exceptions, it's got way more thiamine in it and it's got way more B12 in it. So if you're in a pinch, you know, you could just tell a patient to take 2 adult multivitamins every day, um, in lieu of this bariatric formulation that gets it pretty close for most of these. Um, we're happy to see referrals. We're happy to partner with you to care for these patients, whether they're doing great or whether they're doing, uh, they're having a hard time and they need, um, specialty cares.
