And next, we are going to be going to Dr. Christopher Thompson. He is a professor of medicine at Harvard and director of endoscopy at Brigham and Women's Hospital. He's the co-director of the Center for Weight Management and the director of the Advanced Endoscopy Fellowship Program. He is also a well-known innovator in bariatric and metabolic endoscopy and is really one of the first people in this field to really push the envelope and move these therapies forward into clinical practice. So we are very lucky to have Dr. Thompson giving this talk today on gastric placation procedures, endoscopic sleeve gastroplasty, and primary endoluminal surgery. I'd like to thank Drs. Sullivan, Girapino, and Kaplan for the opportunity to speak on this exciting topic that I've been fortunate enough to work on for nearly two decades now. Here are my disclosures. I have worked with most companies in the space and used every device in this talk with the exception of one. So hopefully they'll cancel each other out. We'll start with a brief but relevant background on bariatric surgery and endoscopic suturing, and then we'll discuss the various suturing and placating procedures in the context of their surgical analogs. There are many types of bariatric surgery, with the two most popular currently being the sleeve gastrectomy and the Roux-en-Y gastric bypass. And what's common amongst all these procedures, even historically, is that they all involve an element of gastric partitioning or a partial gastric resection. So it's not entirely clear how these procedures work from a physiologic standpoint. However, it was thought that this gastric partitioning provided an element of restriction so that patients would become full quicker when eating, and that would lead to weight loss. However, now as we're beginning to understand these procedures better, it's thought that they might actually have a metabolic impact, such as the sleeve gastrectomy, which is associated with more rapid gastric emptying, which can then potentially trigger hind gut reflexes, such as spikes in GLP-1, and then you can see those metabolic benefits. Now, many of these procedures do have small bowel bypass or diversions baked into them, and these, of course, will have more direct metabolic impacts, which can lead to earlier resolution of comorbid illness, such as type 2 diabetes. Now, you're all likely familiar with the Swedish WB subjects trial. It's a longitudinal prospective matched cohort study that involved 480 primary health care centers and 25 surgical departments, and they followed patients out for 20 years. And you can see here on the y-axis, we have the percent total weight loss on the x-axis is years. And what's interesting here is the circles represent the adjustable gastric band and triangles the vertical band of gastroplasty, so purely gastric procedures. And they have very durable, stable weight loss between 15 and 20 percent out to 20 years. Now, when you add that element of small bowel bypass with a room-wide gastric bypass represented here by the squares, you have a more substantial weight loss and similar durability. There are several types of endoscopic, bariatric, and metabolic therapies currently available or in clinical trials, and these break broadly down into two categories, either gastric or small bowel. The gastric procedures having more of a direct effect on weight and the treatment of obesity, and then secondary metabolic impacts likely due to weight loss. And these include your intergastric balloons, suturing and placating procedures, which I'll be focusing on, aspiration therapy, and other procedures. And then the small bowel devices tend to have a more direct metabolic impact independent of weight loss. They may or may not be associated with weight loss, and these include your duodenal liners, duodenal mucosal resurfacing, and anastomotic technologies and the like. And all these, of course, will be covered in great detail in other lectures today. Many of these devices and procedures attempt to mimic surgical analogs, while others are exploring more novel mechanisms of action. The exact physiologic consequence of suturing and placating is not clear. This may act very much like an adjustable gastric band or vertical banded gastroplasty and provide an element of restriction where patients will feel full earlier due to early activation of stress receptors. Or perhaps they delay gastric emptying, more similar to a gastric balloon, and then suppress ghrelin levels. Or perhaps they act more like a sleeve gastrectomy. And depending on suture pattern, perhaps they lead to more rapid gastric emptying or some kind of combination of things. So it's not entirely clear. And I think the more we understand these procedures and how they work, the better we'll be able to tailor these to specific patients. And it's important that we continue to investigate that. Another important thing to note is that these devices are cleared by the FDA for general indication of tissue opposition, but they do not have a specific weight loss claim. So that's another thing to keep in mind. So they can be used, but with that caveat. In 2000, the first endoscopic suturing device became available. It was cleared by the FDA and had approval for tissue opposition as well as the treatment of reflux. And this was some strong work by Paul Swain and Pete Lucan. And then in 2003, I started using the device for the treatment of obesity. We used it to address failed gastric bypass and closure of fistulas, but also started exploring it for primary treatment alternative. And then in the early 2000s, stapling and placating devices also became available. And this is where all these gastric remodeling procedures really started to develop. As we don't fully understand the mechanism of action for these procedures, I've broken them down based on their surgical analogs. And in many ways, these procedures were developed with an eye towards their surgical analogs or trying to mimic those. So it does make sense to organize it this way. And, you know, we'll start with the adjustable gastric band and sleeve gastrectomy as these really didn't pan out terribly well. But then we'll move on to our vertical banded gastroplasty analogs and our imbrication analogs. Starting with the adjustable gastric band, we have the transoral endoscopic restrictive implant system or TERRS procedure. And you can see placations are placed circumferentially around the lower esophageal sphincter in the gastric cardia. And little holes are also placed in those placations. And then little tissue anchors are put through those holes. And then a diaphragm is lowered endoscopically. And you have something similar to an adjustable gastric band. And this was a study from the Netherlands. And they studied 13 patients. And it took about 150 minutes per procedure. They had three months follow up with a 28% excess weight loss and a substantial change in BMI there. However, they also did have a gastric perforation. Unfortunately, this never made it through the FDA. They did pursue larger studies. But there was difficulties with these tissue anchors pulling out and the diaphragms not really doing a great job sealing up the cardia. So this is, of course, not available. There was one endoscopic sleeve gastrectomy type procedure that I was aware of and participated in. And this was a device by Power Medical. It was a flexible linear stapler that could be placed into the stomach paraurally. And you'd pull tissue into the jaws of the device. They would close, firing rows of staples. And then you'd resect the tissue. And there were several good animal studies that showed proof of concept with leak proof resections. However, human trials were limited to the resection of premalignant lesions. And we never were able to use this for bariatric purposes. Now moving on to our vertical banded gastroplasty and imbrication procedures. With the VBG, of course, focusing on creating a small pouch kind of along the lesser curve and excluding the growth curve and fundus. And the imbrication procedure is really focusing on folding in that greater curvature. So this is where we've had a little more success. We will start with the VBG analogs. And there are many types of suturing devices and stapling devices that have attempted to mimic this anatomy. This is what it looks like below in these images here in ex-debo porcine stomachs. The endoluminal vertical gastroplasty was the first endoscopic procedure to explore the VBG analog. And this was performed by Roberto Fogel from Venezuela. And you can see in the animation how the procedure is performed. He starts with a proximal stitch and places a second stitch distally. And then he alternates anterior and posterior, moving proximally again in a shoelace-type configuration, creating a small pouch along that lesser curvature, similar to the VBG. So he studied 64 patients. The procedure took him about 45 minutes. And what was quite impressive, he had a 58% excess weight loss at 12 months. And what was kind of more interesting here was that the smaller the patient was, say with an initial BMI of less than 35, the more weight they lost. And this seemed to be more than could be explained just by the math of that type of excess weight loss calculation with 85% excess weight loss in that category and about a 49% weight loss for those with a BMI greater than 40. Now, the problem with the procedure was durability. And the suturing device was only partial thickness, so the stitches were being placed really in the submucosal space because it was largely a suction-based suturing device. So that was the Achilles heel of that procedure, and it's no longer being performed. Next, we have a device that attempted to more directly mimic the VBG and perform something called the toga procedure. And this is a staple that's placed paraorally. You can see it opens up and has an anvil and a staple cartridge. And in the middle here, we have a sail that can be deployed to divide the stomach. And then a suction is applied and tissue is aspirated into the stapler from the anterior and posterior surfaces. And then the sail is displaced, and the device is closed, opposing the anterior and posterior surfaces, and then staples are fired to create that small pouch along the lesser curvature. This is then repeated, and then a smaller stapler is used to narrow the outlet. So this was an international prospective series of 62 patients. The primary endpoint was safety and endoscopic appearance of the pouch, and secondary endpoints included weight loss and other outcomes. And they followed the patients out for 12 months. There was a 24% excess weight loss at six months, and partial staple line breakdowns were seen in 13 of the 21 patients. And unfortunately, weight loss was really all across the board. So this device did not meet its endpoints. The pivotal trial was not successful with the FDA, and it's unfortunately not available. The most recent of the devices that has attempted to mimic the VBG is the EndoZip. This is a device I have not used, but it's alive and well here. And the device consists of an overtube-like structure and a curved needle. And tissue is aspirated into the overtube, again, from anterior and posterior surfaces, and then that needle is kind of pulled up through, suturing a small pouch along the lesser curve. And here you can see a single-centered prospective series that included 11 patients. Starting BMI was just about 37, and technical success was 100%. They placed two to four stitches. Procedure time was about 54 minutes, and they had a 16% total weight loss at six months with no serious adverse events. So very encouraging early results, and we're going to stay tuned as this is more rigorously evaluated. Shifting gears now to imbrication analogs. So in the early 2000s, while Roberto Fogel was focusing on the lesser curvature and trying to recreate the vertical band of gastroplasty, our group together with the Cleveland Clinic were focusing on the greater curvature and how we could fold that in to recreate this gastric imbrication procedure. And there's principally two ways to do this. One is to oppose mucosa to mucosa, and most suturing devices have approached it from this angle. You could also do this by folding the stomach in and opposing the serosal surfaces, so serosa to serosa opposition. This is really what the placating devices are accomplishing. The TRMM trial was the first study to investigate an endoscopic imbrication procedure, or what really is an early ESG here. And you can see in the video, we're doing complex, short-running sutures along the greater curvature, very similar to what we currently do with an ESG, moving from distal to proximal. And at the end, you can see there's a nice, tight little sleeve along the lesser curve, having folded in the greater curve. So in 2008, we embarked on a prospective series together with the Cleveland Clinic, and we studied 18 patients. The procedure was technically successful in all patients and yielded a 27.7% excess weight loss across the board, with a 30.5% excess weight loss in patients whose initial BMI was between 30 and 35. Patients had a 12.6-centimeter reduction in their waist circumference and improvements in systolic and diastolic blood pressure as well. Unfortunately, a few placations remained intact in one year, and all were disrupted in five patients, with partial disruptions in another eight. And this was likely due to the fact this was a partial thickness suturing device that was suction-based and only placing the sutures lightly in the submucosal space. There were no device or procedure-related serious adverse events, and all subjective measures did improve substantially. However, with the poor durability due to the superficial nature of the suturing device, this device did not make it to market. Now, you're probably sensing there's a common theme here with good early weight loss and then poor durability and long-term weight loss. And we thought this was in part due to the fact that the suturing devices were only partial thickness in nature. So they were suction-based, and oftentimes the stitches were only placed in the submucosa, which then could lead to early suture loss and weight regain. So in 2012, there was quite a development in that we had a full-thickness suturing device that became available. And this could also throw a variety of suture patterns. It could do running sutures or mattress sutures or purse strings or interruptives, a variety that really allowed several more indications as well. So this could be used for closing a fistula, oversewing ulcers, you know, a variety of things, including bariatric indications. Next, I'm going to show you how the device works. However, before we can do that, it's important to understand some terminology or the components of the device. So here we have the suturing handle, which basically you squeeze to open and close this curved suturing arm. Now, the curved suturing arm is what drives this needle, or it's also termed an anchor, through the tissue. And when it's closed, you then can advance the anchor exchange, or another term for that is the pickup, which you can see is this catheter here that runs down the endoscope, to pull the needle off of the curved suturing arm. And then this is a helical grasper, a helix, which is used to acquire tissue. So how does it work? We have this in the animation here. You can see tissue's first acquired and pulled into the device, and the curved suturing arm is driven through the tissue when you close the handle. The needle's picked up, so it's gone now. The needle has to be then reloaded so the device is closed, needle's put back on, and then tissue is again acquired, and the process is repeated. So it's rather straightforward. This is what it looks like in the room. The handle's squeezed, the device is closed, needle's picked up, the handle's squeezed again to close the device outside of tissue to reload it. The anchor exchange is depressed to put the needle back on, and then the process is repeated. This device is, of course, used to perform ESG, and you can see here the original suturing pattern is along the greater curvature, anterior surface, greater curvature, posterior surface. We move proximally and repeat that anterior greater curve posterior, and in two adjoined triangles. And then when that's cinched, you're closing the stomach down anterior to posterior, but also you're shortening it longitudinally as well. And this is, of course, very similar to that original imbrication procedure performed in the TRMM trial. First in human ESG cases were performed with this device in April of 2012, and here is Rob Hawes and myself performing this initial case here, which the suture pattern was very similar to that which we showed you in the animation. And we performed a pilot study in India and enrolled four patients that demonstrated safety and feasibility. We placed between 11 and 12 sutures in each of these patients with 52 to 56 stitches. BMI fell from 37.4 to 34.8 over five months. There are no significant adverse events. After that first in human series, we broadened this out to include several other centers, including those in Panama, the Dominican Republic, and Boston. And we enrolled 126 total patients across nine centers. You can see the baseline characteristics of these patients here. The procedure, we would place roughly 10 sutures, again, over 50 stitches, and the duration was about 94 minutes. There's no significant adverse events. Over one year, the BMI dropped from 36.2 to 29.8, and the percent total weight loss was 19.5. We presented our one-year results from the first in human and some early results from the expanded protocol at SAGE in 2013. It was a very interesting session. There were other procedures, such as one being performed by Santiago Horgan, looking at endoscopic gastric plication using an endoscopic stapler, which was a modification of that terrorist procedure. And really, this was spurring on some other plication procedures as well. On the heels of this work, the Mayo Clinic group was exploring a similar procedure. However, they were using interrupted sutures instead of complex running sutures like we were using. And you can see those here. And they placed many of these, up to 26 sutures per patient. And it led to a rather long procedure. But what they found in studying these four subjects was that there was tremendous durability there. And then that led to us actually incorporating these interrupted sutures as reinforcing sutures, just medial to those running suture lines. Moving on from this early work is some more rigorous studies. We have a prospective series on 91 patients from Dr. Reem Shariah and her group in New York. And they used the adjoining triangle pattern, so the same suturing pattern. But the initial BMI was a little higher than the prior work. And her results went out to two years. And you can see here she saw a 20.9% total weight loss at 24 months with an SAE rate of 1.1%. Now, she also looked at comorbidity resolution, which was novel, and found a one-point drop in hemoglobin A1c at one year in pre-diabetics and diabetics, as well as improvements in blood pressure, triglycerides, and liver tests. Dr. Shariah and her group also recently published five-year outcomes in a single-center retrospective series of 216 patients with an initial BMI of 39. And you can see here 68 patients were eligible for that five-year follow-up. And there was an 82% follow-up rate at five years. So a good follow-up there. And the total weight loss was 15.9%, with 90% maintaining 5% total weight loss and 61% maintaining 10% total weight loss. So very much in keeping with that SOS study that showed durable results for vertical banded gastroplasty and adjustable gastric bands. Her moderate adverse event rate was 1.3%, with no severe or fatal adverse events. So far, all of these studies have been done using that original suturing pattern with the adjoining triangles. However, there's been an evolution away from that pattern more recently with development of different patterns. And the most recent is the U-pattern. There's also variability in use of reinforcing sutures. Many use no reinforcing sutures. Some use running. Some use interruptives. And then the number of sutures also varies rather widely. So this is our current pattern that we prefer. We do a running suture distally. And then we do a U. And then we'll do an interrupted reinforcing stitch, followed by a U and an interrupted reinforcing, et cetera, until we've accomplished procedure. But really, more questions than anything remain regarding what the optimal suture pattern or number of sutures are. Next, we have an interesting multi-center international retrospective study with seven centers of varying experience. So some centers, this was really at the beginning of their learning curve. Others, such as ours, had been doing cases for a very long time. And they all employed the U-stitch pattern and four to six sutures without reinforcing. So there were some rules here. And we performed this in 193 patients. So some interesting findings here. The percent total weight loss was 15% at 12 months. And this was uniform across centers, whether you were a brand new center just starting or a more experienced center. All centers had greater than 10% total weight loss and greater than 25% excess weight loss on average. Predictions of success were also looked at, which was quite interesting, where younger age and male sex tended to do better. However, also, patients with a higher initial BMI did better as well. And you can see that here. Class III obesity tended to lose more weight in general, both at six months and one year. The SAE rate was also rather low at 1%, with two perigastric leaks, which required surgery. And that's quite good, considering many of these centers were at the beginning of the learning curve. The next study was trying to determine if number of sutures were important to weight loss. And it was really looking at a revision of sleeve gastrectomy. So it's just not a lot of data here in ESG on this. And you can see maybe there was a trend towards more weight loss with more sutures. However, there's really not a firm conclusion you can draw from this. And finally, we have the big prospective series from Al-Qahtani in Saudi Arabia. And he studied 1,000 consecutive patients using a U-stitch. You can see the baseline BMI was a little on the lighter side here at 33. And he found a 14.8% total weight loss at 18 months. Again, his weight loss trends were very similar to his patients with laparoscopic adjustable gastric band. SAE rate was 2.1%. Revision rate, this was another interesting point to his study. 1.3% of patients were revised. And many had a redo ESGs. However, what was quite interesting was he was able to reverse the ESGs endoscopically by cutting the sutures. And this was really the first time that's been demonstrated. He was very effective at doing that. And rounding out the ESG data, we have a meta-analysis. And this included eight studies with over 1,700 patients. Baseline BMI was between 33 and 43. And efficacy at one year is what you'd expect at 16.5% total weight loss with a 2.2% SAE rate, including things like GI bleed, perigastric leak, and fluid collections. And we also have many emerging devices on the horizon that promise to simplify these procedures and hopefully make them more broadly adopted. And this is one such device. It has a curved suturing needle that is on a cap that fits on the tip of the endoscope. And it can go on any endoscope, colonoscope, single-channel endoscopes, et cetera. And you can see here, tissue is being drawn into the device. And the needle is advanced through the tissue and just kind of repeat. Very straightforward. And we're doing a typical U-stitch here that we would do for an ESG. So this and many others hopefully available soon. Next, we're staying with imbrication analogs, however, removing from suturing to plication procedures. And there's two ways you can perform these procedures. You can focus on the fundus or you can focus on the distal body. Now, plications in the fundus are thought to prevent or limit fundal accommodation. And this is thought to lead to early activation of stress receptors, so earlier fullness, but it also may lead to a more rapid gastric emptying as food is thought to be transferred from the fundus to the intra more quickly. Now, distal body placations are thought to have the opposite effect where they can narrow the gastric body leading to delayed gastric emptying and prolonged fullness with food sitting in the stomach longer, potentially reducing ghrelin. The system most commonly used to perform placating procedures internationally is the incisionless operating platform. And you can see the various components of this here. It consists of a operating endoscope, which has four large channels, two of which are greater than six millimeters in diameter, one of which accommodates the nasogastric scope or ultra-thin upper endoscope, and the other accommodates a tissue approximation device. And this is used to grab and approximate the tissue. And then a hollow needle passes through this, this catheter here, which then deploys the tissue anchors. And then there's also a channel for the helical grasper. And this is what the user interface looks like. The snowshoe tissue anchors are seen more closely here, and you can see they're made of zero USP braided polyester. They're non-absorbable, and they have a nitinol cinch. And here you see the tissue approximation device holding a full thickness piece of tissue. The hollow needle is passing through that tissue, and the distal tissue anchor is visible here. The needle will then be retracted, the device opened, and the second tissue anchor deposited on the proximal side. And then the two tissue anchors reside in the stomach on mucosal surfaces. However, they're holding together this full thickness plication, pinching serosa to serosa on the backside here. And this just shows that this leads to durable plication formation. So here we see that the serosa is being opposed to serosa, and this forms permanent plications. You can see this in histology, and there are several studies that have shown that these are in place up to two years. And in fact, we've seen them out 10 years and longer. And here we have the fundal plication procedure, and the original pose procedure. And you can see the device being used in retroflexion. And here we're grabbing the tissue full thickness. The device is closed, and the hollow needle is passed through the device, and distal anchor is deposited. The needle is then going to be pulled back out through the tissue, the device opened, and the proximal tissue anchor released and cinched. So this is, again, focusing on the fundus. We were part of the original first in human work in the registry in 2009, led by Santiago Horgan. And we really got less than 30% excess weight loss here. They then repeated this study in Europe and got a little bit better. They were above 30%, but not quite good enough. They then tripled the size of the device and got to a 33 millimeter tissue approximation device. And you can see they really started to get much better results from the 60% excess weight loss range. And this is what the upper GI series would look like a year later. So rather durable change in the anatomy there. This was then subject to a rigorous multicenter randomized sham control trial with two-in-one randomization. You can see the inclusion criteria here. And we had co-primary efficacy endpoints, including the difference in mean total body weight loss with a super superiority margin. And then, of course, a responder rate of 50% defined as a greater than 5% total weight loss. And nearly 600 people were assessed for eligibility. And it was two-in-one randomization within the intent to treat analysis, 221 in the treatment group and 111 in the sham group. There were several issues and limitations with this protocol, one of which was the very limited number of follow-up visits after the procedure. The percent total weight loss in the treatment group was 4.95 versus 1.38 in the sham. And this was statistically significant. However, it did not meet its endpoints. Moving on to gastric body placations and distal pose or pose 2. Here you see a belt and suspender configuration with the blue lines represent belts and the green line suspenders. And in those belts, the placations are oriented in such a way to reduce the width of the stomach. And in the suspenders, the placations are oriented in such a way to reduce the length of the stomach. So we're making it narrower and shorter. And with the poor results of the essential trial, it led many to believe, including us, that perhaps focusing solely on the fundus was not a good idea. And then maybe focusing more on the body, similar to an ESG, might give better results. So here you see a distal placation going in along near the incisora. And again, this is a belt placation. So it's focusing on reducing the width of the stomach. Now, this was originally performed with a small grasper. And now we're doing this with a much larger grasper, which leads to a more narrow stomach at the end of that distal belt. Now you see a suspender placation going in here that's focusing on reducing the length of the stomach. And then we'll do a row of maybe three suspenders and then repeat a second row of three suspenders. And usually that distal belt might have four or five placations in it. Again, focusing on reducing the length of the stomach here with a suspender. And then finally, we'll go back and do a proximal belt following this. And you can see these steps outlined here as well. You can see kind of what this looks like here. It's getting quite narrow with the proximal inlet to the gastric body here. Here you see the results of our initial distal pose series. And we had a 100% technical success with a 15% total weight loss at six months and 100% achieving at least 5% total weight loss and 80% achieving greater than 25% excess weight loss. Dr. Lopez-Nava from Madrid has since published his series on 75 patients with a similar placation pattern. And you can see he had patients with all classes of obesity here. And the mean number of placations was 18. And procedure time, roughly 40 to 42 minutes here. And he had a 17.8% total weight loss at 12 months with a nice reduction in BMI as well. Another finding from that series was that patients with higher initial BMIs tend to lose more weight. So you can see here the green line is obesity class three. And they had roughly 20% total weight loss versus the class one in blue here, which had about a 15% total weight loss. And that's in keeping with the prior ESG study that we reported with similar results. Now for our last device, and this is, again, performing a gastric body placation. You can see tissue is grasped and pulled into the device. And then a hollow needle is passed through the tissue, very similar to the last procedure. They performed a multicenter prospective series with this device on 51 patients. And you can see the baseline characteristics here, BMI 35.1. They placed a mean of 5.2 placations per patient. It took an average of 97 minutes, and there was no serious adverse events. The patients lost 7.4% total weight loss. Now, that was at one year, and this might be in part due to where they're placing the placations. But also, this was, again, one of their very early series. So there might be more strategy in that as this evolves as well. Mean BMI reduction at one year was 7.1. And then follow-up endoscopy between six months and one year showed 87% of these placations were, in fact, still in place. So as we're coming to the end of my talk here, I thought it'd be nice to show you where these procedures fit in our spectrum of therapy, where we have balloons kind of on the lower end. We have our ESG-imposed procedures, or our suturing and placating procedures, sitting at about a 15% to 20% total weight loss. We have aspiration therapy. And then, of course, our sleeve gastrectomy at 25% to 30% total weight loss and gastric bypass higher, keeping in mind that these procedures are really designed for people with BMI between 30 and 40. And you can actually use these suturing and placating procedures in BMIs of over 40, as some of those studies are indicating that the larger the patients are, the more weight they are losing. However, we must keep in mind that they also may be very good candidates for surgery as well. And that should be an important part of that decision. In conclusion, endoscopic suturing and placation procedures are proving to be effective and have an important role in the treatment of obesity. More devices are on the way with the promise of simplifying these procedures and broadening their adoption. Better studies on mechanism and action are now needed to help us better understand how these procedures work and perhaps better tailor them to specific patients. And personalized treatment algorithms and combination therapies, I believe, are the keys to future success. Thank you for your attention.

gastric placation procedures

endoscopic sleeve gastroplasty

bariatric surgeries

metabolic impacts

weight loss

clinical trials

emerging devices