Mustafa Hussain, MD, discusses Updates in the field of Bariatric Surgery.
[MUSIC PLAYING] SPEAKER 1: So the objectives will be to review the scope of obesity epidemic and effectiveness of bariatric surgery. And the bulk of the talk will be update on long term outcomes, in particular, with relation to comorbidities. And then I'm going to shift gears a little bit, talk about some of the surgical trends, as well as endoscopic therapeutics for complications. So if you'll indulge me, I always like to start my obesity talks with this-- and if you'll notice the year on top, and the colors as they get deeper, represent the prevalence as a percentage of state population of BMI over 30. And again BMI over 30 is what we consider to be obese. And as the years go on the states are getting darker with a greater prevalence of obesity. And now we have new colors. You can look at Illinois, it's getting darker and darker. Well, Illinois is a holdout. Oh, there it goes. And Colorado is a holdout there. So in the last few years the obesity rate has stabilized a bit, but still I think something like 30% of the population is considered obese. And 60% of the population is actually overweight. And this is still a problem that is not under control. Just to review some definitions, the patients that we're talking about, again, are with a BMI of greater than 30. And those who are surgical candidates are those with a BMI greater than 35 with a comorbidity such as diabetes, hypertension, et cetera, or a BMI over 40 in of in itself. Not only is the nation getting heavier altogether, but the degree of obesity, or super obesity, also continues to be a problem. And actually is the population that's growing most exponentially, thus highlighting the severity of this problem. To date, the only effective treatment for obesity, and I know that's probably out on a stretch, is bariatric surgery. Medical therapy, very intensive medical therapy, with serial counseling, lifestyle modification, et cetera, does not work. Medications have a modest effect of about 7% weight loss. But nothing compares to bariatric surgery where the least effective is 40% of excess weight loss, which is approximately 20 percent of the total body weight loss in our least effective procedure. Going all the way up to 80% of excess weight loss, which is somewhere in the area of 40% or 50% of total body weight loss. After something very involved, which is called the biliopancreatic diversion duodenal switch, which combines making the gastric reservoir smaller and inducing a significant malabsorption component with intestinal rearrangement. It is the least frequently performed bariatric surgery, but currently the University of Chicago is the only area in the Midwest that performs it on a regular basis. For the remainder of our talk, I'll be talking about bariatric surgery. I framed the issue of the problem of obesity, and I just want to point out that less than 2% of the population that could get bariatric surgery gets bariatric surgery. Again, the only effective treatment for this problem. So how do I know this? That bariatric surgery is the only effective method? Well, this has been well-documented. This is a piece from the Swedish Obesity Study, which is a longitudal study, observational study of 2,000 patients who underwent bariatric surgery of various kinds, and those who underwent medical management. And they can do this in Sweden because of national databases. And as you can see on the bottom, regardless of the procedure they have, at the time of surgery there is some form of weight loss. And despite some degree of weight regain, weight loss is maintained out to 10, 15, and now there's 20 year data that's available, which I'll get to in a second. Those undergoing medical therapy usually gain weight or stay the same. In addition to the weight loss associated with various types of bariatric surgery, the resolution of comorbidities in particular diabetes, has gained a lot of attention. This is an older paper that assembled all the data from all the reports of bariatric surgery summarizing something on the order of 100,000 patients. And for the first time really elucidated that bariatric surgery at a snapshot in time does dramatically affect cardiovascular comorbidities. And it also matters what procedure you get. So gastric bypass, biliopancreatic diversion, those that manipulate the intestine, and as we've later learned, it manipulates the hormones that are released from the intestines have a greater affect on comorbidity resolution. Now, I think one of the major criticisms that there is, is the data is not long term enough. It's not robust enough. How can you suggest someone to surgery for being overweight? So hot off the press, this was presented at ObesityWeek in the fall of 2013, just published in JAMA. This represents those same patients from the Swedish obesity study who were diabetic and looks at their rate of diabetes remission. So the green bar is the surgical group, and the yellow bar is the medical group. So this represents those patients who have seen an improvement in their diabetes. Immediately after surgery in the first two years, there's a dramatic improvement in the remission of diabetes. However, as people regain weight, and probably more so as islet cells burn out, there is some recidivism to that remission. However, at 15 years, which is the last little group there, those patients who have had surgery still have a lower incidence of diabetes. So I apologize, this doesn't project well, but this is actually the first time that we've seen in this paper that diabetes remission actually affects vascular complications. So the green bar is the incidence of vascular complications. To your right, is microvascular complications such as retinopathy, nephropathy. So the incidence of patients out to 20 years, and those who've undergone bariatric surgery, microvascular complications is dramatically reduced. On the other side is macrovascular complications such as heart attacks, stroke, and peripheral vascular disease. And even in that group there is a statistically significant difference observed out to 20 years. And this was up until this point, only hypothesized that glycemic control achieved by bariatric surgery will eventually lead to better health outcomes. But now they've actually observed this in this cohort followed for 20 years. I'm going to pause for a second because I was pretty blown away by that. The other criticism that is out there is that not everybody who gets surgery sees this benefit. So is there a group that would benefit more, perhaps, and is that benefit lasting? And just like with medical therapy, if you have early intervention, and the top group is those who've been diabetic for less than one year, the middle is for between one and five years, and the bottom is greater than five years. Those who have been diabetic for a shorter period of time get more benefit from early intervention, just like it would with medical therapy. Again, probably reflecting islet cell reserve. So that's the long term data. And then the next question always is, well is there randomized data? And again, there was no randomized data comparing intensive medical therapy to surgical therapy for diabetes and obesity until about two years ago. And now this is a three year follow up. This is from the Cleveland Clinic, again, just published last month, which randomized 150 patients to intensive medical therapy. And by the way, that intensive medical therapy is way more intense than most patients see. It's meeting with their physician every three months to assess their progress and their hemoglobin A1c have to be greater than seven. And those were randomized against either sleeve gastrectomy or gastric bypass. So those undergoing surgery, which is the bottom two bars, either of the surgeries see a dramatic reduction in hemoglobin A1c, which is again maintained out to three years. Those in the medical therapy group initially benefit a little bit, but seemed to back up to where they started off at the end of three years. Moreover, those who undergo surgery, about 25% to 35% of those patients, actually what we like to refer to as being cured of their diabetes, that is with a hemoglobin A1c less than 6 and are completely off medication. Now, I think the term generally is remission, but out to three years is pretty good. Again, long term data from this cohort will be very important. Of course, surgical patients lost more weight and they also take fewer medications. Gastric bypass seems to have a greater effect than sleeve gastrectomy, again, probably because of the intestinal rearrangement. The exclusion of the duodenum that you see with the gastric bypass where a lot of hormones, quote, unquote, "antiencrotins" are thought to be made, which have yet to be identified that affect insulin metabolism. So I think at this point we can see there is long term and randomized evidence that shows that bariatric surgery in obese diabetic patients should be the preferred therapy. And actually is in the ADA guidelines and also the International Diabetes Federation, but yet still is not widely practiced. I'm just going to shift gears for a bit in our last few minutes. So if you remember in the last slide I showed you, I showed you that sleeve gastrectomy is nearly as effective as gastric bypass. Sleeve gastrectomy is a much simpler operation performed, much more appealing to patients. Quicker to perform, which is essentially the permanent removal of about 2/3 or 3/4 of the stomach. And much easier to perform in patients with significant comorbidity such as ours. So this operation was introduced as a standalone procedure in the early 2000s, and as of the last couple years it's now become the most popular procedure. This is from France, but also in the United States. But gastric band, which has gained a lot of publicity over the last decade plus is falling out of favor due to high complication rates as well as inadequate weight loss, and probably will eventually go away unless the President has one. All right. Someone's awake, good. [LAUGHTER] All right, sleeve gastrectomy in terms of the efficacy, at three years as good as a gastric bypass if not better, with 60% to 70% excess weight loss reported. But again, at six years plus there is some weight regain. There's a lot of hypothesis as to why that happens, either the sleeve dilates or it probably has more to do with psychosocial factors. In a strategy to augment weight loss after sleeve gastrectomy, the logical step after sleeve gastrectomy is to convert to a duodenal switch that is adding the malabsorptive component of intestinal rearrangement to that operation. When you do that, and this is a little difficult to see, if you can just look at the top line, that's weight loss with just the duodenal switch if you had one. And again very high, highest weight loss. The bottom line where the red arrow is, is those who've had sleeve gastrectomy alone. But when you add the duodenal switch in or add the intestinal rearrangement, which is, as you can see, leave the sleeve alone and add that to it, the weight loss essentially becomes the same, as does the improvement in comorbidities. So I think as sleeve gastrectomy becomes more and more popular, more and more people are getting it, people who fail that operation will become candidates for duodenal switch. I think you'll be hearing more about that operation in the future. And in the final minute, the sleeve gastrectomy tends to be, as I said, much simpler to perform than some of the other bariatric procedures, and more efficacious than the gastric band, which is arguably the simplest. But the sort of dreaded complication of this procedure is a leak from the staple line. It occurs in about 1% to 3% in reported series. These leaks are very different from leaks that we see in other gastrointestinal anastomoses within GI surgery. Primarily because not only is there a leak, but there's often also a distal obstruction because you've now made the stomach very small. And there's probably also either a stenosis or a kink there, which now serves as an outlet obstruction, which keeps this open. The sleeves are very difficult to control and the primary method of controlling these is endoluminal therapy. I borrowed these pictures from our colleagues, Dr. Gower and Dr. Siddiqui in the GI Department, who are international gastroenterologists. So that's a picture of the fistula, this is them cannulating the fistula, they've coagulated it to promote healing. And once you've done that, there's multiple things you can do to try to plug up that hole, there's glues, there's plugs, all of which the aim of which is to seal the hole temporarily. All these materials eventually go away, but the hope is that if you control the sepsis, and then in the next slide as I will show, you need to also open up the distal obstruction to control the fistula. Other methods are these newer over the scope-- I'm trying not to use the name, orthoscope clips, which are much deeper tissue grabbing then clips you would use for hemostasis. And can assist in closing the fistulas. The mainstay, though, I think is probably endoluminal stents. Again, not sort of off label for this purpose, but really useful. They need to be covered stents expanding large diameter usually nine in all stents. And the reason the stents work well, or the best probably, is they not only cover the hole but also open up the distill obstruction. Sometimes you may need more than one stents. Or if you can stack the stents on top of each other to open up the distal segment, and also plug up the hole as well, left in for 6 to 10 weeks. And there is probably, I'd say, 50% to 70% in reports from the meetings, but fortunately there's no large series of leaks. Sorry, last side. So just as a summary of this section, sleeve is becoming rapidly the most popular bariatric procedure. The complication rate is low, but leaks tend to be very difficult to treat. You really need a multi-disciplinary approach. You need to control the sepsis, drain the pus, stabilize the patient, obviously, if it's an acute leak. And gain some sort of enteric feeding, which I did not mention earlier, either surgical or nasojejunal tube, or if the patient can tolerate PO with stenting that is adequate, too. And there's multiple methods, but I think it's important, though, if these are not healing that they be referred to surgery.
