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The cryptoglandular theory. In theory, he explains why fistulas occur. And that's probably also true for fistulas in Crohn's disease a lot of the time. But that is different to what makes them persist. And that bit is the idiopathic bit. So that's why we say that. Um But there is a good theory that talks idiopathic disease with Crohn's fistula. Historically, people talked about the idea that there was an immunological fissure or ulcer within the anal canal which deepened with the passage of stool and ultimately developed into a fistula, which sounds like nonsense, doesn't it? If you think about it? I'm on board with the idea of an, of an ulcer driving a hole in the bowel which then fistulate out because there's sepsis where the hole was. I'm on board with that. But most of the fistulas we see in Crohn's disease are at the dente line, not related to a rectal ulcer. So I find that unconvincing and nowadays, anyway, we talk about etiology within Crohn's fistula as well as within Crohn's more generally, has been this poorly understood mishmash of genetic microbiological and immunological factors. This is a nice phrase that you might take for the exam, if someone asks you what the cause of Crohn's is, is how, well it's not, it's not known, but there is a combination of these factors which contribute and they will all sagely nod and stroke their beards. It's just the beer. No, it's not working. So we won't go into that. So, er, what's key and, and understood is that idiopathic and ran anal fistula occur and behave very differently. So, er, anal fistula outside of Crohn's disease are really quite rare, 1 to 2 per 10,000 patients, um, which is an incidence, whereas in Crohn's disease, admittedly, this is a prevalence. But nevertheless, the distance difference is sufficiently stark. I don't think that matters. So, one in three patients with Crohn's disease will have an anal fistula at some point in their lives. There is clearly a substantial difference etiologically between those two, but they also behave differently. They occur in younger people equally in men and women in Crohn's disease and they're more commonly complex and high and recur er, you'll be aware of Park's classification and this is the primary classification that's still used by most people, although there are others. Uh but if you understand parks, then you'll be ok. And so you've got in sphincteric, transsphincteric, suprasphincteric and extrasphincteric, which I've crossed out because they're not anal fistulas in the same way. They don't arise from cryptoglandular sepsis. They, they're caused by fish bones or diverticular disease or Crohn's or something which drives pathology outside of anal canal. It's also important to recognize the primacy of the intersphincteric space in true anal fistulas and that you can have extensions that run within the esu anal fossa through the levator or horseshoe round in any of the three planes that exist within the anorectum. So, pararectal or supralevator, ischioanal fossa and intersphincteric. Uh just I am. Yeah. Thank you. And so it is that in sphincteric gland, which is so crucial er on you go Jordan. And so the cryptoglandular theory was er, well, everyone calls it Parks's cryptoglandular theory, but he's still on the shoulders of giants and didn't acknowledge them in any meaningful way in my view. But it was Chiari like and Eisen and others who contributed to this and he kind of crystallized it and crucially, he created a beautiful picture, er which er I will show you in a second. Um There are anal glands arranged around the circumference of the er sphincter complex in the insc space at the level of the Dake line and they open up in the dentate line within the crypt there to allow mucus that they produce, to go into the anus and lubricate the passage of the stool, right? And then bugs just go the wrong way. That is the principle of the cryptoglandular theory and having crept up the canals into the lovely warm jacuzzi, that is the gland full of mucus. Er they then develop into the seat of a chronic infection which then bursts its way out. Next slide, please. And this is that beautiful picture where you can see the anal glands between the external and internal sphincters and the canal that runs into the um dentate line. So this is why everyone thinks of it as part's theory on you go. Er, so it can then spread, um, and it does so in any of these directions, it can come straight down as in sphincteric fistula or it can go up either side of this, anyone know what this is? Oh yeah, it is, it there, doesn't it, the longitudinal muscle um and it can come out through the external sphincter and having gone up, it can then go in or just sit there or it can come up and then burst out this, you know, there's, there's all of the different tracks that it can then take and this is all about part of lease resistance as far as we know. Um and Park's theory remains dominant. The cryptoglandular theory remains dominant. Um We all understand it and it gives us an idea about what to do. So it supports treatments which include destruction of the ins sphincteric anal gland. If you believe it still exists after a fistula has appeared and disconnection of the anal canal from an enclosed tract and adequate drainage of the wound. So, if your treatment does all of those things, it's likely your fistula will heal the problem is that the only thing that does all of those things is lay open. Everything else misses out some parts of this process and that's probably why they don't work, maybe why they don't work. Uh Next slide, please. Jordan S Cool animation. Right. Yeah. Yeah. Um Yeah. On you go next one. So why is it that the existing treatments we have other than lay open don't work? Well. Uh It's probably because there is more to it um etiologically and again, I'm talking now about persistence. So we understand about the physical connection within the high pressure zone, right? The internal opening and we treat that we're quite good at that. And we understand about epithelialization of the fistula and the nature of the tract needing to be widely drained or in some way treated. We get all of that, but we're not very good at this. And this is all about uh thi this is actually a slide regarding Crohn's disease. But with complex non Crohn's anal fistula, we haven't really found much evidence that they are immunologically substantially different to Crohn's fistulas. Yeah. Excuse me. Sorry to everybody online. I'm sure that wasn't a lot of fun for you. So there's I dysregulated in inflammation, probably driven by ongoing microbiological factors, not live bugs, but the L PS and other cell wall factors which um sit within the inflammatory cells and drive that propagate that ongoing inflammatory process and also a failure of wound repair which is probably evolutionary, right? Fistulas are there for a reason. Then if you had appendicitis back in the days of highlander, er, you would, er, die or your septic abdomen would drain through a fistula to the outside world and then you'd be alright forever. You'd just have some stuff coming out of your abdominal wall. So, it's an evolutionary protective mechanism, um, which has evolved to persist. So we're really fighting against nature when we try to eradicate fistulas, which I think is part of the problem. Ok. Next slide. So if you've got a multifactorial pathology, then you are ice skating uphill for the youngsters or undertaking a copy and task for the mature classical scholars in the room. In other words, you, you won't fix it unless you deal with everything and we know this right from peptic ulcer disease and H pylori and from anal fissures and straining. If you don't take out all parts of the problem, then the problem will persist. And so we have to think about how we are tackling all of those different parts of the pathology and fistula and we can't do that. And so we fail to treat them very frequently unless we lay them open. Ok. So, um let's talk about how we manage these fistulas. Then the assessment is er initially clinical, of course and often with examination under anesthetic to help complete the examination component along with imaging. And uh we use MRI and MRI is generally favored by most people. But there are some people who think an ultrasound is just better. I feel very passionately about it and it's ultrasound is definitely good for assessing the sphincter complex and it's good for to find the internal opening, but it's not very good for more complex tracts. And that's really when you need good quality imaging. So why would you do anything other than MRI and get good at reading MRI? Well, the answer is resource, you know, you can do it yourself. It's cheap and quick and all that stuff. And if you're in that kind of resource constrained environment, then fine, II understand it. But actually getting an MRI scan for a fistula is not generally very hard in the UK. Nowadays, at least in my experience he says as a consultant. Yeah. OK. Carry on. So, um for the clinical assessment, we're really interested in the history. Importantly, the impacts on quality of life. We're also interested in underlying causes like inflammatory bowel disease. O DS. Why have I said O DS is an underlying cause of fistula? Anyone know because of the bad type of digitation, the type that people do in their ba bums to get the stool out if they can't pass it out in the normal way and they can scratch a hole in the wall of their rectum. So you, you, you all all have heard of solitary rectal ulcer syndrome, but the kind of anal version of that, that's a bit more severe is fistula repair, er, er, fistula creation. And that is not only a way that you can create the fistula, but it's a brilliant way to take apart a fistula repair. You do a nice advancement flap. And the next day the patient puts their finger in their bum to pull out a hard bit of stool, they will destroy your beautiful repair. So it's a really important thing to reverse before you start getting into healing the fistula. What about ischemic heart disease? Why have I put that there as an etiological factor? It's because of a drug. Nicorandil. Well done. He said that. Yeah. Ok. All right. Points to Jordan. So, Nandi brilliant. Er, er, well, it's not brilliant. It's an old fashioned crappy drug for BP. Um, and, but there's still some old people still on it and, uh, they occasionally just let Perianal or Peristomal ulceration and fistulation stop the drug and it sometimes completely melts away, but otherwise becomes treatable. If they're still on the drug. When you try and treat it, it will fail and it can be quite destructive to perianal diseases. Just every now and again, someone gets sued. Colorectal surgeons get sued for not picking that up. So, do make sure you're always asking you about Nicorandil, particularly if they're a heart disease type patient. You're interested in their usual bowel habit and their current continence and whether they might have any occult sphincter injury because that will tell you whether or not you're gonna be able to lay the fistula open, assuming it's suitable to lay open. Morphologically, if they've got a normal bowel habit with good continence and no occult sphincter injury, then you'll be ok. But if they're opening their bowels five times a day to a loose stool or they're already to some extent impaired in their continent or they're not yet impaired in their continence, but they're right on the edge of that, having had a, an obstetric sphincter sphincter injury, for example, then you doing something relatively modest to them might tip them over the edge. Ok. On you go. So, uh er we're on to clinical examination. Now, of course, here's the external opening. Now, here you can see the change that altered demarcation that altered pigmentation, sorry. And that is the outer edge of the external sphincter. So this is a transsphincteric fistula, you can be fairly confident right away. Um Where is the internal opening gonna be? So, I've drawn this transverse anal line slightly on the wonk because otherwise this is just unhelpfully exactly at nine o'clock. So let's say that it's behind the transverse anal line, the internal opening will be and six o'clock and if it was here, it would be going straight in. So this is good. So's law usually true posteriorly less commonly true anteriorly, but still a useful thing if you're trying to work out where the fistula is. Um ok, thanks. Yes, there you go. So, er, we've talked about fissure fistulas. We won't do it again. Skip on please. So who do I image? So I don't scan an anal fistula if I'm confident I can fully assess it and I plan to lay it open, confident that I can fully assess it means that I can feel every part of the fistula between the external and internal opening with no evidence of um extension or complexity like induration or a second opening or anything like that. And if I, if it feels like that and I'm gonna lay it open, then I wouldn't scan them. That is very unusual. Almost everybody I will scan. So it's anybody that I can't fully assess clinically. I don't wanna find out that I couldn't assess clinically afterwards. Anyone whose fistula seems more complex than a simple low tract, any recurrence, anyone in whom I'm planning a sphincter preserving procedure because it will fail if there's a complexity that I didn't know about. And anyone with inflammatory bowel disease, radiotherapy, et cetera, et cetera. So that is the majority of people in my practice and it's probably the majority of people in most practices need a scan. You wouldn't take on a cancer without a scanning, basically don't do any abdominal operation without getting cross sectional imaging, right? So if you don't fully understand the fistula, then do a scan this old um the, the thing that old white men like increasingly I am say to young people. Well, if you knew how to clinically assess people properly, you wouldn't need a scan is bollocks and none of them would undergo a fistula operation without an MRI. None, none of them. So do it for your patients. Uh This is the comparison between MRI and endo anal ultrasound. I've talked about this. The key is that the um complex tracts are definitely better seen with MRI. And you don't know that it's complex until you've scan them. So just scan them and get an MRI rather than end ultrasound. OK. Thanks Jordan. So you can see this fistula really clearly. I'm not gonna point to it, but you can all see it right before I point to it. You can all see it. You know, when someone shows you a picture of an endorenal ultrasound and they've drawn a red line on it to show you how easy it is to spot the thing that they're talking about. Well, you don't need to do that with MRI. Scroll on down. So go back up Jordan for us. Thank you. So, this is a transsphincteric fistula. Here's the internal sphincter, here's the external sphincter, go on up and it's coming outside. Here's external sphincter between. So there's internal, external sphincter between the tract and the internal opening and there it is reaching across to the internal opening. It's very easy to see that, right? You can all see that without me pointing it out. So it's a nice way to assess fistulas. Ok, let's talk about treatment. So, um, this is a lifestyle disease in the main. Um, obviously, it's important to rule out send to pathology first. But with any lifestyle disease, it's important to recognize the value of the symptoms, the importance of the symptoms to the patient and their impact on quality of life. And that will vary according to the nature of the symptoms and the person who has them. It's important to recognize the risks of intervention, but to go ahead and intervene anyway. Ok. So there is risk and a lot of what I'm gonna tell you will make you more anxious about operating on fistulas. But actually, I want you to operate on fistulas more because despite the risks, you can do a lot of good for these patients. It's important to recognize the underlying etiology. Sorry Jordan, to completely characterize the fistula anatomy and to understand the patient's goals and symptom burden and you'll tailor your offer to those. And that is advice that stands for any lifestyle disease. And certainly all the way through the fistula afternoon that we're about to talk about. Ok. There are always three options with managing any anal fistula. Those are to lay it open to place a long term loose seat on or to try to heal it without laying it open. They will all have different risks and benefits depending on the patient and in some of them, one of them will be almost wholly unsuitable, for example. But there are always those three options and I always describe all three with any patient that I'm seeing. Um, so who can you lay open? So, we take a view on this and, uh, there are no hard and fast rules here but most people broadly will agree the patient should have good continence, a normal bowel habit and no underlying bowel disease. The fistula, um whether or not it's in er, an intersphincteric or ex or, or transsphincteric fistula does carry some impact. But in the majority of fistulas that you lay open is the internal sphincter division, which is driving the majority of the continent's impairment. The external sphincter is like kidneys. Ok. You have more kidneys than you need just in case it is true for external sphincters for most people, but not all people to. And so as long as you're leaving behind a couple of centimeters of good quality external sphincter in someone like this, they will be ok broadly with their continence. But any time you cut any amount of internal sphincter, they will immediately incur that risk of minor continence impairment that I talked about regarding fissure, uh um sphincterotomy for fure. So we call that a one in three risk of difficulty controlling wind and skid marks minor continence impairment. Of course, it's up to the patient to decide whether they think that continence impairment is minor or not. And depending on their job and, you know, where they are in their life, they might think it's not, not a, a minor at all. And that's the consent component of this. They'd have to accept that one entry risk if we were gonna lay their fistula open. So, if the fistula is low enough and this is what we think is low enough that you're allowed to take your own view on that and be more conservative. And, and some people will say, you know, 30% of the sphincter complex, anything more than that is high and so on, people take different views. But as long as the fistula is low enough, the patient is um good substrate and they accept the risk, then you can lay the fistula open. OK. This is the kind of decision that you need to uh uh make and then offer to the patient. This is the hard bit a confident that what you're saying here is true. If all of this is true, then you'll be fine. But it's very easy for me to say that. Now, it's a totally different thing when you're dithering three and you're seeing the muscle fibers spring of hearts. I accept that, but this is all true. Now, there are times when laying open is not as safe as it seems. So, first of all, let me remind you the one in three risk. OK. That remains the crucial central part of all of this. But if they've got loose or frequent stool now or in the future, for any of these reasons, for example, then laying open is not as safe as it seems. Those patients need more muscle than the rest of us do. If they've got preexisting incontinence or they're close to it, they've got an occult incontinence not yet showing itself. And you will all have seen those middle aged women who have had a couple of kids and they're not actually incontinent, but they're really uncertain about their continence. They've never had an accident, but they know that they need to know where the toilets are all the time and you can make the argument that they're not genuinely incontinent, but they're super duper close to it and they know it and a small injury to those people could have a big impact. So that's what I'd mean when I talk about occult incontinence and those may well be people who have had no oasis in the past. So those people definitely not this person just uh flick through the scans, please. Jordan. You can see that is an anterior fistula in a woman. Ok. You can see that fistula not quite so clearly, internal opening, transsphincteric tract down to the outside world. So that's an anterior fistula in a woman. And as we discussed, previously, women have shorter anterior anal canals, the deficiency in puber recal anteriorly makes it hard to judge height. So it's not even easy to know if there's a lot of muscle above. It might also be the site of their occult injury. So we should exercise extreme caution. And in fact, most people say you just shouldn't lay them open, you can occasionally lay open fistulas in this setting, but they have to be really low and the patient has to be very clear and well, well counseled this, this is another er, opportunity for, for risk, ok? If you're laying open, now, when you, when you assess the height of the fistula and that two centimeters of muscle that I was talking about and you may use a different length. This is the distance that you're measuring, right? This distance is how much external sphincter will remain after you've laid the fistula open based on the position of the internal opening, right? All of this will remain. However, if the tract travels obliquely careful a through the fistula er through the sphincter complex, then it crosses the external sphincter higher, then it crosses the, then the internal opening is. And so when you feel this and you think, oh, I've got all of that red arrow, I'm laughing. This is golden. In fact, what you would leave behind is the purple arrow and that is not so much fun. So you'll cut up more muscle than you think, identifying keflet obliquity is not possible. Clinically. All you can know is that when you're trying to feel this running your finger between the external and internal openings, you will not feel the fistula tract cos it's 1000 miles away. If it was coming straight across or down, then you'd feel it. But way up there, you're not gonna feel it. So these people are anyway, in your practice now going to get an MRI scan. So you will know that this is the case. So you don't have to worry about it, but you need to be aware that this is the case. Ok. Um And then occult C Crohn's disease and we talked about the frequency with which um patients um present with occult Crohn's disease with an abscess. We know that perianal disease is the first manifestation of perianal dis disease of Crohn's disease in 10% of patients with Crohn's and that it's the only manifestation in a few which makes it an opportunity for earlier diagnosis like Fara said in her talk, but also a danger for fistulotomy. So you have to keep your eyes open and say to yourself, is it possible that this fistula is in the context of Crohn's disease? And that will sometimes be really easy to spot. This is that fissure I was talking about. Yeah, sorry. Carry on this is that deep, horrible fissure that I was talking about that one. but you can see these horrid pictures of um perianal disease and, and in this setting, you would obviously spot it and not lay that fistula open, but it's not always this obvious. Unfortunately. Ok, next one, please. So you're gonna place the probe inside the fistula divide along it and then shape the wound de roofing it or sorcerers the wound using marsupialization and maybe a salmon backcut, which is where you extend the external component of the fistula, er wound in order to allow drainage out into those tissues. So, winds shaping is probably very important. I spend a lot of time on winds shaping and these are some examples. So that's just a drainage really. But here you can do, I've laid open this whole external component and I've marsupialized the edges where it's needed it. And here's the same, here's the um sphincter complex. Ok. I've made my incision outside of that to completely drain all of this external component where there were previously additional additional external openings. And you can see that's really nicely sorcerers and wide. The patient can digitate that wound really easily and that will heal as a result rather than simply skinning over and recurring. You don't need to pack it uh when you're curetting an extension, it may be that you find a bit of granulation tissue that won't go, you keep scraping it and it just won't go away. And that's because you're not scraping the granulation tissue off where it's come from. Instead it's poking out through a hole of an a from a, an additional tract and where it connects to that tract is down that hole, so you'll never be able to scrape it off. So if you have a bit of granulation tissue, you can't remove, pick up a probe, put it onto it and it will disappear down a hole into an extension that you didn't know existed. Ok. Next slide, please, sometimes even placing a seat on is a risky thing to do. Um, here is a straightforward fistula to place a seat on into. Right. You just you put the probe in and it just kind of slips gently up in a straight line, curving gently away from you into the anal canal. Very straightforward. This is a much more difficult tract to put a probe into cos when you get to here forwards is like this. And instead you have to tip the edge of the probe backwards and it's now coming down towards you away from the patient while still inside them. And it's often the case that in this setting instead of doing that nice curve and getting round patients will do this. Surgeons, sorry, will do this, go ahead Jordan and find the internal opening through the top of the tract. So this is an iatrogenic injury. And if you find a fistula with two internal openings, it might be caused by Crohn's disease or it might be caused by a surgeon. It's very important to try to avoid doing this. And if you get to this point and are not sure you can't move forward you're not sure what to do. Then just back off, it's a very reasonable and honorable thing to do. You could also pick up the right angle probe and put it through the internal opening. And once you get up here, you may find it easier to slip around this way. So I would try it from inside first. If you're not sure where the internal opening is, inject some hydrogen peroxide or milk, show yourself the internal opening and then try and probe it from the inside. Avoid that arthrogenic injury like the plague if you can. Next slide, if you don't. And this is just to prove that it's real. Here is the first tract. Click on that, please. Jordan. That's the real primary tract doing that big turn that I talked about and there's the arthrogenic injury up into the rectum. So this is an incurable fistula now and it's a real headache. So it would be best to avoid these things if we can. Er, ok, Setons however, are a really useful thing to, to have in your arsenal. Um, long term loose setons are er, an entirely honorable option for the permanent management of an anal fistula. If patients don't want any more surgery, they don't wanna get abscesses, they don't wanna get continent impairment, put in a comfortable loose seat on and they can live forever like that. The E one C ons that we use are comfortable for most patients. They will last five years before they denature and break. Yes, sir. So, you know, as soon as they get uncomfortable crusty or break and fall out. And so, no, and so for an eon set on, we reckon that they'll last about five years for a Cyla set on, it's probably more like a year because they're just fragile and eventually they just dry out. Correct. Yes. And for a comfort drain, which is the knotless seat on, it will fall out before you have a chance to worry about when you're gonna replace it anyway. That is different. Sorry, Jordan just go back for one second. That is different from a bridge to surgery seat on. It's a holding maneuver that is the same seat on, placed in the same way. It's exactly the same except the ones you've got the seat on in there, they can then pause and you can go on and do something else down the line. So you're not, you're not fixing things. You're not casting the dye when you place a seat on a permanent loose seat on, you're just giving them the opportunity to pause and think and if it stays forever, that's also fine. We shouldn't use it because we don't know what to do. I mean, you can use it temporarily cos you don't know what to do, but you shouldn't use it permanently because you don't know what to do if you've placed it and you don't know what to do. Then refer right. And that's what you would do in any other situation. That's exactly the right thing to do. You have achieved stability. That is a great thing. Now, let someone else think about what they can do next if you're not sure what to do. And these are the different, thank you, Jordan. These are the different types of seats and this is what we use and these are different ways of tying the Silastic ves vessel loop setons. And that's the other way of tying a, an Obon Seton. So those are bulky or spiky your choice. And these are a bit less bulky but still a bit bulky. And this is what we do. There's a single knot, a single surgeon's knot in one ETI bond tied back with 20 silk with a reef knot and a single safety on top. So there's nine throws here, but they're along the seat on rather than coming away from it and they're in a single place and it's small. Not everyone agrees that this is the right thing to do and the clastic setons are entirely reasonable. In fact, that's what most people in the UK use. So it's ok to do that. I just wish they like them anyway. There we go. And then there's the sphincter preserving procedures. Now, if there are 20 ways to do something that means that no one has yet found the right way to do it. And there are more than 20 ways to treat fistulas that aren't lay open or seat on there is of course, a good way to cure fistulas. But that balance between risk if you know, the good way to cure them is lay open. But the balance between that high quality efficacy and the problem of continent impairment is, is the issue and that's why we need sphincter preserving procedures. There's a whole bunch of them. But when you split them up according to how they work, then actually, er er spin on Jordan, please, then actually there's fewer of them if you think about them in that way. So some of them lay open the tract and then try to pretend that they didn't, some of them disconnect the tract from the gut, others fill the tract, some excise or obliterate it and so on. There's just different ways of doing those things with different, different uh some different characteristics. Another way to divide these up is to think about how sphincter are preserving, they genuinely are. So you've got sphincter dividing treatment at one end and then at the other end, you've got things that are definitely sphincter preserving. But in the middle, there's a whole bunch of stuff that we call sphincter preserving, which isn't completely. So advancement flaps carry some continent impairment risk and damage the sphincter, fistulotomy and immediate sphincter reconstitution definitely damages the sphincter. You just hope that having repaired it, they'll be ok. Whereas these things don't but these things don't work well. And recurrent sepsis also damages the sphincter, recurrent sepsis. Recurrent drainage, recurrent surgery will also damage the sphincter. So doing this, if it keeps failing is probably not protecting the sphincter either, you probably have to think about moving along this line towards things that are more likely to work at some point. Ok. On you go choosing which one to do is mostly about unsuitability. So all of the sphincter preserving procedures are suitable or not depending on a um er according to the nature of the fistula. So for example, advancement flaps don't work. You can't do it if you've got rigid scar tissues, cos the tissue just won't move in the way that you need it to, you can't do laser. If you've got a wide track or side branches, you can't treat them, you can't do VAF if the track is too narrow, you can't do a lift if you've got intersphincteric complexity or the fistula is too high or the internal opening is too deep and wide. And so the fistula will tell you what your options are on. You go, please. And most of them want the same similar morphology, which is a straight unbranching transsphincteric tract. And there are minor variations like the width of the thing and the nature of the internal opening which favor one or another. But basically that's what all of the S PPS are designed to treat next slide, please. Um Andy Williams, great fistula surgeon down at guys and Tommy's just retired from the NHS. Sadly says that fistula treatments of any type are successful no more than 60% of the time, regardless of what the literature says, Robin Phillips, my old boss and mentor said lift and Advancement flaps probably work half the time plugs be crap. Everything else is crazy. He was a character but broadly speaking, he was on to something. And what he's suggesting is that there are workhorse operations and then there's everything else which works a little bit of the time that probably is not very effective, but they are preserving of the sphincter and patients like things that won't damage their continent and won't stop them having a chance at something else in the future. And that's what the plug does. That's why people like it. That's what laser does might fail, but it won't make things worse and you can still do whatever else you are planning. And so people quite often want that. So lift, um we're gonna do this in a second. You make an incision in the intersphincteric groove, deepen that incision to identify the fistula and get around it. That's the tricky bit is getting behind all of this. Then you're gonna tie it off or stitch it off on either side. Mostly what people do is put a tie around each side and then divide it, maybe excise a chunk if you can and then close off these openings either side. Ok. So you're in the ins sphincteric space, you're closing off the tract either side of that space and then you excise the external component and close the wound. Uh So you need a single strength tract, no intersphincteric complexity and appreciable intersphincteric space. Cos that's where you're working. If you don't have a space there, you can't do it and the fistula can't be too high. People say because it's hard to reach, which is only partially true. It's mostly because of risk of injury to the rectum. And that is shown by these champagne glasses. So when we draw the anus and the rectum, we draw it like this, right, you draw a straight line down and it goes in a bit and comes out and then you put the muscle here and you say that's what it looks like. Whereas in fact, the rectum and the anus are this shape at least posteriorly. So actually the rectum forms almost a right angle with the pubertal sling whipping around it. Not like this at all, but like this and that matters if you're thinking about a lift because if the fistula is down here, it's OK, you've got loads of space. But if the fistula is higher up, then the space you're working in is right there. Excellent, please, Jordan right there. And that space being small when you go round the back of the tract, which you do blindly, you'll see when we do it. You have a real risk of injuring the rectal wall. So the fistula being too high is a problem because of this space. Not because it's hard to get to. It is better if the tractor is down here. Ok. Uh, this is what it looks like in real life with a lone star. I don't know if we're gonna have lone stars. It's great if we do, but we may not. Um, But you can see the Intersphincter section I've got around the track here. There's the fistula tract itself. Put a tie on either side. Next slide, please cut through the middle, having tied the ties and that leaves you with an end here and an end here. Put some stitches to close those off. Excise next slide, excise the external components. So there are the stitches and then excise the external component down to the external sphincter and then close the wound. So that's the left, right. That's what we're about to do. Everyone got those pictures firmly in their head. That's what you need to reproduce in the pig in a moment. So you Yeah. Oh OK. There's a link to a video. Oh OK. Brilliant. It was no idea. Yeah. As long as it shows the steps uh Yeah. So just go back one slide in closing the wound. Something that Aria Saper taught me is to offset the ends. So instead of just closing the wound with the two ends of the fistula next to each other. What she did is put a stitch one side and then the other side of that. So that when you pull that stitch together, the ends move away from each other and are offset from one another, which may make a difference. Who knows? I like it. I think it makes a lot of sense and it doesn't cause any harm. So I'm happy to do it. So that's what you can see me doing here. Thank you Jordan. And then you just close the window. That's what it looks like. Ok. It's a really, really nice fun operation. 45 minutes. Very technical. It's just you and the anus, you know, you really, you can get into it. It's a lovely, lovely thing to do. Um There is secondary success with this. Normally when people talk about secondary success, what they mean is we did three plugs and they all failed and then we laid it open and they healed. So it's a secondary success for the plug. This is untrue, OK? This is a genuine secondary success because you can downstage the fistula from transsphincteric to inter intersphincteric. Sometimes when it recurs, the external component remains healed, but the fistula recurs down the intersphincteric wound. That is then by definition, an ins spincter fistula, you can lay that open. So that is genuine downs staging secondary success. Unfortunately, it is balanced by upstaging of the fistula where sometimes the transsphincteric tract recurs and you'd get an in intersphincteric tract down the wound as well. That is now a worse fistula than it was. So, that is upstaging most of them when they recur simply recur as transsphincteric. Uh, sorry, why is it worse? Er, because you've now got two external openings, you place two seat ons, you can't do a lift again. You could still do an advancement flap, you could still lay it open if you could ever lay it open. But any other option that you've got, you can't do a plug lasers much harder and more likely to fail. So all of your options are less likely to be effective. Ok? Er, the data we'll just been through very quickly but there's er, systematic review data lift procedure. 70% success. We say 50%. Remember Robin Phillips. Um 2% minor consonant impairment, some upstaging and some downs staging. That is the ups and downs of the lift procedure. Ok. Advancement flaps. Um, they can be mucosal partial or full thickness. They can go from the outside in or the inside out, inside out is what most people do for most fistulas. They can be traditional, the ones that you're used to seeing. And Harry was talking about the idea that the base of a flap should be three times the width of the tip of the flap. Um And those are the traditional flaps that he's talking about. There's the Delon style Advancement flap where you sort of do an intra anal delos raise the mucosa fold down, plicate the um the muscular wall of the rectum to cover the internal opening and then make a mucosal anastomosis. On top of that or the church style flap, which is where you raise the tissue, both sides of the internal opening, close it and then uh excise the the the mucosal level of the internal opening and then make a flap over the top. That flap is on top of the internal opening that you've repaired. So the risk of recurrence is probably higher, but sometimes it's all you can do because there's not enough tissue or not enough space to move a flap from above, very easily. So those are the different types that you can do. Um So this is a picture of a traditional advancement flap and that's what you'll be used to seeing, right? You lift the flap, excise the internal opening at the mucosal level, repair it deeper and then put the flap back on top. Everyone understands this is a, well, this this picture is just mucosal, we'll, but we'll talk about the difference in a second. That's a very, it's an important point. Next slide. So whether or not you should do purely mucosal flap or you should include some muscle is again a balance. The data are mixed. But in essence, they show, I suggest that if you take a deeper flap, there's a greater chance of successful healing of the fistula, but a greater risk of minor continence impairment and a deeper flap means taking all of the internal sphincter and rectal wall or taking part of the internal sphincter and then all of the rectal wall. Um, some people talk about a partial thickness flap, but really, I think what they mean by that is that they don't know how thick their flap is and I sometimes say, oh, I think it's probably partial thickness because there's some muscle in it, but maybe not quite as much as I wanted. It can be very difficult to be certain about that. But the more muscle you take, the greater the chance of success, the greater the risk of minor continence impairment. This meta analysis did not separate them out as mucosal and full thickness, but came up with a success rate of 75% and a minor continence impairment rate on the next slide of about 10%. 8%. I think if you're doing a proper full thickness flap, it's got to be at least 15% and it might be as high as one in three and that's why I can send people for it. Uh This is the F trial um which was designed to show that the plug is amazing. It did not, it showed that it's OK. Uh Compared to other options for um fistulas, fistula repair, cutting setons are probably not supportable in the modern era, although lots of people still do them the evidence that they are a fistulotomy without the risk is not good. People always say that it preserves continence. There is not good evidence to support that assertion. And if you're doing it in a low fistula that you could open anyway, who cares? Except that it's more painful for the patient because the pain lasts for weeks. But if you're doing it in a high fistula, then there's potentially a real risk that you're causing harm, believing that you won't. So cutting seat on is not advocated by any of the international guidelines any longer. Laser er you put the laser probe into the fistula, you burn it as you pull it out and then you stitch, close the internal opening, you can only use it in simple straight tracts. Um Next slide please, Jordan. Um The big study was er Wilhelm and he found a success rate of around about two thirds. I can't get it that high. I don't think most people can. I think it's no greater than 50% and it may well be less. Uh Sam Egba, one of my old research fellows put together a meta analysis on this and identified that the success rates varied quite a lot. There's a suggestion the healing is as high as two thirds. But in practice, I suspect that these numbers are more accurate and probably saying 40 to 50% is reasonable, but it's very safe. The only real risks are those of recurrence without any incontinence being reported and it doesn't stop you doing something else as your next attempt. Ok. Curative Aft is uh a telescope in the tract where you burn out the inner, internal surface of the fistula and then close the internal opening, same principle as laser, but you can use it to get round corners and you can find um branches and cavities and burn those as well. This is what it looks like to go inside a fistula tract. That is the entire, yeah. And then you can just burn all that out and you can see how you can find your way and find this is a branch that's off. You can't see the seat on, it was off over there. This is an extension up in the eu anal fossa that we're running up in and you can burn that separately from the rest of the tract. If you want to, you can spin on er, er Jordan. It doesn't get any more interesting. That's what it looks like after you've burnt it. Uh again, very mixed data. Some people will say as high as three quarters of the time it will work. I think it's no greater than 50%. Um That's no incontinence. Very little morbidity. You just must be careful that you can burn structures that are next to the fistula, the tract. If you're not careful, I have done that to one urethra. That is a bad complication for a fistula repair. So, do be careful over the scope clip. Um, there's probably not enough data to talk about this in a meaningful way, but it's the bare claw that goes over the internal opening that you've probably seen, it's supposed to bend and stretch. They don't, so that it, as the tissues swell, there's not the same tension all the time. And so it doesn't cut through the tissues. That's the idea. Um, they, er, migrate, they cause pain and people have to go back to this and have the clip removed occasionally. Doesn't seem to me that it's any better than a flap or a suture repair. But you know, we'll see, maybe data will show something different in the future and this is fissa or fip the fistulotomy, immediate sphincter reconstitution. The data are limited here because of heterogeneity and complexity and height of the fistulas that have been studied. So it is very hard to determine a true continent impairment rate in high fistulas who are the only ones in whom it matters. So this might be amazing, but I don't think we yet know very high success rates are claimed. The impact on continence in high fistulas is to my mind. Unclear. Proponents say it's low, a low risk. So classify and map the fistula, completely think about how you want to image as long as you do one of them, you'll have a complete understanding of the fistula when com combined with eu A probably MRI is better lay open where you can and where the patient consents. If you're gonna use a seat on, it should be comfortable. Palliation should palliate. And if you're gonna use a sphincter preserving procedure, you've got a fit, the, the one you choose to the fistula and to the patient, but they often fail and the patients must know that up front. If the fistula is the wrong shape for um the SPP that you want to do, you can rationalize the fistula to change its shape, get rid of extensions and branches um by laying those open and simplify the fistula. That's the other important point about these. That's it. H questions about fistulas. That's a lot, there's a lot of fistula information there. I'm sorry, it's heavy but they are complicated. OK? Will spin straight on. This is a more fistular conversation. I'm really sorry about the click here, Jordan. Why don't we try again? Because it's a bit rubbish for you to have to do it. So, one more quick talk on this Perianal Crohn's of vaginal fistula and then we're into doing a lift. Oh Is that you? Ok. Cool. So uh Perianal Crohn's disease um has been denoted by the, oh my God Perianal disease modifier in the Montreal classification of um Crohn's disease, which you will all be aware of. This is not a particularly helpful classification system. Perianal Crohn's is more than just fistulas. You get tags, fissures, ulcers, strictures as well as the suppurative complications here are some tags and these are really postinflammatory polyps, right. That's what they look like, isn't it? This is overgrowth of tissue when, when there's been erosion of other tissue thanks to inflammation. But you can also get these deep fissures which are really ulcers in any meaningful sense with ulceration and tissue loss seen here as well as fistulas. And that's a obviously attract into the vagina with an uncomfortable seat on going into the vagina. They will want aceton in their vagina. We will talk about that later on, but you can see that these all represent Crohn's disease. This is our algorithm at Saint Mark's for managing non fistulated perianal Crohn's disease and it is not rocket science and mostly it talks about medical treatment with a few surgical options. And I think that is true for fissures, ulceration, stenosis and strictures. They will mostly be managed with medical treatment alone, but there are obviously some options, er, surgically. Um The fistulas currently, the way people manage Perianal Crohn's disease should be via an MDT within a joint clinic and is probably mostly things like drainage and seat on medical treatment. Maybe take the seat on out. Occasionally people undertake attempts of fistula repair. Have any of you seen attempts of fistula repair in Crohn's disease, lift or flap or anything like that. It's pretty rare, most people don't do it. Um And then defunctioning if everything's going to pot, that's what most people will see, um that's really not adequate and most of our patients probably don't get anywhere near an attempt at surgical repair, even though many of them could. And the best that we offer most patients is palliation even when their fistula might be surgically repairable. So how do we think about perianal patients? How do we differentiate between them, those that we might send for surgical repair? So this is the new answer to that question. This is a new classification system which encourages us to think about where patients are in their fistula journey in the context of Crohn's disease. So that we can wonder whether they might be suitable for an attempt at repair if they're class two A or whether the best we can do is control their symptoms with medical treatment and C OS or whether they're drifting in the direction of a defunctioning stoma or whether even that is inadequate and they need proctectomy, which unfortunately might lead them on to a persistent perineal sinus. So all patients with Perianal Crohn's disease fit somewhere within this classification system. And we hope that it helps people to decide how to manage them. We divide them, we classify them according to their goal, which is a first as far as I know for classification systems, their symptom burden and quality of life, the anatomy of the fistula and the presence or absence of anorectal disease, which means proctitis and kind of floated perineal disease, like the pictures I showed you earlier. So, um there will be some patients who have very minimal disease and they don't need anything doing. You can ignore them. It may be worth scanning them intermittently. Most patients will be here with chronic symptomatic fistulae class two patients and some of them. Um, and the medical treatment that they can have is much better now than it was a few years ago. It used to look like this five A SAS, no benefits in perirenal disease, corticosteroids, er Luminal disease, but probably make Pernal disease worse azaTHIOprine, some value in controlling symptoms but probably doesn't heal fistulas. Antibiotics, usually in combination with something else can improve fistula symptoms but won't heal them. Tacrolimus and thalidomide again, probably only palliates and improve symptoms rather than healing fistulas. But in 1999 we got the um biologic agents, right. So we've got Infliximab and now a bunch of other drugs as well and they actually do heal fistulas and can lead to very rapid improvement much faster than the previous treatments that existed. These are the original accent two data, which was the maintenance trial of Infliximab and paranal Crohn's disease, which suggested that in the patients in whom the fistula closes. M um a third of them will stay closed at a year on continued treatment. So half of them closed uh at induction of Infliximab and then a third of those half stayed closed at a year with ongoing infliximab treatment. That's not a lot of patients. Once you start to pin it down, we also know that clinical healing predates radiological healing by about a year. And so even when they look clinically healed, if you stop the drug, the fistula is probably still there and it will Resurge. So you need to carry on treating medically for longer than that. More recently, we've identified that um, er higher infliximab trough levels are associated with a better outcome for perianal disease than for Luminal decease. So you need more drug for longer and there's a bunch of other agents now including these and mor besides um all of which have shown some improvement in fistula but not really fistula healing in the way that we might like. So the class two a patients are those class two patients whose fistula is suitable for repair and who want it and they might have a fistula suitable for an anatomical repair like lift or flap or for a non anatomical repair like stem cells, which we can't give or the comparator arm of the stem cell trial, which was a kind of scraping and closing of internal openings. The anatomical repair patients will have more straightforward tracts that can be treated with lift or flap or similar the non islands. Some repair patients can't have one of those operations, cos they've got two internal openings or intersphincteral complexity or something, but the operations don't care about that complexity and something like scrape and close where you simply curette all of the tracks and then close, the internal openings has a success rate of around a third, maybe a little bit higher than that in these patients is a way that we can try to surgically repair these fistulas, which we didn't previously have the ability to do. So this is the first really operation to undertake nonanatomical repair of anal fistulas. You can make the argument that you could do it with a AFT, but most people don't do it with AFT. So the options you have for, for surgical repair in the two, a group are to remove the seat on and do nothing else to do an anatomical repair or to do a nonanatomical repair. Um The anatomical repair options, um er aceton removal alone in the Pisa two study was shown to be pretty good at closing clinically, the fistula consistent with the aim two data. But radiologically the fistulas are not healed. And so when you stop the drug, it will come back. By contrast, if you undertake a lift procedure, probably around half of patients fistulas will heal and with flaps, that rate is also pretty good may maybe round about 60%. Although as I said before, I would consent them for a 50% success rate even in the presence of Crohn's disease. The Pisa two studies suggested quite a high rate of clinical closure at a year, but with half as many patients as that undergoing radiological healing at one year and maybe that they'll go on to radiologically heal in time. We don't know that, but it may be that only a third of these patients are genuinely healing their fistulas. We do know though that if they do have radiological healing that correlates with long term clinical remission and with improved PDA I scores. So that's perianal disease activity index cause. So their symptoms are better. No, I A Yeah. Um we can't really talk about the newer techniques like laser and aft in any meaningful way because there are inadequate data in Crohn's disease for the non A so called repair patients. Again, seat on removal alone is reasonable, but we don't know what the number is. They didn't look at it in Pisa. Um And in the Axon two date, uh um patients, there may have been some patients who had anatomical repair, only suitable fistulas, but we can't know. So I have no idea what that number is. No one can tell you. It's probably no better than it is in the anatomical repair patients. We know that stem cells from the initial trial. The Admire one trial, not the Admire two trial, which is the one that you've heard about in the news. More recently, around half of patients went into combined remission regardless of the nature of their fistula and that there was the comparator on scrape and close in which around a third of patients went into combined remission as clinical and radiological remission. We don't know when we should do it. We know that we should stop them smoking and optimize their medical treatment and ensure adequate drainage and control of the perineum and rectum. So that's drainage of any other perianal disease and control of any proctitis. And then we should probably aim for repair two or three months down the right down the line from um starting biologics, but no one notices there are no D on this. Ok? I'm not gonna talk about Admira. I've mentioned it already. Um uh Yeah, I'm not gonna get into it. This is some of our, this is one of our admire study patients and you can see the fistula on the Sagittal here which is completely evaporated by the time of the repeat scan. So it's exciting but we don't know uh we don't know whether or not stem cells in the long term are gonna be available to us in the UK. So I'm not gonna get too excited about it with you. Um The two B patients, they um are uh the ones that we can treat with symptom control but not, they're not suitable for repair. However, we can still operate on them and help our gastroenterology colleagues, either by helping them obtain disease control, which is a medical thing really or by rationalizing the fistula. So if it's not currently suitable for an attempt at repair, but you can rationalize it, then it may become suitable for an attempt to repair like a lift. And we do sit on control, symptom control with um drainages, sit ons and maybe palliative raft. And we do rationalization. The two C patients who require defunctioning split into two groups. You've got those patients who have got early, rapidly progressive disease. You may have seen these people, they're pretty rare but they come in and their perineum starts to fall apart and over a period of a few months, you see this radical change in the nature of their perineum as this kind of destructive process eats away at their perineal tissues and sphincter. Those patients need defunctioning. Um They'll need it early because they're in real trouble whether or not defunctioning them halts or reverses the process of destruction is not clear, but it is necessary anyway, because they're becoming incontinent because they're constantly in hospital with perianal sepsis. And this is the only way to try and bring it to a halt. It doesn't always work. By contrast with the much more common class two C two gradually debilitating patients who have a two B type fistula that you just never quite get control of. And year after year they come back and they're just never happy and things are always a bit worse and gradually it becomes apparent that their quality of life is damaged. So substantially that a stigma is needed to try to regain it. So those are those two groups of patients discussing stamas with patients with Pernal disease should be done early. And often in my view, not because they need it early, but because the earlier and more commonly that you talk about it, the easier the decision comes becomes for you and them when they do need it down the line and it should not be viewed as a failure. We'll try everything and if nothing works, then we'll do it for you. If we have to, a steamer is an a parachute, it's an opportunity to rescue someone whose quality of life is plummeting to earth. Ok. That's the message that we should be giving these patients and they made this kind of signposting conversation talking about the quality of life impact. How often do you leave the house? Now? Thanks to your fistula. How often do you have sex? Now? Go on holiday, take days off work. What's the impact of your fistula on your quality of life? And that part of the conversation, you can really help them and you to understand whether a stoma is a useful thing and possibly just possibly a stoma will provide adequate disease control, that patients can come back in and maybe have an attempt at fistula repair. That is not the goal of the stoma in most cases. And we should not be selling a temporary stoma to patients to rest the bowel until the fistula heals and then we'll reverse you. Reversal. Of stoma in this setting occurs in about 10 to 15% of patients only. So that is not what we should be selling them. It's not true. Uh Some patients have a completely exhausted perineum or adverse features like RVF S and stricturing within the anus, which means that they're never going to be able to reverse their stama. And those patients may well need proctectomy in order to improve their symptoms and quality of life further. But sadly, 40% of them perhaps will go on to have a persistent perineal sinus, which may be suitable for repair and may not. And these four A and four B are entirely analogous. Two A and two B that I mentioned earlier on. So the idea of this system is that it helps you to picture and place the perianal Crohn's fistula patients that you see so that you can nudge them perhaps from a two B to a two A and make an attempt to repair or you can recognize that they might be drifting towards two C or three. So you can, you can have a framework within which to work out how to manage these patients and not just place a seat on and er get more biologics and then hope that they never come back to your clinic, which is, I think what happens most of the time they're in a place that the same of the week. Here's a good question, potentially. Um It would be nice to take the heat out of things before you do the proctectomy and the proctectomy, of course, has the additional ri risks of the impact on fecundity and the erectile ejaculatory function risk and the risk of wound failure. So, if you can avoid those things, at least initially, then that's probably beneficial. And these patients are often quite young, you maybe wanna defunction them and if they settle, maybe get them to the other side of family before you start doing those more destructive things to them. But often you're exactly right. And you have to do an expedited rather than emergent proxy for people. If the stoma just doesn't do anything for them, but I would usually make the stama first. Ok. RV. Si promise. This is the last few minutes and then we get to go and do something else. I know that this is hard. You're doing brilliantly. So roto vaginal fistulas are miserable. They impair work, social life and sex. They occur in often young women, although not always, they can occur in old women as well and they're difficult to cure with recurrent stomas and misery on the road for any woman who has one, they're also too rare to generate much expertise, which is a problem. There are lots of different etiologies, I mean, really about 41 of them is obstetric injury and this is the most common cause of rectovaginal fistula. Ok. Obstetric injury. Um, they can occur in the presence of inflammatory bowel disease or they can be cryptoglandular in origin or some other driver of sepsis like Bartholin's. Although I think most Bartholins which turn out to have a fistula associated with them with fistulas all along most like. But anyway, and they can occur associated with anastomoses or radiotherapy, some kind of iatrogenic injury. Um, one size in surgery does not usually fit all and this is no more true than in rectovaginal fistulae. Yeah. So how do you assess how to manage these patients? What, what steps do you take? Well, the first question to ask is whether you're gonna make things better when you operate on any rectovaginal fistula, you will almost inevitably make the hole larger if your repair fails. And that means more symptoms, a very direct correlation between size of hole and symptoms for patients in this setting. So if things are actually not that bad, if she is passing the occasional wisp of air or gets a little bit of smearing a couple of times a month, and you talk to her about the options for repair and mention that it might get worse. And she says, look, I don't like the sound of things getting worse. I think I can probably live with this. That may well be the right answer. It is ok to leave a vaginal fistula in a patient who is getting few symptoms from it. And if that's what she determines, that's absolutely fine. Most of the time, however, the symptoms are too severe or people simply hate having them and they want an operation and that's also understandable. So in that case, we're gonna try and assess things to decide which operation is optimal, which will come in just a moment. Then we should wonder about whether there's any surrounding factors that we can influence with a stoma by stopping smoking, by helping them lose weight or by initiating medical treatment in the context of Crohn's disease, for example, and then we should spend time managing expectations. What will we do if this attempt to repair fails? Will we be doing another attempt to repair? Will the second attempt to repair come with a stama? And I will say to them if we start down this road, one ultimate destination is a hill fistula which would be lovely. But another is a worse fistula and another again is a stoma. And so before we do anything we must accept, so that maybe where we end up to avoid the conversation where she says to you, I wish I've never had an operation done. That's the worst thing a surgeon can hear, right? The worst thing. So clinical assessment looks at etiology, particularly if there's evidence of Crohn's or, or radiotherapy, you have to know about those, those will change how you manage the fistula, the height and position of the fistula, whether there's perineal descent or internal interception and whether there have been previous attempts in this setting, an anal ultrasound is preferable because it assesses the sphincter which you need it to do. MRI S are often, er, fistula RVF S are often invisible on MRI scans, not always but often, whereas they're usually seen on ultrasound. In fact, in truth, I usually get both, um, in Crohn's disease, you do all of the above but also assess overall disease, burden proctitis and scarring and tissue fixity, which will also affect whether or not you can do a repair. And if so which one, now this is our, does it have? We got? Uh yes, this is our um original um algorithm for managing these patients and we'll go through it in a second. But it has been adapted because there are some truly anal vaginal fistulas, which might mean that we could think about things like a lift RVF S. We talk about rectovaginal fistulas as any fistula from the gut into the vagina. That's an anus or rectum. Rectovaginal fistulas are really a buttonhole, right? You've seen them, they are just a hole, there's no tract there. It's just a hole between two organs. But sometimes you get anal vaginal fistulas, which are genuinely a fistula, genuinely a tract like any transsphincteric fistula that just happens to open into the vagina because the anterior bit of the perineum that it was gonna open into, there's a vagina there. So that's where it ends up. Those ones can probably be treated like anal fistulas and that includes things like lift laser and so on. And it's also worth wondering whether a transvaginal approach might be reasonable. And that's what we do in pouch fistulas, for example. But in general, this is probably the right approach to be thinking about the RVF S, the actual rectovaginal fistulas. So the high fistulas are usually associated with an anastomosis or there's a hole in the rectum cos of radiotherapy or Crohn's or whatever in that setting. The best operation probably is an abdominal procedure where you undertake a what's called a suave coloanal pulfer. I don't know if any of you have seen a suave type operation, coloanal pul through. So you dissect down to roughly where the fistula is, divide the rectum or neorectum, whatever it is at that point, undertake a mucosectomy from there down to the dentate line and then bring your healthy um er colonic conduit, which is outside the radiotherapy, radiotherapy field or away from the anastomosis, pull that through the neorectal er neorectum, which you have mucosectomy and pull it right the way down and undertake an endoanal hand. So, coe coe anal anastomosis. Ok. It's quite a complicated operation. A very brief description of it. And the bottom line is it's an abdominal operation in which you are bringing the world's thickest advancement flap by having the full thickness of, of colonic wall, pass the fistula down to the dentate line. You can imagine that the problem in that setting, particularly after radiotherapy, for example, is poor function. And about 1/5 of these patients will have poor function such that you need to return them to a stama. If the fistula is lower than that, it's not associated with an anastomosis, then you're on this other side here. And the first question is to ask whether the sphincter is intact. If it is not, then you can open the rectovaginal septal space. Identify the fistula running across it, repair it on both sides and then undertake a sphincter repair as you're kind of bolstering operation, filling in that space and supporting the repair. If on the other hand, the sphincter is intact. The next question is to ask whether there's internal interception, mobility of the rectal wall because if there is, it will facilitate an advancement flap. So you can undertake him in advanced fla. We usually do a delorme style advancement flap in the prone position in this context, but you could do any advancement flap in that situation and pull rectal wall down over the vaginal opening. And if there isn't, if the tissues are too stiff, then again, you open the reco vaginal septal space, divide the fistula, repair it either side of that space and then fill that space with something else. You can't use sphincter cos it's intact, it seems churlish to divide it and then repair it in that setting. Instead, you gotta stick something else in there and we use either omentum or a marshal flap, which is um uh the labial fat pad, although you can use gracilis and you may have come across people who do graciloplasty for this operation. So there's the fistula and you can see the U shaped incision that gives you access to the rectovaginal septal space and you develop that plane opening up. There's the fistula again and you carry on past the fistula. There, it is from the vagina, there it is from the rectum and we're now well beyond it, you can see that the opening is here and we've carried on the dissection up deeper up towards the pouch of Douglas in that rectovaginal septal space. I find this a very challenging dissection. I think it's hard, but it is fun and you know, you can get a good result from it, then you repair it either side and then put in your whatever it is, right. This is a marsh's flap. Um The, the labial fat pad which has got blood supply from two directions. You can make an incision down the labia, divide this blood supply and then swing it down and stick it in to the space based on the um posterior blood supply that it's got. There's the incision, there's the fat pad there. It is coming down through the hole and into the space between the rectum and the vagina. So it bolsters the repair. It's quite a small piece of tissue by the time it gets in there as you can see, omentum huge bit of tissue. So there's a lot of benefit to doing an omentoplasty in this setting. Probably um the er a any um rectovaginal septal approach in my view requires a stama you can do an advancement flap with that one. I don't think you should open the rectovaginal septal space widely without making a statement up. Uh The, the, the septic complication risk is simply too high in that setting. The data are in, in essentially impossible to interpret, you know, the heterogeneity and the techniques and the fistulas that are within them. The numbers of patients and the success rates that you see here make it really, really difficult. All I think we can really say is that none of these techniques is brilliant. We get our best results with the abdominal procedures. They tend to work in terms of healing the fistula, but they have that substantial risk of um LARS essentially because of the low anastomosis. Um Otherwise, I tend to consent for a success rate around 50%. You're picking up the patterns in my practice here. Um And I say that and a mental flap might be a bit higher than that. I think maybe the da the data for a mental, a mental flat, a mental flaps are very limited, very small numbers, but probably the success rate is a bit higher than that, particularly in the absence of Crohn's disease. We don't know whether stama help. Unfortunately, no trial has ever completely asked that question and therefore, we don't really have a good answer, but a lot of patients will be offered a stama at some point. So a prospective evaluation of statements at the first attempt in all patients is the only way we can answer the question really and no one's gonna do that trial. No patients are gonna wanna be involved in it. But that's really the only way in my view to answer the question, we all think that they probably help and we all make them at some point in the process of a patient who's having operations if they're not working. So first and foremost, decide whether an operation is the right thing to do in RVF. It may be that it is not, then decide which technique they need, then decide whether or not you can do that technique and if you can't refer them, don't do the wrong technique because it's the one you can do. That's bad surgical practice. And yet common surgical practice. Wonder about stam making cessation, all the other bits and absolutely plan for the next operation verbally with the patient as you're doing the first one, preparing for the first one because the impact of failure as well as the chance of it is so substantial. OK. That is RVF S in a nutshell and Perianal Crohn's disease. Any questions? Tm. Is there any for us? Yeah. Good. Question. II don't think there is personally, I don't think there is, but it is the kind of thing that people are trying you putting, putting glue, maybe put a bit of biological mesh in the bio lift. For example, people are wondering about whether or not that kind of thing might help tissues stick together, but there's no good evidence for it. And in general, I think inserting a foreign body in this setting is probably the wrong thing to do, but it may be that it's valuable. I don't think anyone can answer p, any other questions you have suffered enough. Let's go and do a lift both. Yeah. Oh, yeah. Thanks. 12. Hi for, hi.