I'd like to thank the previous two speakers for covering two of the imaging modalities we have for the abdomen and the GI tract in particular. But I'm now gonna cover the third way of imaging the GI tract, which is flexible endoscopy. You're gonna need some equipment a bit more sophisticated than a torch, and unfortunately a bit more expensive.
But how many of you knew that Groucho Marx actually did endoscopy? The other thing you're probably not aware of is that the Royal College of I'm OK. The the Royal College have changed the day one conferences for new graduates, and actually now it's considered a new graduate should be able to take x-rays, interpret ultrasound and do endoscopy.
I'm not convinced that that's . Necessarily the right thing. The good news is a new graduate doesn't have to be able to interpret MRIs or CT scans.
So, as I was introduced, I teach small animal medicine at Bristol and do a lot of endoscopy and hopefully want to share with you some of the thing, tips that may help you if you are doing endoscopy. If you have the right equipment, you potentially can reach most of the GI tract if you know what you're doing. But because of the range of our size of our patients, sometimes you may not have the right equipment and you just have to accept that you can't do everything.
But I think just as with the ultrasound. Lecture. The point is that you need to understand how the endoscope works and what you're doing to be able to be successful.
But ultimately, what makes you successful in endoscopy is to practise, practise, and practise. I always tell my residents the 1st 1000 endoscopies are the most difficult. So, I'm not going to run any polls in this presentation, but if you think about it, if you own an endoscope.
Do you actually use it, or is it sitting gathering dust in a cupboard? If you use it, have you got biopsy forceps so that you can actually take biopsies? If you're doing upper GI endoscopy, can you get through the pyloris and reach the duodenum in every case?
And if you can, do you always know what you're looking at? And in answer to the final question, then I don't always know what I'm looking at. But you and I are not the only ones, George Bush had similar problems as you can see.
If I were to ask you what you hope to get from this webinar, you probably have 3 main objectives. The first is how do I get through the pyloris. The second one will be how do I get through the pyloris.
And the third one is probably how do you get through the pyloris. But what I actually want to cover and give you point as to how to get through the pyloris, is talk about getting a suitable endoscope if you haven't got one, when you should be doing endoscopy and when you shouldn't, how we actually do it and how we get biopsies when we're there. And then at the end, if we're not running too late, then looking at, videos and still images of, the GI tract endoscopically in both health and disease.
Endoscopy isn't the answer to everything with GI disease. You can assess morphological changes if you can reach with your endoscope, but you can't assess functional disease. You potentially can't examine the whole GI tract.
You're looking at the mucosa, not the submucosa. And if you can see a cirrhotic liver with flexible endoscopy, then you've got a big problem because you perforated the GI tract. And you would need laparoscopy to be able to see liver lobes like this.
The advantage of endoscopy over an exploratory laparotomy or laparoscopy is it's minimally invasive, the morbidity and mortality, the procedure is very low. The animal recovers and can go home the same day, but there is still a risk, and you shouldn't ignore that. Most of the risk is associated with the anaesthetic though.
However, endoscopy isn't always the right thing to do. There are times when you shouldn't do it at all. If you're not prepared to anaesthetize an animal for surgery, you shouldn't be anaesthetizing it for endoscopy.
And if you've got evidence of bowel perforation, and this dog has a perforating gastric ulcer, then endoscopy's not going to fix that. Surgery is the right option. But there are times when endoscopy isn't indicated because you haven't investigated properly and you may have missed something that would have given you an answer without having to resort to endoscopy, or particularly if you're doing colonoscopy, you haven't prepared the animal properly and the colon is full of faeces, and you're not going to be able to make a diagnosis.
So, an investigation of animal with GI signs starts with a history and physical exam. If it's got diarrhoea, a faecal exam's important. The minimum database of haematology and biochemistry is necessary to rule in or rule out non-GID causes of the signs.
And then as you've heard from Michael and on our speaker, the plane radiographs and ultrasound are critical in identifying things that may not be within the reach of your endoscope. And only after you've done all of that, should you be thinking about doing endoscopy. And here's a a fairly embarrassing case because this dog belongs to one of my colleagues who asked me to do endoscopy because her dog had chronic diarrhoea, and we're in the duodenum, and you may be able to see on the dorsal.
On the upper wall here, a worm, that's actually onsenaria, and presumably there are more further down the intestine, but we, we have a diagnosis, and this dog needed worming rather than the endoscopy. And in fact, after the endoscopy, we did a faecal and we found uninaria over in the faeces. So an unnecessary procedure.
If you're gonna be doing endoscopy, you need some equipment, and it's not cheap. We all know that. You will need the endoscope, but you also need lots of other bits.
You'll need a light source which often contains an air water pump. The light is necessary to illuminate the inside of the intestine. The air water pump is necessary to blow air in so that you dilate the stomach and intestines and can see where you're going and Potentially washing the lens if you've got any blood, mucus or food stuck to the lens.
You'll also need a suction pump to suck any air back out of the GI tract and then as the minimum, you'll need some biopsy forceps. And if you're removing foreign bodies, you may need other types of instruments. But let's talk about what you need with with the endoscope first.
So the endoscope's made up of three parts. The umbilical cord contains a tube that carries the light. It's a fibre optic light cable from the light guy connector, and this is what plugs into your light source.
Then we have the body of the endoscope, which is the bit you hold with the various controls. We'll come on to that. And then the part that goes into the patient is the insertion tube.
And at the end we have the bit that it's steerable the bending section. So what do we need to be able to do upper GI endoscopy in our patients? Should you have a fibre optic endoscope or a video one?
Well, the pros and cons, the fibre optic one is much cheaper, but to be honest, if you've ever experienced using a video endoscope, you won't want to go back to doing fibre optics because it's just uncomfortable for the operator. More important when choosing an endoscope is how long the insertion tube is, and particularly how wide or how big the diameter of the tip is, because that will dictate whether you can get it into the patient and whether you can get through the pyloris. We also need to consider how big the biopsy channel is, and in general we want as large a channel as possible to get as bigger biopsies as possible.
Then the distal tip needs to be able to be moved, and we want, when it bends, we want it a very tight radius curvature because there's not much space within the GI tract for that deflection. So for the insertion tube, we want the smallest diameter possible because then we can get into the smaller of our patients. However, to keep the pathologist happy, we need the largest biopsy possible, which means the largest channel possible.
And that then dictates that the insertion tube diameter will increase. So the larger the biopsy channel, the larger the tip diameter. So what we usually choose is a balance between the largest channel we can find to give us the largest biopsy versus the smallest insertion tube diameter.
And what sort of size biopsy channel do we want? Well, we don't want anything less than 2 mLs in diameter, because then the biopsies will be too small and they're likely to disintegrate. And if we have a channel that's more than about 2.8 millimetres in diameter, the insertion tube diameter becomes so big that we won't be able to get through the pyloris of most of our patients.
The insertion tube needs to be long enough to be able to get to the pyloris and go through into the duodenum. But if it's too long, it becomes really hard to steer, it becomes very unwieldy. So my preference is for a 1 metre human gastroscope, and all human gastroscopes are only 1 metre because however fat the patient, the distance from the mouth to the duodenum is the same.
For some of our patients, the giant breeds obviously have a much longer anatomy and a 1 metre scope will not reach the pylorus. And therefore, veterinary companies selling endoscopes often sell endoscopes that are 1.4 metres long.
This is great if you're doing endoscopy in a giant breed dog, because then you can reach the pylorus. But if you're doing endoscopy in a small dog or a cat, then about 1 metre of the endoscope's going to be hanging out of the animal's mouth, and it makes it very difficult to manoeuvre. In the ideal world, you're going to have a range of endoscopes in your practise to suit every patient, but in the real world, you're not.
And what you're going to have is one endoscope that's a compromise that will accommodate most of the patients, but there'll be some of the extremes that you won't be able to do the procedure. The tip deflection is really important. You need so-called 4-way or two plane deflection, so 90 to 90 degrees left or right, and then in the other plane, 90 degrees in one direction, but it needs to be able to turn back on itself, in one direction.
And as I said before, we want the radius curvature to be really small, so that we've got room to deflect the tip and paediatric gastroscopes are likely to have that small radius of curvature. This ability to retroflex, to look back on myself is really important. You need to be able to see the cardia in the stomach because often that's where foreign bodies will be, that may be where there are lesions, and so the ability to retroflex is essential.
If you look at the handpiece, what what are the controls there? It's a busy part of the endoscope. Firstly, label one on this fibre optic endoscope at the top, this video endoscope on the bottom.
These are the angulation wheels, which will be labelled left and right and up and down. But to be honest, when you're actually doing endoscopy, you manoeuvre the wheels to get the view you want rather than thinking I must use the left right wheel, or I must use the up down wheel. These wheels also have friction brakes, which are a lever here or a knob, which apply pressure to the steering cables so that the wheels are harder to turn, but it means the tip remains deflected.
Now these are not particularly useful in veterinary endoscopy, and if you put them on by mistake, just turn them off again. We then have a button at the back, the suction button, which is usually colour coded red, and when you depress that. If your suction pump is connected, it will suck air or liquid out of the patient.
And in front of that is the air water button where by covering it, you deflect air down into the patient to insufflate and if you push down, it flushes water to clean the lens. We also have the accessory or biopsy channel, which has a little rubber cap over the top to stop air leaking back out of the patient and we push our biopsy forceps through that cap when we need to take a biopsy. Then in a fibre optic endoscope, obviously we have an eyepiece here with an adjustable ring to suit your eye focus, but on a video endoscope, there will be a number of buttons that control the amount of illumination and can can be programmed to control video recording.
So the, the buttons or the valves on the handpiece are really important. As I said, the suction button is usually to the rear, colour coded red, and if you push that down, air or water or liquid will be sucked out of the patient. The air water button has a hole in the top.
So when it's uncovered, air is being pumped from your light source out through this hole. When you then place your finger over the top of the button, the air is deflected down into the patient and it inflates the viscous that you're in. But if you push the button down, it then sucks water from the water bottle down the channel and washes across the lens to clear any debris.
As I said, we have an accessory channel on the handpiece. This is where biopsy forceps and other instruments are inserted, and there's this disposable rubber seal that is necessary to maintain insufflation, but we can push biopsy forceps through the top of the the seal, or if you're putting in bigger instruments we can take that cap off and put a bigger instrument through there. These are disposable, we throw them away after every procedure because they obviously get contaminated and they're the only cheap bit of endoscopy costing between 1 and 2 pounds.
When we hold the endoscope, they're all designed to be held in your left hand, between your fingers and your thumb resting there, you can't drop it with the umbilical cord running down the back of your hand. And then you're gonna use your left hand. The your thumb and fingers of your left hand to move this outer wheel, which is the up down wheel, and you should get into the habit of only using your left hand to move that wheel.
Then one of your fingers on your left hand will also be used used to to press the suction button or cover the air water button. And then for fine control, we may use the right hand on the other wheel to get left right deflection. So how are we gonna steer the insertion tube?
Well, obviously we can push it in and pull it back so we can advance and come back. And then you've got the control wheels, as I said, using your left thumb and fingers for the up down wheel and your right hand for the left right wheel. But if you're using your right hand to put bi biopsy forceps down the endoscope, then you can't use the left right wheeler unless you're very clever, but you can still steer left and right by deflecting the tip with the up down wheel and then doing what the Americans call talking, which is rotating the scope on its long axis, and if you do that, you'll look left and right.
So that's how we steer the endoscope and then. What do we need to be able to take biopsies? Well, we obviously need biopsy forceps, but if you look in catalogues of biopsy forceps, there's a whole range of them and it, they're confusing.
So what do you actually need? Well, firstly, they all work, you work them all the same way. You put your thumb through the ring at the end, fingers on the slider here, and if you open.
Your the palm of your hand, the forceps will open, and if you close your hand, you squeeze your fingers towards your palm, then the forceps will close. But it's the shape of the biopsy cup and the features of the biopsy cup that can be confusing. So there are two main shapes.
These at the top are oval or ellipsoid, the ones in the middle are round. And if you think about it, as the cups open, the oval ellipsoid ones and give you a bigger surface area, so you're gonna get a bigger biopsy. So in general, we prefer to use ellipsoid or oval cups.
Then frequently the cups have a hole in the base, as you can see here. That's called a fenestrated cup. And the theory behind that is that when you close the forceps on the tissue, it can bulge through that hole and it doesn't squash the tissue.
So it preserves the architecture better. And then you can also get forceps that either have a spike like this or a needle to try and hold the forceps in place as you're taking the biopsy. So if you're trying to biopsy a mass in the stomach, sometimes it's really hard and slippery, and every time you try and take a biopsy, the cuts just slip off it.
But if you use forceps with a spike, then they'll wedge into the tissue and stay put as you take the biopsy. So they have fairly specialised use and we wouldn't normally use them. Cos the spike occupies some of the volume that the biopsy would take and you potentially get a poorer biopsy.
So there's the fenestration on that one. And then The other variation is on the edge of the cup, and you can see on the top image we've got this serrated edge, called alligator. Another variation, alligator with spike in the middle, and then these ones have a smooth edge, they're fenestrated as you can see, and they're ellipsoid in shape.
So there's a whole range of possibilities of different biopsy forceps. Another variation you can get is so-called swing jaw. Now most forceps, when you open them, they remain pointing in that direction and you need to be ideally perpendicular to the tissue to be able to get a good biopsy.
But if you're biopsying down the length of the intestine, particularly the duodenum, then you may not be able to get perpendicular to the tissue and swing jaw forceps have a little hinge that allows the cups to tilt, so again you're, you're exerting pressure in the right direction. But these forceps are more expensive and they're more fragile, and they're not essential. If we're doing endoscopy, always take biopsies even if everything looks grossly normal because there certainly can be microscopic changes.
The only exception for that is the oesophagus. If it looks normal, it almost certainly is histologically, and to try and biopsy normal oesophagus, it's very, very difficult. It's very tough, and you'll end up with very, very small pieces of tissue which are of no use.
If it looks inflamed, it is, and if it looks near plastic, then you would take a biopsy, but it's gonna be friable in that situation. But when we're taking biopsies in the stomach or intestine, we want to be as perpendicular to the tissue as possible, which is how, why swing jaw forceps may be ideal. And then exert adequate pressure, and it's difficult in a webinar to tell you what adequate pressure is, and it's something that comes by experience.
But once we've pushed into the tissue, we close the forceps to grasp it and then rip the tissue off. We auls it. The cups do not cut the tissue.
So what what affects whether we get a good quality biopsy or not? Well, partly it's the size of the biopsy cup, and that will be dictated partly by the shape of the cup. So again, ellipsoid cups will give you a bigger biopsy than round cups and also the size of the channel which dictates the size of the biopsy force that you can get in.
So that is obviously outside your control if you only have one endoscope. The fenestration may improve the quality, the needle may reduce the quality, the swing jaw may make it easier to get biopsies, and the tissue type will certainly affect it, so in the oesophagus and also the atrium of the stomach, which are both very tough, you get small biopsies. But what you can control most is how hard you push.
And if you've got the biopsy cups open and push against the tissue and see it moving away from you, then you know you're likely to get a good biopsy and you're not likely to perforate. You have one other choice in biopsy forceps is whether you use reusable ones, which will cost you anywhere between 200 pounds and 400 pounds, or disposable, which a reasonable price now, they're between 10 and 20 pounds, and you can pass that cost on to a client and it's probably the better way to go. I would also, if I had a choice, use ellipsoid, fenestrated, with no spike, alligator, edges to get a good grip, and then depending on where I want a biopsy, whether I use a swing jaw, forceps or fixed angle.
How many biopsies should we get? Well, you certainly need more than one and probably in the stomach you need between 8 and 12 biopsies and. You may want to be systematic and take 2 or 3 from the body of the stomach, from around the cardia and the fundus, and it's important you have to retroflex to reach that area, but place the forceps through the biopsy channel before your retroflex.
Otherwise, if you try and force the forceps through the channel, when the tip of the scope is bent back on itself, you can damage the biopsy channel. And then we may want to biopsy the Antrim, but er it's a very tough area and unless there's a lesion, you may want to leave that area alone. And then again in the small intestine, we're gonna collect 68, up to 12 biopsies, and these should be sort of.
Reasonable sized fragments so that when you see them in the formaling pot, they're not falling to pieces. As I said before, don't biopsy the oesophagus unless you think it's neoplastic. Because to get an answer, the pathologist needs adequate biopsies.
So on the left we've got a pretty good biopsy, we've got lots of villi, we've got crypt tissue, and on the right we've got the most fantastic biopsy you're ever likely to get. And the pathologist will be quite happy with the biopsy on the left. They'll be ecstatic if they, if you give them the one on the right.
What they won't be happy with is you give them this, which one of my ex-colleagues called endoscopic coleslaw. This is just much. There's no way a pathologist can make a diagnosis from from this, and this is just totally inadequate.
So as I said, we want to be perpendicular to tissue as much as we can, so potentially using swing jaw forceps. But also if you deflate the stomach and small intestine as you're taking the biopsy, the mucosa will fold, it won't be under tension. There'll be an edge to a rubble fold, and you can get a much bigger biopsy that way.
Or if in the duodenum, if you can get to the distal duodenal flexure, again, you can be perpendicular. Or if there's a wave of peristalsis, if you're quick, you can hook onto the back of that wave and again be perpendicular. And then, If you haven't got any of those options, if you.
Put the endoscope into the duodenum. Put the forceps out slightly and open them, and then turn the endoscope into the wall and push the forceps out, then you can see where you're biopsy and you're getting adequate pressure. Then how do we process the biopsy?
Well, what I do, because my eyesight's failing, is I just stick the forceps in the formalin, open the cups and agitate it so the biopsy falls out. If you've got better eyesight, then there are two ways of retrieving the biopsy. You can just open the forceps and then wipe them on some sort of material.
And the biopsy will come off, or if you've really got keen eyesight, you can pick the biopsy off with a needle and orientate it. Either on a piece of card soaked in formalin or you can buy these cassettes with a foam insert and you can lay the biopsies out. And then when you close the cassette, you immerse the whole thing in your formalin pot.
And you can buy these cassettes, from various veterinary suppliers. I certainly know Burs will sell them. Now coming on to the procedure, if we're doing gastroscopy, the only part of patient preparation is not to feed it before the procedure.
So we want to withhold food for at least 12 hours. If there's food in the stomach, as you can see on the right, it impairs your ability to see small lesions. It makes getting through the pyloris difficult.
The food will clog up the suction channel, and if the animal vomits during recovery, it may inhale. So ideally we want the stomach empty, but if we have definitely withheld for 12 hours and we see an image like this, it tells us that there's delayed gastric emptying. So we get a little bit of functional information and that delayed gastric emptying may be because there's an obstruction of the pyloris, or it may be because motility is abnormal.
So when we're starting the procedure, the first thing to realise is you can't do it on your own. You need someone there to monitor the anaesthetic and make sure you're not overinflating the stomach and compromising the animal. For the anaesthetic, give a pre-med to sedate the animal before induction.
If they get agitated before induction, they'll swallow a lot of frothy saliva, and it makes it difficult to see. Then use the anaesthetic routine that you're most familiar with. So IV induction, carrying on with maintenance, inhalation anaesthesia.
You need a cuff ET tube in place because there's likely to be leakage of gastric contents back up the oesophagus as you push the endoscope in and out. Don't use nitrous oxide. Probably most of you don't ever use it anyway, but if you inflate the stomach while you've anaesthetized an animal with nitrous oxide, then the nitrous will diffuse into the stomach and the stomach will just get bigger and bigger and bigger.
But sometimes the procedure is a little bit uncomfortable for the animal, so even though it's anaesthetized, it's showing some evidence that it's feeling pain, there will be a change in heart rate, a change in respiratory rate, things that nitrous oxide being an analgesic might avoid. So what can you do in that situation? Well, what we do is we give a a a small top up with intravenous diazepam, just to get through the animal through that painful episode.
The anaesthetic or the pre-med may have some effect on getting through the pyloris, and this is a small study was done by one of our anaesthesia residents. He's just had it published, where we looked at the ease of passing the anti script through the pyloris when they were pre-meded either with butterphrenol or methadone, 1 being easy, 4 being difficult, and you can see with butorphrenol, you were, it was easier to get through the pyloris, whereas with methadone, it was harder. And this isn't, this study wasn't done with me intubating the polaros.
This was done with residents doing that. So I think it is a, a real difference and certainly, statistically, it, there was a significant difference. So if you're gonna pre-med, probably use burophrenil over methadone.
You're gonna need a general anaesthetic, and then you need to tie the ET tube in because you're pushing your endoscope in and out of the mouth and it's quite easy to drag the ET tube out. And I prefer to tie it either to the mandible or the maxilla, but in brachycephalic, dogs and cats, obviously that's not possible, so you're gonna have to tie it around the back of the head. And then we place the animal in left lateral recumbency.
That's essential because we, when we inflate the stomach with air, the air will rise, fill the antrim, and you'll be able to see the pyloris. And then always, always, always insert the gag because the animal comes light and starts to chew, you really don't want it chewing on your endoscope. And now some of you say you don't use gags in cats, we do use a gag, but we don't open the mouth very wide.
And this is sort of the arrangement you'll have, a bird's eye view. So you're doing the endoscopy with the animal in left lateral recumbency, with your, endoscopy tower and monitor here, and the anaesthetist to the side, or the person monitoring the anaesthetic. To monitor the patient, there should be IV access, ECG pulse ox, checking the gags in place, and as I said earlier, the person monitoring the anaesthetic is in charge to stop you overinflating and compromising the patient.
So when we do upper GI endoscopy, obviously we go in through the mouth, we'll examine the oesophagus, and then we'll take a quick look at the stomach to find our way around and make sure that when we come back into the stomach from the duodenum, anything we see is not an artefact caused by the endoscope. But ideally you want to try and get on and intubate the pyloris and examine the duodenum fairly quickly, and then come back and examine the stomach and take your biopsies, and then at the end of the procedure. We'll suck all the air and liquid out of the stomach, and as we come back up the oesophagus, if there's any liquid there, we'll suck that out as well.
So when we would want to look in the oesophagus, well, for signs of esophageal disease, which you're all familiar with, we obviously can remove certain foreign bodies, particularly fish hooks like this, and, and dilate strictures, but there's not time to talk about those procedures. So as we insert the endoscope, it's always debatable whether you should put some lubrication on the endoscope to help it down. Personally, I don't, but if you do, make sure you don't get it on the lens.
So things like KY jelly or other lubricants, if they get on the lens, they make the image very out of focus and smear, and you have to take the scope out and wipe it clean. And generally it's wet enough in the GI tract that you don't need lubrication. We then extend the head and neck, and we need to get the tip of the scope past the upper esophageal sphincter.
You can either do that by pushing blindly, or you may look at the image and and directly visualise the upper esophageal sphincter. Once we're into the oesophagus, blow air and keep blowing air because most of it is going to escape back out through the mouth. But as you go through the the sphincter, you're gonna get what's called red out where you can't see anything.
And that's when you get beyond that, you hopefully can start to see the lumen and you deflect the tip until the lumen is in the centre. And what you'll see in the proximal oesophagus is this bulge, which is the trachea adjacent to the oesophagus. We pass down the oesophagus, we'll have to steer to keep get around the bend at the thoracic inlet, and we keep readjusting the tip of the scope so that the lumen remains in the centre of the screen till we get down to the low esophageal sphincter.
The normal oesophagus, the mucosa should be a pale grey pink colour, but we wear in those devil dogs like the chow chow and the Sharpei that have pigmented tongues, they often have areas of pigmentation in their oesophagus. This is not pathology, this is just pigment. In cats, the wall is a bit thinner and you may see submucosal vessels, and the oesophagus is generally quite flaccid, so it may stretch quite a lot as you inflate it with air, and it's difficult to judge its size, what's normal.
But there shouldn't be anything in it apart from maybe a little bit of clear fluid or bile. There certainly shouldn't be any food in the oesophagus. Now in cats in the distal oesophagus, the submucosa is causes folds, so you get these ridges, and that tells you you're in a cat.
As I said, you may be able to see the trachea in the proximal oesophagus, pushing against the wall. And at the thoracic inlet, the great vessels going up the neck, you may see pulsating, and as you get to the heart base, you'll see the heart and aorta pulsating. That's always a good sign because it means the animal's still alive.
But remember, the oesophagus is really hard to biopsy, so don't spend any time trying. We get to the lower esophageal sphincter, it's not a straight line, and if you're trying to blindly intubate the stomach, you'll end up poking the wall of the oesophagus and causing a little bit of damage, as you can see here. So you have to angle slightly to get through the sphincter.
But sometimes the sphincter is wide open. The clinical significance of that is highly debatable, but what you will see in a normal animal is a very sharp demarcation, this line here between the pale esophageal mucosa and the redder gastric mucosa. So this is normal.
This is not reflux esophagitis. It's red because it's gastric mucosa, it's not red because it's inflamed. One thing you may see at the lower esophageal sphincter is, or may recognise it's a hiatal hernia, and sometimes it's really obvious you get this sort of, Crease are running around the sphincter, there may be evidence of esophagitis, or if it's closed, the low esophageal sphincter may bulge towards you as the animal breathes in, or if it's a brachycephalic dog, which is where we most frequently see hiatal hernias, if you temporarily occlude the airway for about 3 breaths, the animal will then suck its stomach up into its oesophagus, and you can make the diagnosis.
So what does that look like endoscopically? Well, here's the lower esophageal sphincter. You can see this sort of crease, we can see evidence of esophagitis, but as the animal breathes, it's sucking the stomach in towards the oesophagus.
And eventually you'll see bile reflux through the lower esophageal sphincter. So that's a hiatal hernia. When would we do endoscopy or signs of Gastric disease, obviously vomiting, vomiting blood, but some animals with gastric disease just stop eating, so that will be another indication, and again, obviously we can take, Foreign bodies out, and we can place gastrostomy tubes, but again there's not time to talk about that.
Although retrieving things like socks, from the stomach of a dog is always very rewarding. It's about the only time a medic actually cures an animal. But when you're doing gastroscopy, you need to be aware of the anatomy.
You need to have a mental picture in your head as you're doing the endoscopy, so you can work out where you're going. So when the scope comes in, it's looking at the greater curvature in the body and in the dog and cat, a small blind ending fundus. If you rotate the tip of the scope, you'll be looking along the length of the stomach, and you'll see the angle of the lesser curvature, and below that, the entrance to the antrim and the bottom of the antrim, the pyloris.
So you have to have that mental image in your head to know where you're going. So as I said, we have to angle slightly to get through the lowest social sphincter and often as soon as we get into the stomach, we get read out. Which is where you can't see anything.
So redout occurs when the tip of the scope's just too close to the mucosa and you can't see anything. And it's quite normal to see that and when you start doing endoscopy, it's what you see most of the time. But as you become more experienced, you learn how to correct it, so what you would do would be pull the scope back slightly, blow some air in to inflate the stomach, deflect the tip so you can then start to see the lumen.
So I said, as you enter the stomach, you're looking towards the body and fundus, then you deflect the tips slightly upwards, we'll give you a more panoramic view down the length of the stomach. And you're then gonna slide the tip of the scope along the greater curvature to get into the Antrim. Sounds easy and it isn't always that easy.
Often you get into the stomach and you can't work out which way is up, which way to go, you're completely lost. So what can you do to orientate yourself? Well, the first thing to recognise is that the rugal folds on the greater curvature run parallel and run down towards the Antrim.
So if you follow them, you're likely to reach the Antrim and you know you're getting to the Antrim cos the rugle folds disappear. Because there are very few local faults in the entry. You may see waves of peristalsis, and if you follow one of those waves of contraction, again it will migrate down towards the Antrim.
And sometimes you're in the Antrim and you don't realise it, but you'll suddenly see the pyloris open and bow come bubbling back towards you. But if you're really lost, this is where being able to retroflex is really important. So you turn the tip of the scope back on yourself, you inflate the stomach, you push the scope in, and you're gonna be looking at the endoscope coming in at the cardia.
And then you know below that will be the lesser curvature, and if you release the retroflexion gradually, you'll be looking at the antrim. So here on the left we can see Rugal folds, they're running parallel. The Antrim is probably somewhere up here.
And here we have a wave of peristalsis in the Antrim and there's the pyloris at the bottom. But this is the view you really wanna get, if you're lost, this is the retroflex view. So we've got the endoscope coming in at the cardia.
That shelf of tissue is the lesser curvature. Below that is a pyloris with bile bubblings towards you, because that's at the bottom of the Antrim. So if you can get that view, you know where you are.
So we're coming down to the low esophageal sphincter in this dog. We'll be angling the tip cos it's a slight angle through into the stomach, and now we can see some rugal folds. And they're running parallel, so let's just follow them without particularly inflating, and there we can just see the edge of the lesser curvature and under there with no ruble folds, is the antrim.
As we come round the greater curvature, there's the pyloris at the bottom. And so if we can get that in the centre of the screen, that's where the tip of the scope will go, and we're gonna pop through, through the pyloris as soon as we get in the right position. And you're thinking that looked really easy, and yes, it was, and if it was always that easy, you wouldn't be bothering to tune into this webinar.
And it isn't always that easy, but sometimes it is, which is great. So now we we've finished taking biopsies, that's a biopsy site there. We're coming back up the duodenum.
And into the stomach, so again there's the pyloris. And then with retroflex and we're inflating the stomach, and it's just deflated again, inflated again. There's a scope coming in at the cardia.
Beyond it is a blind ending fundus. So the lesser curvature is gonna be down here. And release the retroflexion, there's a lesser curvature, there's the antrim.
So again, we've got that view. And then if we deflate, we can see the, the mucosa flattens out, it's not infiltrated. And here's a good place to start taking biopsies.
So it put the forceps out, push them into the tissue, grasp and avos. But this video is more typical of what you're likely to be seeing. So we get into the stomach.
There's quite a lot of liquid around which kind of interferes with the view a bit, but we can't see where the rugal folds are going. We, they're not particularly parallel in this one. Which way is the Antrim?
I'm lost. OK. Looks like they, it might be that direction, let's try.
Mm, I have no idea where I'm going. OK, and I'm sure this is a a scenario that's familiar to a lot of you when you started endoscopy. So now I've turned the scope back on itself.
I've retroflexor tip, I'm inflating and now I can see the endoscope coming in at the cardia. There it is, with the blind ending, fund us beyond it, and if you rotate on the long axis, we can look all the way around that. But if we get back to the neutral position, that's the lesser curvature.
That has to be the Antrim down here. And if we come round the greater curvature, we're gonna see the pyloris, and it was buried under all that foam. But if we're lucky, we can get through that and actually see the Polaris.
And if it's open like this, hopefully we can steer through fairly quickly. But the problem is, as you're pushing scope towards the pyloris, you're stretching the greater curvature and the pyloris may move, so you have to keep readjusting, but now we've reached the duodenum. So putting air into the stomach is essential if you want to avoid red out, you need to suck out any fluid, but try not to overinflate because if you do, the greater curvature gets bigger and bigger.
The scoop, the scope loops within the stomach and you won't reach the pyloris. But ideally, you're going to take a quick look at the stomach and then go on to intubate the pyloris. But if you over extend the stomach, it causes a problem.
The greater curvature gets bigger and bigger, the scope can't reach the pyloris, the polaris. The stomach folds and the polaris moves out of your way and you stimulate motility and gastric contractions will get in your way as well. But also it's gonna upset the anaesthetist because you're gonna compress the cordial vena cava, it's gonna affect venous return to the heart, you're gonna splint the diaphragm so the animal can't breathe properly and you're gonna compromise the anaesthetic.
So overinflation is your enemy. If you overinflate as you push the scope in, the greater curvature gets bigger and bigger. The scope bends back on itself and you end up looking at the cardia, and the pyloris disappears around the corner and you just can't get to it.
So if that happens, pull the scope back. Suck as much air out of the stomach as you can and then go forward and try again. So in real life, we're gonna get you into the stomach and have a quick look.
We're gonna intubate the pylorus, we're gonna examine the duodenum, we're gonna take our biopsies, and then come back and do the full gastric exam, and then take our gastric biopsies. What I, what I wanna do is just finish off how we would examine the stomach. So as I said, you're looking at the greater curvature as you go in, we can go up to the antrim.
We'll skip the duodenal part. We're gonna come back and do what the Americans call the J manoeuvre, except they don't spell it that way, where you retroflex and look at the cardia. And then having examined the whole stomach, we can potentially do breast cytology, but we should always do biopsies.
OK, so this J manoeuvre is where you're retroflexing, seeing the scope come in at the cardia, and then if you pull the scope out the lens is gonna get closer, so you're gonna get a much better view, and if you rotate around the long axis, you can examine the whole area. As you can see here, here's the scope of the cardia and here's the fundus beyond it. So we're look, examining the cardia to make sure we've not missed a lesion there.
Because in this cat, there was a little tumour right at the lower esophageal sphincter. We didn't see it as the endoscope entered, but we could see it when we retroflexed and here we're taking a biopsy. The normal stomach should be empty apart from a little bit of liquid.
The surface should be smooth, pink. It's gonna be a darker colour than the oesophagus. And sometimes in the fundus you'll see submucosal vessels and you'll see occasional strands of mucus.
But if you see a lot of mucus, that might suggest gastritis. So the rile folds should be be fairly parallel, and if they're distorted, there may be a tumour. They should flatten on inflation and they should reform as you deflate.
And there may be a few folds around the pyloris, but in general there aren't any in the antrim. Now occasionally you see these red areas of hyperemia. These are not pathological.
We don't know what causes them, it's probably a reaction to the anaesthetic because they're transient. If the surface is ulcerated, then that's significant, but in this situation, it's just a reddened patch. Also look at the lesser curvature here, here's the scope of the cardia, here's the antrim.
The lesser curvature's getting very narrow, the stomach is folding on itself and the narrowness of the lesser curvature tells you how much you've inflated the stomach. And then occasionally in normal stomachs we see, we'll see these dark spots. These are normal lymphoid follicles.
To look at The duodenum, obviously if the animal has diarrhoea, that's important, but also the intestine may be the cause of chronic vomiting. So if you're investigating vomiting animal, it's important that we get through the pyloris, and it's essential to make a diagnosis, unless there's an obvious lesion in the stomach or oesophagus. OK.
It is the most difficult bit of upper GI endoscopy. So we try and do it as soon as possible so that we don't stimulate motility in the stomach, but don't rush it, OK? Try and keep the stomach as deflated as possible, keep your view centred, and if you can't reach the pyloris, pull the scope back, deflate to, collapse the stomach and try again.
As I said, if your scope is only 1 metre long, you're not gonna be able to reach the pyloris in giant breed dogs. So we go along the greater curvature, we wait for any wave of Paracelsus to finish, keep the tip of the pyloris centred, and push into the pyloris. And I make it sound simple and sometimes it is, but sometimes it's not.
And so don't get too frustrated and give up too soon. As you reach the Polaris, you're gonna be up against the mucosa and you'll often get read out. But within that red out.
Aim for the darkest red spot. The textbooks tell you as you go through the pyloris you deflect left and up. I have no idea what I actually do.
I just keep the red spot in the centre until I can see a new one. Try blowing some air intermittently, it may open the pyloris, or if you've engaged with the pyloris, sometimes actually sucking air out will make the stomach collapse and the only way the tip of the scope can go is forward through the pyloris. And if the red out that you've got is moving, keep pushing because either you're gonna end up going into the duodenum or it's tip of the scope is gonna have missed the polaris and you'll end up looking back at yourself.
As you get into the duodenum, the colour will change, and you may not get a good view as you go around the proximal flexure, but keep inflating, wiggling the tip until you can see the lumen, and then keep that in the centre and keep going forward. What if you're really stuck? Well some people.
Use the biopsy forceps as a guide, they pass the biopsy forceps through the pyloris and then try and advance the endoscope over them, sort of a modified singer technique that you might use to put an IV catheter in. In most cases it doesn't work. You can't get the biopsy forceps in very far and it's difficult to advance the scope.
You're obviously gonna cause trauma where the forceps are embedded into the wall of the duodenum, but you may, if you're really desperate, get 2 or 3 blind biopsies. But if you, you wouldn't take more than that because there's a risk of biopsy in the same place each time. So here, I think we're coming near the end to show you this fairly normal, .
Pyloric intubation, so we're coming down the oesophagus, keeping the lumen in the centre of the screen. We can see the lower oesophagus sphincter. In the distance That looks relatively normal.
You gonna angle slightly to get through. And into the stomach, and we can see ruel folds, and if we could follow those, there's a string of mucus, follow those parallel ones, we're coming along the greater curvature now, and we can see the antrim with fewer rubble folds. There's the lesser curvature at the top, and then we're into the antrim, and there's the pyloris in the distance.
So if we get the polaris in the centre of the screen. As I said, as you push the scope, the polaris will keep moving relative to the tip of the scope, so you have to keep readjusting and you can see some bile coming back towards you. So you know that's a polaris and .
When you see turbulence like that, that's when I'm blowing air, so there's the pyloris, and it's starting to open up, but as I go towards it, it moves away, so I have to keep readjusting the tip. You know it's flipped up to the top, bring it back down into the field of view, it keeps going down. I need to get this into the centre and then that's where the tip will go.
So I need to move it back up here. So I'm still struggling, I'm trying to. I'm starting to think, is my scope too big now, it's just I haven't got the pyloris in the right position.
Now we're really engaged and if, if I were actually to suck air out now, I'd probably force the tip of the scope through into the duodenum. No, it's gonna go, it's gonna go, come on. We're just catching on this edge, but if I position it, we're now into the duodenum.
And you can see some areas of spontaneous haemorrhage. It's clearly a disease in the duodenum, and we're gonna go on further down and take our biopsies. So ideally we're gonna get to the distal duodenal flexure.
In a big dog, you may end up with the handpiece in the mouth, which is why a bigger endoscope's preferable because then your face isn't in the dog's mouth either. If you're running out of endoscope, if you start to pull it back, while watching the image, and you may be able to reduce the looping in the stomach and then going forward again, you may be able to push the scope further down the duodenum, or you get, you can push on the abdomen and sort of feed the duodenum up over the scope. But as you get further down around flexus, it becomes harder and harder to steer because .
The endoscope's constrained by the intestine. And so finally, Because we're running out of time. They're into the stomach.
Real lows Flattening out, there's the lesser curvature. There's the pyloris, and that's your dream, it's wide open and we can steer straight through into the duodenum. And we can keep going, and we keep in small dogs and cats you can get quite a long way down.
In a large breed dog, you may only get the distal duodenal flexure. And you can see this mucosa isn't completely normal, it's got a regular appearance to it, and we're definitely gonna take biopsies. And almost certainly this is inflammatory, but we can't be absolutely certain it could be lymphoma and therefore, we definitely need biopsies.
That white area there is a payer patch, that's lymphoid tissue, recognise that and don't biopsy it. So we're now just inserting the biopsy forceps. There they are.
So we opened the forceps, turn the scope into the wall, push out, and then we'll get a biopsy. And I think that's a good place to stop. OK.
Thank you for listening in. So I was just saying though, thank you very much. I think that was very insightful.
And for those who, logged in hoping to understand how they could get past the pylori, so hopefully, now know how to do that with confidence and, be able to go on, perform the biopsies that they need to and some great little hints and tips there on how to do that. So, thank you very much. We have got a couple of questions for you.
OK. One of the ones was, where can I buy the single-use biopsy forceps? OK, it's certainly Olympus sell them, and Olympus are based, if you search for Olympus Keymed, is the company in Southend, they sell them in packs of 10.
Or, or 20, so you have to buy multiple ones, but as I said, they're, they're about 12 pounds each, and if you charge the client 20 pounds, you're not gonna lose out. So that they're available and and make sure you get the right size, so you want ones that have the right diameter to go down. The channel and the right lengths to come out of the end of the gastroscope.
So biopsy forceps for a bronchoscope, which tends to be shorter, would not come not be suitable. Fantastic. I've got another one from Siobhan, she says, how do you biopsy cardia when retroflexed?
OK. You need, if you want to biopsy the card here, the first thing you do is with the scope in the neutral position, so looking at the greater curvature, put the forceps through so that the cups are just extruded beyond the tip of the scope, you'll be able to see them, and then your retroflex pull the. Go back towards you, so the tip will get closer to the cardia and then you can advance the forceps.
What you shouldn't do is retroflex and then push the forceps in, because if you've got a very tight bend on the scope, the forceps may go on in a straight line and put a hole in your biopsy channel. Fantastic, thank you. A message from Julie Simpson, how far into the duodenum would you view?
It depends on the size of the patient and the, the length of your endoscope. If you've got a 1 metre insertion tube, then in a, a large breed dog like a a retriever or a German shepherd, you should be able to sort of get into the Descending duodenum in a slightly smaller dog, you get to the distal duodenal flexure, and in a small dog or a cat, you can often get round several flexures into the jujunum. If you've got a longer scope, if you've got a veterinary gastroscope, which is up to 1.4 metres long, then obviously you can go further.
And if you've got a giant breed dog with a 1 metre scope, you won't even reach the pyloris, that'll get the logo anywhere down the duodenum. Fantastic. One from one of our regular, webinars, er, Terry Crow says what diameter scope would you use for cats, small dogs, etc.
Ideally, the smallest one you can find. So the smallest video gastroscope you can get has a 5.2 mil diameter.
It's actually a human gastroscope and it's made for so-called transnasal endoscopy rather than inserting the gastroscope through the mouth, they put it up your nose, and that's ideal for cats, but in the real world, you're probably not going to have that scope. You're going to have one scope and it will be a compromise. So you If you've got something that's about 7.5 to 8 mils in diameter, that would suit most cats and small dogs, but kittens, chihuahuas, whatever, you may not be able to get through the pyloris, and that's just, you know, a fact that you have to bear in mind that you're using one that's a compromise.
Now storts make a video gastroscope that is about 7.5 mil diameter, it's 1.4 metres long.
So yes, it will get through the pyrus of a cat, but because of its length, it's. It's a bit unwieldy, but it's a, it's a nice video, endoscope that is within the reach of, of finances of most practises now. Fantastic.
A couple of comments, very good talk, thank you very much. Great presentation, thank you, a fantastic webinar, thank you very much. So, obviously been well received.
We got two more questions for you, Ed, if that's OK. One from Jamine Patel, what additional equipment do you need to retrieve foreign bodies? OK.
I mean, if you've only got biopsy forceps, then you may be able to get out the odd foreign body cloth, socks, things like that you can grab. But, generally you ideally want a pair of grasping forceps, and then a pair of basket forceps is also very useful. You can Get some irregular objects with them.
And if you can get it something called a Roth basket, which when it opens is a wire loop with a mesh basket hanging from it, and you can sort of scoop up foreign bodies that way. But be aware that dogs swallow foreign bodies that are much bigger than you can ever get out with an endoscope. They swallow squash balls and things like that, and you can waste a lot of time chasing them around the stomach and never get them out.
So if you Done your imaging, your radiographs, the ultrasound, as you heard earlier, they're important before, looking for foreign bodies, then if it's a big rubber ball, just go straight to surgery, it's gonna be a lot quicker and a lot less frustrating. Fantastic. One last question, is it possible to practise on a cadaver patient?
To a certain extent, but. What you don't get is the the movement, it's obviously not the right colour, it will be a horrible grey colour, . You can do that, but it just doesn't, you haven't got the sort of tone in the stomach wall.
It just doesn't move quite the same, but it's certainly better than some of the sort of rubber models that that are available and are very expensive. But there really is nothing that beats doing it on the live animal, unfortunately. So if you're starting endoscopy, don't set yourself a target of getting through the Paris the first time.
Just get into the stomach and find your way around. OK, and, and then if the Polaris is wide open, great, but often it isn't. But if you think I'm gonna get through the Polaris the first time and you don't, that's gonna, you're gonna be disillusioned.
I mean, I, I, I learned to do endoscopy 20 years ago. I was self-taught and I used to spend 2 hours looking for the Antrim, let alone getting through the pylorus. So don't be disheartened.
I said, practise, practise, practise. Fantastic. And I think that's the real key there is just keep practising and obviously, your, webinar will be on our, in our library, from probably the 29th of January, so a week on Monday.
So obviously, please, we will be sending out messages to let you know they're there. So please do go back, review the, webinars. They're there for you to use time and time again for the next 12 months.
So please do review that. So thank you very much. To all of you, thank you first of all to yourself, Ed, for joining today.
That was absolutely exceptional, webinar, and it was obviously part of, our diagnostic stream as part of Virtual Congress 2018. We first of all heard from Mike Hertage, talking about how to get the most from your radiography equipment and in how to improve your radio radiographical interpretations. We then heard from Rob Cruise talking about how to revolutionise everyday general small animal practise.
Using ultrasound and then obviously we've finished with Ed. So, a couple of things just to let you know what's coming up on Virtual Congress, where for the rest of this evening, we are focusing on orthopaedics, we're focusing on behaviour and we're also focusing on emerging. See critical care.
So if you are looking at something to to do this evening and you're not going out, then please do tune into one of those streams and I'm sure you'll pick up some excellent er tips. And then tomorrow we're concluding with our large animal day, we're gonna both have both an equine stream. And a farm stream running simultaneously.
So if you do have an interest in large animal, then please do tune in tomorrow. My colleagues, Lewis and Megan have helpfully posted some links on the right hand side in the chat box. Please do have a look at them.
As I mentioned previously, we do have a diagnostic imaging expertise series, which starts on the 28th of February, 97 plus VAT, but if you sign up this weekend. With the, discount code, all in capitals, VC 15% off, you'll receive 15% off that. And also, if you're not a member and you're interested in membership, please do have a look at our membership pages.
We've got some great, memberships there for you. And once again, we're offering 15% off all those memberships today. So, once again, thank you very much for joining us.
Wish you all the best for the weekend, and we look forward to seeing you on a webinar soon. Thank you.