Thank you for the invite to, to speak, and thank you to all the attendees who are up at midnight in the UK. So, my remit today is to talk about surgical solutions for nasty ears. And, in this, procedure, we are essentially going to look at the role of surgery in the management of otitis externna, which is, where we use the procedures of either a total ear canal ablation and lateral osteotomy.

Or a lateral canal resection. And then lastly, we'll look at the role of surgery for the management of otitis media and of course, we'll discuss the ventralbu or osteotomy. In, in essence, today in this section of the, of the series, the seminars, I'm what you would say is the brawn, whereas, dermatology friends are the brains.

So, what are the indications for surgery in the management of ear disease? Well, the easy to answers are, of course, titi externa. To facilitate medical management, that's a good question.

Can we do that? Or to manage end-stage otitis, and there's indications for surgery to facilitate or assist in the management of otitis media. There are unusual circumstances where we need surgery to Any stenosis of the ear canal, neoplasia of the ear canal, and cats, particularly nasopharyngeal polyps, and in even rarer cases, trauma or congenital malformations such as segmental atresia of the ear canal.

So the techniques, now, if we go to the textbook, we need to always be cautious with textbooks. Textbooks tend to have, lean towards putting every described procedure down on print, whether or not they're useful. So if we look at the techniques that are described, the total e canal ablation and lateral osteotomy.

Our lateral ear canal resection and the ventricle osteotomy are the only techniques that really are justified. A vertical ear canal resection is an old description that really has virtually no use whatsoever in veterinary medicine and surgery nowadays. So let's focus on the total ear canal ablation and lateral osteotomy.

So again, what are the indications that this procedure specifically, while the help in. The management of chronic chronic otitis externia is particularly if medical management has failed in the management of chronic end-stage otitis externa and for those dogs with stenosis of the ear canal. There's also indications if, a lateral ear canal, sorry, a lateral ear canal resection has been performed previously and has failed in those dogs with neoplasia, congenital abn abnormalities of the ear canal, and very severe trauma of the ear and the ear canal, and in cases of a para oral abscessation.

A good question though is, should we be utilising to canal ablation and lateral osteotomy in those patients where the dog or the owner are difficult, and that is very much a point of discussion. So, prior to performing a totally canal ablation and lateral bull osteotomy, we should be asking ourselves some questions. And the big question that we're all Aware of and we tend to.

Sort of discuss is what time should, what is the timing for this procedure? And the answer to that is classically, is when medical management has been exhausted. And what we need to understand and recognise is that a tika is not a substitute for accurate evaluation of the ear disease and appropriate medical management.

So this is a procedure that is considered a salvage procedure in the dog that has run or cat that has run out of options from a medical perspective. But how do you define exhausted medical management? So, if we, if we sort of go to the textbook, it's when otitis external slash media has failed to respond to whatever intensive medical or dermatological management the owner or the dog will tolerate.

But what does that look like from a clinical perspective? Well, some indicators can be that you have calcification of the external ear canal, that corticosteroid therapy does not reduce the degree of ear canal stenosis. Or you have permanent loss of the tympanic tympanic membrane, where you are experiencing repeated accumulation of debris within the middle ear.

What sort of pre-operative evaluation is useful? Well, imaging can be utilised, though it's, not always going to change the management plan, because a lot of the management plan is, based on the history, so the extent of the medical management that's been performed previously, and also the discussion with the owner with regards to what are their expectations with regards to you as the vet and the outcome for the pet. But imaging can be useful, so radiographs can give us an indication of the degree of mineralization of the ear canal.

And if nothing else, this can, can give us an indication of the challenges that may be faced when doing the surgery. So those dogs with extensive mineralization of the ear canal, the dissection of the ear canal is certainly more complicated than those dogs without, because the ear canal itself becomes incredibly stiff. And in some dogs, the mineralization is so.

Extensive that the ear canal has to be transected from the skull with an osteoone and a mallet. MRI is probably a little excessive and CT, but these modalities give us very good information about the middle ear and can preemptively warn us that there's extensive or very severe middle ear disease, particularly with CT that can indicate that there is, Extensive osteomyelitis of the base of the skull and the, and the, and the bulla, which may give us an indication that the t might need to be combined with the staged or single surgery ventral bu osteotomy to remove all of the diseased bone. If you have masses within the ear canal, then biopsies are certainly indicated, because the pathology of the mass will change the expectation and the prognosis following surgery.

It's always very wise to perform a cranial nerve examination. If you identify there's pre-existing facial nerve paralysis, or that there's pre-existing. Evidence of ocular sympathetic nerve dysfunction or vestibular disease.

Then of course, if this is present postoperatively, it's an indicator that it was there preoperatively. But it's also an indication to you that it may well be a case that after surgery, these symptoms will be more severe, and of course, you can communicate that to the owner. When we're talking about any surgery, but ear surgery as well, it's always wise to consider the potential complications before considering the surgical procedure.

And it is absolutely essential to sit and have a conversation with the owner with regards to expectations and the complications that may occur. There is a very long list for tikka, and this is not a complete list, but the, the primary 5, I guess, the top, top of the list is deafness, which is very common postoperatively, haemorrhage, which can be fatal if not controlled, facial nerve paralysis and palsy, which is a very frequent observation. Vestibular disease, which is less likely, but if the dog has any indication that has pre-existing vestibular disease, as earlier stated, this could be markedly deteriorate and be very severe postoperatively, and then fistula formation or what's often termed a parallel abscessation is a more medium to longer term complication.

Ehi cellulitis and infection is surprisingly uncommon. Horner syndrome, particularly in cats, occurs in nearly all cases, and loss of ear carriage, which is a cosmetic, concern, but for some owners, a significant concern. Some of the rare complications that occur, things like avascular necrosis of the pinna, which is in cases of people where theirsection.

It's far too aggressive and hypoglossal nerve dysfunction, which again is, is a good indicator that the dissection of the ear canal has been far too aggressive. So why do most of these complications occur? Well, it really comes back to the anatomy of the ear and the surrounding structures.

So if we look at A, a, cross-sectional image of the skull. We have the parotid gland directly, ventral to the horizontal ear canal. We have the bulla running underneath the, junction, and this, this image is not quite correct.

The junction of the horizontal ear canal and the vertical ear canal, we have the facial nerve. And that close association of the facial nerve to the ear canal is why that we see so many dogs with at least facial nerve palsy following surgery. If we look from a lateral projection, we can see the facial nerve exiting the stylo mastoid foramin, and I'll just get a little annotation going on here.

Oh. So that just here, oh, that's showing up, just caudal to the ear canal and then wrapping just ventral to the junction between the vertical and horizontal ear canal, and then just cranial to the opening of the ear canal to the external osseous meatus. We have here the maxillary artery and retro glenoid or retroarticular vein.

Oh. Ah, why can't we progress, I wonder. Just having trouble here with it, there you go, found it.

OK. Oh dear. Do we have any help here to get rid of the scribble on the page?

No, sorry about this, guys, we'll just keep going. So have you put the scribble on the page or? Yeah, no it won't, now it won't clear.

Right, usually there's the little clicker just on the left hand side, it's a little transparent arrow, but if you click on that, that should. Sort of take them backwards and forwards, there's a backwards one and there's a forwards one. Oh, I can advance, but I can't remove the annotation I put on earlier.

Sorry, and the tool, hang on, the toolbar is coming and it's. I won't make that mistake again. And.

There we go. Well done. Did it go, yeah, cool, alright.

And now we'll just get rid of that. OK, sorry. So, if we go to the live patient, and we'll just step through doing the procedure, and during the procedure, I'll try and give you some tips on how to successfully do a total e canalation and lateral bull osteotomy without the complications.

So, this is a dog which is being prepared for surgery. Please note that the entire pinner has been clipped. And you need to clip wide of the ear canal.

You also need to have the ear canal elevated, so it seems a little bit, unpleasant, but that's a towel clamp that's been put through the ear canal, so it can be suspended from, from the ceiling on a rope. And that, that really facilitates appropriate surgical prep of the patient. So here's the patient, now in theatre, draped up.

Now textbooks again will often talk about a T-shaped incision where you make a circular incision around the opening and then a single, from dorsal to ventral incision along the length of the vertical ear canal. I find that is of really no use, and does not facilitate dissection. So I tend to just do an elliptical incision, as I have done here.

The incision needs to be on the margin between the very diseased horizontal ear canal and the pinna itself, and you can see that that's being performed in the second picture. Now, the absolute most important piece of information I can share with you is that the ear canal needs to be dissected as close to the cartilage as possible. If you stay right on the cartilage, two things happen.

One is that you get significantly less haemorrhage and you don't get lost. And secondly, structures such as the facial nerve will not be inadvertently transected. One thing you need to be aware of is ventrally.

And again, this is one reason why I don't like the T-shaped incision, is if you go too far ventral, you'll find the parotid gland. And if you're finding the parotid gland, you're not close enough to the cartilage of the ear canal. So keep right on the, on the cartilage and good things will happen.

With regards to the facial nerve again, if you stay on the, on the cartilage of the ear canal, you'll tend to miss it. But the picture in the top right demonstrates a patient with significant, significantly mineralized ear canal. It's very severe in this case, and just down deep, and we'll just try that annotation again, grab a pen.

With that. Oh. Much luck with this at all, are we?

The pin. Here we have here the facial nerve, that's a bad colour, we'll just change the colour on that. Here we go.

Try again. Just here is the facial nerve. You can see that hopefully.

And that essentially is, the problem, the more mineralized the ear canal, then the, the, the closer it is. And sometimes it's actually incorporated in that mineralization and is very, very challenging to dissect from the ear canal. On this bottom right-hand picture is a dog.

Having a ticker with virtually no mineralization of the ear canal, but this is a dog that has lost its tympanic membrane and has chronic and repeated accumulation of debris within the middle ear. And here's the ear canal here, sorry, the, the, facial nerve just here, which is far easier to identify and easily dissected from the ear canal. So one take home message.

You should be taking is, if you haven't done a total egg canal before, and it's a procedure that you would like to learn, please select your case very very carefully. Don't select a case with extreme end-stage, disease with marked mineralization of the ear canal because that is one of the more challenging cases to perform. Right.

One thing to consider as well is that if you are excessively aggressive with your retraction, then you'll find that you'll tend to stretch that facial nerve, and that can result in facial nerve palsy. Again, just looking at this picture and you can see the facial here and the skull picture of the skull at the bottom, just of the tympanic bulla, and this little rim at the top of the tympanic bulla is called the external acoustic, . Osseous acoustic meatus, sorry, and the facial nerve is represented by that little piece of suture coming out the stylo mastoid foramin.

And we can see that in the actual surgical image. And that's, that's understanding that orientation allows you to understand where the structures exit and therefore preserve them during surgery. Again, if we look at the left hand bottom picture, we can actually see the very close association of the zygomatic.

Sorry, of the temporomandibular joint at the base of the skull and it's just this part here. So, if you are very, very aggressive with your lateral bullet osteotomy, you can actually crack the bone through into the temporomandibular joint. So some care needs to be taken when doing that.

Dissection On the ear canal is successfully dissected from the surrounding tissue, it is amputated at the insertion of the acoustic meatus. Now, what we need to remember is the orientation of the facial nerve, which is caudal to the ear canal, and the orientation of the maxillary artery and retroglanoid vein, which exits cranial to the, external ear canal. So when we transect that ear canal, we need to drive the blade from.

Cale to cranial to miss the facial nerve halfway through the ear canal, then remove the blade, and then drive it from cranial to caudal to, avoid hitting the maxillary artery such retro glenoid vein, halfway through the ear canal. So we need to sever the ear canal from both directions halfway through. Otherwise, we have, the potential to inadvertently transect either the facial nerve or the retroglenoid, vein.

Now, the second component of doing a is lateral osteotomy. Now, a lateral osteotomy is always performed, and if it's not performed, then you are certainly running a risk of a medium to late stage complication of a para oral abscess. Now the intraoperative, image that's here on the right-hand side shows the facial nerve, which has been protected with a Penrose drain, which is not something that I would typically do.

But what you, isn't maybe not so clear, but we'll put a little yellow around it, is right here. This is the opening into the buller, and that is the OSI, meatus, as, as such, this little bony rim, which we can see down here again on the picture of the skull. Now, one mistake that junior surgeons do is that they remove that external external osseous meatus, that little rim of bone, and then they believe that they've done a lateral bull osteotomy.

And in intraoperatively, particularly The dog with a moderate degree or marked mineralization of the external ear canal, there can be a lot of bone there that gives you the impression that you have actually done a lateral bullar osteotomy. But you need to remove more bone. Now, and very important tip, and again, is demonstrated by this image here in the intraoperative image is right here.

And the yellow line there is the opening of the external osseous meatus, but down here below it. There, I'm drawing is the lateral aspect of the bulla. And what I'm doing in that picture is I'm using a free elevator to elevate the soft tissue from the lateral aspect of the buller.

And what that will allow is that the jaws of a ranjo, one side of the ronjeur can go in. To the opening of the meatus, and the other jaw can slide down in that space that you've created on the lateral aspect of the bulla, and it allows you to take an appropriate bite of bone out of the lateral bullet. So what you want to do is this, is create what they call a keyhole in the lateral aspect of the bullet.

So a rectangular osteotomy with the round circular, opening of the external osseous meatus. Now, if you're extremely aggressive, and there is a description of a subtotal bulla osteotomy, on the medial aspect of the bulla, so the underside is the carotid artery and the hypoglossal nerve. But you would have to have removed a very large portion of the bulla in order to find those structures, but it's worth being that noting and understanding that they exist.

So, doing the bull osteotomy can be very frustrating. And often enough, you have to ask for every pair of ronjes in the practise. And if again, if you haven't done a tikka before, one of the things that you need to consider before you start is, do you have the appropriate instruments?

So, at least 2 gelpies is an absolute requirement, a freer elevator to elevate the soft tissues from the lateral aspect of the buller, preferably electrical quadry. I would personally say that is, compulsory. And then a range of, rejours.

A lot of people like the love kerosene ronjeurs as they are in this picture. They're not my favourite. You need an appropriate size.

Really, what you need is small and big, usually double action standardronjes. The problem you find is, particularly in breeds like English bulldogs, is that their bullas are extremely thick. So lighter, smaller ronjes are not strong enough to cut out the lateral aspect of the buller, but the larger, heavier ronjes are too big to fit into the external meatus.

So you can't actually get the jaw inside the bulla to cut out the lateral. So you have to use everything you have in the practise to muddle your way through. In very extreme cases, if the bullet is too thick to cut it successfully with rounds, you need an osteoone and a mallet.

But creating a lateral bullet osteotomy with the osteoton and mallet is a very alarming practise and something I'd caution you to be very careful if you consider doing it. There's also other components to consider whilst doing the bullet osteotomy. You need to avoid damage to the dorsoedial structures within the bulla, and that, that's the carotid artery and the hypoglossal nerve.

And you need to stay cranial on the buller because if you go to quarterly, And particularly if you twist the ronjus as you close the ronuls, you can shatter the bulla and you'll get a fissure propagating up into the stylo mastoid foramin where the facial nerve exits, and it will crush the facial nerve and lead to facial nerve palsy. When you do that, there's a very large Angular piece of bone that will need to be retrieved, that you've actually smashed off the temporoppetris bone at the base of the skull. If you're extremely aggressive, you can actually shatter the bulla into the temporomandibular, joint.

So the key here is you need to have rons of appropriate size, and you need to use the action of the ron. To bite out the bone rather than a twisting action to snap out the bone. So if you excessively twist, you'll shatter the bulla and then shatter, the, the temporoettris bone at the base of the skull and potentially damage either the thyom mastoid foramin or the temporomandibular joint.

Once the bullet, lateral osteotomy has been performed, the goal at this stage is to remove the epithelium, from the bullet, but also from that bony rim, the external osseous meatus, and frequently it is the epithelium that lines the external osseous meatus that is left behind, that can lead to a para or abscess. What we need to recognise, though, is that the round and over window opens into the bulla on the dorsaledial aspect. So if we aggressively, the bride with a cure dorsally and medially, then we potentially will traumatise the inner ear and the, and the patient will, recover from anaesthesia and surgery with, vestibular, symptoms.

On, in contrast, and this is where the issue really is, if we fail to create the buller appropriately, then we predispose the patient to subsequent para or abscessation of fistula formation. So during surgery, we walk a tightrope between excessive debridement and incomplete debridement. In my opinion, one of your best friends is Lavage.

So if we lavage the ear and the, and the, tympanic bulla, repeatedly and use suction to remove the lavage solution, that frequently facilitates removal of all of the debris within the buller, and we don't have to use a quite as aggressively to get an appropriately bred bullet. At the end of the lavage and debridement, if we look into the bulla through our lateral bullet osteotomy, we should be able to clearly see white bone. And it is very obvious once, once you've sufficiently debrided, because the bone glistens.

It's, it's, it's like you would imagine it would be nice shiny white bone. Once you see nice shiny white bone, you've sufficiently debrided the bulla. So at the end of that step, most people would take a sample for culture, and if there's any masses, of course, you'd submit them for histopathology.

And I tend to submit the ear canal itself for histopathology. It's surprising the number of times you find a neoplasia or mass is the underlying cause of the chronic otitis external slash media. So I would do that as a matter of course.

This was for some time a question about the use of drains. Initially, it was, advocated that drains should be placed as part of the closure, but subsequently, there was, a paper demonstrating there was no benefit to drain placement, and now most people wouldn't place a drain, just do a primary closure as depicted in the image in the bottom right-hand corner. Just a very quick recap of another patient.

So here's the patient on the left, starting from the left. That's the incision around the opening of the external ear canal, what I really wanted to show here is that the best place to start the dissection, which is in the middle picture, is on the dorsal aspect of the vertical ear canal. Now, at this level, all the muscular attachments to the pinner itself exist.

And this is where I use a lot of electrocautery to cut those muscles staying on hard on the cartilage of the external egg now. I can't emphasise that enough. Using Mets and balms, you, in a, in a blunt dissection manner, so push him into the tissue, running the metembalm.

Along the cartilage, and then opening them to spread the, the loose fascia and then snipping it. So it's a case of bluntly pushing the fascia off the ear canal. But initially, as in the middle picture, you need to cut those muscles of attachment.

So the very first part of the dissection, so the initial dissection of the ear canal from the surrounding tissue is relatively tough, but once you're through those muscles, it becomes easier and easier. And once you've created a reasonable dissection plane from the, from the ventral aspect, then you come around the sides and start working on the, on the dorsal side or the lateral side of the ear canal. So you could say, rather than vent, Sorry, I got confused there, starting on the dorsal aspect first, moving to the ventral ventral aspect, or you could say, starting on the medial aspect coming around to the lateral aspect.

There's the e canalis. So further on in the surgery, it's been dissected from the surrounding tissue. Note the gelpies are in position providing retraction.

I've got an assistant in this case, just with a handheld retractor though, rarely assistance, assistance required. And in this case, this is a dog that Doesn't have, any mineralization of the ear canal. I'm using mets and bands to transect the ear canal, but preferably, and what I would tend to do would be a scalpel blade, initially running from caudal to cranial halfway through the ear canal, then coming across to the other side from cranial to caudal through the other half of the ear canal.

The picture on the right, that's what you're presented with once the ear canal is removed. If you use a little bit of suction, you can usually find the centre of the opening of the oy, external meatus, and that is a little bit, a little rim there. Just here of cartilaginous tissue just attached to the most lateral aspect of the bulla or again that external osseous meatus, which needs to be removed with ranjus.

And then again, this is the free elevator in position, just elevating the soft tissue from the lateral aspect of the bullet to allow you to put the rondu one inside the bullet, one on the lateral aspect of the bullet to get a good bite of bone to create that lateral osteotomy. And then finally, a closure, which is typically a single suture line in the loose fascia and then sutures, sim simple interrupted sutures to close the skin. What do we need to do in that post-operative period with regards to tikkas?

Do we use a bandage? I don't tend to. In a small number of, of patients, they will get fairly significant swelling, and maybe they would have been, the patient to put a bandage on.

Certainly don't use drains. If you do place a bandage and the dog has pendulous pinna, you need to draw on the bandage where you've placed the the, the pinner, because the person who takes the bandage off may take a pair of scissors to the bandage and cut the pinner right off, and that certainly has happened. You need to check for facial nerve function.

If there's decreased or absent facial nerve function, particularly in the, in the bulldog type breeds and pugs, you need to lubricate the eye. I've seen many dogs over the years, develop a central corneal ulcer due to a loss of their blink reflex. And we, of course, need to analges our patients, and for me, an opiate is an absolute necessity.

Typically, I would use a fentanyl, CRI, but methadone, every, 4 hours or at least an analgesia assessment every 4 hours. And that would be in conjunction with non-steroidals. Is there any difference between cats and dogs?

I guess the first thing to say is the dissection of the ear canal and the cat is certainly simpler compared to the dog, a lot to do with the size of their skull and the depth of the ear canal, but also they rarely have mineralization of the ear canals. The biggest difference between cats and dogs is they have two compartments in the tympanic bulla, and both compartments need to be opened. And this is, gives you a little bit of a view after transection of the ear canal in the cat.

And again, Is that external osseous meatus right there. And this is with all the epithelium removed. And then here just shows you a glimpse inside the ear canal and this little shelf of bone right here.

Is the division between the two compartments within the bullet of a cat and that needs to be broken down. So the quartered and the craniallateral compartments of the bullet both need to be opened to facilitate appropriate debriment and lavage and drainage of the bullet in the cat. Cats again, simple interrupted, positional closure, and if you do that nicely, you can maintain the ear ear carriage.

That takes a little bit of practise, but it's certainly not that difficult. Now, the reason for this slide is just to show that in patients, and this happens to be a cat with an upright ear carriage, what we can do is do a little bit of an advancement flap, so essentially, advancing skin. In this direction like that, because we've extended the incision this way and this way can help facilitate an upright ear, carriage postoperatively and help stop the, closure, putting tension across the pinna, and folding the pinna in a downwards direction.

It's a fairly simple little trick, but it works very nicely. OK, let's just talk about lateral ear canal resection. So, this is somewhat a disputed procedure.

Does it have a role in veterinary practise whatsoever? And I guess there's questions to ask. Is there any indication for lateral ear canal resection?

Now, this is compare and contrast to a total ear canal ablation slash lateral bullet osteotomy. So, lateral osteotomy, end-stage ear disease, one thing that we do need to be aware of is the definition of end-stage ear disease, which I touched on, but we do need to accept that and the definition of end stage is a discussion between vet and owner. It's not just simply the vet's opinion.

Because for some people, End-stage ear disease may be a lot, lot earlier than other people because their dog, for example, is extremely aggressive. So if you have a dog who cannot have his ears medicated, then why would you wait? For it to end up with a mineralized ear canal and pus pouring everywhere, because that is an inevitable outcome for that dog because the owner cannot medicate its ears, and hence that dog will have a tikka done a lot earlier than a very compliant dog and a very compliant owner who's willing to go and see a dermatologist and do all that's required.

It could be said the same said about the owner, not that they're going to be a very aggressive owner, but a very poorly compliant owner. Maybe they work overseas, they cannot do the medication frequency that is required. And again, why would you wait for that dog to end up with minimalized ear canal and pus pouring everywhere when it's inevitable that it's disease will become end-stage at some point because the owner can't treat it appropriately.

And again, that particular dog will end up, or may well end up with the tikka done a lot earlier. Now, if we come back to the lateral e canal resection, it's a completely different mindset. And the big question is, is there any indication for a lateral e canal resection?

And it depends who you ask. So if you ask people like me, typically we would say no, because all of the years that we see are end stage, and that, as a, as a result, They need a total ear canal ablation, lateral or osteotomy. Or if they're not, they can be managed by, the, a specialist dermatologist, which happens to be in the building that I work in.

So I just say to them, go and see the guy across the corridor, and he or she will sort it out for you. If you ask the dermatologist. The same question, and let's remember, they don't like things like scalpel blades that much.

They'll tend to say mostly no, because any ear that could be managed, with a lateral ear canal resection, they can manage successfully medically. But most of us will recognise that dogs with extremely hairy ear canals like the bichon frieze or the poodle, there may be, and I'll just say maybe, an indication for a lateral e canal resection. If you ask a general practitioner, well then they're seeing a different population of pet owners and the general practitioner is more likely to say.

Well, yes, to, there is an indication to a lateral canary section, because unlike the clients that specialists see, there are clients who are less committed and compliant, and, the medical management may not be carried out as well, but if they combine the medical management with the lateral e canal recession, then they may be able to get control of the otitis externa that the dog has through that combination. So, it's very much a point of discussion, and it depends on the discussion with the owner, between the owner and the veterinarian who's intending to do the procedure as to whether or not there's going to be the indication for the lateral ear canal section. The only real circumstance where it's more certain is the dog with the very hairy ear canal, where you need to improve the microenvironment of that ear.

So, what are the indications? So aitis external without significant hypoplastic change, and they will require adjunctive medical treatment. So that is an absolute fact, and dogs with extremely hairy ear canals.

Very, very rare. And to be completely honest, in the past 20 years, I've never done this, but a lateral ear canal, resection for a dog with neoplasia in the lateral aspect of the vertical canal. To be honest, I'd be very nervous about that choice.

I would much prefer to do a total ear canal ablation and lateral bull osteotomy, because if we think of the surgery from an oncologic perspective, wide margins is what we're after. Why would I compromise the margins by doing a lateral ear canal resection? And then access to remove inflammatory polyps protruding into the external canal.

I've never done that either, because essentially, we can remove those usually with traction or a combination of traction and a ventral bu osteotomy. If we are going to do a lateral canal resection, it is very important that it is performed before irreversible, irreversible hyperplastic change. If we do them too late, it is a hopeless procedure.

And what are we trying to do? We're trying to improve the microclimate of the year so that we can improve drainage and help facilitate application of the topical medications. And for nearly every case, the owner has to understand it's not a cure, it's a, it's a, it's a concurrent procedure with ongoing medical management required.

As a very high failure rate, and that is because it is done in the wrong patients with pre-existing irreversible change and poor owner compliance. One of the most important questions that has to be asked and discussed with an owner is if they're willing to do a lateral egg canal resection, would they be willing to convert to a total canal ablation slash lateral osteotomy if the procedure was to fail? And they really need to say yes to that.

Otherwise, you are sort of walking on thin ice, because if it goes wrong, there'll be a lot of complaints coming your way. So what goes wrong, well his, about 30% of cases, and that's the nature of the surgery. It is a contaminated site typically, but there's also a relatively high degree of tension across the suture line, ongoing otitis externna, which is nearly in every case.

And if we look at the results, only 30 to 50% of dogs benefit from the procedure, and usually they fail because the surgery is done far too late. So, in short and long, is a lateral e can now resection done frequently? No, it's not, because there's very few cases in which it would be bene beneficial.

And also our ability to manage dogs medically has improved substantially. So the complications, well, pre-existing pathology that results in failure of the procedure include proliferative dermatitis, the medial walls, the vertical canal, pathology in the horizontal ear canal, failure to diagnose tympanic membrane rupture and otitis media, and severe proliferative mucosal disease with calcification. Essentially, if a dog has Fairly advanced, otitis externa or any evidence of otitis media, it is not a candidate for the procedure.

How do we do it? Well, we need parallel skin incisions that are 1.5 times the length of the vertical ear canal that extend to at least 1 centimetre ventral to the floor of the ear canal.

And if we, sorry, I don't have intraoperative, images, so I've had to steal them from a textbook. So we make the incision in the skin and the subcutaneous tissue over the, lateral aspect of the ear canal and preserving the, parotid salivary gland. And the rostral and caudal cuts thickness are made through the cartilage using scissors.

The lateral margin is, the intragic fissure and the medial margin is the pre-tragic tragic fissure. And we continue distally through the cartilage of the ear canal until we get to the annular cartilage and the annular cartilage is the junction between the vertical ear canal and the horizontal ear canal. So if we just look at this image of a, from a total ear canal ablation, just here.

This is the vertical ear canal, this is the annular cartilage. And it's very clear and very distinct at surgery because it has these little hinges here and here, which tell you you're at the level of the annular cartilage. So if we were doing a lateral, ear canal resection, sorry, then we would make our incision here and down here, and then fold the cartilage, ventrally to create the new opening.

So there it is schematically, and here it is in the dog, and we now have a new opening at this level just in here. So the cartilage flap that you create as you make those cuts is too long. You need to reduce the length to about 1/3 of the length of the original, vertical ear canal, fold it ventrally and then suture the cartilage directly to the skin, and you need to do that under as little tension as possible.

Really, the idea of this procedure now is you've made the canal a lot shorter, so there's good ventilation and the drops or topical medication can be applied directly. The complications to hissin usually is a result of excessive tension, but in, some cases, postoperative infection. Stenosis of the new opening of the external ear canal is a result of making the cuts in the cartilage to narrow or tapering instead of parallel.

So you end up with a very narrow opening. And poor management of the otitis is a case of inappropriate case selection. But they're the three big complications that occur with the lateral ear canal resection.

All right, moving on, and we're running out of time a little bit to the ventralbu osteotomy. When do we do a ventralbu osteotomy? Well, to treat otitis media that has not responded to medical management.

So again, like all ear surgery is not the first line of management. And in cats, it can be the first line of treatment for nasopharyngeal polyps. However, traction is a good choice in the first instance.

So if we identify a nasopharyngeal polyp in a cat, using traction alone, particularly if it's combined with corticosteroids, can lead to resolution of the nasopharyngeal polyp in about 50% of cases. If that fails, however, the choice of the ventral osteotomy to facilitate traction can reduce recurrence down to anywhere to 0 to 8%. But traction is very simple, so it should be offered as the first line of treatment.

What are the advantages of a ventral boostomy compared to a lateral osteotomy? I, I, I don't know really why people talk about this and compare it, because a lateral bo osteotomy, of course, has to be performed in conjunction with a total ear canal ablation and hence to me, If you're interested only in the middle ear, why would you be talking about a lateral bull osteotomy? But if we compare the two, ventralbu osteotomy certainly gives us improved exposure.

It gives us far more consistent ventral drainage of the tympanic bulla. It allows us to access both bulla in the same surgery if they have bilateral otitis media, and the likelihood of facial nerve injury is very low. But like all surgeries, it has the potential for complications and in cats, corners, following the surgery is essentially has to be expected, is pretty well every single case due to the sympathetic trunk that runs through their bulla.

Hypoglossal nerve paresis is very rare but occurs when the dissection is, a little aggressive, or, there are complications in identifying the anatomy, which certainly can be the case in very domed-headed dogs like the bulldogs. It's very hard to feel their bullet and the bulla are relatively small. Thetibular disease like the lateral bullet osteotomy, if there's aggressive deprivement of the bulla on the dorsal medial aspect, and if you have inadequate drainage, then you may not resolve the otitis media.

How do we do it? And again, I apologise, I don't really have very many intraoperative, photographs in this case. We make a paramedial skin incision that's just medial to the mandibuous salivary gland.

It's midway between the The angle of the jaw, or the angle, angular process of the mandible, if you want to call it. So here to here, basically on the red line and the wing of the atlas, and the centre of the incision is level with the ear canals of the external auditory meatus. And if you think about it, and this is something that's sort of so obvious, you don't consider it, if your incision is at the level of the ear canal, the ear canal attaches to the buller and therefore, you're in the right place.

Now, one thing to be aware of if you haven't done a ventribullar osteotomy is firstly, select a cat or a dog with a long snout, because those brachycephalics, their bullet can be very hard to find and a very deep incision to the base of the skull, which becomes extremely alarming when you start to consider structures such as the carotid and the, and the hypoglossal nerve. So, Be wise in your patient choice. The other thing to consider is the pla platysma muscle, which is effectively the cutaneous trunci, the head and neck is a very thick structure.

And when you cut through it, it doesn't feel right. You sort of start to wonder which muscle you're cutting because it's so thick, because in my mind anyway, a cutaneous trunci type muscle is very thin, but not around the head and the neck. And then we use blunt dissection.

So again, mets and als, putting them into the tissue closed, spreading them open to stretch and spread and divide the tissues rather than sharp dissection cutting with the scalpel to bluntly dissect between the diastric muscle, which is on the lateral aspect, and the stylohyoid and the hypoglossal muscles on the medial aspect. So, in this image that we have here, lateral is on the left, medial is on the right. And what we'll see is that the hypoglossal nerve is just lateral, so here.

To the, to, the hypoglossal muscle, but both of them are on the medial side and on the lateral side, we have the lingual artery, which, and, and, and the carotid artery. And if we look at the skull, we've got the dash line over the bullet, which is where we want to make the incision, and that gives us some reference with regards to the angle of the mandible and, and again, The ear canal would be out here. Here's the angle of the mandible here, and they're really the big landmarks.

In a cat, if you push relatively firmly, you can actually feel the bulla through the skin. What do you do if you're lost? And this certainly does happen.

And even now, after all these years, there's times when I'm doing a ventral osteotomy have momentary panic and think, jeez, I'm not sure where I am, and there's lots of things I'd prefer not to cut down there. So, the tympanic buller, again, just go back to palpation through the skin. So in the cat and the long-nosed dog, it can be palpated.

If you're feeling the, terragoid process, which is getting that pen out. Which is here, which is sort of over the soft palate, then you're far too rostral. If you can feel the jugular process, which is not that developed in this skull, but it can be quite big in other patients, which is here, then you're far too caudal.

One other thing to consider is the hyoid apparatus. The stylohyoid attaches lateral to the midpoint of the bullet. So if you can feel the hyoid apparatus, follow the syr hyoid down, and then you're just lateral to the bullet.

And remember, if you're dissecting down and you see a nerve-like structure or an artery, the bullet is in the angle, so it's in the V or the division between the hypoglossal nerve, lingual artery, and the maxillary artery. Once you start making your way down and these are intraoperative images. You, you essentially you separate the muscle fibres over the bullet and use the gelpies to retract these fibres.

So you just push them apart. Once you have the buller exposed, as in the picture below, you put a simmon pin into a handheld chuck with just the tip extending from the jaws. And the reason for this is that as you penetrate the bulla, the jaws of the, of the chuck will prevent the pin continuing its merry way straight into the base of the brain.

So if you only put a tiny bit of the pin beyond the jaws, that's your safety mechanism to stop you pushing that pin in too far. If you put a long length this diamond pin into the jaws and then you use that pin to create the opening, as I have done in this picture at the bottom, you have no idea of the depth of the pin inside the skull. So just remember that, just the tip of the pin into the jaws of a chuck, use that to create the initial opening into the puller.

Once you've, once you've opened it with a simmon pin, then you use Ronjus to enlarge the opening and you can actually take away most of the bullet very easily. Then you remove the epithelial lining of the bullet. If you're removing an apharyngeal polyp, then you remove the polyp.

Make sure in every circumstance that you remove the polyp from the bullet, you then look down the ear canal after surgery and remove the remainder of the polyp from the ear canal, and also look behind the soft palate, because it can be an extension of the bullet down the sorry, extension of the polyp down the eustachian tube into the back of the, sorry, nasopharynx, and you can have very large polyps sitting there underneath the soft palate. It's very embarrassing if you forget to remove it from there. As with the lateral osteotomy, you need to take care with the debridement on the dorsomedial aspect, because that is where the round and noble window is.

And if you're too aggressive, you could render the patient with vestibular type presentation on recovery from anaesthesia. Remembering again in cats, there's two compartments, the ventromedial, the large bit, and the dorsolateral aspect, which is a small part. And then this cat, you can just see here, there's a little shelf for bone, which divides the two.

Both compartments need to be opened, particularly when you're looking for nasopharyngeal polyps. The ventral medial part, which is very large, is a bit that is naturally opened first when you push that stymmon pin through the bullet from the ventral aspect. And then you'll see, and it's often not that obvious, little bony plate across the floor, and that needs to be punctured to open the dorsolateral compartment.

And here is a picture stolen from a, from a textbook, which really clearly shows you the division, particularly on the right, between the ventral medial aspect and the dorsolateral compartment. All right, so that's the ventralbu osteotomy. So really in this, this, lecture, I've tried to outline the roles of surgery in ear disease, that the total ear canal ablation, lateral osteotomy is for end stage ear disease.

Try to show you some tips to help avoid postoperative complications. Try to discuss that we recognise that a tikka is a salvage procedure, that the definition of end stage certainly varies from patient to patient. That if we're going to choose to do laterally canal resections, we need to be very careful of the patient choice.

We need to be very clear with our communication with the client because they need to understand that it is not an standalone management of otitis externa and it certainly has no role in more advanced disease. And when it comes to otitis media, again, ventricle osteotomy is an adjunct to medical management and for those cases that have failed medical management, and we need to be very aware of where the anatomy is because finding the bullet can sometimes be challenging. All right, thank you, and we can take questions from here.

Sorry Arthur, I was just muted there as I was chatting to you, so . Greater introduction to ears there, almost as we said, starting you at the beginning with those ones that we've kind of given up on as dermatologists. I had a little question, with lateral wall resections, I often thought, you know, with a sharppe, which has nil sort of ear canal, that it was often worth, Considering that early on if the dog was, you know, starting to have ear problems, have you ever thought of that as a potential reason to do a lateral wall resection?

I, I have to say I'm very spoiled person because I, I don't have to think too hard. I get told to do it by a dermatologist. So, yeah, absolutely, I've had those sent to me.

We're lucky, actually, in Australia, we, we're rarely seeing Sharpeys now. They're nearly extinct, with any luck, that will be seen. So I, I can't remember the last time I, I did it for Sharpei.

I, I guess my, I, I'm sure you stressed the same point to, to practitioners. It, it, it's a very careful discussion. And the owner needs to understand what we can and can't achieve.

So, yeah, I, I, I like the comment though. So you, you feel if they, if they inherently have a very narrow ear canal like the Sharpei, that there's a role if you do it quick enough or early enough. Yeah.

Yeah, you're doing it to help, you know, with getting, the, the ear preps in, because otherwise, you know, you don't get them in there and it's not really worthwhile. I don't know, Klaus, have you got any thoughts on, on that and just the sort of general. You know, where you might do surgery if you're here.

Yes, I am. I have a, yes, I have a lot of sharpes in my little end of the world, unfortunately or fortunately for, I guess, my surgeons in my end of the world because they're often so bad so early that I send them for a complete TA at the time. Yeah.

I find that the young 12 year old trapeze are often almost born with complete mineralized and severely malformed, not just kind of grossly on the pinna, but often with almost a twisted longitudinal. Acoustic made is that that creates that extra kink at the junctional section of the vertical and horizontal canal that almost makes it impossible to medically manage and surgery surgery often becomes necessity of that reason. I, I guess one thing that we all need to, state and, and, and sort of make people aware of too is we've all been there, we've, done the lateral canal resection or lateral wall resection, and, and then the owner's complaining cause the dog's rubbing its pinner because it still has opic dermatitis.

So we sort of got, I, I probably should have mentioned that too. If the owner wants the dog to stop rubbing the side of his head, the surgery won't help you. Yeah, no, no, good point.

We have obviously got some of you on the line. Do you, does anybody want to ask any questions? We've got a few minutes, if anybody's got any questions about that, about what perhaps you're doing in your own practise with with ear surgery, but .

Can I ask a question, Arthur? Yeah. So, what is your position?

So I agree lateral resection is, is a thing of the past. The only scenario I can think of where in the last 15+ years I've recommended is if I had a mass in the lateral wall of a, of an upper ear canal mass that I couldn't resect through the tris and, and, and kind of the bulk. Or get out with reasonable areas and I can think of maybe two cases where I've done that.

But what are you position on intraluminal surgery, minimal invasive procedures, trying to, reduce some of these masses within the ear canals. Is that something that you would entertain? I, I, I, I certainly entertain it, and, I seem to get a lot of, dogs rather than cats that come to me where I'm, I'm, the, the understanding is that they have an inflammatory polyp, as in a nasopharyngeal polyp, and, and they don't, they just have a, a big pendulous hyperplastic lesion hanging off the, off the, usually the vertical canal, and I find you can cut those off and Send them back to, for medical management, they do really well.

So if, if it's that sort of circumstance, yes, certainly, we, we get quite a lot of seruminous gland adenocarcinoma. So, of course, they need the whole lot taken out. Weirdly, I seem to get quite a lot of, plasma cytomas down the ears, and they, they, they again, they seem to come more from The, middle ear itself.

So again, you, you, you're having to do the whole lot. So I, I have a handful of cases where I've got a benign mass that I can get out, preserve the ear. The, the other thing that I didn't talk about was that modification of a total ear canal ablation where you leave the opening of the external acoustic meatus and you make a vertical incision over the mid portion of the vertical ear canal.

Then you dissect it out, you transect the, midway down the vertical ear canal and over so and then continue on doing a tikka as per normal. Now, you still got all the potential for facial nerve paralysis and haemorrhage and deafness, etc. But it's very nice for preserving the, the, the, the, the structure of the ear, you know, the owners really like it because the ear looks completely normal.

So I do utilise that a fair bit as well now. For cosmetic reasons. Yeah, for cosmetic, but it's, it's actually, it's a, it, it is not, it doesn't complicate the surgery, so it doesn't make the surgery any harder, and it certainly, it certainly, in some ways, I think it makes it a little bit easier because you're not trying to reconstruct the the pinna at the end of the end of the surgery.

Chris has got a little question, asking about antibiotics and Tika. What's the current thoughts as often it is dirty with chronic infections. So would you use antibiotics at all there?

Well, anyone who's a microbiologist and worried about antibiotic resistance probably loves me because I, I don't use a lot of antibiotics. I, I, I think people get a bit bent out of shape and They forget that the role of surgery is to remove the infected tissue. So you, you're taking away that infected vehicle now and you're scrubbing out, essentially the tympanic bulla.

So at the end of it, there's not much left. So if, I, I, I, I don't use a whole range of fancy antibiotics because the dog happened to have pseudomonas preoperatively. And, the, postoperative cultures are generally fairly unexciting.

So, I, I just get a little bit of peroperative, cephalazole and, yeah, as you would routinely, and, and a broad spectrum antibiotic to go home on. And I suspect my broad spectrum antibiotic they go home on does very little for them. It's because I've done surgery and removed the infected, infected materials.

So, I think of them as an abscess, and of course, the most important Important part of that is to remove the, remove the mucky bit first. Claus probably has a much, much more refined answer to that question. Well, I go by the, there, there was a nice paper done at at Penn, a couple of 10 years ago where they looked at the the preoperative and the postoperative, flora, and it was pretty scary.

So when I have my surgeons and, and I absolutely, I with nightmare can recall the two ikas I participated in as a resident and I never want to do that again. But I have them with the rounds as they are removing the, the bulla mucosal lining if you will. I have that being submitted for macerated tissue culture, so I use that, instead of the, the swap, I basically have them take it and just send it down in a in a blue, yeah, and just have them marate that for aerobic anaerobic culture so that I don't get any post-surgical surprises.

Yeah, and that's the thing, isn't it? Your, your culture after cleaning out the buller and what you're growing before are often quite different. But I just have had some of those where they come to me and they have had draining tracks all over their head where have maybe not been completely clean to the same level that you showed and, and so I, I just ask them to really make sure I don't have any nightmares.

Yeah, I, I, that certainly is a, so if you, if you're managing a parrot or abscess, that's a completely different circumstance and that's, yeah, often very, very challenging, and you have a bug in there that you're gonna really struggle with. So those ones, they need a much higher level of respect than a first time round tikka for me. Yeah, that's great.

So I think that's probably all the questions. I can't spot any anymore. Let me just check.

Oh, Susan's just said thank you, very informative. I used to do lateral wall resections commonly early in the progression of the disease with success, but didn't have cases with polyps, etc. I improved ventilation was sufficient, and then Katrina said we're rather unsophisticated surgeon have only ever attempted lateral wall resections.

Maybe it's careful case selection, but 70% of cases have improved, with reduced but not eliminated need for medical management. So yeah, I think you've always got to carry on, managing them, the ones that they're seeing, and then, yeah, I think that's all the questions. So, Arthur, thank you so much.

It's, it's nice and early in the morning in, in, Australia, presumably warmer weather than sort of 12 degrees as well. Yeah, yeah, I'm struggling with, I think 30 today. Sounds good, sounds good.

Listen, thank you so much for for speaking. It it is such an interesting area because I think ears are, are not necessarily looked after well in, in general practise. So I'm hoping that this session and this session following it with Klaus will really help people to get a better take on, on how to look after ears, so thanks so much for that.

My pleasure.