Welcome to this edition of the Webinar vet entitled Equine Soft Tissue Surgery. We're gonna cover some hints and tips for mass removals and get into a beginner's guide to skin grafting. I am Matthew Sinovic.
I'm a surgeon and las diagnostician at the Lippo Equine Hospital in Hampshire here in the United Kingdom Today, we're gonna be going into some of the practical hints and tips and decision making, hopefully to help you with some mass removals going to some basics of that and then and how to get the best outcomes for your patients. We'll also have an overview of some skin grafting, and cover pinch and punch grafting and how to get started with those. Hopefully, after this talk, you'll all feel comfortable to give these extremely useful techniques a go.
The learning objectives for today's talk are listed here, which is, as we said, getting through decision making for mass removal, tension relieving techniques, some of the closure techniques covering skin grafting and some of the physiology around that, and then getting into the pinch and punch grafting, which is very basic skin grafting but is accessible to most practitioners and is a good place to start before getting into anything more, specialised than that. So mass removal is most commonly indicated for what are known and or suspected tumours. Excisional biopsy works very well in many situations, and that's where the full mass is removed, if possible.
And then a portion of that mass may be submitted for history pathology and then pinning. The outcome of that follow up treatment may or may not be needed. Hist theathers.
Very useful to determine if you've if you've, resected all the borders or if there's any local infiltration of tumour or mass tissue into the subcuticular tissue that you've left behind. Most commonly indications are for things like sarcoid, melanomas and squamous cells. We're not gonna be covering a lot on sarcoid because that is covered pretty much elsewhere.
So most of the things we're talking about here would be benign masses. Melanomas, et cetera, would apply to things like granulomas as well. And other types of lumps which may or may not know the origin of obviously patient restraint in these situations is vital.
Some people love twitches and under some circumstances, and with some horses they can prove invaluable. However, do be aware that of a horse that doesn't tolerate a twitch, and that they can react quite explosively when a twitch is on. Even horses which do tolerate it well can suddenly react violently when twitched.
And in my experience, some react more violently and quickly, So don't get lulled into a false sense of security. Similarly, heavily sedated horses can and will kick and can also strike out, sometimes using high doses of por and I suggested to force the horse to plant their 4 ft more ST. There's a question over the usefulness of morphine in this situation as well, but none of these are fail safe.
So whenever performing surgical procedures on horses from mass removals to stitching up always be vigilant, obviously local or regional anaesthesia will provide a much safer patient to work on and is vital for resection in these cases. Now, again, we're not gonna cover regional anaesthesia. Most of the masses resected will just have a local infiltration of of, an of anaesthesia under the skin.
And for this, generally we use mepivacaine, which is non irritant, has a very rapid onset and duration of approximately four hours and is the usual, anaesthetic of choice in limbs as well should be available to most practitioners using four nerve blocks. If that's not available, lidocaine will suffice in most instances as well, but may not always work quite as well in the distal limb. So for some masses, general anaesthesia may be indicated.
If that is the case again, you need appropriate facilities and experienced people to perform this, invasive blood pressure monitoring gas, monitoring all those sorts of things and preferentially positive pressure, anaesthesia and and facilities to do that, it will depend on the size and the site of the mass. Some masses are not accessible unless the horse is upside down. Sometimes there are a huge number of masses, and in order to facilitate or expedited general anaesthesia and a quick G, a may be the best option.
And sometimes these things can also be performed in the field with a quick knock down just to get a big mass off, and that, obviously the other part is the temperament of the horse. Sometimes they will let you get a needle into the neck but nowhere else. And that's a consideration to be taken into account for embarking on resection of masses antibiotics.
We're all very aware of the current conversation around a responsible antimicrobial stewardship. In general, for most mass removals, these should be done under a sterile condition or a septic technique. So perioperative use is indicated, but, extended courses should not be needed.
Generally speaking, you should use the first line antimicrobials board spectrum, and those are the best and can be used perioperatively, As we said at the correct time, timing the correct dose. Use a responsible choice. These are combined with a premedication of a non steroidal and then depending on your sedation practise, can be used with AC, P or things like that, in order to smooth out your sedation.
Also, remember when we're discussing antibiotics that, we should remember to check the tetanus Stasis of the horse and provide relevant prophylaxis if it has not been vaccinated, within the correct time frame, what are you gonna need embarking on this though the surgical kit for most, mass removals is fairly limited. You don't need a wide range of materials. What's very important?
Obviously, scalpels and handles, hemostats, a good pair of scissors. Generally, you can get away with the Mets and balm for this. But mayos may also suffice as well.
Decent thumb, forceps and suture needle holders. Suture drivers, and then a selection of sutures, which we'll get into a little bit later. I've put in there that a Penrose drain is optional, and then access to formula or something like that.
So which is sometimes difficult for some people? But if you send it off for Histopathology, that's a consideration to make sure you have all of these things ready before you embark on a resection of the Mass and, surgical interventions. The overall goal in the management of any surgical incision.
Or for that case, any wound really, regardless of whether it's treated by primary closure or D or secondary closure is to allow or is allowed to heal by second intention is to achieve a result that is functional and as cosmetically appealing as possible. And the best way to do this will always be primary closure, and this should always be your goal. When removing a cutaneous mass.
No matter the size or shape. Successful surgery relies heavily on an adequate blood supply in mammals. There are two types of vessels that supply the skin, so we have perforating muscular cutaneous vessels and direct cutaneous vessels.
Perforating muscular cutaneous arteries generally pass through the muscle to supply the skin. This is found generally in humans and pigs. Horse skin, like that of dogs and cats, is supplied directly by cutaneous arteries, which reach the skin by passing through the facial cept between the muscle bodies.
Direct cutaneous vessels usually run subdermally and are parallel to the skin surface, and they closely associate with picul muscle in areas where the structure is present. And that's especially important in the horse. In the distal extremities, where there's no picul muscle, the direct cutaneous arteries run beneath and parallel to the dermis.
And this is something important to remember when you're planning your skin incisions. You wanna try and preserve the blood supply as much as possible. Limit dissection.
Where possible? Through, arteries or blood vessels. So that you have good blood supply to the skin, which will be well, perfused and ensure adequate healing the skin has three structural components that impart tension and viscoelastic.
These are cogen elastic fibres and the ground substance, which is primarily proteoglycan. It's important to know that these components vary considerably between different sites of the body. This easic materials are those for which the relationship between stress and strain depends on time, So if the stress is held constant, the strain will increase with time.
This is called creep, and if the strain is held constant, the stress will decrease with time, and this is known as relaxation. Tension is the magnitude of force the skin can exert, and there are two types of skin. Tension.
Static tension, which results in the skin clinging to the underlying body, and dynamic tension, which results from the pull of the underlying muscles and is generally seen as wrinkles on the skin during movement. Understanding the physical and biomechanical properties inherent to skin allows you to manipulate them to your advantage. Both of these things will cover a little bit in the the later slides, but they're very important when it comes to closing your incision and planning your skin incision.
These it is these properties that contribute to both creep and stress relaxation, and both of these are important things in ensuring a good outcome. Static skin tension is a result of the elastic fibres, the dermis, and this is the skin. The reason that the skin edges retract when you incise them.
Langer was a human medic, and he mapped these in people, but didn't always consider movement. And since skin is an isotropic, skin tension lines are influenced by muscle contractions to movements as well as other external forces. So these Langa lines are now referred to as relaxed skin tension lines.
Incisions made at oblique angles to these lines tend to become curvilinear, whereas incisions made at right angles to the lines of tension gap widely and will require more suture for our position, they'll heal with scars that over time may become stretched and are often less cosmetically appealable. Acceptable. Sorry.
Dynamic tension lines can be seen as wrinkles in the skin when the muscles contract. When possible, incision should be made parallel to these lines to reduce tension across the suture line. So to find the lines of tension, generally, we pinch the skin, try again at a at a different angle, the angle at which it's easiest to pinch the skin up so that where the skin seems the loosest is the same angle in which you should make the incision.
So try this on the dorsal part of your forearm. The lines of tension generally run longitudinally, and you'll be able to feel this and see it wherever possible. A plan of attach should be made prior to creating an incision, so the location of the lesion, the elasticity of the tissue, the available blood supply should all be considered.
When you plan a new surgery, the extensibility of the skin should be assessed in both a relaxed position and during movement. And as we said, this can be done by grasping the S, the skin surrounding the mass or the lesion with a thumb and forefinger while moving the body. Part.
Careful assessment will identify areas from which skin may be mobilised and areas that are under tension whenever possible. Planned removal of masses on the limb should involve incisions that are parallel to the long axis of the limb incision. Placement for management of lesions of the upper body is site dependent.
But generally these have slightly different blood supply and often will heal a lot better, positioning the horse's body during surgery so that the affected region is under the greatest tension. Facilitate selection of your closure techniques and may minimise the risk of post-operative. Deists.
Sutures should be placed as close together, as is necessary to approximate the skin edges accurately Wounds along tension lines. Clo close with fewer close with fewer sutures, then do those, perpendicular to the line of tension. Most more sutures are required for thinner skin than in thicker skin.
For wounds and tension. Increasing the number of suture bites is preferable to increasing the su. The material size and in human sutures.
Generally placing interrupted sutures at about half a centimetre apart provides good tissue acquisition and mini minimises tension on individual sutures. This is, extrapolated to equine wound closure, and generally we follow fairly similar principles to facilitate optimal healing. Accurate apposition of the skin edges with minimal interference to the blood supply should be the goal when suturing wounds the pattern and techniques of suture placement.
The number of sutures and the suture line support are all important in ensuring an optimal outcome. Apposition is generally best maintained by maintaining the needle perpendicular to the skin during penetration, and spacing of sutures plays an important role in maintaining optimal apposition of the skin edges. As a rule, sutures should be placed at a distance from the skin edge, equal to the thickness of the skin itself.
Aversion of the skin edges, which was once thought to be sort of superior cosmetically, is now considered unnecessary. And what we're more worried about is proper Apo position of the skin edges, with a nice even tension across the skin. This has led to the development of certain different types of sutures in human medicine, including barbed and unidirectional and bidirectional sutures, which maintain an even tension across the skin.
But for the purpose of this, we're gonna leave those alone. Sutures, as we said, are used to approximate the skin edges. Reduce the tension as well as reducing dead space.
The proper placement and use of appropriate suture patterns is important and is also a very important technical consideration. The selection of a suture pattern is often based on your personal preference. Whatever you're comfortable with and what you're used to using.
However, in some instances there are definite advantages and disadvantages, associated with particular patterns that should be taken into consideration. The choice of suture material is generally of much less importance than the actual pattern being used generally for skin. We're gonna use a monofilament, and that can be either absorbable or nonabsorbable, depending on your preference, as well as the patient's temperament.
While absorbable suture material is generally chosen to reduce dead space, and skin tension, either absorbable or nonabsorbable suture may be used in skin closure, with a generally found to be an equal cosmetic outcome. When cosmetic appearance is important, Sutures should generally be removed by 10 to 14 days, regardless of the type of suture used generally in the skin as well. We're going to use a cutting needle and in the sub Q a, taper cut or a round bodied needle, depending on the tissue that you're rating on.
Simple Interrupted are the mainstay and generally provide excellent tissue adposition if they're not placed too far back from the skin edges or pulled too tightly, both of which will cause inversion of the skin edges, which is undesirable the ability to vary the width of their placement in irregularly shaped wounds. And those and those with variable skin thickness often facilitates better alignment to the skin edges, than do continuous patterns. The tension across individual sutures can also be easily adjusted.
And if one is what one's tension along the wound edge has changed and one's not right. You can remove it and replace it. Skin edges closed with interrupted patterns have been shown to have greater tensile strength and less compromise of the microvasculature on the on the skin edges than those closed with simple, continuous sutures.
As with all continuous patterns, the biggest issue is not failure or suture breakage, cos that will result in breakdown of a large P portion or all of the incision line. Continuous patterns are very quickly placed, and that's a pro, but it is also not possible to vary the tension on the suture line to the same degree as it is with an interrupt pattern. Continuous patterns have been shown to result in increased Edoema and Co and may compromise circulation.
They may also have a prolonging effect on the inflammatory phase of wound healing, posing wounds under tension should always be performed with caution but is sometimes a unavoidable careful judgement is required when increasing stress on the suture lines. However, clinical experience suggests that equine wounds can be closed under a reasonable amount of tension and provided there's good blood supply and that the suture line is well supported by some form of coaptation. Afterwards, healing is usually not delayed the near far, far near suture pattern or in its modified form.
Near far, far near pattern combines a tension suture with the far portion and then an appositional suture with the near portion, with the name denoting the order in which the relative distance and sequential suture bytes are taken from the skin edge. This pattern has a much higher 10 cell strength than either a simple interrupted or a mattress pattern, but does have the disadvantage of requiring that a wound has a large amount of suture material placed in and around the incision. The three point, or half buried mattress suture is a corner suture that's used to secure a sharp intersecting point or a Y shaped incision.
The intersecting apex of a Y shaped incision is predisposed to ischemia and the design of the suture pattern is such that it will not further compromise the blood's flow. It's also a good place to start and secure a flap if you have ended up with a Y shape or a corner, and means that your your tension can then be adjusted for the rest of the suture. Along the long axis.
The three point suture can also be used in other situations in which there's an angle of skin when sutured and it's predisposed to ischemia. So it's a very useful pattern to remember and something that people often forget about, when they are using mass removals or suturing skin in general. Simpler, interrupted, provide good and are probably the best ACS position.
A forward interlocking suture is probably the best of a continuous, as it applies some pressure across the wound. Tension relief is often required, and, as is shown there, my current favourite is a near far, far near or mattress and you can then add quills to that to dissipate the tension and to prevent local necrosis and pull through. If there is significant tension, horizontal mattress, sutures and aversion, may save some of the blood vessels, But certain suture patterns like those can also lead to some vessel compromise.
So it may be that vertical mattress is preferential to horizontal mattress. It may provide good cosmesis, but all a lot of, potential releasing sutures do lead to a lot of material in and around your incision. And that may slow, some of the healing due to the infla inflammatory process.
Walking sutures in the sub Q space are excellent for reducing the dead space, and May for reduce some of the fluid accumulation. So always remember, if possible, to do a sub Q layer that can be a walking suture or a continuous suture just to minimise some of that dead space. Staples are often quick, and they are usually inert.
In some places, particularly where there's no tension like over the face. They're very, very useful, but they can be uncomfortable to remove. And that's something to remember.
When you have to go back in 10 days or two weeks time to remove sutures. And you have a grumpy patient and have to sedate the horse again, to get the staples out. Supplying adequate support for sutured wounds can make the difference between success and failure.
In your reconstruction techniques, once a mass is removed, the method of choice is D is determined to some extent by the location of a lesion and the amount of tension on the suture line. In many, many areas, bandages can be used to support a suture line, particularly in lower limbs. They immobilise the adjacent skin and the joints and they minimise edoema formation, and they help to obliterate dead space.
So these are very, very useful. There are some new developments in this area, and this paper by Camino it all used such as packets to good effect. And we'll get into some of the details of that study a little bit later.
The things as we said, stents over the suture line in the initial phase are often very good. Those are only usually left on for 24 to 48 hours. Particularly if they're soaked with blood.
They then become a NUS for bacteria. And in some instances, particularly like in the foot, et cetera, using a cast may be beneficial. Drains are useful in removing oxidate and preventing fluid accumulation, which could disrupt the special planes, especially if there was a large dissection, during your mass removal.
And if there's excess of tension across the repair, and there may be harbouring of infection if your mass was infected. They're especially useful when gravity does not aid drainage. But do remember they can also be a port for bacterial translocation.
Correct placement is critical, or it will just act as a foreign body within the wound. Generally, your placement should be deep within the wound orientated to make make the most of gravity and exit remotely. There are various active and passive drains, but in practise, the Penrose drain is the most commonly used.
These are tubular latex drains, which rely on surface tension forces to promote drainage. And therefore they should not be frate. They're effective simple to use, but as we said, they should be removed when drainage is no longer necessary or has stopped, or they will start to act as a foreign body, and they may then delay wound healing and the longest they should ever really be.
Left in is up to four days, so getting into it, a fusiform incision is generally made around the the mass, the long axis along the lines of tension. The length should be approximately 3 to 4 times the width you needed to remove the mass to facilitate closure. Subcutaneous tissues are then dissected, freeing the mass from the surrounding tissue.
Subcutaneous closure may be skipped, or, alternatively, a simple, continuous pattern is used to close the dead space. If you undermine quite a lot, as we said, walking sutures at this point may be good. And then you can use a subcutaneous closure with a simple interrupted over that.
If the dead space is large, Penrose drain may be placed, which can be placed through the bottom of the skin incision or parallel to it. And then routine closure would be a simple, continuous or forward interlocking option for closure of the actual skin. Generally, we start closing from both ends, and this is good to even the tension over the sutures, and that's it all over the line.
If you're using simple, interrupted sutures, start at both ends, work it up towards the middle tension relief sutures in certain parts of you near far, far near vertical mattress or horizontal mattress. If needed. You can undermine the tissues to allow stretch or use relief incisions, and we'll come on to that in a little bit.
Make sure that you secure your knots by first placing granny knots or using three throws rather than two for the surgeon's knot, and follow that with the square knot. Granny knot can be tightened with the later throws, meaning you can tighten it down in two steps. Three throws provides more friction, and that will often keep the throw the knot in place and then either place a stent over the incision or a bandage in the area if needed, particularly if you've created dead space due to a lot of dissection.
Undermining the skin edges around the wound or excision site prior to closure is often the simplest way of providing tension relieving or is the biggest, the simplest tension relieving procedure. Undermining is accomplished either by blunt or sharp dissection, with very careful attention to the blood and nerve supply to the given region. Blood dissection has the advantage of minimising damage to the cutaneous blood vessels and is a preferential over sharp dissection.
This can be achieved by opening the blades of scissors. They have been inserted into a closed facial planes or using the hand of a scalpel in a back and forth motion. And both of these are acceptable methods for blankly.
Undermining skin sharp dissection. Using the scalpel or scissors is often necessary, to separate the skin edges from underlying planes. If you have, chronic or fibrotic reaction around a mass when sharp dissection is used, there's obviously an increase in bleeding.
And that's usually because we've perforated those parallel vessels under the skin. And there's a and that may lead to he term of formation, which does put your incision at risk of breakdown. In this case, placement of a drain prior to skin closure or pressure bandage may mitigate this in the post op period.
The degree to which skin needs to be undermined can be estimated by drawing the skin edges together with a towel clip. As a rule in a fresh wound, the distance sh should be equal to that of the width of the defect itself and should be elevated on each side of the wound. So basically, in a nutshell, you can undermine about the same width as the wound.
On either side. You shouldn't really need to go more than that, and you'll be able to see that by using a towel clip to pull the wound edges closed in small animals. It's thought that undermining can be quite extensive without causing necrosis provided there's limited interference with the blood supply.
Clinical experience suggests that the same is true for horses, but generally you don't want to undermine too much if you can help it. This is often used in conjunction with the mess mesh expansion technique, in the limb of dogs or horses. And you can do 360 degree undermining, which is not necessarily associated with any more major complications.
In some studies, attention releasing incisions are longitudinal incisions that are made adjacent to the wound margin, and these can aid in advancing skin to cover the wound. When the tissue between the wound edge and the incision is undermined, the elevated skin acts as a essentially a bipedal advancement flap. This technique is used more to allow the movement of a limited amount of skin in those areas where simple undermining alone does not adequately relieve tension.
But the size of the defect to be CLO does not justify a more elaborate sort of plastic reconstruction procedure. A release incision can be made on either side of the wound or on both sides. Do be careful and conscious of your blood supply when you're doing this.
When making a single release incision, the incision should be placed at a distance of approximately the width of the wound away from the wound's edge over healthy tissue. When using two release incisions. The placement of each incision is similar to that of a single incision, and the release incisions are generally not closed but allowed to heal by second intention.
Mesh mesh expansion is a simple technique that, when combined with undermining, can increase the amount of skin available for mobilisation and therefore increase coverage, particularly of largely created surgical wounds. The mesh mesh incisions are created when the skin is being freed from the attachments of underlying fascia, and small incisions are made in staggered rows in parallel to the wound edge, again staggered to ensure that you have adequate blood supply to the edges of the wound. A V to Y plasty technique for relieving tension requires a V shaped incision with the point of the V directed away from the defect to be closed when closure of the original defect has been accomplished.
The V incision is then converted to a Y through a through simple interrupted sutures. The longer the legs of the V, the greater will be the degree of tension relief. However, this mes method provides only a limited amount of skin movement not really suitable for large defects.
Then we have some skin stretching and expansion techniques. Some of these are very useful if you have a large mass and you have some time to plan. Prest is based on the phenomenon that skin is held in.
Tension will gradually stretch. It's an ideal method to consider when you have time, and it's an elective procedure such as an excisional biopsy, or if you have sutured something and you have need to, have scar revision or if there's delayed wound closure, are being considered. It relies on the physiological response of mechanical creep, which results in skin expansion and can be achieved when sutures are placed several hours prior to the removal of the lesion.
So that can be done either the morning of or the the day before using local anaesthesia. Basically what sutures are placed to placate the skin over an area of the planned incision. The direction of suture placement is chosen according to the anticipated direction of your primary closure.
Wounds of the body and Ali are generally the most amenable to pres suing. What you generally use is large nonabsorbable sutures, so number one or number two and usually a polypropylene or nylon, they're placed through the skin perpendicular and 2 to 6 centimetres on either side of your lesion. The sutures are then tightened to elevate skin and fold the skin over the lesion or the wound.
If pres suing is used in conjunction with tumour excision, you should be careful to place the sutures distant to the leg and avoid iatrogenic seeding of tumour cells into healthy tissues. So that's something to keep a very good eye on. If you're planning to use this technique, appropriate tissue expansion has been advocated as a means of decreasing incision closure, tension and expansion can be obtained by techniques as simple as the place the tar clamp across the wound and pulling the wound edges together for a short period of time, so that will just be clamped close and then allowing them to stretch.
You can also use things like a foley catheter and inflate the balloon. And variations of this technique have been described, ranging from tension being applied in three or four cycles of 3 to 5 minutes to a single loading cycle of approximately 20 minutes. What is often also useful is if you've created a very large wound, is to use towel clips to close the incision at a number of points.
When you start suturing, start suture at the end, or either end of the incision, suture up to your tail clamp and then suture past it. Leave it in place, which will just help relax some of that skin as you're going. If they do get in the way, you can take them out and replace them on a different part of the incision.
Although expansion was initially thought to occur because of the elect stick properties of creep, this explanation is currently being challenged and histological studies have failed to confirm the dermal changes associated with Mechanic creep. It's far more likely that expansion results from essentially the extensibility of skin, which is its inherent elastic property. And we're just manipulating this with using the tile clamps.
Skin stretching devices take advantage of the viscoelastic properties that creep and the stress relaxation, which we've discussed a lot there. And these are properties inherent in skin Technique can be used safely and in close proximity of infected, wounds or masses, and can be used to stretch skin proposed for skin grafts prior to harvesting or transfer. It's also been shown to reduce skin closure tension more effectively, often than in skin undermining.
Although there are a variety of commercially available devices, I'm not advocating the use of the device on the screen. Now, much simpler are the use of minimalist techniques, for example, using spinal needles, which is woven, or skin staples, which are placed approximately half a centimetre adjacent or parallel to your where your wound is. And then interrupted sutures are placed across these, around the exposed needle shaft or through the Staples cross over the wound or your planned incision and through the other side, directly opposite.
Then when the sutures are are tight, they exert tension, which leads to stress relaxation. Although the greatest gains and skin recruitment are seen somewhere between 48 and 72 hours, stretching can be achieved in a short time as 20 to 30 minutes. And you can definitely use these things to help you in your planning.
Tissue expanders, are made of a silicone elama. And they are balloons of varying dimensions, which, after being implanted subcutaneously can be distended. Some of them can also just be left in place, and they will grow in time.
The technique is common in human reconstructive surgery. Reports of its use in horses are limited, although there are now a couple of, case series, and elastomer, with a base size 2.5 times that of the defect that is to be reconstructed is selected and implanted below the skin adjacent to the lesion.
Now, these are quite advanced techniques, and probably require a lot of planning. And for the purposes of this talk, they're probably more for information rather than, for actual use the mass removals, nemesis, skin puckers or dog ears. These often develop at the end of the suture line, particularly when closing an oval or slightly regular shaped defect.
Or when you you've used a skin flap as part of a reconstructive procedure. These dog ears, if ignored, will often flatten out to some extent over time and maybe of little consequence. If the puck is small and the cosmetic appearance is acceptable and they're of limited importance, they can be managed by placing small sutures through half the thickness of the skin, just to flatten them down.
In some locations, however, the conservative approach may result in an unsightly blemish. And because correction of dog ears often requires lengthening decision, it's worthwhile to assess the extent to which the cosmetic blemish will be compromised if the pucket is left alone. But if you do wanna remove them, it can be stabilised with an appropriate instrument and removed by incising around the base, which results in a lengthening of the incision or an alternative method, is to close the incision until the dog ear becomes well defined, and then to extend the initial incision through the middle of the dog ear.
This converts the packet to small triangular flaps of skin or burrows triangles, which then can be excited at their base, and you can close the skin accordingly. Right? What are we gonna do once we have removed our mass?
Well, we want to minimise motion for at least 3 to 5 days, and then limit motion until the sutures are removed. Generally, sutures are removed in 10 to 14 days. As we said best for cosmetic appearance.
If you're using dissolvable sutures, and you have a horse with a non amenable temperament, those can be left in place. But you will still probably need some type of external cation depending on where you have made your decision. Generally, non steroidals are given for sort of 3 to 5 days to help minimise the swelling and the pain associated with the mass removal complications.
Generally, these the biggest one of these is de his. This usually happens about day three, and can be managed usually conservatively, depending on how much of the wound has. Deh if you've done significant, cleaning and had proper aseptic technique.
Infection should not be a problem, But remember that horses do live in dirty environments. Owner compliance is not always great. So infection would be another, complication.
And then if you have removed a tumour, tumour recurrence can occur particularly if what you thought was something benign is something like a sarcoid or a squamous cell. And then you may get poor healing. If the tumour cells have invaded the the wound margin, or if you have metabolically compromised animals with EMS or in older animals as well, right, we'll move on now to skin grafting.
This is a surgical technique which is reserved for wounds with large skin defects, and it's used to decrease healing time and ensure a functional and cosmetic outcome. The procedure involves transplanting skin from one part of the body, from the donor site to a wound, which is a recipient site, or using skin from another source to promote wound epithelization and contraction. All of this is aimed at reducing healing time.
The decision to perform skin grafting is influenced by multiple factors, including the size, the location of the wound, the presence of underlying structures, structures like joints and bones, financial constraints of the owner, and the overall systemic health of the patient. Although skin grafting procedure itself is relatively simple, procedure success largely hinges on identifying when a graft is appropriate. For the wound bed environment.
This is a very useful article, which, will come up again later in the talk. As we said, it's used where there's extensive skin loss. If you're looking for improved cosmetic result, requires very good early wound management, and you need a healthy granulation bed.
You can't have infection and movement. These are the two biggest causes of failure. It may also be expensive, depending on where and how you're doing it.
Primary closure is always and should always be attempted where possible. We will never do better than the normal skin, both for form and function and in all wounds in all mass resections. This should be your primary game.
Get the fund in order to preserve and restore what is normal as much as possible. However, this is not always possible. Second, intention healing is usually slow.
Does come with poor, functional and cosmetic outcome and may be expensive. And this is especially true of the distal limb, where there's very little contraction with a very poor, functional and cosmetic outcome, as is shown in the the healing of the wound over here. Second thing is that with all the ongoing care, the bills also rack up pretty quickly.
And although the upfront costs of primary closure and primarily managing a wound may seem a lot when it's compared to months and months of wound care, this is often false economy. So a retrospective study by Willink and ah in 2002 so well over 20 years now showed that up to 72% of equine wounds that was horses and ponies closed primarily had some type of deists, which was either total or partial. This is obviously not a great outcome.
And why is this? Well, it comes down to a couple of assumptions that wounds can't be closed after the golden period of sort of 6 to 12 hours, so many of them get left to heal by second intention. One of my thoughts and this is shared by a number of other surgeons is that poor debridement in the initial fate phase leads to poor healing.
And also people don't often understand the difference between static and dynamic tension. And we've discussed that quite a lot here, So hopefully you've you've come to grips with those concepts. As we said, Static tension is where it's difficult to pull the skin edges together and dynamic tension is due to movement.
So, for example, in the previous wound when you had a wound over the hook, it's easy to close at the time of surgery. But once the horse moves, there's a lot of tension across the wound edges, and that leads to the wound breaking down and de hessing, if you haven't planned for that and taken that into account in your management. So how do we overcome this poor result?
Well, this is work from Dylan Gorby, and basically the three phases of managing wounds in the first and most important is meticulous debridement, then tension release as appropriate and obviously then adequate immobilisation. Short term afterwards and long term as needed. Coming back to the paper by Camino ol this paper turned the tables on those results as you can see here they managed to greatly increase the success of primary healing, with only 16% of horses having partial deists and 15 horses having severe deists.
And they used it through a number of means as previously discussed. Made sure that wounds were very well derided back to very healthy bleeding tissue. And then they used proper tension releasing techniques.
And what was described here was the use of these skin tiles. This was the subject of the paper, and these were U used in conjunction with IMMOBILISATION techniques, and that was how they achieved these results. So when do we graft?
Basically, if you have a wound that you cannot close primarily, you should be planning to graft and your wound Management should all be geared and appropriate and based around the fact that at some point you are likely to need to graft. This is obviously apart from small wounds and wounds that are situated on the upper body that will probably heal by themselves. But when you're talking about lower limb wounds and wounds over the carpets and the hock, do warn your clients in advance that these may need grafting and that grafting should not be a last resort.
So plan your graft. Two basic types of skin graft are the pedal pedicle graft and the free graft. A pedicle graft remains connected to the donor site, at least temporarily, by a vascular pedicle.
And that is what sustains the graft and ensures its viability. These are seldom used in horses as they're often not appropriate, and the blood vessels don't always allow for this. A free skin graft is a piece of skin that has become completely separated from its local blood supply and is transferred to a wound at another site, where it must then re-establish a vascular connection to survive.
Free graphs can be categorised in several ways, one of which is by their source. So an autograph or is graft is a graph that's transferred from one site to another site on the same individual. The recipient of an autograph mounts no detrimental immune response against the graft because the recipient and donor are the same person.
So a grafting is the most common and practical type of grafting in wounds of horses. A graph transferred between members of the same species is an allograft and a craft transferred between one species and another is a xenograft. The recipient of an allograft, or a xenograft does mount an immune response against the graft.
Causing the graft to eventually become rejected because of the immune mechanism is highly specific, and allograft from a different donor is not necessarily affected by circulating lymphocytes. Sensitised first against the allograft. Although allograft and Xenos are rarely apply to wounds and horses, these grafts are occasionally useful as biological bandages.
So types of skin grafts. In essence, we divide them into full thickness and split thickness. More advanced ones in the split thickness will be mesh grafts and meek grafts.
And while those are useful, what we're gonna be covering today as the sort of basic graft are your full thickness grafts, which are pinch punch and tunnel grafts and sheet grafts. And we'll get into the how two of pinch and punch grafts in this talk. Advantages and disadvantages are listed here and that come this graphic comes out of that nice, review paper.
It's filled with some very good graphics and some good explanations. So if you want some extra reading, do look that up. I'll give you the reference again later.
A primary exit for free grafting is a recipient bed that is vascular and free of infection and devitalized tissue. A free graft cannot be expected to survive if placed on bone or denuded of Periosteum tendon denuded of peritenon or cartilage denuded of Pero but practically any other tissue is really capable of supporting a free gra graft. Joint capsule ligaments and adipose tissue are capable of of of, of accepting a skin graft, but they do not readily accept them.
Fresh, surgically created wounds or fresh clean wounds caused by accidents of vascular and free of affection are the ideal recipient sites. Granulating tissue is also capable of accepting a graft, although not as readily as fresh tissue. Once placed, a graft goes through a process of adherence, and this is the followed by serum inhibition, revascularization, then organisation before acceptance.
Reasons why grafts may fail include accumulation of fluid beneath the graft, excessive movement and infection. And generally grafts applied to horses fail most frequently because of infection. So taking care to prepare your bed, swab it to be sure that you have no bacterial infection there and the use of topical antibiotic therapies are all indicated prior to performing a graft.
Preparation of your recipient site is the most important contributor to survival of a free graft. So factors to consider when determining whether your wound is prepared sufficiently to accept a graft are the wound's vascularity, and the potential of wound infection. Grafting should be delayed if the wound appears to have inadequate vascularity to support a free graft or if it appears to be infected or have a higher than normal or higher than ordinary vulnerability for developing infection.
Highly vascular granulation tissue readily accepts a graft, but as granulation tissue, it CS its vascularity and ability to accept a graft diminishes so fibrous poorly. Vascularized granulation tissue, or granulation tissue plagued by unremitting infection, should be excised to a level below the margin of the wound to allow the wound to form fresh vascular granulation tissue free of infection before a graft is applied. Because granulation tissue has no innovation, it can usually be excised with the horse standing, delaying the grafting of a fresh wound for several days.
That may also decrease the time required for the graft to revascularize. The sprouting capillaries are capable of rapid revascularization and the graft will develop in the wound within 48 hours. So by delaying grafting for two days after wounding the time before the graft begins to revascularize can be reduced by about half.
As you can see all the wound on the right, there is a nice, healthy granulation bit and probably about ready to accept a graft. In general, the donor site for pinch and punch grafts should be in an inconspicuous location. These are generally performed in the pectoral region, lateral aspect of the neck under the main, the lateral abdomen or the lumbar region.
Generally, pectoral and main are the ones most use. The region should be clipped and aseptically prepared, in preparation for grafting. And this is then desensitised with local infiltration of an anaesthetic.
The skin is then aseptically prepared. You should always use physi physiological saline to flush the donor site. To be sure that there are no chemical traces prior to harvesting.
Although grafts can be harvested prior to the preparation of the recipient site, the amount of time should be minimised to ensure the health of these grafts. Once harvested grafts should be stored in saline soaked in laws to keep them moist, so removing punch grafts directly from the horse's skin with a bumpy punch creates small blemishes at the donor site. Therefore, the graft should be harvested in a symmetrical pattern, about one centimetre in part to improve cosmetic outcome.
Small wounds created by the biopsy punch need not be closed necessarily, but Su suturing or stapling each wound may produce a less obvious blemish subcutaneous fascia, and that should then be sharply excised from each individual graft before it's implanted to facilitate plasma plasmatic inhibition. Punch grafts can also be harvested from elliptical or full thickness sheet of skin. Which is usually harvested from the cranial aspect of the pictorial region.
So in that case, you can use a 10 centimetre long by four centimetre long or four centimetre wide incision, or remove that section of skin. You can dude the, fat from underneath it and then use a punch graft to take those out, as is shown over here, you will need two different sizes of punches, one to take the sample and then one to prepare your donors your, recipient site so the recipient holes are created, as we said, with a slightly smaller biopsy punch than that used to harvest the grafts to allow for contraction of the graft. So, for example, if your grafts were harvested with a seven centimetre diameter biopsy punch, the recipient hole should be created with a five millimetre biopsy punch cotton tipped applicators.
So these just basically cotton buds, which have been sterilised, can be inserted into the recipient holes in a granulating wound. And that makes the applicator enables the hole to be localised easily and also prevents a blood clot from forming in the hole. The grafts are then inserted into the recipient holes, and the grafted wound is covered with a non adherent dressing and a bandage.
Consideration can be given to the direction of the hair growth when the graft is inserted. But the outcome. The cosmetic outcome is little affected, by properly orientating the hair in one direction or another as a best hint and tip when you are performing grafts, as is shown in the picture here, start at the bottom and work your way up that means that bleeding from the top won't, obscure your surgical sites.
Lower down. And you can work in a nice, systematic manner and not have blood clouding your surgery site. Pinch grafts are small discs of skin that are harvested by exciting an elevated cone of skin.
This is usually done by bending the end of a needle, elevating the skin and nipping it off with a scalpel. A pinch graft is sometimes referred to as a reverent graft. The donor sites before obtaining pinch grafts are the same as those for punch grafts.
Preparation of the donor site is identical to that described for punch Grafting. A cone of skin, as we said, is elevated using a needle or a tissue forceps or a suture needle. However you want, and as in then exci with a scalpel blade, usually a number 11 blade is most suited for exciting the cone of skin.
The grafts are stored on a gau sponge, moist and again with the saline until they are implanted. The recipient site is prepared in the same way. As for punch grafting the recipient pockets can be created in advance, to ensure a haemorrhage free wound.
But locating the pockets afterwards, may be difficult, so to implant. In essence, you take a number 15 scalpel blade and that's stabbed into the granulation tissue in the recipient bed at an acute angle to create a shallow pocket, and the graft is then inserted into that pocket. Implantation should begin at the distal end of the wound, so again, start at the bottom and work proximal.
Because otherwise the pockets are obscured by haemorrhage. After they're created, graft should be implanted about 3 to 5 mils apart. Each graft is laid into the wound, epidermal side up proximal to the pocket and then slid into the pocket using a hypodermic needle, A straight suture needle or the scalpel blade used to create the pocket.
Consideration again can be given to the direction of hair growth. But Semetic outcome is little affected by this. Following the placement of the graft, a bandage is applied to protect the freshly grafted wound.
Applying pressure to control the haemorrhage and maintain graft position and maintain a moist environment conductive to epithelization type of bandage applied depends on the extent of the location of the wound. Mineral bandaging is often required for pinch grafts. Punch grafts do require more pressure.
So soft padded bandaging to control the haemorrhage and keep them in position is better wound should obviously be covered with a non adherent dressing that's been coated with an antibiotic ointment or cream. It's helpful to secure the initial layer of the dressing in place, using elastic adhesive tape to avoid slippage and movement that will disrupt the graft. Finally, a routine standing standing bandage is applied over the dressing, for wounds over the hock and the carps.
These can be difficult to maintain in a stack wrap, so the entire dressing should be covered in an adhesive tape so elastic or something equivalent to protect the graft but also to allow joint mobility. The band is should be changed daily or every second day initially to monitor graft acceptance, and clean the surface of the wound if needed. Very, very carefully.
Sedation is advised at the time of initial bandage changes, even in good horses, and this is because you don't want to inadvertently remove the grafts. When the horse moves, or by moving or agitating the bandage over. Over time.
Bandaging interval can be increased to every three or four days. If the wound is not producing a large amount of exudate. And again, caution should be applied when removing the bandage because you don't want to dislodge your grafts or pull any that may be stuck to the gentle or to the dressing.
So gentle spraying with some sterile saline. And patients prior to removing the the noher layer is often advised. Bandages should be maintained for 3 to 4 weeks, or until the wound has completely healed and epithelialized so initially during the adherent phase, grafts are held in place by fibrin, and that's exuded by the recipient site.
And they receive temporary nutrition via plasmatic inhibition. As we've said, revascularization of the graph begins 24 to 48 hours after grafting, and eventually the host vessels anastomose the vessels in the graft and that supplies the N, the nutrition. In addition, the blood supply to the graft is often established by capillary buds from the recipient site, invading the graft By 3 to 4 days.
Fibroblasts have begun to invade the graft, and they form adhesions between the graft and the recipient site, and by 9 to 10 days. The grafts are pretty firmly attached by a fibroid adhesion, and there are functional vessels Cro Crossing the graft host interface. Pinch grafts initially appear as dark spots within the granulation bed, approximately 1 to 2 weeks following grafting as the granulation tissue over overly the graft sloths by 3 to 4 weeks following pinch or punch grafting.
A ring of pink epithelium can usually be detected around the grafts, and this means that they are, all starting to work properly. And by 42 to 56 days, hair growth will begin to grow from the grafts. In general, a 50 to 75% survival rate can be affected with either pinch or punch grafting.
And generally that's more than adequate to achieve success. So grafting a granulating wound will usually simulate epithelialization along the wound margins as well as wound contraction, which both contribute to the successful resolution of your wound. And you said this is a very good review article for those of you who want to read more on what we discussed today, and also go into some of the more advanced techniques, like sheet and micro grafting.
Oh, sorry, meek micro grafting. So hopefully this has given you the confidence to start doing some mass removals and, highlight some of the techniques you need to get you started. Remember to plan, take into account ST static and dynamic tension, and be prepared for some immobilisation afterwards.
Pension punch grafts should be considered at a relatively early stage in the wound healing process. If you're if you have a nonhealing wound or a large wound that couldn't be closed primarily, and definitely rather than a last resort, meticulous preparation of the wound bed and attention to aftercare will result in a very rewarding outcome with minimal investment of time and money. And you should be encouraged to consider the use of these simple techniques as treatment for one of the most common problems in equine practise.
Thank you very much for your attention, and I hope you enjoy the talk
