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This interactive on-demand teaching session led by retired cardiac surgeon and visiting professor Darigan will explore the art of dissection and touch upon surgical operations based on fascial layers and anatomy. Attendees, who represent 51 countries, will learn tips on the best instruments to use for dissection such as the Mackin do scissors and a lay, and how to develop tissue planes with the lightest of touches. Using models of sausages, oranges, and a real-life example of redoing an aortic valve replacement, surgeons will gain the necessary skills in the art of dissection and come away equipped with the knowledge of how to identify and separate tissues without damaging the underlying organs.
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BBASS has covered how to use the scissors and the blade in previous sessions. We no combine the two arts in the techniques for dissection. We aim to get you to think about tissue plane and how to use them to your advantage as a surgeon. The majority of tissue planes are blood less (BBASS will explain the exceptions) enabling the surgeon to explore the anatomy and respect the tissues. Orthopaedic surgeon have to go through soft tissue to get to the bone - the periosteum and the soft tissues are integral to bone healing! Caress and respect the tissues because your patient depends on these skills.

Learning objectives

Learning Objectives: 1. Explain the importance of identifying and understanding primitive layers in dissection. 2. Describe the different instruments used in dissection. 3. Examine the principles associated with manipulating tissues during dissection. 4. Demonstrate techniques for developing planes with scissors and forceps. 5. Analyze how to identify and preserve neurovascular bundles during dissection.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

Hello, good evening. Good day. Good morning, good afternoon, wherever you are in the world. And I say that because our analysis of the past six months tells us that 51 countries are represented in the audience. I'd like to thank you for followers. 4233 on Facebook, 604 on Instagram. And you the regular followers on me. Welcome if this is the first time and I hope it makes sense and please spread the word. I'd like to thank me for their platform to enable us to reach you in any part of the world from here in a caravan park in Yorkshire in the United Kingdom. My name is Darigan. I'm a retired cardiac surgeon, a past director of the Faculty of Surgical Trainers for the Royal College of Surgeons of Edinburgh and a visiting professor at Imperial College in London. Thank you indeed. And thank you, Gabrielle. This is supposed to be an interactive session. So please put your questions in the chat. Gabrielle will read them out and I'll hopefully address some of your answers beforehand. Tonight, we're going to be talking about the art of dissection and I think we start the story with the embryo, the endoderm mesoderm, ectoderm. And to remind you that the ectoderm gives rise to the central and peripheral nervous system, the mesoderm to the muscles and the bones and is the source for angiogenesis. And the endoderm, the foregut, hindgut and midgut giving rise to the organs, the thyroid, the liver, the lungs, the stomach, pancreas, small bowel and large bowel. Now, all of this in embryonic development is folding and convoluted and turning and rolling over in all sorts of planes. Quite a remarkable development in such a short period of time. But as the endoderm and the ectoderm and the mesoderm all rolled over, imagine it like three different ice creams, the GEOS and you're mixing them and as you're mixing them, you see the swells and colors and at each boundary, there are layers and this is important. It is the layers which are condensation of connective tissue between these folds. I'm reminded of the making of a Katana. It's the folding of the metal over and over again, that adds to the strength and the composition of the samurai sword. But in embryonic development, we get folding and folding, involution. And in particular, the angiogenesis means that it is going from the mesoderm into the ectoderm and the endoderm. And as it does, it's invaginated and carrying with it later. This is important when we think about dissecting and tissues because one of the best plans to follow. In dissection are the vessels, arteries usually define the various segments, particularly in the lung with the bronchopulmonary segments. And you will know there are 10 on the right and 10 on the left or on the left is consolidated in the lingula and on the right, in the middle lobe in the liver is not directed by the arterial supply, but by the portal vein and the biliary duct. And there are eight segments. Likewise and understanding that distribution and being able to follow and have the confidence to dissect along the layers. And the fascia of veins and arteries enables you to tease out the individual segments and loads of solid organs. There was an anatomy book that I was familiar with during my surgical treatment and I forget the name and I'll ask you the audience to help me that was described surgical operations based on fascial layers and anatomy. Now, the thing is about the fascial layers, they are bloodless by and large. With a couple of exceptions. The exceptions are around the exocrine glands, the adrenal and the thyroid. As you know, they need to get hormones into the bloodstream and therefore have a rich and varied venous supply. You also know now that the veins are very thin walled and these need to be carefully identified in each ligated and divided. They do not die for me. And if you do not care for you end up with a messy bloody feel which it hinders of view and dissection. The neurovascular bundles usually traverse across these primitive layers and then doing so form their own channels and fascial layers as well. So when you're going through a fascial layer and you come across these, it's not just a condensation of tissue, but beware, it is probably a neurovascular bundle. And a lot of surgical anatomy is defined by these neurovascular bundles that either run on the surface or close to the edge of a muscle layer. For example, the phrenic nerve and neck dissection is always identified as running on the front and the anterior surface of skes anterior and as the key area for those people operating in that part of the neck. Likewise, the anatomy and other parts of the body is equally important like the rectal sigmoid junction and the place of the ureter behind. It is a common place and understanding the relationships that have evolved with this convolution and evolution and folding and of tissues. It enables you as a surgeon to understand that. So what instruments do we use for dissection and asked you what you prefer, I like the knife and I like a big knife. And remember we cut with the belly of the knife. I think the utmost respect should be given to the mac do scissors. And if you don't know who Mackin do is we have discussed who he is in the past. But if this is your first time, please look it up because this is ergonomically designed for perfect dissection. The forceps themselves are used for traction to hold tissue but the forceps do offer a blunt instrument to tease out the tissues. My last and favorite instrument for dissection is a lay and the he is beautiful to enable you to get in the fa layer of round vessels to enable you to sling. Now, I was going to go on today to talk about stitching, but if you were with us last week and I was demonstrating incision, I got to a special plane with a neurovascular bundle. Um and I thought I cannot waste this turkey leg. I have to keep it in the freezer for tonight to demonstrate these principles. The other half of the turkey leg we have consumed this evening for dinner. So therefore, in a lovely stew with mushrooms and Dijon mustard and er green beans and mashed potatoes, we propose sustainable surgery and there's no waste. So I'd like to take you through the use of these instruments this evening and evidence the different aspects in the art of dissection. Please interrupt with questions in the chat room and Gabrielle will answer. And as I concentrate on the models, Gabrielle is also going to point out if it's out of field, I am gonna start off with what we've covered before to demonstrate a few things. I'm gonna take you over to the overhead camera, that's our menu for tonight. And I am going to zoom in here on the sausages. Now, the sausages, uh, oh, oh, fabulous because the sausage has a skin and the skin of the sausage is not unlike, I'll take it into the light and you can see it not unlike a fascia layer. You see that condensation of tissue there. I'm going to put my scissors underneath it there. What a satisfying feeling tang. She open it up and then put your scissors behind. You can see there's nothing behind my scissors at all. And therefore, I can confidently use the scissors, remembering to only use the tips to develop. And the progress through this fascial play is not too dissimilar to the progress that you've made. Dissecting the adventitia of uh the of the tissues around vessels. And you need to be able to get, I remember advocate that we hold the scissors with the lightest of touches with the tips of the fingers, index finger extended down and we do not open the scissors any further than necessary to do the job we've discussed before that you can open, take out close, never close the scissors without seeing the tips, keeping it open just like that enables you to develop planes. And once you're in the plane, as you can see here, I can keep the point up and I can run my scissors down and literally strip off that nail. Having done that, I can also use my scissors to tease off the layer with a blunt, blunt dissection with a balance between traction and countertraction all the time. And there we go, I'm able to literally skin the sausage. What I like about this model is that the sausage is not very forgiven because I can easily damage the flesh underneath. So it gives you feedback and immediately tells you if you're using your instruments perfectly and with the lightness of touch. But the scissors here is perfect for the job. And when I'm developing planes, I'm using a combination of snip snap brush brush, using the tip of my scissors. Of course, as we dissect, we are also separating the tissues. And to have a way of example, I'm just produced an orange here and the segments themselves are separated as you know, by condensation of tissues. So taking an orange and taking the skin off, you can practice yourself developing tissue planes and developing these layers. And the scissors are very useful for insinuating opening, retract. Once you develop the plane cutting as we go down, we can use the scissors to separate. And the idea behind this model is that you are not separating too widely because if you do, you start cutting the flesh of the orange. So the challenge here is to try and develop the plane of the orange with progressive snip snip gently separate and I can use my forceps as well as a retraction and good. No, do not try and work across and focus one particular area. The important thing with dissection is that if you get stuck in one area, move to another area and continue dissection, you're beavering away from all sides to try and expose a different area. Be mindful as you do this of your anatomy, knowing where something might be. I remember doing a redo aortic valve replacement and somebody had done an aortic valve that also put an internal mammary artery to the lad. I knew this was sitting behind the sternum and I knew where it was coming from as a plum line from the second part of the sub clay straight down to the left anterior descending. It was sitting behind the sternum and I was faced with thick tissue. As you see on the kids here, all I did was patiently dissect away and tease the tissue away to develop this. I found the internal mammography. I was therefore able to secure it and preserve it, put a clamp on it as I delivered cardioplegia to the heart and preceded, there is no rush for the dissection. And if you're hasty, you're more likely to damage the tissues. And I like this orange model because it's a newly telling me if I am actually entering tissue and I'm at risk there on this side of entering the orange segment itself as you find dissecting around the lung or doing a pericardectomy and finding in the wrong plane. And that's when you start getting the juice and when it starts bleeding, the thing about these models, they're here not to actually make it easy for me. They're here to make it difficult and it's only by being awkward and difficult that you are going to learn the patient's and necessary skills in the art of dissection. I am sure if I spent longer, I will tease this out with patients and our gaze get the orange segment out. But looking at the amount of adhesions in the tissue here, it's going to take me a little while to get there. I have a question. Yes, I'm John Redd. Uh Would you ever advocate the use of a skin hook as opposed to forceps for fine direct? Absolutely. I think the skin hook is actually very good. But the thing about and II, I use the bay forceps because that's was used in vascular surgery in cardiac surgery. They're supposed to be crushing forceps. Well, we know they're crushing but to hold the tissue gently, whether you're using a skin hook or whether you're using your forceps. The principle is the same. It's the lightness of touch and holding tissues back. I think skin hooks and the use of assistant and appropriate retraction is always very, very, very important. And as the dissecting surgeon, as you'll find in looking at me here, trying to do this without an assistant, makes it very difficult. And therefore, the operating surgeon needs to be aware of how to use the assistant in the traction and countertraction process. This orange is proving to be quite difficult, to be honest. And you can see if I'm aggressive with the scissors. I've just gone straight in to the orange segment there. What I've actually gone most of the way down in that segment there. And if I develop the pain on this side, I will find I will eventually get that out. It's going to take me however long it takes, it does not matter. The important thing is that I am being patient and working on all the areas and deliberately and carefully separating the tissues in the plane. The orange, I think is the most difficult. You might want to start off with a tangerine or something a little more straightforward. So we have the turkey leg from last week, we talked about the knife and the incision and the importance to hold it in the palm of your hand and maintain the 90 degree sagittal plane with your index finger extended down giving you the proprioceptive feedback as you cut through the planes. The other important aspect of dissection is the ability to use the knife to brush the tissues. You see here that I'm stroking this tissue here and yes there, loose areolar tissue that's fluttering the use of a knife. But you get the importance of that. Let me just add about the wrong side. You get the importance of this that I'm brushing the tissue and using the flat of the mouth to brush against what I'm trying to dissect out and in doing so, I'm not cutting directly into the edge. I'm not cutting into that. I'm brushing out and developing the plane. This also enables me to feel if there are any vascular bundles. There enable me to identify and recognize these. If I come across something that is a little bit sticky and is not working, then I use a combination. The combination is taking my scissors and separating. And the other thing you see that a little condensation of tissue is that a nerve is that a vessel, I'm not as sure, but I can develop it and it was just a condensation of tissue. Yeah. Likewise on this aspect here. Yeah, I'm feeling it. I can feel the resistance at the tip of my fingers because I'm I'm not grasping and holding my scissors tightly and I can brush my tip of my scissors across this as a blend instrument. I can see a condensation of tissue there but and I can perhaps develop the plane underneath and put my scissors underneath and you see that I can put my scissors underneath. I am actually going to zoom in a little bit and you can see that I've identified a vessel and my scissors have enabled me to get under that plane note that I'm putting it in, opening it up, taking it out and I'm never closing my scissors without seeing the tip. Once I've identified the loose area of the tissue, I can actually confidently isolate that vessel round either side and there we have the vessel now that it's easier to ligate and secure as part of your dissection. So let's assume that I've ligated this. If that is the size of a vessel that you'll find around an qui gland, it does not die for me. And as a vein it will bleeded. And I strongly recommend that you tide that off. And so we can progress no dissection. The other thing is with the scissors as a scraping exercise, I can use it to scrape off the tissues much of the same way as I use the flat of the blade to scrape off the tissues. This you can use if the tissue is a little bit more dense. So why I can't? This joint from last week is as I've gone through the incision through the different planes. And you see the muscle that comes from the mesoderm is all developed into planes. And I'd recommend all surgeons should identify the pains. And in general would also recommend instead of cutting across a muscle that you split, split the muscle along it's fibrous, therefore maintaining the integrity. So more and more people are doing this when opening rather than transecting your muscle is fine, the pain of the muscle and split it. Ok. If we have to go through, do not cut the muscle in half cause that will actually increase problems and breathing. It's always better to reflect the muscle rather than go through it. So, is it possible to pull it off to the side and identify the plane, preserving the muscle in uh origin insertion? What instead of going through it go around it underneath it and identify the pain? Why I like this particular specimen is that we had an opportunity to look at this neurovascular bundle sitting here. And you see it's sitting in fascial layer. The fascia over the top is not too dissimilar to the skin of the sausage. It is also sitting in fat. So as we talk about carotid sheathe, femoral sheath, the vein does not actually sit in the sheath. There's a space lateral to that, particularly the femoral and there's a lymph node and fat and the lacunar ligament. And why does this space lateral two veins if you think about it as the cardiac output increases? So does the venous return and what actually directs our response to exercise is increasing our venous return. And if the vein was actually in a sheath with no space either side, you would not get an increase in venous return because it'd be bounded by exterior factors. So those of you who are go working in a gym, you can see when somebody's working out because the first thing that happens is that the veins in their arms increase because of the increased venous return there is a little vein, but for the purposes of this evening, I'm going to dissect that. And you see, now, this fascial plane is not too dissimilar to that sausage and I can dissect it out and remove that layer of the top underneath. I now I got a vessel and that's quite a big vein. And veins are very, very, very fair job and please exercise caution, stopping, venous bleeding is problematic compared to arterial bleeding. And this is where I like the lay because the lei is a traumatic but I can use to gently separate the tissues either side and in doing so slowly and deliberately try insinuate my leg here underneath and there you go, vessel isolated in many vascular dissections. You do not want to cut the vessel sometimes and you use a sling and I'm gonna use a rubber band here. I'm putting a rubber band around this not only and they come in different colors, not only identifies the vessel with a hemostat. On the other end, it enables you to retract as well, so I can retract the vessel. And there you go, there's a branch outside very thin, but my leg is allowing me to just tease off that tissue and develop the plane. I now can use a knife if necessary just behind there because you can see there's nothing over the tip of my lay. Yeah, you develop the plane and there you go. And that now is ready for time, you can use cotton whatever for time. Now, for the purposes of this, I am actually using a little bit of dental floss fine and we can tie off the vessel, keeping the tie on one side. I can use that as a tractor as I secure the opposite side of this vessel as well. Same principle making sure that the vessel is clean that there is nothing underneath. The best thing to do is pass it as a on the leg here and then pick it up and secure the vessel the other side. So you're now making progress, do not leave the tires on the retractor because you might inadvertently pull them and pull them off. So underneath, let's see what we've got is that the artery underneath there probably looks like an artery slightly whiter thicker or could it be a nerve? That's what I'm thinking as I'm dissecting these layers, I've now got that vein completely free. I put my scissors underneath clean fascial layer and therefore can cut that or no, could be a nerve. That's a con condensation of white tissue and it could zoom in a bit further. It's a condensation of white tissue. I'm not familiar with the anatomy of a Tukey leg, but I do know that condensations of white tissue sometimes with a little capillary running in it indicate that you're looking at a nerve, do not grab it because you cause ne apraxia, but it is possible again with your leg. He Yeah. So to work under it. Oh There you go. Look at that. I think that is the artery, that side. There you go. That's a niy feels thicker. It feels more like the real thing. So I've held the vein out the way in all vascular dissections. If you're doing a vascular operation, you want to sling it above and below. So in doing so you have control. Remember that the arterial blood supply is very, very important for healing. And if you don't have to cut the vessel, but it's just in the way, the best thing to do is get a heavy silk stitch and using a bit of string here and pass it around twice around the vessel. Ok. Pass it around twice and there. I can now secure the vessel, stop the bleeding until I've finished the operation and then I can actually take it off and restore the blood supply, respecting the tissues, the veins and the arteries and each and every stage of the procedure. It's again a combination between sharp dissection, blunt dissection and understanding how to mix it. There you go, there's an artery disappearing into a tissue plane down there. And I am using my scissors to develop that plane further. And you can see that I'm not able to enter into the tissue. If this was a solid organ, the liver or the lung, this will be guiding me into that organ fabulous this is what I love about this. Se I find it all engrossing and don't be afraid to find that thin layer on top of the vessel and separate it off. Remembering that you can put your scissors behind and not only are you looking, but you're feeling the tissue as well then? Ok. So we've just dissected out the vein indicated that you need to respect the vein. It is easily damaged, these little branches that I see here, you might consider inconsequential, but they will bleed and bleed and bleed. They don't die, sir. Me and bleeding actually leads inflammation because thrombus and thrombin is a powerful inflammatory agent that would lead to fibrosis, not any pain, but long term fibrosis and scarring. So as a surgeon respecting the tissues, identifying each and every one of these branches as you go through like gating them appropriately means that the function of the tissue as you bring it all together in apposition, not strangulation at the end is preserved, your results. As a surgeon will be far superior and your outcomes, the patient. Well, likewise vein, thin walled collapsing. As you see there, artery, thick walled and we had a condensation of tissue down here that I thought was probably the vein, the nerve, I mean, there it is, there you go. There's a nerve. The reason why I kept this was to demonstrate the neuro and neurovascular bundle. Yep, that is the nerve do not ever pick it up, do you not stretch it? You're gentle as you move it because it is very easy to cause neurapraxia. But it doesn't mean to say that you need to be very nervous. All you need to do is learn how to hold your instruments carefully and be able to identify and develop. There you go. That's the nerve. So I think this is a femoral artery, femoral nerve and femoral vein in a turkey leg, neurovascular bundle exposed. And you can see it's all beautifully packed in this. And as typical of veins, there's space around it and a lot of fat to enable it to increase in size and increase the venous return in exercise, Gabrielle. I think it went slightly out of focus. You didn't point that out, but there you go. It's back in focus, I think. And there's a vessel if you are to open an artery for dissection. As I said, the best thing to do is vascular cramps and I haven't got a vascular clumps, vascular clumps or using stays and stay or tie around the vessel. There you go. I can put it on twice as a sort of temporary literature. We're gonna do this to demonstrate and we're going to open this vessel, shall we? And I will use the other sling my elastic band on the other side to hold it up and isolate the vessel. And now my vessels isolated and ready for dissection, vascular clamp either side and let's see if we can actually carefully open this vessel and I haven't got a 15 blade on me or a poor, let see if we can open this one right there. I do a little bit too far. Good. I mean, a little splash of blood from the I can therefore put my boxes in there and open up the vessel and then opening up a vessel. Then of course, guess what the artery is made of three layers, isn't it? And what is an endarterectomy? This is actually taking out the inner layer and developing the plane of the vessel. There you go, uterol vessel inside. There you go. Now with small vessels, when closing them, you put a patch on it. Likewise with veins as well. The best thing with the vein is close it with interrupted sutures to allow the vein to expand. Because if you put a continuous suture on it, it would not expand because be bounded by the proline there. But there you go in a vessel. I hope this has all made sense to you. And I hope you appreciate that. We've used the combination of scissors, forceps, lay mosquitoes, sutures, traction, countertraction. But what we've done is developed the planes. I coined the phrase it's plain sailing. If you find in these planes, you inspect the tissues and the tissues will look after you. And that is what surgery is all about. And that is where you get the outcomes from surgery. I had to laugh when I was presenting this at a conference and teaching the basic surgical skills to surgical tutors. And somebody said, well, you know, I'm an orthopedic surgeon. True. So remember that the bones are on the inside and you have to get to the bones by cutting through soft tissues. And the blood supply of bones is from the periosteum and the periosteum. Guess what is a layer and therefore developing those layers, exposing those layers, respecting those laws will help you as a surgeon, the address develop but more importantly, the patients will thank you because your outcomes will be better. I'd like to take questions from anybody at the present moment and thank you Emmanuel for saying wonderful demonstration. I'm glad the cameras working and the internet is working this evening. I worked hard on trying to get the internet improved. So, apologies if there is a lag in the the voice. I'm still exploring how best to get internet connection where I am. Any questions from anybody, please? They're very nice thing. Thanks Christina. Thank you very much. I see you, Mister Dy in the background. How's my fellow sense? And what are your thoughts? I know you're probably crawling because I didn't have a skin hook and I need to dig it out there and you're quite right. A skin hook is very useful for re contracting tissues, atraumatically, but also be mindful using your assistant and their use of retractors some of the retractors have sharp edges and if in use of them will dig into the tissues and if you pull too hard, may cause your apraxia or damage as well. So just because it is uh large or big, doesn't mean to say that you put lots of muscle in it. As I say in ka, it's all technique before power and speed and surgery is all about technique. There's no power and there's no speed. And if you're employing both, you're probably doing it wrong, like you to fill in your feedback form or for comments, uh please spread the word. Welcome you back next week. As we start our series exploring stitching, what we will explore is simple geometry, eli the theory of circles, 90 degrees, the perfect angle and the theory of parallel lines in equal angles as well. Why you might ask is very simple because surgery is all about set up. It's not about the doing. It's actually setting yourself up properly to do it. And if you set yourself up properly, the flow and the rhythm is restored, set up, of course, is making sure that your team, your assistant and everybody is with you and knows the plan the direction and can help you on the way. I have a question from Prince. Um Could you just uh say again, what is your special? Of course, I say I've been a cardiac surgeon for 22 years, but I trained as a general surgeon in the first place. I know there's a lot of and we debated it. I debated it with Richard Rene at the Faculty of Surgical Trainers conference last year, whether surgeons should have a general surgical training before specialization. My own feeling is is that a good surgeon knows can operate and any part of the body provided, they know the anatomy and the more surgical experience you get in practice in different tissues, the better your appreciation of tissue handling will become. Of course, that's not possible today. Unfortunately, but what I'm trying to do with the Black Belt Academy is introduce you to a whole lot of low fidelity models that I hope will give you a similar appreciation of haptic feedback and feel of tissues in organic tissues. My colleague, since a Mr Dy has come in with a bit of bit of afs, I don't understand that. Yes, practice and very good Don mania and I'll say proteins and thank you very much indeed to everybody who's participated this evening and I hope you enjoy this. Please spread the word and Gabrielle. Thank you very much indeed for hosting and extremely well done in your exams. Gabrielle's past her first year and I'm sure is going to make an outstanding surgeon in the future. Thank. Thank you.