Hello, and welcome everybody to the Wiki Bet stream of the Virtual Congress. So thank you very much to everybody for joining us this evening. I'm joined by Luke and Alice from the webinar Bet.

They're doing all the techie trickery in the background. So thank you very much to them. And this stream is sponsored by JHP Recruitment Limited, who are a specialist recruitment company working with the veterinary industry.

So thank you very much to them for sponsoring this stream. So I'm really excited about the, the next 3 sessions which make up the Wikibet stream. I'd first like to take the opportunity to actually thank the webinar vet for inviting us to host this stream and for their ongoing support and partnership of Wikibet.

We're a small and struggling charity, focused on worldwide online veterinary education. And it's fantastic to have such a, a wonderful partner. So we're thrilled to be able to welcome some fantastic speakers.

We've got some great topics lined up for you. And they're all gonna be approached from the student perspective, tying in the pre-clinical theory with some more clinical tips and techniques. And I personally can't wait to hear all three topics, all of which were chosen on the basis of requests from our student Wiki about users.

So hopefully they'll be really useful to everybody listening. So, with no further ado, I'd like to warmly welcome our first speaker, Doctor Stephen Baines. So, Stephen qualified from Cambridge University and undertook an internship at the North Carolina State University, followed by residency and small animal surgery at the University of Liverpool.

After that, he completed a PhD in tumour Immunology at the University of Cambridge and was appointed clinical surgeon. He then moved to the Royal Veterinary College, where he was senior lecturer in small animal surgery and head of surgery. He's currently head of soft tissue Surgery at Willows Referral Service and is a diplomat of the European College of Veterinary Surgeons, and holds a diploma in comparative Oncology.

He's a European specialist in small animal surgery and an RCVS specialist in both small animal surgery and veterinary oncology. And his particular clinical interests include clinical oncology and particularly cutaneous neoplasia, wound healing, and reconstructive surgery. Stephen taught me on rotation whilst I was at the RBC.

So I'm really looking forward to this session on the ubiquitous X lap, one of those procedures where knowledge of anatomy is so key, and there's always more to learn. If anybody does have any questions, just type them into the Q&A box as we go along, and then we'll do our best to get them answered at the end. So, over to Stephen, thanks very much.

Thanks very much, Bev. Thanks for the introduction and thank you to you and the webinar vet for the invitation to speak in this session. It's lovely to be able to speak on exploratory laparotomy.

This is one of my favourite subjects. I've lectured on this topic before and presented practical classes on this topic. And one of my favourite feedbacks from delegates attending those courses was, you know, I never knew there was so much stuff in the abdomen.

And hopefully this is the sense of enthusiasm and wonder I want to convey during this presentation, while still retaining a very practical element. So let's look at the outline of the lecture over the next hour, this is what we're going to do. We're going to look at some key points when it comes to doing an exploitative laparotomy and perhaps common mistakes that we might make if we don't adhere to these points.

We'll inevitably look at some anatomy. We'll look at a few perioperative considerations prior to undertaking the surgical procedure, and then most of the lecture will be a guided tour of the abdomen, very much an anatomy-based tour of what we can actually find in the abdomen, and how to find it all, and then a few comments about closure of the surgical procedure. So let's look at some key points and common mistakes when it comes to doing exploratory laparotomy.

First up, and perhaps the greatest error to make is this. If we're going to do a true exploration of the abdomen, we need to make a large enough incision, a small incision here in the cranial abdomen is not going to be large enough to look at all the abdominal viscera. And ideally, we need an incision that goes from here, the shy sternum, all the way to the pubis, or at least most of that way, if we're going to be able to explore the entire abdomen.

More about that later. Second key point then, is to be thorough, and ideally stick to a plan that you do in all cases, so nothing gets missed out, nothing gets forgotten. And for instance, here's a patient who quite clear at exploitial laparotomy, has alication of the intestine, and has a linear foreign body.

But still, things don't look quite right, and the reason they don't look quite right, and the reason we have this obstruction is that the patient also has A mesenteric rent. We should always look at everything, we shouldn't curtail our exploration just because we find a lesion that accounts for the clinical signs, we shouldn't miss the patient who has more than one lesion. The 3rd, and perhaps just as big as not making a large enough incision, is this, we should always Take appropriate samples.

If it's worth doing the exploratory laparotomy to try to get a diagnosis, it's worth pursuing that beyond just visual examination of the organs, and we should take appropriate samples of the viscera, for cytology, for histology, for culture. Particularly for those not used to doing exploratory laparotomy, we should do this. Avoid what's termed the peak and shriek, opening the abdomen and finding you something you didn't expect or don't know what it is, and don't know how to deal with it.

And the way to avoid this is as follows. Ideally, we should gain as much information as possible before we do the surgical procedure. Ideally, with abdominal imaging in particular, obtain a diagnosis and, if appropriate, stage the disease, so we know what we're going to find.

If we can't do that, then ideally, we should try and ensure that we can deal with all the likely eventualities. Make a list of the most likely diagnoses and make sure that you can deal with all of those findings. And if you can't, think about, well, what do you need to be confident about doing so?

Do you need an assistant? Do you need another piece of equipment? Do you need some advice?

Do you need to consider referral of the patient? Ideally, put yourself in a good position before doing the exploratory. And it seems strange on when lecturing on a topic such as exploratory laparotomy, but the point I would make is we should, wherever possible, avoid doing an exploratory laparotomy, and ideally prepare ourselves for doing a definitive and defined procedure prior to operating.

Moving on from that, then we should be clear about the indication for surgery. Why are we doing the procedure? We may do a laparotomy for a number of different reasons for diagnosis.

Perhaps we can't preoperatively diagnose whether this patient has a small intestinal obstruction, a small intestinal mass, perhaps an interception. We do it for a prognosis. If it does have a tumour, do we have evidence of tumour spread to lymph nodes or other abdominal viscera, which we can't detect on pre-abdominal preoperative imaging?

We might do it for therapy as well. Here's our lesion. We're going to remove that with an enterectomy, and we may also do it perhaps for prophylaxis if this patient does have an interception, we may consider enterplication as a prophylactic measure to stop that happening again.

So anytime we're thinking about doing an exploratory laparotomy, we should consider what our aims are under these four headings above here. We should be clear about which we're doing in any given patient. We may do more than one thing at once, very commonly, we'll do diagnostics and we'll do a laparotomy for therapy.

And we still explore. In most of our patients, we still explore, even if we've got a diagnosis and even if we're doing a defined procedure, depending on what that procedure is. Again, prior to doing the procedure, we should ask ourselves this question, why am I doing an exploratory laparotomy?

And be absolutely clear about the reason. Let's look at anatomy. Although anatomy is not everyone's cup of tea, when read from dry books like this, we'll put a clinical spin on it and show just why elements of anatomy are important in terms of guiding the surgeon.

So these are the topics we're going to look at the anatomy of the abdominal wall, which is important on opening and particularly closing the abdomen. We're going to look at the distinction between intraperitoneal and retroperitoneal structures, which again has a an important concern when it comes to finding organs. We'll look at the topography of the abdominal organs as they sit in situ, and then look at the anatomy of the individual organs, but that's going to be done in the guided tour with pictures of a real animal rather than line diagrams.

So let's look at the anatomy of the abdominal wall, and here it is. So, essentially what we have is 4 muscles. Firstly, this one, rectus abdominus, which runs from cranial to caudal either side of the midline.

And then we have 3 additional muscles, external abdominal oblique, internal abdominal oblique, and transversus abdominius. Now, at different levels, A, cranial, B, mid, C, caudal abdomen. The exact arrangement of these muscles with respect to the rectus abdominus varies.

So let's go through that. Cranial abdomen, A, we have external abdominal oblique, contributes to the external rectus sheath here, on top of rectus abdominus. Transversus abdominus contributes to the internal rectus sheath here, and internal abdominal oblique can't make its mind up and contributes to both.

If we look in the mid abdomen, by this time, internal abdominal oblique has made its mind up and joins with external abdominal oblique to create the external reus sheath, but still transversus abdominus creates the internal rectus sheath. Right in the caudal abdomen, all three muscles have joined to make the external rectus sheath, and there is no internal rectus sheath, which will become apparent when we talk about closure. The other thing to glean from this picture is compared with cranial, caudal and mid, you can see that the lunar alba is very wide cranially and narrows as we go further cordially in the abdomen.

Let's look at the topography of the intestinal tract, which explains where we're going to find various organs in the abdomen and guides our exploration, as we'll see. So, in a normal animal, if from mouth to anus, if the gastrointestinal tract was just a straight line, well, it would be simple to explore, but we wouldn't fit much intestine in the abdomen. So to get around that, the evolutionary way to do that is to elongate the intestinal tract, but then to have it disposed differently within the abdomen.

So what we imagine is we've got a long intestinal tract, which, based on this, the root of the mesentry sitting at about the first lumbar vertebra, the entire mesentry undergoes a 270 degree anti-clockwise rotation, which then leads to the descending duodenum here and it's long mesentry, and the descending colon here and it's long mesentry sitting together like two interlocking hooks. These two structures have long mesentries. And cradle the rest of the intestinal mass between them.

The descending duodenum and the descending colon can then be used to cradle or to move the intestinal mass over to one side or to the other side and inspect the paraluba gutters on either side, and I'll demonstrate that in the real animal. The other point to make here is that the ascending duodenum and the ascending colon have short mesenteries. The ascending duodenum is attached to the descending colon by this, the duodeno colic ligament, and tethering the duodenum and its transition from the descending portion to the ascending portion is this avascular peritoneal reflection, which we'll also see as well.

Just to show, that's true in the real patient as well, so here we have. Ascending duodenum. Duodenal flexure, duodenal colic ligament, transverse colon here and descending colon here on the left hand side.

All of the pictures on the, when we look at surgical patients will either be cranial at the top, right and left, surgeon's eye view from standing at the foot of the table, or pictures with cranial to the left, right up here, left down here, left up here, right down here, again, surgeon's eye view for a right-handed surgeon standing on the right side of the patient. So, what does that allow us to do? Well, because the descending dude and descending colon have long mesenterries, as I've said, we can investigate the para lumbar gutter on either side.

So, here is a patient, transverse section at the level of the duodenum, and there's our pancreas, the right limb of the pancreas. At laparotomy, duodenum may be moved medially and then over to the left-hand side, which exposes the right para lumbar gutter and associated viscera. And the same can be done on the other side using the long meantry of the descending colon, and we'll show that in more detail later on.

Retroperitoneal versus peritoneal structures, and this is something that tends to cause a lot of confusion when it comes to trying to identify which organs deserve either of those labels. We may, of course, make too much of it because in our patients, which are long in a dorsoventral direction and narrow in a lateral lateral direction compared with people, that's less of concern. It's less useful as a designation, but nevertheless, let's just think about it.

Essentially, all organs start out in a retroperitoneal position, but essentially they all invaginate into the peritoneal cavity by greater or lesser degrees. Some, like the intestine, invaginate all the way, such that the parietal peritoneum that becomes the visceral peritoneium overlying the organ forms a mesentry. Other structures like the kidney invaginate a little bit, but that enveloping by the peritoneum does not go all the way around the organ.

Thus, most structures in the abdomen are truly intraperitoneal. The major organs, liver, spleen, pancreas, almost all of the gastrointestinal tract apart from the rectum as it departs the peritoneal reflection, the bladder, and the distal third of the ureters, which means that the other things that are left behind, the kidneys and the proximal 2/3 of the ureters, the large vessels, aorta, vena cava, seen up here, the lumbar and iliac lymph nodes, and the adrenal glands are therefore retroperitoneal. Its relevance may be relatively small, from a surgical point of view, retroperitoneal structures can be approached here from a lateral approach, from a retroperitoneal approach or a flank approach.

It gives you excellent access to single structures, but not to the rest of the abdomen. And it may be important from an imaging point of view. Rupture of the kidney, of the adrenal, or the proximal ureter will lead to retroperitoneal accumulation of fluid, blood or urine, whereas rupture of the intestinal tract or distal ureter will lead to intraperitoneal accumulation of fluid, and the appearance of those two on radiographs or ultrasound is different.

Let's look at some perioperative considerations now. So we talked about surgical access and many textbooks will refer to a full and complete laparotomy being one that goes from the ziphy sternum here to the pubis here. As illustrated on this cartoon.

And whilst that's the case, if you don't want to explore all of the pelvic canal and caudal abdomen, that might be perhaps too long of an incision, and we'll look at what might be more important. If we want to extend it cranially, we can usually go through the ziphy sternum, and depending on the confirmation in deep-chested dogs, perhaps the two caudal sternumbra, we can split those in the middle, still be in the abdomen, and give us extra access to the cranial abdomen. A compromise in many patients is to go here, from the xiphoid to about halfway from the umbilicus to the pubis.

And that will give us access to most of the viscera, perhaps not everything in the caudal abdomen, but again, it depends why we're exploring the patient and what we expect. As a general rule, And this is a useful landmark. If we can see the avascular peritoneal reflection, and that allows us to navigate the descending duodenum to the ascending duodenum, our incision is probably long enough.

If we can't do that, it probably isn't. A caudal abdominal or caudal laparotomy is illustrated here. So umbilicus to pubis.

Now, that's not going to allow us to look at most of the abdominal viscera, but will this allow us to do defined procedures involving the caudal viscera. Collon. Bladder and irritters, for instance.

If we want to increase our access still further beyond xyphoid to pubis, here are a few things we can do. I've talked about already, cranial extension through a sternotomy. Beyond the 1st 1 or 2 sternnari, that's going to put us into the chest.

Alternatively, we can make an incision in the diaphragm to gain access to the cranial abdomen. To retract the cranial viscera and to look at the chest if necessary. We can extend the incision cordially, either in the midline with a pubic osteotomy, or, sorry, by either side by removing a section of pubic pubic osteotomy or pubic ostectomy, or by splitting the pubis in the line of pubic symphysiotomy.

And finally, if you read surgical textbooks, you can see that we can create a paracostal incision as well as our midline incision to look at the cranial abdomen, particularly on the right side to get the right side of the liver, which is difficult to access. Realistically, with the use of retractors and a long incision, this is seldom, if ever, necessary, and I've yet to need to do that. Other things that will help our exposure then.

Well, we've talked about an incision, sufficiently long, right location, and one that we can extend as necessary. Having abdominal retractors as illustrated here, these gossip retractors and handheld retractors, if we have the benefit of having an assistant, a very useful, stay sutures and organs to allow retraction, say, cord the retract. In the stomach, retracting the bladder out of the way, and placing swabs to move abdominal viscera out of the abdomen, under the stomach, under the liver to elevate it into the surgical field.

We can tilt the table from one side to the other, as long as that doesn't cause abnormal shift of the abdominal viscera to put pressure on the diaphragm and difficulty ventilating. We can remove organs from the abdomen and pack them with moist swabs, so that we can either operate on those that are outside the abdomen or operate with more space on those organs that are still left within the abdomen. Bright, adjustable theatre lights really go without saying, that's what we need to operate appropriately.

And if we can have the luxury of an assistant, many procedures are simpler, easier, more rapidly done. When it comes to equipment, we don't need a lot, but if you only buy one thing to make your exploratory laparotomies easier than a set of retractors, either Balfour type or Gosset type, as I've also illustrated. If you have the benefit of an assistant, these malleable or bendable ribbon retractors are good ways to retract viscera out of the way, in a gentle fashion.

The typical forcep for thoracic or abdominal viscera to manage those atraumatically is these debay forceps with fine serrated teeth like this, which come in a range of different sizes. And for dissecting around linear structures in particular, nerves, ureter, blood vessels within the abdomen, a set of these mix of forceps, fine, tipped forceps of different lengths with transverse serrations like this. And for removing fluid accumulations within the abdomen, either fluid that has accumulated prior to surgery or fluid that you put in during surgery for lavage, a pool suction tip is warranted.

So let's get to the meat of the matter. Now let's talk about a guided tour of the abdominal viscera. So, as I said, most of our pictures are either going to be in this orientation, cranial at the top, right and left as illustrated, or with cranial to the left and approaching from the right side of the patient.

So there's our patient prepped for surgery. Here's our incision from xiphoid to halfway between the umbilicus and the pubis in this patient. Diothermic for small bleeding vessels in the fat that we've just incised here using bipolar or monopolar, but both of those are appropriate.

And here we just check linear alba, we can see the linear alba. We should resist the temptation to strip the fat off the linear alba to make us able to see it better, since the linear alba has a poor blood supply, and these segmental vessels that run in the fat provide that blood supply. So we run the risk of devitalizing that tissue if we strip off the fat.

There's no necessity to do that, and it also increases the amount of dead space in our incision. An incision is made into the linear albert. Remember it's wider cranially, rather than cordially, and the viscera will drop away from the cranial abdomen, because the abdomen is deeper cranially, so that's the place to make our incision.

Here's our incision, we should just now, we've made a small incision, just check it. Is it in the midline? Remember the linear elbow is potentially narrow, palpate, put a finger in there, palpate for an adhesions, particularly if the patient has had previous surgery, including a spa, of course.

And then extend our incision from cranial to caudal under control, ideally with scissors to keep a straight cut right in the midline. Of course, if you're doing a cord laparotomy in a male dog, we have the penis in the way and we need to navigate that and ideally what we're going to do then is a parapeile incision around the penis, but still make an incision in the ventral abdomen, the ventral midline through the linear elbow. So there's our parapenile incision, some small bleeders to deal with as we do that, and that's going to show us here the prepucialis muscle, one of the branches of the piniculus carnosis muscle, and we'll find approximately here, and then much further back, just in front of the pubis, the two branches of the pudendo epigastric trunk, which we need to divide, depending on how far back this incision is going to be made.

In this patient, we've transected the propucialis muscle, and here's our branch of the pudendo epigastric trunk, which will need to ligate and divide. And having done that, we can retract fat over there with this handheld retractor and then continue to make our midline incision in the caudal abdomen. Once we've made our incision in the linear alba, we'll encounter the falciform fat, which will be a variable thickness depending on the age and body condition status of the patient.

We should at least incise it in the midline to improve visibility, but most of the time we'll elect to incise it, to excise it, sorry, to remove it, watching out for segmental vessels here along its course, and two major vessels at the front which need to be ligated. Once we've done that, it'll be easier to see the abdomen and we'll make our closure easier without this tissue in the way. If we've had previous surgery, or indeed previous trauma, we may have adhesions to the body wall, and we should be careful on it, opening the abdomen that we don't transect these adhesions and granuloma or what else we have.

So, gentle, opening, palpate for adhesions and deal with these ligate and excise the cemental tissue which is attached to the ventral part of the abdomen. And then here we've got the abdomen open. So right at the beginning, here's our first inspection.

Do we need to do anything in an emergency? Do we have active bleeding that we need to do something about? Do we have active leakage, which is contaminating the peritoneal cavity even as we speak, but the rest of the cavity is relatively free of that.

Did we do the laparotomy for obstetrical reasons, caesarean section, for instance, or is there other trauma that needs to be dealt with straight away, say a ruptured diaphragm and perhaps abdominal viscera in the thorax. If there is, these need to be dealt with straight away. If not, then we'll follow our general plan for our guided tour.

We also should just look and see, are all the abdominal organs, at least on first inspection, in the right place? Spleen in the right place, stomach in the right place, liver in the right place. If there's peritoneal fluid, we should use this opportunity to take a sample with a syringe and save it for cytology, for culture.

Now, hopefully, if there was a large volume, we'd have sampled that preoperatively to try to make a diagnosis and work out what was going on. We can also always discard the fluid later, but taking the time to take a sample now makes a lot of sense. And then the rest of the fluid should be removed by suction, and then we can get on with the rest of the tool.

So here's our patient, laparotomy swabs in place, so with warm saline to protect the wound edges. Gossip retractor used in this case rather than the Balfour retractor. And we're ready to go.

So here's the plan for systematic exploration of the abdomen to make sure we find everything and don't forget anything. Makes a lot of sense to do this, you can do it whatever way you want, but this makes a lot of sense to go from cranial. To caudal in these five regions, mainly to go from essentially cleaner parts of at least the GI tract to more dirty parts of the GI tract when it comes to the number of bacteria within the the lumen.

And we use the GI tract as a way of taking us from cranial abdomen to caudal abdomen. If we do this, we're not likely to forget anything. So, cranial abdomen first.

Then we move to proximal gastrointestinal tract. At the level of the duodenum, we explore the right paralumbar ver right paralumbar region, using the duodenal manoeuvre. Then we go back to the gastrointestinal tract, do the rest of it down to the left, descending colon, then look at the left para lumbar region using the colonic manoeuvre, and then do the caudal abdomen.

That will take account of most items. We should just not forget certain things which sort of don't appear on that track, and these are the mesentry itself, the omentum, although we will bear that in mind, and the parietal peritoneum, the lining of the abdominal cavity. Of course, we may do a laparotomy and find something like this, and that's rather going to curtail our exploration until we've dealt with this, this large splenic mass, and then we can move on to the rest of our explanation, our exploration.

So let's start here. Cranial abdomen, what are we going to find? So cranials at the top.

We've got our central tendon here. We've got here the caudal vena cava, coronary ligaments around it, and we can just about see the confluence of the left hepatic vein which enters the caudal vena cava, just cranial to the liver here. Central tendon of the diaphragm will have the sternal part up here attached to the sternum, costal part, which is most of the diaphragm all the way around on the left and right.

And then the lumbar part, which we'll look at later when we look for the dorsal in the abdomen, forming the two rua either side of the aortic hiatus. So I've already made reference to the cava hiatus here. We'll see the esophageal hiatus here when we look at the proximal GI tract and the aortic hiatus later on, particularly on the left hand side.

We also need to be aware of the triangular ligaments, which we'll look at from the side. And the coronary ligaments, which again we'll look at from the side, we called the vena cave already talked about, and they're the red vessels supplying blood to the diaphragm. Here, looking from the side now, here's our central tendon of the diaphragm, costtal external and costal parts, liver's retracted here, and here's our left triangular ligament.

Normally 1 or 2 on either side, particularly on the left hand side, they're often larger on the left hand side. These are avascular, these may be transected, and if you do so, you can retract the liver further cordially and therefore, the stomach further further cordially. So, useful for abdomen, and increasing access in the cranial abdomen.

Here, we're called the vena cava, coronary ligaments all the way around it. Generally speaking, we leave these alone. Transecting them doesn't give us much extra exposure, and it's nice that these take the pressure or the tension off the caudal vena cava, then we don't damage that during our cranial abdominal exploration.

Falciform ligament may be very well developed in certain patients. Here we are very thin patient, not much fat in it, but you can see how well developed the falciform ligament is. And here, first view of our liver, we can see.

The gallbladder sitting here, which means that to the one side, this is our right medial liver lobe, and to the other side, this is our quadrate liver lobe. This is the way we orientate ourselves, and then we can look at the rest of the liver lobes, and then we'll show that as we go. So, once again, gallbladder here, right medial liver lobe on one side, quadrate lobe on the other side.

If that's the right medial, the next one over must be right lateral. If that's the quadrate, the next one over must be left medial, and then left lateral, the largest lobe is over here, all the way on the left and dorsally within the abdomen. Papillary, the chordate lobe is not that easy to see and has two processes.

The papillary process, which we'll see later when we look at the less momentum, which is a finger light projection around here, and then the chordate process, which sits here in close connection to the hepato renal ligament just above the kidney on the right hand side. So we'll have a look at that as we proceed. There's our liverhylus, so we slightly move the liver to the left now.

So right medial, right lateral lobe, we're seeing, can't quite see the chordate lobe. Here's our gallbladder, and we can now start to look at the four components of the biliary tract, the extra hepatic biliary tract. So gallbladder, which we can see here, and on the next side, we'll find the other bits.

The cystic duct, which communicates with the gallbladder, hepatic ducts from each of the lobes, and then the bile duct, which communicates to the intestine. We can gently apply some pressure to the gallbladder to confirm anatomic patency if we wish, but we should be careful about doing that. We don't want to cause rogenic rupture.

And then the other thing we'll look at in the cranial abdomen near the liver hyallus will be this trio of vessels, hepatic artery or celiac artery, as it gives rise to the hepatic artery, hepatic portal vein, and the vena cava. Here, the liver has been moved up to show the highness of the liver. So gallbladder up here, cystic duct tissues from it, small hepatic ducts come in, and it's difficult to show those on an image, but they can be found at exploration, and then extending from that, extending to the duodenum, the bile duct.

Within the lesser momentum, we'll also find two ligaments as well, which may be greater or lesser well developed in any given patient, but often they're palpable as taught piano string like ligaments within the lesser momentum. Hepatogastric ligament between the liver and the stomach, hepato duodenal ligament on the other side. Again, just to take the pressure off structures that are perhaps a little more flimsy, such as the bile duct.

Three vessels we've already talked about, and then either side of the venic, either side of the portal vein as it approaches the liver will find hepatic lymph nodes. Not generally present or visible in most patients, but that's where we're going to look for them if we're going to stage an abdominal malignancy. So that's the cranial port part of the abdomen.

Let's move now to the proximal gastrointestinal tract as far as the duodenum. So, although it's not the most proximal, we'll start with the stomach, we'll start with the greater curvature, because that's the most accessible. So here we have greater curvature.

Gastropoloic vessels on the left side and the right side will join up on the greater curvature. If we apply some caudal traction, we'll see lesser curvature here, less momentum in front of it, left and right gastric vessels. And remember, all of these vessels form a complete ring around the stomach, accounting for its excellent blood supply.

Body of the stomach here is most of it, as we go further forward, deeper in the abdomen is the fundus, the cardia is here just caudal to the oesophagus, and then pyloris round here on the right hand side, which you'll see as we look at the duodenum. Let's retract the stomach cordially and over here, and that will show here the abdominal portion of the oesophagus and the cardia. On this side here, we have the left crust of the diaphragm.

The opening in the diaphragm, the esophageal hiatus, and the right crust of the diaphragm is here. It's more difficult to see, it's less well developed and it's covered in the lesser momentum. And then the frenico esophageal ligament around here, which we may need to incise in patients where we need to mobilise the oesophagus, say, for reconstruction of a dog with hiatal hernia.

And we've got an early view here of the left adrenal gland, which is more or less visible in different animals, but we'll look at that when we look at the left para lumbar gutter. Here is the stomach retracted. We have an excellent view here of the left and right gastropaic vessels, stomach's retracted, and here's our less momentum between the lesser curvature of the stomach here and the porta hepatis, which is just sitting here.

This less momentum will then blend on the right side into the meso duodenum, and we've already mentioned hepato duodenal over here, hepatogastric over here, ligaments, which may be palpable within the less momentum. Let's move from the lesser momentum then to the greater momentum. In many patients, this is what we'll see on opening the abdomen, a well developed less greater momentum, full of fat and obscuring most of the viscera.

We talk about the momentum like it's one object, it isn't really. The greater part of it is what we call the bursal part. There is another part which is called the gastrosplenic ligament.

So on the left hand side, attaching the left side of the stomach to the. Of the spleen. And although perhaps it's not a separate part of the omentum, it's worthwhile thinking about the dorsal leaf of the omentum as the left pancreatic part of the omentum, because that's where the left limb of the pancreas sits, and probably the left limb of the pancreas is the bit that most people forget to look at in the abdomen.

It's fairly well hidden unless you do a particular manoeuvre, which I will demonstrate. So, here's the greater part of the omentum, the bursal part. There are two leaves, a dorsal part and a ventral part.

And within this omentum, the splenic vessels will course. Now, this animal doesn't have much fat. You can see pretty much through one leaf and see the other leaf on the other side in animals with a lot more abdominal fat.

That's much more difficult to do. We may have to open the omentum to find these splenic vessels, and as I'll show you, you may have to open that to see the caudal and dorsal part of the body of the stomach as well. Just to look at some anatomy.

So back to our line diagrams. So now a transverse section. Here's our stomach, issuing from the greater curvature of the stomach is the greater momentum, the bursal part, and this is our ventral leaf, which comes all the way here.

You can see how long it is all the way to the bladder, and then retroflexes here then as the dorsal leaf or visceral leaf all the way back to then pick up the left limb of the pancreas. So that's the totality of the burstile part of the great momentum. It has a potential space between it.

That's why it's the bursal part. And we'll look on the next slide as to how you get into that a mental bursa, which is here through the epily foramen. So the epily foramen is here on the right hand side.

Here's our duodenum. This is a transverse section at the level of the 12th thoracic vertebra. Duodenum's here, pancreas is there.

This is the mesoduodenum, the portal vein and celiac artery, and then later hepatic artery sit here. And between those two structures and the caudal vena cava. We have the opening, the epilo frame and into the versatile part of the great momentum.

We also will see this, the chordate process of the chordate lobe but well. And again, remember this close proximity of these vessels, because that will become important when we look at the epiplo for Amen. So, here's the epilo for Amen.

These surgeon's fingers here are inserted into the epiloic foramen, so you can see the fingers here very well, and beyond the epiloic framen here, you can see the fingers are within the bursal part. Here is the hepatic mortal vein, the hepatic artery, acedic artery, and hepatic artery much smaller, but they will also sit here. Stomach's in front, these fingers underneath, that's where the caudal vena cava will be.

Why do we need to know this? Well, if you insert your fingers and then curl them back on themselves, you will occlude. The portal vein and the hepatic artery.

And if you do that with a tourniquet, you can achieve the same thing, although you don't have to leave your hand there. This is called the Pringle manoeuvre. This is a useful way of occluding the blood supply to the liver, if you have a bleeding lesion in the liver for a short period of time, say up to about 20 minutes or so, while you deal with that, while you deal with appropriate hemostasis.

So for bleeding lesions in the liver, it's a useful temporary measure to reduce the blood flow to the liver. Let's move on to the next portion of the omentum then. So, the gastrosplenic ligament, bursal ports parts down here, gastrosplenic ligament joins here, the head of the spleen to the greater curvature of the stomach.

The rest of the spleen is the tail is much more freely mobile, whereas the head of the spleen is more tethered. And I guess while we're here, we should look at the rest of the spleen. We have a hylus which runs along its length.

That's where we'll find the blood vessels, and like many of the abdominal viscera, the lymph nodes tend to parallel the major vessels within the spleen. So let's have a closer look at that. Splenichylus runs along here.

We're just concentrating on the splenic head. The tail is now out of view. The blood vessels to the spleen are as described.

2 large blood vessels here, attaching into the cranial third of the spleen, 3 shorter, short gastric vessels joining the head of the spleen to the greater curvature of the stomach, and then 2 longer vessels here, leaving the spleen and surround and supplying the rest of the omentum. So 2 vessels here, 3 there, 2 there. When doing a splenectomy, you can either tediously ligate all of these smaller vessels here at the Hlus, or you can just move a little bit away from the spleen and ligate with care, these 2 large vessels, 3 short gastric vessels, and these 2 other vessels.

So that's a quicker and simpler way of doing splenectomy. Finally, the third part of the omentum, the dorsal and mental leaf, so here we've taken the omentum, we've flipped it forwards, we're now looking at the dorsal or visceral leaf. And here's the pancreas coming into view.

If we move that piece of small intestine out the way, here's our left limb of the pancreas. Aum is essentially lifted up and the forwards or cranially over the stomach. Here's our left limb of the pancreas, and from this view you can actually see the body of the pancreas as well, and then the other side of the right limb of the pancreas.

And here we'll find a mental lymph nodes, duodenal lymph nodes, and hepatic lymph nodes. Here's a reason for opening the mental bursa. Remember I said the dorsal leaf will cover the stomach, and if we don't open it, we're not going to see the stomach.

Here's a patient with a punched out ulcer in the caudal and dorsal part of the body of the stomach. If we don't open the omentum, we won't see that. So if you need to look at that part of the stomach, depending on how much fat there is in the mental versa, you may actually have to open it up.

Let's move around then. Now we're over to pyloris. Here's our pyloric Antrim, pyloric canal, and the pyloris, the valve itself.

So stomach here, descending duodenum here. Here's our duodenum running all the way down, right limb of the pancreas sitting here next to. The duodenum.

We know it's duodenum, because it's relatively well tethered. It's quite wide, and it's quite thick walled. And you can see the proximity of this, the pancreatico duodenal vessel to the Dedenum.

What it does mean is that partial resections of the Dedenum without concurrent partial resections of pancreas or vice versa. It is extremely difficult because of their shared blood supply. And bear in mind, the duodenum has a blood supply, which is a parallel vessel with short vessels that lead off.

We'll look at the enum and show that it has a completely different blood supply, whereas the colon and rectum moves back to this pattern, parallel vessels with short vasareta. Judeal lymph nodes will also be situated in this location. So we've got hold of the duodenum.

Let's now do the Dudenum manoeuvre and look at the right para lumbar gutter. You can see that we've started to move the duodenum and it's meso duodenum over to the left hand side. The mass of the intestine is still bulging into the para lumbar gutter, so we need to move that a bit further.

With a hand, we can do that. And here we can see. The right kidney.

The chordate process of the chordate lobe and the hepato renal ligament, which will be here, our trio of vessels, vena cava, portal vein, celiac artery. We'll see hepatic node, at least on the right hand side here, adrenal gland, that's difficult to see, and we'll need a special manoeuvre to see that, and then ovary and uterus, of course, on that side. Here's a good view of the epilo Freeman.

Here's our epilo framen bordered by. Portal vein, celiac artery and hepatic artery, caudal vena cava down here, chordate process of the chordate lobe, and right kidney here with hepatorenal ligament between them. And there's the lovely entrance to the epiloic foramen.

The right adrenal gland, adrenal glands are sometimes known as suprarenal glands. So we're going to find the medial to and cranial to the kidney. Here's our kidney, covered by the chordate process of the chordate lobe, can't really see it, and the adrenal gland will sit slightly under or dorsal to the vena cava.

So in most normal animals with a decent amount of abdominal fat, we're not going to see it very easily. Here's a very thin cakectic animal. Retraction of the chordate process of the chordate lobe shows this, the better renal ligament, which we can incise if we want to increase mobility of this organ.

Here's our kidney, not much fat, and there's our right side adrenal gland poking out from underneath the coral vena cava. You can see that the right adrenal gland is difficult to get access to. While we're looking down here, here's our caudal vena cave, and it's always good to bear in mind that the right gonadal vein, testicular or ovarian, drains directly into the vena cava, whereas on the left hand side, it drains into the renal vein.

So important on the right side for hemostasis, because you've got a direct communication with a large vessel, and on the left side, important consideration when doing a left sided nephrectomy in an entire animal. We don't really need to dwell on the anatomy of the ovary in the uterus, that'll be familiar for most people, so ovary, uterus, suspensory ligament, round ligament, and then mesovaium down here. As we said, here's our descending duodenum, ascending duodenum.

This is our avascular peritoneal reflection. We can transect that and get more mobility of the distal duodenum, differentiate this thin, relatively vascular structure from this, which is an adhesion from previous abdominal surgery. You can see this has a better blood supply, but is not a normal anatomic structure and can be simply transected.

So we've done our mesenteric manoeuvre to look at the right para lumbar gutter. Let's move on. So we've got descending duodenum, ascending duodenum here, dudeo colic ligament as we talked about before.

And then onto the jujunum. We know it's jujunum because it's much thinner, narrow in diameter, thinner walled, and it's blood vessel is arcade-like. Here it is all laid out, root of the mesenter here, most vessels run here, perpendicular rather than parallel.

We can see blood vessels, we can see lactalales if the animal's had a recent fat meal, and we can see mesenteric lymph nodes. Most people, when thinking about abdominal lymph nodes, this is what they would lean to first, these large mesenteric lymph nodes, but they're not the only lymph nodes within the abdomen. Just to close up, you can see mesenteric lymph node here, just how close it is to the root of the mesentry.

If we're going to biopsy these lymph nodes, then be careful about doing so, biopsy a portion away from the blood vessel and consider a guillotine biopsy rather than taking the whole thing out to avoid iatrogenic damage to these very large blood vessels. Moving on to the ilium, well, we know it's ilium because it's even smaller diameter still further, and even thicker wall, which is very obvious on palpation, and we have this accessory or anti-mesenteric, additional anti-mesenteric blood vessel, which is sometimes very long, sometimes very short, sometimes on the antimeicteric wall, sometimes on one side or the other. And then as the ileum runs into the sum, we have this ileocal fold.

Moving on then from Ilium and to the mesenteric vessel to secum with in the dog it's corkscrew shape, which is maintained by this thing, the secret fold that we just talked about, and this thing, the accessory seal fold, as it joins the colon. In this location, we'll find the right colic lymph nodes, and if we want to inspect for the presence of lymphatic vessels in the abdomen, this is the largest collection of lymph nodes and lymphatic vessels. This is the place to look.

Accessory sequel folder mentioned, which gives this secum in the dog, this corkscrew appearance, whereas in a cat, it's a much more blind ending sack that doesn't have that twist. And then we move on to the colon. Now, rather arbitrarily, we move from ascending to transverse to descending colon, although there is no flexure at either site or low flexure maintained by a ligament like there is for the duodenum, but rather arbitrarily we term the right side.

The hepatic flexure, and not surprisingly, because it's on the left side, the left side, the splenic flexure. We have some mid colic lymph nodes, although they're not very obvious in this specimen. And then move on to the descending colon.

We should be able to recognise descending colon as soon as we look at it, rather than palpate it, we can palpate it because it contains faeces, but it's larger in diameter. It's on the left hand side. It's slightly more purply blue than the rest of the viscera, salmon pink nature of the small intestine, and it has these linear striations that you can see.

So you should be able to identify colon just by looking at it. Now we've got hold of the descending colon. We can look down here for left colic lymph nodes, and we can also then move into doing the colonic manoeuvre.

So colonic manoeuvre is very good, particularly for the left caudal aspect of the left paralumbo gutter, just as the duodenon manoeuvre is good for the cranial aspect of the right paralumbar gutter, simply because of the way the mesentry is. Again, we now come back to a blood supply, which is large vessels parallel to the intestine with short vasareta, the same as the duodenum. So, we're looking at left para lumbar gutter.

We can see we still have some structures in there, spleen and a bit of momentum. So let's move those out the way. Move the spleen cranially.

Here's our left kidney, much more mobile, projects more into the abdomen, of course. We're going to find the adrenal, the phrenic abdominal vein, and of course the ovary and the uterus in an intact female animal. There's our kidney, we can move it out the way and in doing so, here's our left adrenal gland with the frenico abdominal vein essentially running over it or bisecting it.

Close up of our adrenal gland easy to see on the left, much more difficult on the right. And then in this syntact female, there's our. Urus.

Here's our ovary, suspensory ligament, proper ligament there and mesovaium with the vessels running here. So that's most of the exploration done. Let's move now to the remaining viscera in the caudal abdomen.

So, just to look at another patient with another exposure. So, we've got a caudal midline ventral laparotomy. We can see that firstly, in the caudal midline, I said there was no internal recture sheath, and here you can see the rectus abdomens.

There is no internal rectus sheath. We can also show that the midline becomes much more thin and In this case, we've strayed off from one side. So, on this side, we've got rector sheath and linear alba on this side, we've transected too far to the right hand side, and we've got external rector sheath, but no internal rector sheath and no linear alba on this side, despite the fact there is a bit of an internal rector sheath there.

The other thing that this illustrates is the bladder in situ, and this, the ventral median ligament of the bladder, the umbilical remnant of the artery remnants. Now, this is a structure that is redundant, we can transect it. In fact, it's been partially transected in approach to the abdomen.

That's fine. The same is not true of the lateral ligaments of the bladder, of course. So, here's our bladder in situ, ventral ligament of the bladder.

In the caudal abdomen, if you need increased exposure, usually putting some gelpie retractors is a, a useful thing to do on either side, if you can get them to engage into the abdominal wall. Here's the bladder then retroflexed further cordially, which shows. The two lateral ligaments of the bladder, one on either side, it's important to be wary of these because these or this structure is where the ureters will run the distal or the terminal.

1/3 of the ureters will run the lateral ligaments before joining the bladder at the urethra of a cycle junction. Let's look on the right hand side, let's look at ureters while we're talking about the causal abdomen. So approximately, or cranially, the cranial 2/3, the ureters are retroperitoneal.

Here's our kidney. They're difficult to see, but if you look hard enough, you can see this tortuous veil structure. There's our proximal ureter.

In the cordial abdomen, it's much more difficult to see, but the ureter will run here and the easiest way to find them is actually to elevate the lateral ligament, look at the urethra of a cycle junction and actually follow them back that way. In an intact female animal, here's the uterine body, here's the cervix, and here are the lateral ligaments on either side, and the ureters running in the lateral ligaments, you can see them here. In a male dog, then, descending colon comes down here.

We've talked about the ureters already. So vast tepherins here, this Y shaped structure, which is much paler and much firmer than anything else in the abdomen, and then the testicular and deferential blood vessels here running. Both of these structures then will run cordially and slightly dorsally, slightly ventrally, slightly up towards us as they go towards the inguinal canal.

And the remaining viscous that we've not talked about yet. Here's our bladder, cordal to the bladder, is the prostate here. So we really do need a caudal laparotomy to do that, and retracting over the abdominal viscera here to expose the prostate, and you can see the prostate has an excellent blood supply, so we should expect that any biopsy procedure of the prostate, our biggest concern is going to be haemorrhage, and then further cordially, we're going to find the urethra.

One thing that's often forgotten when we're exploring the abdomen is the lymph nodes. So we'll just spend a little bit of time doing that. The abdominal lymph nodes can be divided into two groups.

The visceral nodes, those that drain the viscera, and the parietal nodes, those that drain all the other non-visceral structures of the perineum and the pelvic limbs and the tail. And we can further describe or divide the visceral nodes into two groups, those that are constant, those that we would expect to find in all our patients. So hepatic, splenic, cranium mesenteric, and the three colic lymphocentrums that we talked about.

And then those in constant nodes, which may or may not be present in any given animal or may or may not be visible, which makes it a little bit difficult to know in any given patient, whether if they're present, they're normal or abnormal. And these are the gastric. The duodenal, the mental, and sometimes these are joined together as the pancreatico duodenal nodes.

The parietal nodes are a bit more easy to understand. We have the lumbar aortic, the medialliac or what should now correctly termed the external iliac nodes, the hypogastric nodes or interliate nodes, the sacral nodes, both medial and lateral, and the deep inguinal iliofemoral nodes. Now, viscera versus parietal, that sort of works, except when you come down to the genital tract and the kidney.

These are viscera, but for some unknown reason, these drain into parietal nodes and not the visceral nodes. So, a series of line diagrams and then a couple of examples. So, here's a patient with most of the abdominal viscera moved over to one side.

Either side of the portal vein at the porta heitutis is where we find the right hepatic and left hepatic nodes. As we said, paralleling the vessels to the spleen, we'll find splenic nodes, and we talked about how the cranial mesenteric artery, and the root of the mesenter is where we'll find the mesenteric lymph nodes. If we flip the momentum forwards as though we're looking at the dorsal veil, so we can find the left limb of the pancreas, we'll find the mental nodes here, duodenal nodes either side of the duo of the pyloris, right hepatic node will be here, but underneath the pancreas, of course, and then we can see mesenteric nodes we've already talked about.

This is the best way of explaining the colic lymph nodes, so, ascending transverse and descending colon, right colic. Middle colic and then left colic nodes down here, again, quite a large collection of left colic lymph nodes. And then if you want to understand the parietal lymph nodes, we'll go back to our original diagram.

So we'll start at the back. Here's our aorta trifification, external ilia vessels, internal vessels, median sacral vessels. We've got sacral nodes down here, medium ones, which are relatively easy to find in the midline, and sacral nodes which are on the lateral walls of the sacrum and pelvis, which are more difficult to find.

Internal iliac here between or between the internal iliac and the median circle, often smaller, the largest nodes here, external iliac between the external iliac vessels here, and this, which is the deep circumflex iliac, Easy to see because it comes out perpendicularly to the aorta, whereas these vessels do not. So some clinical examples then. Here's the stomach, greater momentum down here, greater curvature here, lesser curvature here, less momentum here, and here's an enlarged gastric lymph node, just where it should be at the less momentum, large, firm, shouldn't be, shouldn't be as large in that location.

Here's another patient Stomach sitting here, greater momentum's there, and again, just immediately caudal to the greater curvature and on the medial surface of the duodenum, decently duodenum, we have this enlarged a mental lymph node here. Here is a pancreatico duodenal lymph node, so quite a thin animal, as you can see, not much body, body fat, stomach's here, duodenum's here, right limb of the pancreas, and a small pancreatico duodenal lymph node, and it may well be that if this animal was better fed and had more abdominal fat, you wouldn't be able to see that. And again, as we said, for many of the abdominal viscera, the lymph nodes tend to parallel the blood vessels.

Here's a spleen, head of the spleen, one of the two major vessels supplying the spleen, and here is a splenic lymph node paralleling that vessel. So, a few comments about closure of the abdomen. We've opened it up, we've had a good look.

We need to close it once we've done the procedure and done all of our diagnostics, therapeutics, assessing prognosis and, other prophylactic measures if warranted. So, we should have a checklist in place prior to closure to make sure we don't miss anything. The things that are most commonly missed are leaving swabs behind, remote should count them in and count them out, use them singly and sparingly to avoid doing that.

We should count the instruments and other disposable items. It's much less likely to leave an instrument or other item in the abdomen, but we should make sure that we've still got our full complement of instruments. We should just take a time to think, have we taken appropriate biopsies?

What was the reason for doing the exploratory laparotomy? If it's worth doing the laparotomy, and we haven't got a diagnosis, and we haven't applied treatment, then we should take samples for at least cytology, if not histology, we're best placed to do that because we're there with the abdomen open and for culture. We should think about changing the instruments and gloves if we've done anything other than a clean procedure.

So that when we do the clean part of the procedure, closure of the abdomen, we're doing that with not contaminated instruments, and we should consider lavage of the abdomen, to remove any pre-existing contamination if the animal had septic peritonitis because of a hole in the intestine, to remove any contamination that we may have introduced, say we're doing an enterotomy, and enterectomy, and unfortunately, there's been some spillage, and we should also do that as a measure to consider active core rewarming in a hypothermic patient as well. Let's look, closure of the abdominal wall, what do we do? Firstly, suture material, absorbable versus non-absorbable, as long as we use a long lasting absorbable suture material that will provide enough support for the viscera, for the abdominal wall, sorry.

Remember, we're closing the linear alba, the white line, it's white because there's no blood supply, so it will take longer to heal the vascularized tissue. So long lasting absorbable suture material is what we need. Unless the animal has a serious concern about wound healing, there's no real need for non-absorbable suture material.

Monofilament versus multifilament, well, throughout, any surgical procedure, kind surgeons who respect tissue will use monofilament material because there's less tissue drag, and indeed, the only real indication for multifilament material is going to be for increased knot security for ligatures. So for the most part, absorbable monofilament, long-lasting, polydioxinone or PDS or something similar. What suture pattern, simple interrupted versus simple continuous.

If you place the bites correctly in the right tissues, which we'll go on to talk about, then a simple continuous pattern will be as strong as simple interrupted, and the same risk, and very low risk of failure. So simple continuous is quicker. Saves money on suture material and puts less suture material in the abdomen, so less likely to potentiate infection.

So simple continuous is to be recommended. Engagement of tissue, we want to engage the linear alba, and we want to engage the external rectus sheath. These are the suture holding layers.

We could consider where it's present, engaging the internal reus sheath, but there's no necessity to do that. And indeed in the caudal abdomen, we can't. Should we engage the peritoneum?

No. If we engage the peritoneum that sits between the two sides of the linear al external reus sheath, that can slow down wound healing. So there's no necessity to do that.

And in fact, it's probably counter contraindicated. Do we include the rectus abdominus? Do we close the muscle layers of the abdomen?

No, we close the muscular aponosis, the linear alba and the external rectus sheath, but do not incorporate the muscle because it's painful. Because it will potentially strangulate the muscle, and then the muscle will atrophy and we end up with a loose suture. Placement of the sutures, well, it's difficult to do that.

It depends on the size of the patient, of course, and essentially, I think it's difficult to teach other than the bites look about right, but not too close and not too close together, which would be the the principal mistakes that are made. So 3 to 10 millimetres from the edge and 5 to 10 millimetres apart. Of course, it should not be possible to insert any instrument between successive bites, to make sure there's no holes that are large enough to cause a visceral herniation.

So let's just go back to closure again, look at the abdominal wall. I've said, it's the linear alba in the midline and the external rupture sheath, which is always present. But the linear alba is narrow as we go cordially.

So, here's a diagram. I guess it shows that we should perhaps not believe everything we see in surgical textbooks. It's a useful illustration, but you can spot the deliberate mistake, perhaps.

So here's a suture in the cranial abdominal wall. The suture goes through this, the external rector sheath. And should then come along here above the rectus abdominals go through the linear alba, and again on the other side.

Here it's illustrated going through the medial portion of the rectus abdominus, and there's no necessity to do that. And indeed, we should try to avoid that. The caudal abdominal wall, well, you can see we've been successful.

Here, external rectus sheath, we should have a dotted line that comes along here through the linear alba or below the linear alba, and across to the other side. Why do we do that, rather than just the linear alba, which is easy to find. This is the reason.

Experimentally, if you place sutures here, just in the linear alba, and sutures here, linear alba and external reture sheath, if you look at pullout strength of the two groups, those that have a wider tissue bite and incorporate the external recture sheath, have a greater resistance to pull out. So in the clinical patient, we're less likely to get the hissants. It's not surprising more tissue gives you a stronger repair.

So, Linear alba and external rector sheath is the layers we should engage. Just to illustrate that, if we make a parameian incision, so we've got an incision in the abdomen, there's a representation of the left side. Here's a representation of the right side.

The incision is too far to the left, so you can just about see external reus sheath at the top, but mostly exposed rectus abdominus, and on the right hand side, we can see external reus sheath, linear alba, in fact, full thickness linear alba, and even a bit of the rector sheath from the opposite side. Here are incision are our suture bits then are going to grasp the external reus sheath here and external reture sheath and full fit this linear elbow on this side. So that concludes the guided tour of the abdomen.

I hope that was useful from an anatomy point of view and a practical surgery point of view. I'm happy to take any questions and well, back to you, Bev. That's fantastic, Stephen.

Thank you so much. That was a really fascinating and very detailed summary of exploit laparotomy. And you managed to make an ask me interesting and relevant, which was fantastic.

We've got a couple of minutes for a couple of quick questions. I've just got some coming in now. I've got one question here.

Do any openings created in the Omentum need to be sutured closed? I think that's a good question. We always worry about internal hernias when we create a hole in the omentum or the mesentry.

Realistically, in the No, as long as the hole is large enough such that any visceral that goes in can get out again. No, that's extremely rare. The same is not true about the mesentry, and we should always consider closing that.

And there are reports of, of internal herniations through any acquired defect, particularly in the duodeno colic ligament. The problem we have, particularly in the mesentry of the of the jujunum, is that it can be difficult to get enough of a tissue bite to close it. Without damaging the vessels, which lie very closely on either side.

So, the answer is yes, we should close internal defects in the supporting mesentry, unless they're so large we're not going to get a problem, but better to close those, the momentum holes in the momentum, no, it doesn't seem to matter. That's because the momentum's a great organ, it just kind of gets on with things. Brilliant.

That's great. Really useful to know, and just to clarify that. We've not got any more questions coming through.

We've got lots of people on the chat saying, thank you very much for an excellent and useful and interesting talk, which I can only second. So thank you very much, Stephen. That was absolutely fantastic.

I will definitely be approaching my ex laps in a more systematic way after that.