 This time we will be demonstrating the contents of the abdomen after the anterior abdominal structures have been removed. By the way, my name is Dr. Sanjay Sanyal. I am the professor and department chair in the western hemisphere. The camera person is Ms. Selvi Krishna and Mr. Doug McLaren. And I am happy to be here with you. So first an overview of what we have in front of us. You can see that these are the abdominal contents. All the anterior structures have been removed. What we can see here is the abdominal cavity. We can see the liver here. We can see the diaphragm here. The left dome of the diaphragm. The right dome of the diaphragm is hidden by the liver. And we can see the aorta here. We can see the inferior vena cava here. We can see the pelvis with the terminal part of the sigmoid colon continuing to the rectum. And we can see also the bladder here. And this is the medial ligament of the umbilical ligament. We can see the two kidneys. And we can see the ureters. And we can see the posterior abdominal structure. So this is an overview. Now let's go a little deeper. This depression that you see on either side of the vertebral column. This depression and this depression. These are referred to as the paravertibral gutters. Now how is this paravertibral gutter created? It's because the vertebral column in the lumbar region is jutting forward. It's anteriorly because of the normal lordosis. And the posterior abdominal structures are moving or backwards. So therefore a depression is created on either side which is called the paravertibral gutter. And if you note carefully the kidneys are located in the paravertibral gutter. Now this has got a clinical significance which I shall tell you a little later. The second point I would like you to notice is that this structure that you see here and this structure that you see here. These two are the soas major muscles. The right and the left. The right and the left. The soas major muscle. The soas major muscle it forms part of the posterior abdominal wall. And later to that we have the quadratus lumbarum. The soas major muscle and the quadratus lumbarum also forms the posterior relation of the kidney. But we shall not talk any further about that. What we can see are a few fibers here. These are the some fibers of the lumbosacral plexus. Specifically the lumbar plexus. Okay now that we have mentioned this a quick word. This is the left dome of the diaphragm and the right dome of the diaphragm as I told you is hidden by the liver. So this is the right dome of the diaphragm above the liver. Having mentioned that now let's come to we shall describe the aorta and a few of its clinical correlations and its branches. Then we shall describe the inferior vena cava and a few of their tributaries and their clinical correlations. And then we shall talk about the kidney, the ureter and some of their clinical correlations. So let's start off with the aorta. So this is the abdominal segment of the aorta that you see here. Where does it start from? It starts from the aortic hiatus in the diaphragm. The aortic hiatus is the level of D12 and it continues slightly to the left of the midline and it bifurcates at the level of L4 vertebra into the left and the right common iliacs. It bifurcates into the left and the right common iliac. So therefore the extent of the abdominal aorta is from D12 to L4. It is remember the aorta is situated to the left of the inferior vena cava. What are the branches or the cut sections of the branches that we can see in the aorta? Let's take a look at something which is immediately obvious to us. First of all we can see this opening here. This is the celiac cut section of the celiac front, celiac axis. This is the superior miscentric and this is the region of the inferior miscentric. Celiac is at D12, superior miscentric is at L1, inferior miscentric is at L3. These are the unpaired misceral branches which supply the foregut, midgut and the hindgut respectively. Just about the celiac axis there is another which which is the inferior phrenic artery. The inferior phrenic artery are the paired parietal which supplies the inferior surface of the diaphragm. We do not see the lumbar arteries because they have been removed here. So these are the structures that we can see. Additionally we can also see the renal artery. We can see the right renal artery dividing into the two segmental branches. Three segmental branches to be more precise which I shall tell you a little later and the left side we cannot see them so clearly but once we lift up the renal vein we can see the left renal artery because the renal artery is situated posterior to the renal vein. I shall tell you more about the renal arteries when I talk about the kidney. So these are the branches that we see. Let's continue further at the bifurcation of the common of the aorta. So as I told you these are the two common alieic arteries. The two common alieic arteries, they run along the pelvic bridge and they give rise to divide into an internal alieic and the common alieic then continues as the external alieic. The common alieic continues as the external alieic and then this is the region of the inguinal ligament and under the inguinal ligament if you can see my finger has gone in under the inguinal ligament. Once it crosses the inguinal ligament, it continues as the femoral artery in the femoral triangle. Okay, the internal adiacs divides into an anterior division and a posterior division. The anterior division has got most of the branches which supply the structures in the pelvis in the perineum. The posterior division supplies a few structures in the gluteal region. So this is a bore. So this is the brim of the true pelvis. Now let's mention a few important clinical correlations pertaining to the aerotub. In a thin walled individual, a person who's got a thin abdominal wall, we can palpate a normal pulsations of the abdominal aorta in the region of the L4 vertebra with the heel of our hand. So if you can palpate the pulsations in a thin walled individual, then it is not considered abnormal. That's the first point. Second point is a very important condition and a very serious condition called abdominal aortic aneurysm. Now where does this abdominal aortic aneurysm arise from and how does it arise? It is usually due to a weakness of the tunic up media of the abdominal aorta. Maybe associated with hypertension and usually the cause is atherosclerosis, so it can also be seen in other conditions like collagen tissue disorders and Marfan syndrome etc. What is the usual location of an abdominal aortic aneurysm? Take a look at the origin of the renal arteries which are usually at the level of L1 or L2. The aneurysm usually arises from just below the renal arteries and they usually extend right down to the bifurcation. So this is the usual region of the abdominal aortic aneurysm and when such an aneurysm occurs the inferior miscentric artery arises from the apex of the aneurysm. When we have an aneurysm which is a rather serious condition, we can quite often see the pulsation in the abdominal wall itself in the patient and we can definitely feel it as an expansile pulsation. If the aneurysm has seen in imaging studies if it is more than six centimeters in diameter and definitely if it's more than seven centimeters then it's about a very high chance of rupture with a very high incidence of morbidity and mortality. So that's about the abdominal aortic aneurysm. The next important point which I want to mention was the arteriogram which we have been talking about in the class. If you take a look again, as I told you this is the femoral artery here. Similarly we have the femoral artery on the other side holes. So this is the usual route that is chosen to do an arteriogram and the so-called modified celling or technique. What we do is we palpate the femoral artery one inch below the middle point and then we cannulate it. And we pass the cannula under image intensifier and see arm image intensification and we pass the cannula through the femoral artery, through the external iliac, through the common iliac, aerotub, and then depending on which vessel we want to visualize whether the inferior miscentric, celiac, we cannulate it and we inject the dye and we take multiple serial extremes. So that's the usual or we can do it even in the renal artery. We get a renal arteriogram. To continue the same story we can even extend the cannula further up into the thoracic area and we can keep on extending it up till we reach the openings of the coronary arteries, the right and the left coronary arteries in the aortic sinuses and we can thus do coronary angiogram also. So this is the route that is used to perform all these angiograms by the so-called modified celling or technique. So these are some of the clinical correlations pertaining to the aerotub. Now let's come to the next important vessel, namely the inferior vena keva. The inferior vena keva has been severed at the top and this is the opening where my forceps has entered. So this is the opening of the inferior vena keva. Where it is, what is the extent of the inferior vena keva? The inferior vena keva as you can see is situated to the right of the aerotub. The inferior vena keva has got a bigger extent in the abdomen than the aerotub and let's see how it's soaked. It pierces the diaphragm to the right of the midline at the central tendon of the diaphragm at the level of T8. At this juncture I can give you a rule of thumb. We have three major openings in the diaphragm, T8, T10, T12. T8 is the cable hiatus, T10 is the esophageal hiatus through the right crust of the diaphragm and T12 is the aortic hiatus which I told you just now. So let's come back to the inferior vena keva. It extends from the cable hiatus at T8 and it bifurcates into the right and the left common iliac veins at the level of L5 which means it is one vertebral level below the aortic bifurcation. Therefore the extent of the abdominal inferior vena keva is a little more than the extent of the aerotub. Having mentioned that, let's see what we can see here. We can see, for example, we can see the opening on the right side. We can see this is the gonadal vessel which opens into the aortic vena keva. On the left side, the gonadal vessel will open into the left renal vein that is not visible here. Additionally, it also receives many of the tributaries but most of the tributaries are not visible here but what we can see here is this vessel here. This is the left renal vein. The left renal vein is anterior to the left renal artery and it runs anterior to the aorta and it is longer than the right side because the inferior vena keva is situated to the right and this is the cut section of the right renal vein. Most of it has been cut off and this is the right one which is again anterior to the right renal artery. So, this is the left renal vein and the right renal vein. At this juncture, I need to tell you a very important clinical correlation here. Take a look at this stump here which we can see. This, as I told you earlier, is the stump of the superior vena keva and you can see how close it is in relation to the left renal vein. The superior vena keva runs down here like this and it supplies the structures of the midcut. Sometimes what happens is the superior vena keva as it runs in close proximity to the left renal vein, it can compress the left renal vein and produce what is known as the left renal vein entrapment syndrome. Not only does it produce symptoms pertaining to the left kidney but remember the left gonadal vessel especially means the left desticular vein also opens into the left renal vein and can also, by the same condition, it can produce obstruction of the left desticular vein and produce varicoseed of the left destes in the main. Unrelated to this particular condition but related to the superior vena keva artery, the superior vena keva artery as it runs down, it runs anterior to the third part of the diodenum. So, therefore, it can produce compression of the third part of the diodenum also and produce diodenal compression syndrome. So, that is what I wanted to mention about the superior vena keva artery. The next point which I want to mention but which is not visible here is that this is the region of where the spleen was located. The spleen is located in this region. So, therefore, the spleenic vein comes like this and it is in very close proximity to the left renal vein. So, therefore, the spleenorenal shunt or the spleenorenal anastomosis that is done in portal hypertension is possible by virtue of the close proximity of the spleenic vein with the left renal vein. The spleenic vein as you know runs behind the pancreas which of course has been removed here. So, these are the two important clinical correlations that I wanted to mention to you pertaining to the inferior vena keva. So, I think we'll stop our video here and we will continue the next video after this. Thank you very much for watching. Have a nice day. Thank you, Doug and Selvi.