 Good day everybody. Dr. Sanjeev Sanyal, Professor, Department Chair. So this is going to be a demonstration of the pelvic vessels. Just to bring you up to speed, this is a supine cadaver. We are standing on the left side. Camera person is also on the left side. We have completely opened out the abdomen and the pelvis. This is the bladder. This is the left side psoas major. This is the aorta. This is the inferior vena cava. So let's take a look at the aorta. We can see that it is bifurcating at the level of del 4. And this is the left common aliac. This is the right common aliac. So we will focus on the left side. The common aliac, external aliac, continues as the femoral artery under the inguinal ligament. So this is the external aliac. This is the internal aliac. This is the blood supply of the pelvis and the gluteal region. Now I am going to lift up the internal aliac. We can see that it is dividing into two divisions. This is one and this is another one. We can better see it from this side again. If we disregard the vein, we can see that this is one division and this is another division. This is called the posterior division. And this is called the anterior division of the internal aliac. So let's take a quick look at the branches of the posterior division. The posterior division has got three branches. The first one that you can see here is this one. And we can see it is running laterally towards the aliac bone. This is the aliac. This is the ilio lumbar artery. The ilio lumbar artery runs laterally and it anastomoses with a deep circumfix aliac which runs along the inner surface of the aliac crest which is the branch of the external aliac artery. The second branch is the lateral sacral artery. The lateral sacral artery runs medially towards the sacrum. And we can see the venous counterpart of that here. Lateral sacral artery anastomoses with this artery. This is the medial sacral artery. So therefore the lateral sacral artery from this side, the lateral sacral artery from this side and the medial sacral artery they form an anastomotic arcade in front of the hollow of the sacrum. The counterpart of that is the lateral sacral vein. And the lateral sacral vein we know is a route for spread of pelvic cancers to the vertebral column and through the intervertebral venous flexors right up to the cranium and to the brain. Through the occipital sinus and the inferior patricial sinus. So that is the second branch of the posterior division, the lateral sacral. And the third branch of the posterior division is this main one which is continuing. And we can see it is disappearing here. It exits the pelvis through the greater sciatic foremen above the pyriformis and that is the superior gluteal artery. So these are the three branches of the posterior division, eniolumbar, lateral sacral and superior gluteal. Now let's take a look at the anterior division. So this is the anterior division. Let's take a look at the branches of the anterior division. The first branch that we can see is this one which I have lifted up here. This is the umbilical artery. The umbilical artery as we know in embryonic life it can deoxygenate blood for oxygenation towards the placenta. But after birth distal portion, the most of it portion becomes obliterated and we can see that here. And it forms the medial umbilical ligament. However, the proximal portion remains patient. And from the proximal portion we can see these branches going towards the bladder. These are known as the superior vesicle arteries which supply the superior surface or the dome of the bladder. There will be many branches like that on both the sides. So that is the first branch. The next branch that we can see is if you look further on the lateral wall of the pelvis, we can see this artery here. This is the operator artery. And we can see that the operator artery is accompanied by the operator nerve. And it is accompanied by the operator vein. And these three structures then they exit through the pelvis where the instrument has gone in through the operator canal. This is the opening in the operator foremen and it goes to the medial side of the thigh. In this particular canal we can see an accessory operator artery and I will draw your attention to that here. This is the accessory operator artery. This accessory operator artery we can see is arising from the inferior epigestric artery. Inferior epigestric artery is a branch of the external alia artery and this is the inferior epigestric artery. This accessory operator artery sometimes is also called the replaced operator artery if it completely replaces the main operator artery. It is also called the coronomortis artery. This runs along the lacuna ligament. This is the lacuna ligament which is on the medial side of the inguinal ligament. And femoral hernia surgery we can endure the accessory operator artery and lead to profuse bleeding and that is the reason why this is also called the coronomortis artery. Femoral canal is located right lateral to the lacuna ligament. So this is the next branch that is the operator artery. The third branch that we can see here isn't only in males not in females and we can see a branch going to the bladder from behind near the base of the bladder. This is called the inferior recycle artery, this one. Then we have a middle rectal artery which is located rather deep inside and it runs in the lateral ligament of the rectum. We can see the venous counterparts of that. The next branch that we can see here is the continuation of the anterior division. So for that again I'm going to lift this up. And we can see that the main anterior division continues like this. This is the inferior gluteal and the internal pudendal. In the females there is no inferior recycle artery. It is replaced by branches of the vaginal artery. And in females they have an utrient artery. So therefore to summarize the branches of the anterior division are the umbilical artery which gives the superior recycle, the inferior recycle, the obturator, the middle rectal, inferior gluteal and the pudendal. The inferior gluteal and the pudendal, they also exit the pelvis through the reticillic foramen below the pyriformis. Now if we were to take a look again at the posterior division, we said that this was the continuation of the posterior division. So this is the superior gluteal. And just below that we can see this is the inferior gluteal. So superior gluteal is above the pyriformis, inferior gluteal is below the pyriformis. And they go out to the gluteal region and they supply the structures in the gluteal region and they participate in various types of anastomosis. At this juncture I will just digress one minute to tell you something of surgical significance during laparoscopic surgery for hernia. If you take a look at this region here, when we are doing a laparoscopic surgery for an indirecting venal hernia, this is the region where we are doing the surgery because this is the location of the internal ring. And we can see coming out from the internal ring into the abdomen are these structures. One, this is the doctor's difference which is going medially. Then we have this structure going laterally. This is the gonadal vessels and we can see that on the left side they are opening into the left renal vein. And the gonadal artery will come out from the abdominal hernia. So therefore this triangular region is referred to as the triangle of doom. Triangle of doom is bounded by the doctor's difference medially, the gonadal vessels laterally, and infinitely there's a fold of petronium which is visible only during life. And deep to that triangle forming the floor of the triangle of doom are the external aliac artery and vein. So this is the region where we operate laparoscopic surgery for inguinal hernia. When we are strengthening the wall of this hernia after the repair of the hernia, we are likely to injure the external aliac artery and external aliac vein because they are located just under the peritoneum which are liable to injury and that is the reason why this region is referred to as triangle of doom. The precaution to be taken is we are not allowed to put clips in this region when we are strengthening the wall with a mesh. Located lateral to the triangle of doom is what is called the triangle of pain which has been coined by the laparoscopic surgeons. This triangle is oriented in the reverse way as compared to the triangle of doom with the apex below. Superially it is bounded by the heliopubic tract, medially it is bounded by the testicular vessels and laterally by the peritoneum fold. And this triangle contains the femoral cutaneous branch of the femoral nerve, the lateral femoral cutaneous nerve and the femoral branch of the genital femoral nerve. Here also we should avoid staples because injury to these nerves can produce chronic pain. These are the branches of the various divisions of the internal iliac artery that I wanted to show you on the left side.