 Coming to how I do it, what I want to say is it is not a supine position with a slight head tilt. What I learnt from Winker Dolens is the more you tilt your head, the pyramid of the clinoid will become parallel to you. So it is like this, it is down below. So if you are just supine with a 5 degree tilt, your clinoid will be dipping down. You are actually putting your drill like this but the moment you put it like that so your pyramid of your, of the epsilon-atyl-clinoid will become more parallel to the floor. That is very important. You have to actually drill along the direction of the pyramid like this. That is very important. Psycho-matic, we realize because I love cartoons since childhood so, so it is a very simple approach, a standard terional, two burrows, key burrowl as well as at the superior temporal crest. A small terional craniotomy, it can make it as big as possible. The important thing is to take off the base of that and drill the sphinoid ridge. The important thing are the cuts. If you are doing an obridsagomatic, then your cuts will be like these. If you are taking an extended temporal, this can be enough but the main thing is the moment you take this off, this is the extra exposure you need and this is our focus. The more anterior your lesion is that if you are talking about a clientoidal meningioma which is more towards tuberculum cellae, even this approach would be good enough with an orbital groove. The more it is towards the tentorium and the temporal like meningioma, even this, you may not be removed, even this part is enough. That is what I believe is important. This is the cadaver. This is the left side. The orbit, you have already done it, the orbit is agomatic. Reduction of the sphinoid ridge, that is the specimen I drilled maybe a year ago as the orbital wall, lateral orbital wall. This is important. Now, this is the Petrus pyramid. It is practically parallel to the floor. That is what I mean by extradural. You are actually cutting not only the meningo-orbital artery but the complete tentorial duplicature. Dolan's uses the word tentorial duplicature because this is the fold of tentorium from a temporal dural. It folds over the anterior clientoid process and merges with the lateral orbital wall and then with the frontal dural. The moment you cut this over the Petrus, you are actually cutting this tentorial duplicature over the clientoid process. The moment you cut it, the pyramid of the tentorium of the anterior clientoid process becomes completely visible. This is the pyramid, you see. It is... Otherwise, you are only seeing this tip. If you are not cutting the complete tentorial duplicature, you will be actually drilling into just like you are doing a root canal treatment. That is very risky. That is the reason why you can rupture the aneurysms. But if you are drilling it like a pyramid, you will... Because the ICI is here. That is the Dolan's triangle, the ICI is here. If you drill it like a root canal treatment, like a canine tooth or a molar tooth, you will actually injure the vessel there. So you actually have to make it into a shell, dissect the complete shell around it. Don't pull it out. You have tendency to do that and take it out. And that is the ICI. You see that? That is the ICI. Chances of rupture of an aneurysm would be if you are drilling it right into it. But if you are drilling it as a pyramid, you will never... For the pyramid exposure, you need to expose the... That is the cavernous hemangioma of the cavernous sinus, a pretty old video, a large cavernous hemangioma of the cavernous sinus. So taking off the clinoid process, the initial part can be done with a cutting drill and then a diamond. This was one of my earlier cases. So I was very hesitant. So to drill it right till the shell, took it off like a projection in the end. But it is very important that you must see what you are dissecting out. You should not pull it out. But there can be a middle clinoid process which may not be an ossified, a middle clinoid process. If you see the skulls, the anterior clinoid and the posterior clinoid, that area can be in 0.1% of anatomical variations, can be a middle clinoid process, which may be fibrous, which may be calcified. If it is calcified and you pull it out, that strut, that small spicule can injure the carotid artery. You have already opened the cavernous, anterior cavernous sinus there. That is the V2, the V3, these are very bloody tumours. Best approach is extradural approaches. So it is all extradural. You peel the outer, the two layers of the cavernous sinus, already done the anterior clinoid removal there. So the third, fourth nerves and the V1, you have to go between. So you can see now V2, V3, here was the 3, 4 and the V1 coming there. So you are going between the 4th and the V1, the Parkinson's triangle. That is the angle of, that is the superior orbital fissure. That is the clinoid which has been removed, that is the joint gel form, something there. And you can now see the third, the 4th, the V1, the V2 and the V3. It is all splayed over the cavernous sinus and that is the dura, the temporal dura. And then you can open the Parkinson's triangle here, do a decompression. That is the 4th nerve. I learnt from Professor Dolan's that 3rd and the 4th nerve should be really respected. The 5th can tolerate traction. The 3rd and the 4th, even intradurally will not tolerate traction. 4th will not clinically manifest, 3rd will remarkably manifest. You just give a slight traction because of any meningioma, your 3rd will go. 4th can be reversible, 3rd is usually may not be reversible if you feel. Then you rapidly decompress it. Look for the internal corroded artery in the cavernous sinus. Along with that there will be a 6th nerve and there will be some sympathetic plexus along with that. These patients can have post-op horners because of this thing. Look for a meningo-hypophysiol trunk branch which is going into the tumour, coagulate that. Then this tumour goes into the cellar. If you saw the MRI, you can take that out. These tumours should not be coagulated in mass and then try to take out because if you do that, you will damage all the cranial nerves. You will be having a complete ophthalmoplegia. Yes, there will be ophthalmoparesis in such patients but that will be transient. The most important nerve which may not come back in these patients will be the 6th. That is the only true intra-cavernous and that is a giant paraclynoidal anism. That is again forgotten like Dr. Gupta, which is left. I think temporal. This should be frontal. This is the orbit. I am sure of. This is temporal. That is temporal. This is the right side. This is the right side. So, we are drilling the clientoid and then because this is open, you are going in the direction of the pyramid and that is the optic nerve. So, all the time this is the optic nerve and that dissection is, you have to see what you are dissecting. There is always some bleeding from the cavernous sign is there. If you cannot drill it out completely, just leave at the tip here if I could remove, then the dura is opened. I will just complete that sentence later. That is the area where the clientoid was removed. So, that is the Dolan's triangle. That is the ICA. That should be the ICA there and which continues here, intuitively. Dissect your falciform ligament. Look for the optic nerve. That is the optic nerve, it's extraordinarily. Follow it down. That is the ICA. Nicely turned and that is, we are putting a clip at the PCOM, one, another one at the A1. This is giant anism, coagulate anism. That's one neck. Look for the other neck. That is the optic nerve, that's blade area. This was an elderly lady, so it was very much calcified. We had to put many clips. Despite that it was not closing, so maybe I think six, seven clips we put. These anisms can be difficult and actually, Dr. Mathuria was saying that one of his anisms, he had to put an artery clip because bleeding did not stop with the normal clips. I didn't know what to do after that. So that's the ICA and the PCOM which is preserved. So like this, that was the y-extradural. If you see this image, these clips are just protruding out from this area. So in the usual intradural, you cannot put clips like this. You have to fashion it parallel to the ICA. Your clips will be always like this. Here it helps you to fashion your clips like this, especially in giant because they do not respect the anatomy, the giant anisms. These are broad neck ones. So I think this is the left one, left, left. So cutting the territorial duplicature, the temporal side, that's the orbit. Superior orbital feature is removed, that's the ACP, yeah, it shows. And you have to peel it down. You cannot start drilling here. You have to peel it down right till the apex, right till you see the tip, till you feel the tip with your disector. Open the anterior cavernous anus there. This approach I think is too big for small anisms. So I think intradural is the best approach for small anisms, but for giant ones in which you have to refashion the neck and everything, this is a very safe approach. And then you have the petrocephalic, you are actually drilling like this. Then you are not drilling into the tip. You can actually feel the tip of the clinoid here, drilling the whole pyramid of the. What we realized is, we realized that once you do, I will finish this first. That is the optic canal and that is the last bit. So this is not the tip. The tip is already out. This is just a part of the ridge over close to the optic nerve that is removed and the dura is cut. Small durotomy, I usually put the curvilinear along with cut straight cut down to the clinoid. So it becomes a T because all the clips will be approached like this. In an intradural approach, all your clips are like this. So this is the giant anisms, opening the falciform ligament, look for the distal ring, look for the A1. The A1 was stuck so that is being dissected. Usually after dissection we puncture the anism, decompress it, but something happened here before I keep this video. Needless to say, I think every case gives a challenge. It humbles you. Then we drilled the rest part of the firs of the optic canal and that is the optic nerve. And we thought, then this is the ICA, typicom, choroidal, coagulated anism released the A1. The A1 is stuck there. This is important because that will give us the exposure of the neck. So all this maneuver, extradural is important because all your clips have to be directed like this. That is what I think. That is what I was trained with. And then that is the optic nerve. We are trying to separate. And while we are trying to separate, I saw this video at least 10 times after the surgery but I could not, I do not think I was trying, but I did not rupture it, it ruptured on its own. I thought, then again repositioning of the clips, the multiple clips were applied there. This should not happen. This why I always keep it because here you have to be careful that if your aneurysm ruptures, despite your temporary clips, your clip at A1, picom and there will be some cross circulation on the opposite side of thymic canal and they will be bleeding. So this is something you should avoid. A better thing would be to do a planned rough puncture because the problem is if you put random clips, this is the area of which you can actually take in your clips. That is the pituitary stock. So that is something, if you have two long clips, you can actually take the pituitary stock in your clips. That is something that you have to look at the pituitary stock when you are doing these cases. Two things it helped. It gave a better trajectory at the lateral part of the ICA. You could not do the complete resection. You could try to with an intradural approach, the complete resection. But there was a vein. Always there was superficial middle cerebral vein which was coming and attaching at the lateral water. For that you used to get injured while you were doing a complete resection intradurally. That was I think to preserve that in complete resection and the third nerve. Extradural was better for a complete resection. But in cases where you only require partial trailer resection, maybe a small aneurysm, maybe a small client nodal meningoma, I think that would be the best way to think.