 I will be very frank with you, the main aim of this is to tell you that endoscopy is a very important tool that every neurosurgeon must know endoscopy. You cannot be ultimately known as an endoscopic neurosurgeon or a micro neurosurgeon, these are two tools which are essentially important, we cannot do without them. Yes, you have to gauge that what where all you will have to use them, it does not mean that you have an endoscope that you put your scope in every meningioma or a petroclastic meningioma from the nose and every hydrocephalus can be treated. So just a humble impression of what exactly endoscopy can do, endoscopy we are talking about you had a very fair idea what all we can do it from the nose, what all we can do from the after having the anatomy and the beautiful videos. Now you know you have a fair idea of where all you can should put your endoscope, where all should not put an endoscope. So this is the major two indications, hydrocephalus and intraventricular lesions, ventricular shunts have been the gold standard, shall be the gold standard and are the gold standards. We have to actually identify that yes, this is a necessary evil, we all have faced that evil that how can we prevent some, can some of these shunts be replaced by thermonucleosome, that is a humble answer that we have to give to ourselves. So it is very important when you are I would say even hydrocephalus, it is not that you should put a scope in every hydrocephalus you see that is not the treatment. Learning a technique is all right, but here our main aim is giving you the technique, telling you the right indications, telling you a very humble situation of what exactly is to be done and not to be done and then you can take your decisions when you are going. So we know that these complications are everywhere, these are from my center and every one of you will have the complications of shunt going into wrong places, having haemorrhage inside the brain, outside the brain, remove while removing it and they can cause infection, they can coming out from different places going into different situations. So what exactly are the indications, well-accepted aqueductal stenosis or arachnoid cysts, we have seen third ventecholostomy is helping them and arachnoid cysts and in neoplastic etiology you can take a biopsy along with third ventecholostomy, 60 circles we have seen all indications. So and relative indications are patients with repeated shunt infections, post-menusetic hydrocephalus, intramendric haemorrhage, pre-operative evaluation the most important investigation is an MRI, please do not attempt a third ventecholostomy in any hydrocephalus without an MRI, you must see the MRI T2 sagittal to look at whether there is an aqueductal stenosis and before you plan you must have the mental image which size ventricle is larger, whether it is because you have to go from the larger size or non-dominant side, the firm and monorho or the third ventricle should be dilated and the floor of the third ventricle should be attenuated bulging down, these are some criteria that you have to estimate beforehand because your entry point will also depend on that. Yes, a lot of surgeons have been very adventurous going and doing these patients under local anesthesia and sedation but this is something which is a contraindication, please only do these patients under general anesthesia, the position your patients to pine on a head ring or a horseshoe, incision has to be planned, it is not a incision that I'll put it on the coronal suture or somewhere between the two hairline, take your number because we've had, we burnt the fingers once or twice by not planning them right, always look at the intramendicular system, the line joining the intramendicular system, the firm and monorho frontal projection would be the borehole for the third ventricle ostomy on a T2 sagittal, you'll always see the firm and monorho nicely in their intramendicular, if you're planning for an aqueductoplasty or a tumor, this will be the borehole, so anything between the two, this will be the borehole will be here but if you're planning both of them from the same borehole, it is better that there are two things that are very important, the firm and monorho must be dilated on your MRI and that is one thing, second your borehole should be not a small 8 millimeter or a drill borehole which is around about 5 millimeter in diameter, should be a nice 8 to 10 millimeter martin borehole which we can negotiate and fulcrum and both the sides because the main problem where the scope hits and damages is here, is the phoenix, that you must plan. So for the fenestration, you have to fenestrate the third ventricle floor at the thinnest part of the tubal sinurium, between the mammary bodies and the intramendicular recess, the best ways to fenestrate it is a fogarty or a bipolar, don't use current and or a feinsis after some practice, a feinsis over the nose, I'll show you. Then dilation is very important, dilation of both the membranes, sometimes the second membrane is not there but it's nearly 70% of times the second membrane is always there and you must fenestrate it and dilate it with the ventricle ostomy probe that can also be used. It is very important when you're doing children, in less than 2 years your success comes down to around 50%. After 2 years in aqueductal stenosis, your success is as high as 80 to 90% and sometimes even some series say 100%, a series from GVPAN hospital said 100%. You must have a right indication and plan your third ventricle ostomy. In children, even until they are 5 years of age, there is higher chance of CSF leak. How to prevent the CSF leak is when you're making a burble, don't take linear incision, semi-circular, semi-lunar incision, the burble being in sitting in the center of that, you can take a small flap, put it down, or you can preserve all the bone dust and pack it back along with some gel foam. Try to make a flap of the dural incision so that you can pick it back. But the most important is plugging of the cortical wound. Once you've taken out your scope, do not just put some sponge stand over that and make a big cylinder of a gel foam and just plug that wound so that a sum of it coming back, so it doesn't drop in, actually. That is the main idea so that you can, this is a simple third ventricle ostomy with the tectil plate lesion. You can conjure it with a Fogarty or with a bipolar without any current. You can see the second membrane, that's the mammary bodies, be as away from the mammary bodies as possible, just close to a translucent structure, which is the dorsum cellae. Then you start dilating with the three, four, four or five French. When you're dilating, it's very important, just see the movements. When you're dilating, your balloons should start coming out. You should not dilate between the brainstem and the clivus. So your balloon, you inflate it and when you're dilating, you keep on coming out, otherwise you'll evolve the perforators. They were dilated when you're between the two. That is the most important thing. And this is something you must see in the Basilar. After some practice, you can do some difficult ones. These are younger children who have chronic hydrocephalus and these, the membrane becomes thin, really transparent. You'll see that thing. In the previous one, it was an acquired hydrocephalus because of the tectil plate tumor. It was translucent, but this is transparent here. This is the dorsum cellae. We're trying to puncture with a three-four inch, a four-four inch and a five-four inch. Nothing happens. It's pretty transparent. You think it's pretty thin. Nothing is, it's not puncturing. These are the cases for the first 10, 15 cases, please abandon. You can, because this is dipping down till the mid-clivus. They're arachnoid. So we tried with the five-four inch. All the time going towards the Basilar. We tried with the bipolar as well. But after some cases, the simplest thing which we realize is rather making punctures. It is to just give a slit over the dorsum cellae. The moment you give a slit because this membrane is already tense, it just slips back. Slips back and it starts flapping there and you can see the second membrane as well. And you can see the second membrane as well. And the flapping is yet not come because the CSF pathways have not yet opened. The moment you open it and you see the flapping there. Now you have to dilate it and your dilation, like I previously said, it is, there's hardly any space there. The moment you're putting a balloon, keep, start withdrawing it. Always fill your balloon with water or celline, I'm sorry, but not with air. Fogarty is, and cardiac enol is all right, but in neurosurgery, because what happens is if you're just putting in, putting in air, your balloon dilates in asymmetric proportions. When you're putting in celline through that, it is asymmetrical and a slow dilation. What we want is a slow dilation. These were the aqueductoplasties which we used to do 10-12 years ago. We don't do any more because once you learn a procedure, you want to go with your endoscopes everywhere. So, but when you start having literature complications, your own, because you're, yeah, we used to do aqueductoplasties, this is the third vindiculostomy. Then we used to bend our scopes back, put in, reach the aqueduct. These are clear-cut indications like membrane stenosis or membrane, or an aqueductal membrane which you can dilate. And these are clear-cut indications and that can be possible. But yes, you don't need to put stents now, now literature has gone against stents. That is an aqueductal stenosis. We used to put a Fogarty, dilate it, put some stents earlier, not doing any more. Why I'm showing this is, this is something that should not be done. So, how do you know that it is technically good? Your flap starts, your second membrane starts flapping, it's a signal. You must do a regular circumference measurement. Serial series scans are not required, but early series scans followed by a slightly delayed MRI scan will be six months down the line. The hole you have made, you must see the CSF flowing on a T2. We'll have a senior film showing that. This is something very, we always, when we do thermodynamic last means and some people who are already doing them, we realize that small kids, you do a thermodynamic last mean and after a week or two, the head is still big, the fontanel is still level, it's not tense and you have a double mind whether my thing is not working and you'll read literature to start doing lumbar punctures, lumbar punctures and don't do all that. Because if it is not functioning, it will not function. You cannot make it function. You have to just withhold the child there with you, do not discharge. If the fontanel starts bulging and if your pseudomeningoseal start not frontal and your wound starts bulging, there's pseudomeningoseal there and the first drop of CSF if it leaks. So that is the sign that it is, there's an absorption failure, please do a shunt. These are the small things that you must note. A 10 to 50% reduction of ventricular size, disappearance of a peri ventricular ooze, presence of a CSF flow on through the through the ostomy area, straightening of the floor of the third ventricle, resolution of the suprapinular third or the posterior third ventricular recess and prominence of the sulci. This is something, this is a very, this is something that you have to note on your CT scan or MRI that the peri ventricular lucency disappears. The ventricular size is the same. The child is better but and the sulci and gyri are better seen and on a third three month MRI you can see a CSF flow. That was an aqueductoplastia as well we did. When does ETB fail? This is a very important question. ETBs fail. They can be nearly failure because of the absorption problem usually within the first four weeks but they can fail till five years. An ETB which does not fail till five years never fails. So the longer you have a follow-up, the longer the chances that your ETB will not fail. That is very important thing that you have to keep on following up this children or these adolescents for at least five years when you are doing rare failure has been reported off to five years. So the etiology is the most important predictor. Previous meningitis, myeloma ninglesil, shunt infection, previous shunt, malfunction. So what are the complications? Third ventricular ostomy is not without complications. This is something that is you cannot prevent at all. This is not preventable at all. CSA absorption failure. You have to do a shunt. What are partly preventable is that is something that you can do and CSA of leaks, meningitis, tomaclosure, gliosis. Don't use monopolar or bipolar when doing a thermal claustomy. There will be gliosis, natural reaction, a difficult perforation. Totally preventable is something that directly related to your skills. A second membrane perforation you must see. You must not be happy with only one membrane and this is damage to a hypothalamus or thalamus or injury to a basilar artery. Wherever in doubt you're putting an endoscope, put convert into a shunt. Shunt is a gold standard. Believe me. Yes, you can, by doing a third ventricular ostomy you can prevent repeat shunts and maybe 30 to 80 percent of your patients will be cured forever. So what is the plan? When you have a patient with hydrocephalus do a third ventricular ostomy, follow him or her for the next five years. The patient is unwell. Do an MRI. If the CSA flow is there that means your ostomy is not functioning. Do a VP shunt. If it's not there you can explore again. You can plan to do a redo if there is no stoma is closed but if the stoma is open that means you're good but it's not your fault. It's nature's. So there's not too much of difference statistically till now between shunts and and and ask me. But yes, there has been over the last several series throughout literature. Average success is 22 percent to 94 percent depending on etiology. Overall around above 90 percent. We have our share of publications from our department. Overall the ideology is that post meningitis, post myelomeningosil, post infectious, post hemorrhagic, the range has been 20 to 40 percent success. Pediatric, less than one year comes down to 40 percent. One to two years is between 40 to 60 percent and more than two years it's comes around about 80 to nearly 100 percent. There's some series with 100 percent. So it doesn't necessarily even you should plan it. Thank you. Endoscope is something very remarkable. It gives you a better vision. What you could see in a racnoid system all in colloid cysts. Yes, the gold standard is micro surgery. We have largest series in the world. We have nearly 78 cases out of that 45 to 48. I have none myself. But still after doing everything then you realize that the residual cysts throughout the literature. We have around about 18 percent residual cysts and out of them maybe we have operated three of them. I have operated one. My colleagues have operated another two. So you cannot remove the complete cyst nearly 20 percent. In the early part of your experience maybe 25 percent, 30 percent. Later on you can come down to 18 percent. Now over the last two years my residual cysts have been practically nil because I'm selecting my cases. Even in large ventricles if you have a colloid cyst you have to select your cases on the basis of the MRI. Do not take calcified colloid cysts with very bright and hypo and T2 and these retro projecting colloid cysts. These are the cysts which you can plan. But if you plan them well, if you select them well then your results can be 100 percent. Because that's another problem with colloid cysts. You cannot just put your scope into the caucus point and take it out. You have to plan on the MRI because your attachment is here. Your attachment is not here. So you have to put your scope in such a manner around about four centimeters in front of the coronal suture that you are actually seeing the back of your cyst. That is where it is adherent to the corret flexes and adherent to the internal cerebral veins. That is the reason why the subcoroidal and supra coroidal approaches were defined. So that you can enlarge the form in a monorho by a micro surgical approach and remove those retro projecting cysts. Retro projecting cysts you cannot just put a scope through the form in monorho and pull them out. You will damage the patient or leave the cyst behind. It will be better to leave the wall behind than to, we else walls do not recur but yes in our series three of them have have recurred. Go from the larger side and this is something we've already talked here. Even if there is a similar dilation and you can see central septum polycytum, look at the corret flexes where you can see more of the cyst medial to it. You can punch up that it there. These are nice cysts to operate colloid cysts. If they are projecting into the septum polycytum they are one of the variants in they hide the form in monorho down and they are projecting into the septum polycytum. They are very good micro surgically and they are very beautiful by endoscopy. You can just cut over the septum polycytum and aspirate the cysts because they are not projecting into the form in monorho at all. The form in monorho is hidden and that's the corret flexes. You can just aspirate these cysts. What you can see and visualization is much better. The only problem is bleeding. If you have some bleeding from the corret flexes areas you have to, may have to convert or have to wait for some time. Once you start aspirating you start seeing the form in monorho. Never coagulate at the wall because that's the wall. The wall will be always adhering to a single or a bilateral corret flexes. Keep on gentle aspirating on the cyst wall. That's the colloid that you have to take out. If the colloid is thick you can take a biopsy forceps and break them in portions. Then you have to with the new system the lotus system you can catch hold of the part of the capsule. Coagulate the the corret flexes and by holding it and cutting it with sharp dissection that's the only way to remove the cysts even micro surgically. Just imagine if now this form in monorho is open because the cysts come up. Had the cysts been projecting down like this so you could have seen this portion but not this portion. So you couldn't have pulled it out. So that is the reason why the micro surgical approaches like supracooidal or subcoroidal approaches have come in. You should only attempt on colloid cysts if you have done at least 20, 25, 300 minute glass meets. You deliver it like a gall battery you deliver because it's pretty so now we can we can finish