 This is just a pictorial view of the anatomy, because all of you are now using endoscopes. You are familiar with the anatomy, but to have a three dimensional picture in your mind is important. I will not speak much, I will just show you different images from different aspects, so you can have a form and an idea in your mind that when you inside the ventricle what you are going to expect. So it is important when you are operating upon a ventricle anatomy, especially when you inside the ventricle everything looks you are in a cavity. So unless you have in your mind an idea about where you are you get lost, it is very easy to get lost in the ventricle. So just go through these pictures and try to find a sort of a three dimensional idea about what structure you are dealing with. So these things, these are all taken from different text books which you have already seen somewhere and all. So I do not need to speak much, this is a size section, this is a superior view of the various structure you have already seen in a different coloured format. Same thing, I will just spend some time so you can have an idea about what you are looking at when you enter the ventricle. You see this anatomy differs the different sections, these are the sectional atotomy at A, B, C and D, temporal lohn, occipital lohn, middle of the body, the frontal lohn and how it looks different. When you enter the ventricle it may not be an endoscope in the, while you are doing a trans-colosal approach, interim is very, sometimes it is very easy to get confused which ventricle you are in, right or left. Also you have to add an idea about how to identify right or left, so this will help you in that thing. Same thing, this is a superior view, so the structures which can help you identify where you are a two import structure, one is the chloride plexus or as the veins, ok. Coral plexus always leads you to the phenomena of monorho and then the veins. The major weakness of the lateral voile of the ventricle, when you talk about sub-coroidal, this is the coroidal plexus. So this is attached to here somewhere, this is the lateral ventricle going to the third ventricle. You have to dissect here, you have to retract this, this coroid plexus and then go, but most of the times we are not using those approaches. So this is how it looks like, the same thing, the different recesses will be already infundibular recess, laminar terminal is the chiasma, this is the endoscopic view of the infundibular recess, mammillary bodies and where you make a third ventricle occipital. This is how it looks like. This looks better in the pictures than in the graphs, I do not know why, but it looks better in the pictures. It is the same thing, vagal trigon, hypoglossal trigon, the area of the stream, sulcus limitants, facial colliculus, ok. This anotomy which you have already seen has to determine the, decide the approaches to the ventricle. This is from roton. You see when you enter the lateral ventricle, where you want to enter depends upon which tumor or which areas you want to approach. The approaches used for anterior lateral ventricle will all of you are using are, one is a intramusperic approach, other is through the middle frontal gyrus and the frontal lobe through the frontal lobe. The choice of approach, you will have to decide depending on the, where the maximum projection of the tumor is and more important than your familiarity with the approach you are using, ok. So lateral ventricle normally we enter into the frontal lobe either by an intramusperic approach, usually anterior and or through the middle frontal gyrus. What is the problem when you enter intramusperic approaches, you have to be careful about the bridging veins. Sometimes your ideals may not be possible because the bridging veins come into view. So that will determine your approach anterior and intramusperic. And sometimes because of there are so many veins, you may have to abandon the procedure because you have damaged those veins, you can have problems. So that is important. You see what is important? So once you open the temporal horn and see the colloidal plexus, that leads to the colloidal fissure. And you have to open that fissure and once you open that fissure, you have reached your medial limit of the hippocampus. Okay, you know if you go beyond that you are likely to damage perforators from coming to the posterior communicating artery. This is important to know the colloidal fissure. Other important thing to know about colloidal fissure is do not retract superior to the colloidal fissure. If you retract, you will do damage what section? That area, thalamus lies there. So do not retract there or be very gentle at it. So this is why you should know where the colloidal fissure lies. So this is your medial limit. You have to open the rachnode there and then try to nucleate the hippocampus from all the sides. This is what is being done here, the same thing I have shown you. If you breach this rachnoid, then you see these vessels. So the idea is to know these vessels are there and not breach the rachnoid once you are doing it. But this is only for people who are doing epilepsy surgery or you are operating with tumors in the middle temporal lobe. And the same thing what I talked about is being shown in this one. So colloidal fissure is an important landmark. It must be important to know what is safe. Beyond this is unsafe. This is what epilepsy surgery we are talking about. So these things are just various ways of antigen. I mean there are so many avenues which will, this will depend upon what pathology we are dealing with. So there is nothing much to discuss about it. So you can enter into a ventricle from various ways. So you have to know what is a safe area depending on the tumor or the lesion you are approaching and what the venous not mean this area. So these are all commonly used approaches for entering into a ventricle are either a frontal as they are like this or like this or sometimes in the temporal lobe. We are talking about lateral ventricle. This is the same thing shown in a different way. And sometimes when you are not going intramasphiric or to the middle frontal gyrus you can do sometimes trans-cellulose also depending on where the tumor is pointing. This is anti-intramasphiric. Posterior intramasphiric nowadays is rarely used. I mean the classical trans-closal approach Posterior is rarely used nowadays except for that finally in tumors it is not used for entering into the ventricles nowadays most of the times. Is the anti-intramasphiric approach or the trans-ventricle approach? Sometimes yes. Sometimes to enter into the temporal horn especially on the non-dominant side you may have to do a small anti-intramasphiric also. Sometimes it is safer to do a lobectomy rather than retracting if you want to enter into the temporal horn a non-dominant side. For approaching this area of the brain this is the posterior part and sometimes your lesions are in the medial part of the occipital lobe. So the posterior intramasphiric is occasionally used for this thing. The advantage of the occipital lobes they are hardly in the bridging veins there. So that makes your job easier. So in otmium as a third ventricle you have already seen normally most of the times we enter a third ventricle through a phonomer of Monroe. You enter into one or other lateral ventricle and then enter through a phonomer of Monroe because most of the times when we are entering the phonomer of Monroe we are entering in a pathological situation where it is already enlarged, okay. But ideally if we are doing an ideal approach with no distortion on otmium the ideal position of the third ventricle will be through the septum polysodium. If you are able to remain strictly in the midline you will be like this. You are septum polysodium. You will not be opening each lateral ventricle through the septum polysodium and enter into the roof of the... Then you reach the roof of the third ventricle. Then you do an interfurnishable approach and enter into the third ventricle. This is the most least invasive but for that it is usually not possible in pathologies because there is a distortion. You usually enter one of the lateral ventricles then through the phonomer of Monroe enter into the third ventricle. There are many procedures described how to enlarge third ventricle. I usually don't do enlarge. If you have to think you have to enlarge you have to change your approach because you may damage the phonics or damage one of the veins. If it is not already enlarged with a tumor it is better not to try to enlarge it artificially by cutting. I know in the textbooks they may describe you entering the posterior part as you cut it but it is always better to avoid it. So this you decide depending on where the tumor is pointing and your experience whether you want to go transclosure or transcartical. These are just showing a diagram of DTI images showing different tracks. There is more for fun rather than practical use but I mean at present I am not using these things for planning massage. It may be helpful for people who are using DTI regularly in planning their approach and doing interoperative monitoring of the tracks and all those things. So this is again pros and cons of each approach. This is the same thing as I said. Then you can enter here or here or here. Sometimes you cannot decide after you enter you will decide which side you have entered. Then the correct Texas and the Salmos side will help you. And ideally if possible it is very beautiful. So once in a while out of four or five times you will enter into the middle. Then you see such a beautiful anatomy here. You are very happy to see then if you want you can enter both the sides. The remaining in the midline is an art and you want to go into the midline you will feel much happier and you have a better non-automobile view of what you are doing. Sometimes you see both the ventricles then it can be retrospect. You see both the ventricles then you identify the midline. So this is just the same things again. For example, I mean theoretically or even practically sometimes left side is better view from the right side but in generally I will always like to plan from a non-dominant side. Of course the extent of the tumor always determines your approach. But it is that you have a better view across tangential view. So left this side tumor is better seen from this side. This is the standard. The incisions I am not very strict about which incision ideally should be. That is your decision. Some people use this incision. Some will use a small incision. Some people I mean that is your decision. But in general these are standard description for a bicoornal incision for a trans-closal approach. And of course your angle this is an endoscopic. These are the different what I was talking about. So many incisions we used. So this is no right or wrong. The word I am saying this is no right incision or wrong incision. This area is broader. This may be you may have a canotomy like this also. You can have a canotomy like this. You can have a canotomy like this. So you don't need any exposure here. Only exposure you need is here. And this length is determined by your veins. The determinant of this length is veins. And nowadays initially you make one burhole. Either you make mid-burhole or it's contralateral burhole or two burholes. But nowadays because everybody is using it on me one or two burholes is sufficient. But even now, even when I am using drills and microtome sometimes I make two or three burholes in the midline. Safety is always better. Sometimes if you have a large I would prefer to make two or three burholes on the midline or across the way rather than have a damage to the sinus. So that is not a concern. Common approach which is using and these are just what I talk about. You can leave this vein along with the dura. You can leave this strip of dura, open the door here and then you can find corridors. And have patience. If you have patience, once the seaside starts coming out, coming out you will get enough space. I think corpus clausum, God made only for neurosurgeons to split. So we keep on splitting the corpus clausum and going where so many procedures we need to by splitting the corpus. So this is the same thing seen from different point. And one must always be aware that all of us have seen phonics as a single thick bundle. Sometimes there are variations in the phonics also. Phonics can be flat. It may not always be bundled. It may be flat. So be aware that whenever you are trying to do subcoroidal or interphonics approach, there can be variations in otomy. Have a look at MRI before if you are trying to do that. The specialized approach is subcoroidal or interphonics. Anatomy in various views. I mean endoscopic in otomy and gross in otomy. This is the subcoroidal approach we talked about. Thalmosad vein, coroidal. This is the subcoroidal approach. And this is that sitting position. We use sitting position for this approach for lesions which are small and below the tendorial edge, okay. Because this is the area where the veins are usually superior. So this is supposedly a better a vascular, avoiding the veins of the vein of gallin and all those things. And the only thing which you have to careful about this approach is the racnod here is different from the racnod in any other place in the brain. A racnod is very thick here. So you have to be careful while opening the racnod you may damage some of the veins because the racnod here is very thick even normally. I am very fond of this approach because I think this is the best approach for a posthumous and ventricle region that you have to decide because this gives you maximum access. You can cut the tendorium, you can cut the fox and have a full approach access. I prefer this approach for most of the posthumous and ventricle tumors which needs surgery to an open approach. There are two positions described. One is the park bench or lateral position with the operative side down. And this is prone. This is the standard description of this position where you may not be on the downside. Otherwise the lobe falls away. But some people including me prefer a prone position and you can tilt the table tilt the table to one side. And it's easier to make that position easier for the patient for the anesthetist and for surgeon. I am a personal advocate of a prone position for this thing. Because we are good tables you fix the patient and then you turn one side. And you cut the tendorium to have a view at the along the side sinus. Parallel to the side sinus you have a view below the tendorium and if required you can cut the fox and see the legions of the body side down. So fourth ventricle you can either enter the fourth ventricle by splitting the vermis or if the legion is more inferiorly you can just you can just without opening just inferior medullary vellum is there. You follow the vellicula the lift of the tonsils and enter the tumor. But sometimes in medulloblastoma when you have large tumors it may not be possible to do it but there is no harm in splitting the vermis. Just trying to go and damaging anesthesia is also not required. But most often this is okay. This is the second the transfer maybe it is routine. So I will just show you endoscopic endoscopic endotomy. This is how it looks like. All of you have seen this. This is a diagrammative representation of what it looks like. Mammulary bodies infundibular recess the fluorescent ventricle same views end point of ETV nice ETV done.