 So, this is my checklist of endoscopic procedures and I try to and it's very important to check before you begin with your surgery that everything with the endoscope is well functioning. The nurses they have a lot of experience in dealing with the microscope but I think they have less experience than dealing with the endoscope and so the responsibility is in you to say that everything is fine and everything is functioning and if you are in the ventricle and you have a problem with the endoscope and the equipment you cannot go in and out and in and out this is too dangerous. So before beginning with the procedure assemble the endoscope and the camera that means look for the focus look that you have the white balance look that the orientation of the camera is fixed and that 12 o'clock is 12 o'clock 6 o'clock is 6 o'clock look for the suction and the irrigation systems what we have learned to that we have to irrigate all the canals because after the sterilization of the endoscopes there may be some agencies in the canal and it can result in an aseptical meningitis so try to irrigate all the canals and it's really helpful and we saw that. Ensure that the drainage canal is open because you always have a free irrigation via a tube and if the irrigation canal is closed you have an increase in the in pressure so you it really can result in a metriasis. Ensure clear visualization and illumination before surgery look for the light cable that is not black that is optimal function provide here video recording system and there was one story it was I think was in Netherlands or something like that mostly the camera and the recording system they are switched like this that that is a loop so from the camera it will go to the video system and then to the monitor so the monitor shows you that what the endoscope of the video system shows you and so there was in this story the surgeon began a surgery and he said please record my surgery and the nurse she not pushed the buttons for the record but for play and so the surgeon saw the surgery of the last procedure yes and he was there's the for a monorail for a monorail and then he was about 10 centimeters in the ventricle that means he damaged the brain stem so look for it that it's work and and these are things they can happen and there happen if you are in the ventricle and you're disorientated go backwards to saw the landmarks in case of hemorrhage do not go out don't assist and go out with the endoscope stay there irrigation and look what is and what can I do if you're going out you will never find the source of the bleeding again yes if the ventricle is full of blood you will never find this site again if if you are in doubt or if you cannot reach your goal abandon the procedure don't force anything and be prepared to perform a craniotomy if necessary so I show you some examples this was a young lady 18 years and she presented as an emergency case with with headaches in some days and what you see she in the city scan the the ventricles are enlarged you see some hypodensia around the ventricles and you can estimate that there was a kind of a tumor and the MRI shows the tumor of the talamus and occlusive hydrocephalus so what we planned was you see here again the tumor the enlarged ventricles and what we planned was tumor biopsy and the ventricle ostomy what you do first the tumor biopsy or the ventricle ostomy first three the enlargement first three hydrocephalus yes if you have a bleeding after the tumor biopsy you will never reach a ventricle ostomy so first plan the ventricle ostomy and then the the tumor biopsy and so the optimal trajectory to do the the ventricle ostomy would be for Ram Monroy and the flow of the third ventricle and the optimal trajectory to reach the tumor is this trajectory so you have to choose a burr hole in the middle of those twos and this is the video so you see we're in the lateral ventricle the coreate plexus leads you to the forearm of Monroy yes and you see you are in between those targets the target for the ventricle ostomy is here and the target for the tumor is here but you can reach with this intermediate burr hole you can reach both and both targets so the first thing is to perform the ventricle ostomy and we also perforate we try to perforate with this Fogarty catheter and then dilute you see basilar artery here memory rebodies and you see the pulsating and that shows that you have a successful ventricle ostomy we are using in some cases the the monopolar to shrink the floor that the ends will not come together again and that you have no scarring which which can glue the stoma again and you see there's no other membrane and so you have reached your your ventricle ostomy now going for the biopsy and sweet it bleeds but it was not that much so with the coagulation we could reach a gotemostasis and this is postoperative image in some cases we are doing a small graniotomy it's only reach a better cosmetic if you have it it's very near to the friend of you have a bar head and you see the burr hole always yes and if you're doing a graniotomy and replace it with some granular fix holders you do not have these burr hole so it for cosmetic reasons it may be sometimes better to use a graniotomy and you see the ventricle size and the tumor still is stable it was the astrocytoma create two tumor and still stable disease very basilar in the front and this is the video you see the forearm of monoe and now going in the third ventricle and you see aqueduct is here so this is inferior this is superior you see here the cyst and you see this is the roof of the third ventricle you normally do not see it by doing a ventricle ostomy but here you can see the roof and i'm in favor of using these coagulation so we did a perforation some perforations and then we cut with a scissor to perform a wide opening of the cyst you see this wide opening and you can go in the cyst but you cannot control the opposite part of the cyst so it would be too dangerous to do another opening here but this anterior fenestration is sufficient and now you see again the aqueduct and you see it's it's wide open now the post-op image you see the cyst is collapsed the aqueduct you see a flow in the aqueduct here and this was the burr hole here as planned before and in this case we covered it with a with a PMMA bone cement this was a young boy one and a half years with a macrosephalus and some developmental delay and he also had some episodes of nausea vomiting which were more frequently and so he developed in the last days before the presentation he welled it regularly and opistotonous and he came like this and one saw beside the macrosephalus the enlarged ventricles and the typical signs of a supercell assist with a with this cystic lesion so typical sign of a supercell assist this is the video it was a pre-corona approach on the left side and you see the cyst is bulging into the lateral ventricle you see it's overlapping the borders of the foramen of monorail and the first thing we're doing is to shrink the cyst and you see the the foramen is becoming more and more free and you have a good control you see what is on the other side again the fenestration with a scissor and we shrink these borders of the cyst and the treatment of a supercell assist we do this fenestration to the superior part of the cyst and we try to perform a ventricleostomy as well and you see the the the membrane is very very bulged into the pre-apontine space and you see this is ocular motor now there was ocular motor nerve and there was the the abducent nerve and we were not able to to cut this this because it was bulged inside but working along the clivus as Dr. Sui said is a good technique and now we saw there is another membrane here along the clivus so the ventricleostomy is not done yet and you see there is one membrane here so it was like this and we have to cut in this direction close to the abducent nerve which came in view there is abducent nerve here and this was too small for a permanent ventricleostomy so we tried to dilitate it with a fogatica theta and you see we're working away from the abducent nerve to the midline while inflating the balloon and now we had a good opening of both uh membranes this is the window to the now third ventricle and looking for to the fornix there are no contusion it looks good no bleeding in the ventricles inspection of the canal there are no bleeding and okay