 So, what are the differences between the microscopic and the endoscopic approach? The microscopic approach is still the gold standard, it has good to excellent results. The microscope is a familiar visualization tool for the neurosurgeon and you have this binocular depth perception that means you have a 3D dimension. With the endoscopic approach you have the improved visualization due to a better illumination of the surgical field. You have this panoramic view and you can see on this slide. With the microscope you can always have a good access and a good illumination along the spiculum. With the endoscope you have this panoramic view and if you're using angled endoscopes you even can see more to the side and above and below. So you have this panoramic view, you can use the angulation of the scopes and you have a better maneuverability because with the spiculum you are fixed and with the endoscope you can look around. So the idea of the endoscopic approach first is that you can avoid complications that are due to poor visualization and it is not always possible to see the carotids with a microscope but it's always possible to see it with the endoscope and to see a structure that means you can be work safely on a structure. And another step is that you can with the endoscope it's a step to more extended procedures that means you can deal with pathologies you cannot deal with a microscope with. This is the technique as said the endoscope is put at the 11 o'clock position and you're working along the endoscope with a binostral or mononostral approach and there are some special instruments necessary so most of them are coming from the ENT surgeons they are not known by a neurosurgeon but you need these instruments to work in the nose. You need a special bipolar forceps because if you're using the common bipolar forceps you cannot open it in the depth and if it's too narrow the tips are cruising and you cannot work with such a bipolar so they are all so-called shaft instruments working through a shaft and you have to use the best video system that is available for optimize your visualization. These are as shown the angled scopes and we are using at least for the first step the nasal step such a irrigation and suction sheet that means you have a handpiece you have a irrigation and a suction canal and you can control the irrigation with a fingertip. There are special items you have to consider before start your first endoscopic surgery. Once I have to which is very important for me this is a training program and it's styled by the CASAM group and this makes a lot of sense and this is really important to go from one level and if you're safe in one level then go to the next level if you start with an extended that means an intra-dual procedure you will get lost because you need more than one hour for the approach afterwards you need more than one hour to reconstruct the scalabase so go stepwise and in these extended procedures it makes a lot of sense to have two teams that mean one team for the approach one team for the tumour section and then the first team for the reconstruction of the scalabase because after a surgery of five six hours standing like this and you're really exhausted and it makes a lot of sense to do it with a second team. What is very important is the prioriative image we do in all cases a high resolution CT scan to look for this the individual anatomy that means for some deviations for some spurs at the nasal septum to look for this finoid septis and then with these images you can orientate during during the surgery you see these kissing carotids this is on one side a very elongation to the medial part of the cavernous part of the carotid and if you have this on the other side as well you have this what we call kissing carotids that mean the carotids are almost coming together in this part yes and you have to know it before surgery sometimes it's very helpful to do a three-dimensional reconstruction of the CT scan this is an example and you see you have your optical canal and then you have an additional form what is it it is what we call a carotico-clinoid bridge that means there is the medial clinoid have a bony bridge to the anterior client and so the carotid is fixed very still in this area and you cannot mobilize the carotid if you see it in a plain CT scan it's not that easy to interpret it and so if you're doing a three-dimensional reconstruction you clearly see the structures and you know what about the situation is and most workstations of the CT scanner they can do these reconstructions it is said about the steps of the surgery these is in a cadaver dissection so there is no blood and it's more easier to follow you see first look in the nasal cavity you see the inferior terminate you see middle terminate and you see the nasal septum now going down going along this angle and you will reach very easily the koane with a tubal elevation and the nasal pharynx so this is the key landmark at this at this stage and now lifting up the endoscope you see the attachment of the middle terminate you see superior terminate here and you see the ostium here and so what you will reach is the opening of the anterior wall of the sphenoid sinus and you can do it in different ways you can first begin to enlarge the ostium on one side then enlarge it on the other side and then go for the midline you can begin in the midline and go lateral you can start while enlarging one ostium crossing the midline to go through the other ostium it is depends on the individual anatomy if you have a septum deviation it may be easier to come from the from the wider side of the nose to do this in the first steps i think it's easier for the beginners to begin when opening both ostias and then go to midline because then you have reached the lateral borders if you begin in the midline you have the intention not to go as far as lateral as you have to go so it's easier to start lateral go medial then medial to lateral because maybe you're not that far enough lateral and this is shown in in this dissection so this is left side now there is the septum inferior terminate superior terminate and first you see the ostium is enlarged and so you have the first view in the sphenoid sinus here this is colibus this is cellar flaw and then right side again superior terminate middle terminate sometimes it's necessary to remove the posterior part of the superior terminate which is possible and now after the enlargement of the ostias you perforate the midline there is an area of very low resistance and you can very easily push the septum over there remove the mucosa you see the mucosa of the contralateral side is still intact and you can remove it with the foreseps but best with the drill because the rostrum is a very stiff and hard bone and after that you're incisized the contralateral mucosa and from this step on you can work bilaterally you see you have one instrument the angioscope in the right nostril and you have your instruments in the opposite nostril and the same with the drilling you have angioscope in one and so the maneuverability is better while doing it with a binostril approach always remember that you're coming from below to above and you have to deal with this area i've shown these slides before i show you now some videos some interoperative videos only the the tumour section nasal stage we have seen in the cadaver dissection you see this is the opening of the cellar floor sometimes it's very thin and you can break it you open it with a punch and you see now these are the four blue lines here there's corona sinus on both sides and we also did a horizontal incision with a diamond knife in this case the diamond hook was a little bit it was not not that sharp so you can also use scissors and we do it in a horizontal and then to the side so you have an inferior flap and then the cut upwards so you have also the superior flap what i always try to do is first to come extra capsular that means you have very safe area in the inferior part and the lateral part and you have good control if you first go to the dorsum cellar and then go to the lateral side to free the tumour you see you go in between the sheet of the pituitary sac this is the the meningial layer of the cellar you see there's intercavernous sinus in between those two layers so first free the tumour in the inferior part there was some septiles you have to cut depending you need sometimes really a sharp dissection along the tumour margins and we are still extra capsular and then if you have a good orientation you can do an inoculation of the tumour not push upwards against the the not push the the tumour against the chiasm then first you have to do an inoculation and there you see there is pituitary here and the tumour is very stiff connected to the pituitary so you really have to to to make a sharp dissection along the the rim of the pituitary there's a diaphragm here and there were those septiles you have to cut and you almost often can see where is the pituitary in the in the preoperative MRIs and because of the consistency of the the tumour it was at parts it was very soft and other parts it was very firm and I think with these extra capsular dissection it's more likely to to remove the whole tumour then do it with a curret from inside you see this is pituitary this is dialkenate and in this case because there was some CSF rinsing we put this this abdominal fat we do not use it in all procedures only if we have a minor CSF leakage this is pre and postoperative image pituitary function is normal and this is in the case a macroadenoma patient presented with a visual disturbance and you see there are two critical structures there's one here there's a part of the tumour which seems to be extra dual this part it may be that this part also is intradural and meanwhile this was the surgery three months ago and you see the opening of the swine rate we do it in macroadenomas now a little bit different we try to create a flap and the bone still is covered with mucosa so you have the bone and the mucosa as one flap the last lamella you can break with a hook or with a small punch and then you can flip the whole flap down you have to widen a little bit in this case because it was not wide enough with a punch to reach the four blue lines and then again a horizontal incision and again try to to keep in the first stage extra capsular and separate the tumour from the dura and for this you need a bimanual dissection so you have the approach must be wide enough to not to interfere with the instruments you really have to do a safe bimanual dissection the creating of an inferior flap and then you can work along the wall of the cavernous sinus to free the tumour in the first step it's not that hard the tumour but in the first step you can and then you do the inner creation then you gain a lot of space and then you can the tumour came down these are the same principles like in operating meningioma for example yes but these are safe areas and and it's a pity to to leave some some remnants at this place so if you so and sometimes it ends in in a let's say the common technique with a curret we do not forced to do it really extra capsular but but the part which which are safe i try to to first keep extra capsular and you see here is the pituitary there is the diaphragm here if we cannot find the pituitary then we do it let's say the common style but at the beginning i try to to keep extra capsular and you see you have a good overview this is lateral wall of the of the pituitary or the the middle wall of the cavernous sinus this is the direction to the dorsum with these close up few you have as you say the good control of the tumourous section so there were no csf leakage and we only put some jail form in you can use these flaps to to cover it and then this is the bone flap put back on the approach in this case we placed some jail form above but meanwhile i would use search itself only one layer of search itself with blood it has a good gluing function and and so nothing else and in this case only one layer of of jail form this part is a small part which seems to be a residual tumour so the surgical technique we begin with a ent surgeon and we learn a lot we have learned a lot of techniques and tricks from the ent surgeon so you need a really an experienced surgeon and an ent surgeon or two experienced neurosurgeons to do this procedure because there is a team of a pilot and a co-pilot and they have to work together there are four hemispheres working together and they have to be familiar with each other what about the reviews up to now the endoscopic versus microscopic technique this is about yeah 2011 meanwhile there were some new reviews but at this time the total resection rate and the endocrinological normalization was more or less similar in endoscopic and microscopic technique with the endoscopic technique you have an increased rate of csf leak because you have this good and excellent visualization and you you try to force to remove everything and so the risk of the csf leak is a little bit higher but on the other hand with the endoscopic technique you have an improved resection control especially in the super cellar tumor extensions and in the lateral tumor extensions to conos two tumors and we have less nasal complication less blood loss decreased incidence of post-op diabetes in zibitus decreased time of surgery and decreased time of hospital stay so in summary the endoscopic transnasal approach to the pituitary is a feasible and effective technique in the treatment of pituitary adenomas you need an experienced team you have to use special and sophisticated instruments and you have this learning curve and not only for yourself but also in the team and it's a step in gaining experience to more extended surgical procedures and my personal prediction is prediction is that the future studies will show that the results of the endoscopic technique is at least as good as with the microscopic technique and that's the morbidity will will decrease only some words to the extended procedures these are all meningiomas the frontal meningiomas and you can all do them via an endoscopic or via a transcranial approach but there are only some signs you have to consider in your in your decision you see this is a not that much that that large tumor but there seem to be a lot of edema around the tumor and doing it via a transcranial approach it may be that you have to force a little bit the the retraction of the brain so a lot of edema maybe the Agu for a transnasal surgery this which is a planum sphenoidalum meningioma you see it have a huge dual tail so this is an Agu against the transnasal approach you can do that but you also can do it with a as well maybe better with a transcranial approach this is a small meningioma of the tuberculum cellae and you see that the optic nerve is superior to the meningioma so you have to deal with the inferior and medial part of the optic and this is a good Agu for the transnasal approach because you first see the tumor and you have on the safe side the the optic nerve and the neurovascular structures and again this was a Cordoma and you see what is the best approach for this we think it's to the nose because this is the axis of the tumor you're coming through the nose with the endoscope and you're working especially in the axis of the tumor yes and so the axis and the extension of the tumor is also important for the decision-making so this was a young lady operated on a planum sphenoidalum tumor via a transcranial approach some years ago and she had a recurrent tumor at the tuberculum cellae here and in our opinion this is a good case for a transnasal approach and so we went for a transcranoidal approach you can see this is floor of the cellar, colibus, tuberculum cellar and the planum sphenoidale so the tuberculum is removed the cellar floor you it's not necessary to remove this is the superior intercabular sinus yes planum sphenoidale and so the opening of the dura you see the chiasm here and you have really a good overview of the infra chiasmatic area and what you see here there were some tumor infiltrations at the pituitary stalk and you cannot see them on the MRI so it was surprising for us and you would never see this via a transcranial approach yes and it's not that difficult to remove these parts so for these cases it is a good technique to come or a good idea to come from the from the inferior root and it was a soft tumor so it's it's not that difficult to remove it and after surgery after the resection the urinate mostly is intact you see the the superior hyperfusil arteries they are running in the urinate and this is the flap to cover it so factors for our decision making belonging to the size and the extension of the tumor brain edema encasement of cerebral arteries that means if there is a cortical cuff or not also of the consistency of the tumor if you have a calcified meningioma it would be very difficult to remove via the transcranial approach relation to neurovascular structures if you have a dual tail in in in meningiomas and what is the axis of the tumor if if you're working a long one axis and the axis is from above to below so it will be a good good approach for this the advantages of the transnasal surgery you have in meningiomas an early divascularization of the tumor you have the possibility to remove as well the the bone of which may be invaded by the tumor you have no brain retraction by removing such a tumor depending on your planning you do not have to cross neurovascular structures you have an early optic nerve decompression if coming from superior to a let's say tuberculum cell meningioma you have to lift the optic nerve which is stressed due to the tumor and so you may harm the optic nerve coming from below you do the an early decompression of the structures so the infarachiasmatic area the infirmedial aspect of the optic nerve is excellent for visualization and you have a better control of the very important superior hyperfusil arteries and the paranoid membranes the disadvantage is that you have the need for a sophisticated dual reconstruction you have nasal injury and the we were talking and discussing this morning we are very aggressive in doing extended surgeries some years ago and now we are a little bit more reluctant than rebalancing what is the best approach because creating a flap and removing a terminate this is not without mobility and the patient have really may have some problems with this you have a risk of infection you have a prolonged operative time again especially in these cases you need two teams you had difficulty control of pile tumor vascularization you have no visualization of structures lateral to the mid orbit and you have a poor visualization of the superior lateral aspect of the optic nerve so this was published in neurosurgical focus this meaning yoma you can remove and they did really a good job but these is not without mobility in the nose so patient they will have problems and if you're doing with a small granule to me they have no no risk for csf leak and surgery will maybe half half of the time like this thank you