Our first presenter today is Dr. El Wahhabi from Morocco, Rabat University, and he is going to talk to us about management of large vestibular schwannomas, how to improve facial function. Dr. El Wahhabi. Thank you, Mr. Chairman. Dear colleagues, first of all, I would like to thank the organizing committee for giving me this opportunity to share with you my experience regarding the management of large vestibular schwannoma. Okay, thank you. As you know, the primary and the gold standard of treatment in large vestibular schwannoma reminds today surgery, and the aim of surgery is complete tumor removal with preservation of vital structures. But the surgery is a challenge because of high risk of facial nerve injury. Radiosurgery is not recommended for large lesion associated with brain stem completion. And in this large schwannoma, the house Bruckman grade 1 or 2 has achieved in only 50% to 60% in CUS4 after tumor removal. The question is, can we improve the facial nerve function in this large tumor? We reviewed the literature, and you can see that in major cities that treat large vestibular schwannoma more than 3 centimeters, CUS4, the range of facial nerve function preservation is around 40% to 70%, 80%. And even in large cities of Professor Msami, as you can see that the grade 1 was achieved in only 25% of the patients. That means that we try to look for a new strategy protocol to improve the facial nerve function. And the last decade, it has been a shift from radical surgery to less aggressive surgery by subtotal removal and combined treatment with radiosurgery. And we are going to share with you our experience during the last 20 years. We went through the same protocol, starting with doing radical surgery in our patient, and then the last seven years, we shifted to less radical surgery. And our material consisted of 146 patients that harbor vestibular schwannoma grade 4, of course. All of them were treated by retro-sigmoid approach, and what's important to say is that in our experience, the incidence of large vestibular schwannoma is very high. Almost all our cases we treated are very large tumors. And we divided our study in two groups. The first group, we did radical surgery the last 20 years, and then from seven years to now, we changed to subtotal removal and gamma knife radiosurgery, and we compare the results regarding the fascial nerve preservation. And you can see that the clinical presentation in this large tumor is very particular in the way that we are treating a very bad condition patient. And you can see here that almost all the patients had Karnovsky less than 80% of the patients. And that means that we are dealing with patients very sick, and presenting of sign of intracranial pressure with hydrocephalus with 40% of the cases there are lower nerve cranial nerve palsy, and even in one-fourth of the patients, they have preoperative fascial palsy. So the MRI finding in our study, you can see here that in two-thirds of the patients, the tumor was extra large. That means more than 40 millimeters. And we found in our study that there are three bad factors, prognostic factors for function preservation. The extra large tumor, when the tumor is cystic, and if it's accompanied with hydrocephalus. These three factors when are associated, they predict a very poor prognostic factor for functional nerve after surgery. The surgical procedure, we operate almost all of our patients with park bench position, and we reserve the semi-sitting position for the cases with tumor that's extra large, especially when the tumor is developing upward. And we operate all our cases with the conventional retrosigmoid approach. And when we go through the surgical procedure, I will not go through all the details because of the time, but... Sorry. Can you go to the video, please? Yeah, just... Just click the... Okay, okay. Yeah. No, no. Click the actual slide. Go to the middle. Okay. Okay, thank you. So the tumor removal, there are some steps. I will not go through all this detail, but it consists of first to aspirate some CSF from the angle to make the CSF depletion, and then the tumor bulking using ultrasonic aspirator, C-SER curate. And the second step is to try to make a capsule dissection with conservation of arachnoid plane, and we have to protect the lower nerves. And the normal monitoring is very important to identify the fascia nerve, and you can see that we are trying to dissect the capsule. And this is the end of the surgery when we can remove all the tumor, except you can find some cases where there is some adherence of the tumor with the fascia nerve, and in this particular case, we have to lift a residue on the fascia nerve to preserve this fascia nerve. But in other cases, you can go to a complete removal if there is no risk for fascial nerve injury. And this is some illustrative cases. The first case we treated, it's a patient presented with hearing loss, intracranial hypertension, and cerebellar syndrome with a preoperative fascial nerve paralysis. And you can see on the MRI that there is a large cystic vestibular schwannoma. We can achieve the total removal with anatomic preservation of the fascial nerve, but unfortunately, the postoperative outcome regarding fascial nerve function was bad because the patient developed graft-4 Hodgkin-Bruckman paralysis. The second cases we show here, it's a very young patient who presented with CP Angle Syndrome with right deafness, non-fascial Percy, and we operated him by retro-sigmoid approach. We can achieve near-total removal, but we left behind the intracranial residue. The postoperative course was uneventful, and the patient had fascial function graft-2 which recovered to graft-1. And six months postoperative MRI, you can see that the remnant is here and the patient is following. And we can propose this patient for adjuvant treatment by radio surgery. The results in our series, regarding first the completeness of tumor removal in radical surgery group, and you can see here that we can achieve a total removal in 82% of the patient. The total removal was achieved more common in solid than cystic tumor. And we can see here that the anatomic preservation of the fascial nerve in our series was around 81%. And the fascial nerve function, we obtained a good fascial nerve function, grade 1 to 2 in 58% at one year. And as I said, fascial nerve function is better in solid than cystic tumor in our experience. So the question is how to improve fascial nerve function preservation in a large vascular sphenoma. And you can see that today, the best fascial function result achieved with modern microsurgery techniques is around 30 to 85% to have grade 1 to Hauss-Brackmann after total resection in major reported series. In the recent meta-analysis of large vestibular sphenoma between 1985 and 2011, we found that the fascial nerve function grade 1 or 2 reported in 65% of the patient. And the fascial nerve function grade 1 or 2 is better in subtotal than in total resection, and you can see 92% versus 47%. So can we improve the fascial nerve function preservation in a large vestibular sphenoma? What are the opto-therapeutic options? The first opto-therapeutic option is to make a complete tumor resection and wait and scan protocol. But we know that there is a high risk of recurrence, mainly in young patients, and the risk of tumor recurrence is 12 times greater for patients with a subtotal resection. The second option is, and you can see here that if you leave a remnant, the percentage of growth is between 30% to 70% in the literature. And this is a case that has been followed with progression of remnant in our city, 2007 near total removal, 2014 recurrence. The second option is to make a complete tumor resection and radius surgery, and the rationale for that is that in small vestibular sphenoma, radius surgery can achieve a tumor control rate between 90% to 98% in literature, with the risk of facial paralysis less than 200%. Is it a protocol of choice? We decided to move and to shift to the second protocol by treating a second group of patients with combined treatment, which we called nerve-centered approach. 35 patient grade four, of course, were treated with planned subtotal removal and gamma knife radius surgery. And you can see here that the results regarding the housebrockman and facial nerve function is grade one or two was achieved in 91% of patients at one year. There have been a lot of... Have been a lot of... This is illustrative cases. We operate a patient with planned subtotal removal and the radius surgery, and the patient is followed for one year. There is no recurrence. And there have been a lot of papers for this combined treatment, and in a recent meta-analysis, you can see that the functional facial nerve grade one or two can be achieved in 82% to 100%, and there is also some chance to preserve hearing. And the tumor control in this combined treatment is around 79% to 100%. So we think that this protocol could be a solution for this large vestibular schwannoma, but there is some difficulties to this protocol. The first is inadequate resection. Sometimes optimal is not intracapsular, and you can see here this is the patient that has been treated with neurosurgery, but you can see that it is just partial removal, not subtotal removal. The second problem is when we go through excessive resection, there is a risk for damage of the first seventh nerve, and of course the learning curve is necessary to perform adequate subtotal resections. Today there is no randomized study available to compare subtotal removal versus subtotal and gamma knife radius surgery. So in conclusion, large vestibular schwannoma represents a formidable surgical challenge in severely disabled patients. Bad prognosis factors for fascial nerve function are extra large tumor and cystic schwannoma. In large vestibular schwannoma, planned subtotal removal, resection, and post-operative radius surgery is a logical strategy to preserve fascial nerve function, but there is a need for longer follow-up to evaluate results from gamma knife and the risk of recurrence. And thank you very much. Thank you. Thank you very much, Dr. El Wahabi. I would just like to ask all the speakers to stay on the course of their 15 minutes. I think our next speaker, Dr. Eid Bashir, Location and Course of Facial Nerve and Vestibular Schwannomas. While he is preparing, I am going to ask just for one question from the audience while he is preparing. Dr. Omefti, I believe, has a question. Oh, thank you. Could we discuss? Microphones are on, sir. You're presenting a congratulations for working with this monstrous tumor, but you're presenting here a very concept that needs to be discussed, too. You're presenting that deliberately. Before you operate, you will operate with the intent to not remove the whole tumor, subtotal removal, and with the intent to give radiosurgery afterward. Now, I do have a very several problem with this concept altogether. Number one, you're deciding to stop even if you don't have to stop. Right there, you're depriving the 50% of the patients from being able to cure their tumor forever, and they still have a good function of the facial nerve, because that's what you had, 50% preservation with total function. So that's one problem. The next problem is, when you give the gamma knife immediately after surgery, and when you did not give gamma knife and you just observed, the control are the same. So to rush giving the gamma knife with residual automatically, there is no basis for it. I understand that you could go on those giant tumor and find yourself you're not able to remove everything. That's what happened with your cases. And then you've been left with a small piece because you do not want to, can't resect anymore. And then you observe that piece to see if it's going to grow. That's happened to all of us. But before you go in, decide that I am going to just remove a part of the tumor, and I'm going to automatically give the rest of the part a radiosurgery. I'm very troubled with this. All right. Response, Dr. Al-Wahhabi? Yeah. I think that you raise here a very important question about the distinction between trying to go to total removal and starting the surgery with planned subsural removal. We went to that conclusion after, as you say, for 20 years and also when we see the large series of the literature. Even in skilled hands, the percentage of facial nerve palsy is around 25 to 30 percent, and only 75 percent of the patients are grad 1, 2. But if you go to this group of patients, there is less than 25 percent that has grad 1. That means normal function, even in skilled hands. So the idea was at one year's, at one year's, So when we looked at the literature, this kind of protocol started almost 10, 20 years ago. And when we applied it, we found that we improve the function of nerve in postoperative period and at one year's. It is true that the question is when to stop, because sometimes you see that tumor can be taken out. This is the big question. There are two criteria, either electrophysiology criteria, when you are stimulating with 2 milliampere, you see that you are around, the thickness of the capsule around 2 to 3 millimeters, and also from anatomic observation, microscopy. But still, there is a problem for that point. I agree with you. When should we start? This is a big question. Thank you very much. I'm afraid we'll need to move on.

Dr. El Wahhabi

large vestibular schwannomas

facial function

surgery

radiosurgery