Welcome to Module 4, The Role of Surgery. So, in the previous three modules, we've focused more on normal sinus anatomy function, how to treat and manage acute and chronic rhinosinusitis from the medical side. This module will focus on surgery. And for those viewers, we'll be also having some surgical video so you can see intraoperative views of what we do, actually, during a sinus case. So what are the presumed benefits of surgery? One is to address the structural issues that we can see in certain patients who fail medical management. The CAT scan can tell us is, there a cell or a polyp that is blocking the sinus opening, that's potentially increasing that patient's risk of developing infections? Second is to enhance delivery of topical therapy to the sinuses. We've touched on module three the importance of topical steroids, topical saline irrigations. By opening the sinuses, we allow a better delivery of that medication into those cavities. And third, to reduce the disease burden by the removal of osteitic bone, as well as to allow the drainage of infected material from the sinuses. Allow that inflammatory and infectious process to hopefully be relieved and treated. So, what do we code patients? There's an approximate 90% success rate with Functional Endoscopic Sinus Surgery in those patients who meet the indications for the procedure. What we mean by improvement is that, in the setting of asthma, we see in patients who suffer from chronic rhinosinusitis, sinus surgery doesn't always just help the sinuses. We see also an improvement and better control of their asthma. In this patient, they looked at 891 patients. There was an overall improvement in asthma control of 76%. And the frequency of asthma attacks decreased to 84% and decreased steroid use was seen in 64% of patients. Now what are the indications for surgery? Greater than three infections per year, failure of maximal medical management which we touched on in module three, that we suspect an extrasinus spread of infection that needs to be addressed. A complete sinus obstruction with expansion, even in a patient who's asymptomatic, if we see complete obstruction of that sinus in the expand cell process, relieving the pressure and draining that sinus is important, even if they're asymptomatic. And lastly, if there's a suspicion for a tumor, especially if a CAT scan shows a unilateral process in a patient in the right age group. The suspicion of tumor should be entertained and surgery should be considered. So we talk about sinus surgery, we use the term Functional Endoscopic Sinus Surgery and we say that all the time to our patients, but what is it? It's essentially a way of doing surgery where we enlarge the natural sinus drainage pathways. When you see in this picture on the right, the sinus drains at the top of the sinus, here, in this region. What used to be done traditionally, is that we did not know that the sinus drainage was in this fashion. No matter where you create an opening, the cilia within the sinus will move mucus toward that natural opening. So what happens is what we used to create an inferior medial antrostomy, make an opening in a nice low location, let the sinus drain more easily. But even though you think since it's at the floor of the sinus and this opening will be more useful, the sinus does not care. It will actually send all that mucus around that opening and still up through the natural one. So Functional Endoscopic Sinus Surgery is taking that normal opening and enlarging it. The last thing is, it also preserves normal mucosa within the sinus. Initial thought was that if we see disease or infected mucosa just remove it or strip it from the lining. The problem was that new lining would grow back and the cilia density in that new lining was less than what there was in the first place. So you took a sinus that was already infected, removed the lining, and now gave it new lining that's less functional than the original. So one of they key concepts is actually preserving mucosa, not removal. So take a patient like this who has an obstructed maxillary sinus that you see here. They have an outflow obstruction in this region. And you see inflammation building up within the sinus. What we do with sinus surgery is we essentially take down each one of those areas, the bulla, the uncinate process, and enlarge that natural draining pathway while at the same time preserving mucosa. You see this very thin rim of mucosa over the bone. Very important to preserve that to help retain function. And, that's essentially what the goals of sinus surgery are, to enlarge the natural openings and preserve the normal healthy lining. The surgical components of the procedure are one, maxillary antrostomy, two, ethmoidectomy, three, sphenoid sinusotomy, four, the frontal sinusotomy and last advanced procedures. When these initial four are not successful, sometimes we have to go to more extended procedures in order to enlarge those openings even further. The lamellar system is in our understanding of embryology helps us perform a more systematic functional endoscopic sinus procedure. If you look at the turbinates here, more specifically the middle turbinate, and we remove it. You see that the sinuses lie just lateral to it, here each one of these lamella, or vertical partitions serves as an anatomical boundary that help create a very systematic surgical procedure. The first one is the uncinate process. Second, the anterior face of the anterior face of the bulla. Third, the basal lamella which is the vertical attachment of the middle turbinate. And fourth is the face of the sphenoid sinus or the vertical attachment of the superior turbinate. By going through each one of those lamella and doing that in an inferior location, we preserve the integrity of the skull base until we get to the sphenoid sinus. Where in the sphenoid sinus, that helps us find the skull base and then move at a posterior to anterior direction up to the frontal sinus area. So, finding the skull base in the sphenoid at its lowest point is the safest area. Once we do that, now we can move from back to front, towards that frontal sinus. And you can see the skull base has a very gradual slope to it. This slope can be in variable degrees in different patients. So that's why it's always important to find that skull base within the sphenoid sinus. Also preparation, probably the most important thing prior to any surgery is what you do before entering the operating room. Preparing yourself and seeing, are there any anatomical issues with respect to that patient's CAT scan or internal anatomy? And we see in this picture here, the patient who has a haller cell which is what's called an infraorbital ethmoid air cell, it's an air cell that aerates along the floor of the orbit. This patient also has multiple air cells on the left side, and removing each one of those cells, as well as each one of the partitions here in a ethmoid cavity is critical. Because, over time if you don't open up this cell or that cell that area can be trapped, and form over time what's called a mucus seal which is an entrapped area of mucus that is unable to be drained in the surgical issue. The other structure to keep in mind is this thing right here. This is the anterior ethmoid artery. And you can see here we talked about in the lamellar system, we kinda go from back to front along that skull base. Well the anterior ethmoid artery lives at or below the skull base. And if it's below the skull base as in this patient, what we want to do is make sure we don't cross it and injure it in any way, cuz that can lead to a complication or an orbital hemorrhage. So in that case, when we work along the skull base, we'll skip underneath it, preserve the bone around that blood vessel, and then reestablish our dissection at the skull base. And by far the most important step in a functional endoscopic sinus surgery is the removal of the uncinate process. Now in this schematic drawing here you see after we remove the uncinate, what that does is it tells us here is our maxillary sinus. It also tells us where the medial orbital wall is. The significance of that is that this is the lateral limit of our dissection. By keeping the orbit in view, it makes sure that when we're cleaning the skull base here, we're as lateral as we need to be. The reason why is that the roof of that dissection, as we talked about in module one, is very thick frontal bone, a much safer roof in order to avoid any inadvertent injury to that overlying bone. In addition, by finding the maxillary sinus, the roof of the maxillary sinus is a landmark for the sphenoid sinus. The sphenoid sinus as we talked about gives us the roof of the skull base. And by finding the roof we now follow it anteriorly to the frontal recessed area which is located here medial to the uncinate process. So by removing the uncinate, it tells us what's a safe way to dissect an ethmoid. That tells us where the maxillary sinus is. It also tells us where the ethmoid sinus is, and helps direct our dissection within the frontal. After we move that uncinate we go sinus by sinus. The first sinus to be addressed is the maxillary. Now what's critical is many times we're using a zero degree scope. And the maxillary sinus is a structure that's located off to the side, or laterally. And whenever we're doing a maxillary using a 30, 45 or 70 degree endoscope is important in order to look into the lateral aspect of that sinus as well as the floor, to make sure we're not missing polyps, infection, mucus. Something that could be left in the sinus that could be missed by using a zero degree scope. Also you want to irrigate the sinus to obtain any cultures. Because the sinus extends down to the floor of the nasal cavity, if your opening is up higher you want to make sure any dependent mucus that's hanging by the floor is irrigated and flushed clean. Because if it can't get out in surgery, it will not leave that sinus after. And also, extended maxillary openings are sometimes necessary in the patient where they have a disease process where the sinus is dysfunctional, despite performing a functional endoscopic procedure. In those cases, creating a large opening or an extended maxillary opening may be necessary. Now in this video we touch on a patient who has a very severe acute rhinosinusitis. And it's important to see how to handle a difficult case, one where the uncinate and the opening is not as obvious. As you see here, we're using a 30 degree endoscope, initially a zero, in order to take down the uncinate process. And divide it into two pieces, the superior and an inferior portion, with the back biter. Once that's done, we can now help identify where that maxillary sinus ostium is. It will always be at the junction point where the superior and the inferior uncinate meet. Once we have found the osta, now we remove the uncinate in its entirety and enlarge the maxillary opening posteriorly with straight through cutting instruments. Once we clean the sinus, we've been using a zero degree scope, but now moving to an angle scope helps us look into the lateral aspect of the sinus and see a polyp along the roof of the sinus that we may have missed. So frontal sinus instruments can here be used to remove those polyps. But the point is that whenever doing a maxillary, putting on an angle scope is critical in order to make sure you haven't missed any pathology located laterally or inferiorly within that sinus. So what about the ethmoid cavity? Important to palpate behind bony partitions. What we mean by that is the partitions along the ethmoid are attached at the roof. The roof slopes from posterior to anterior. So if you can feel behind the partition, you know that the skull base is about where you are and that partition is safe to take. And it sounds mindless, but it actually is a very critical component of how to do an ethmoidectomy. You also want to know the skull base height, and that's something you know based on your pre-operative imaging, as well as identifying the skull base sphenoid. Third, that anterior ethmoid, we talked about that. We want to make sure, is it dehiscence, or is it protected by bone at the skull base? And as we touched on, must clear all partitions. Here's an example of an inter-op review where we're cleaning out the partitions, palpating behind bony partitions, and using a microdebrider, a powered instrument, to remove redundant mucosa. And once we do that, we once again feel behind those partitions, as you see here, and keep removing them. And we do that sequentially until we arrive at the skull base. So, a third dissection in clearing out every aspect of that ethmoid is critical, cuz the reason why is you want to start out with a patient like this where the entire ethmoid cavity is filled with polyps. And hopefully in the office see them once they've healed where we see a open ethmoid cavity. Here that medial orbital wall will be showed in that schematic. And the skull base completely cleaned from the sphenoid all the way through to the frontal sinus. So before, and after. You can see how topical therapy irrigation can now more freely enter into that sinus. How we can suction a culture of sinus in the office in order to see, does a patient have a bacterial or fungal infection there? So a good clean out, removing all those partitions. Preserving all the normal structures and lining helps the cavity heal just like this. What about the sphenoid sinus? The sphenoid sinus is the one located all the way in the back. And they're multiple landmarks that can be used to help us identify where that sinus is. Because sometimes there can be isolated pathology within the sinus and we can go straight back and take care of that without opening other sinuses in the process. So some of the landmarks we use are, the ostium is at the level of the roof of the maxillary, like we touched on in the previous slides. We find that ROOF, now we know the level of the ostium. Also the ostium is 10 to 12 millimeters from the rim of the choanae. Very easy to find the choanae, most frazier suctions are three to four millimeters in size. And you gradually just palpate along the choanae up until that point of 12 millimeters, and you'll fall into that sphenoid. But falling into that sphenoid should not be done with the suction, cuz you risk traumatizing the mucosa. But using a freer elevator is probably the best way. Working medial to the middle turbinate, the visualization is poor, and the ethmoid is another great way to work in a bloodless field. Using that freer like we talked about, to slide into the ostium and dilate it. That way you can allow larger instruments to enter, and open up the sinus more fully. And entering the sinus with a suction tends to avulse mucosa and hurt what we're trying to achieve which is preserving normal mucosa. Lastly you always want to irrigate the sinus. Irrigating the sinus that sphenoid is also dependent on flushing out any mucus or polypoid debris from the bottom of the sinus. That dependent portion is where you're going to have the most problem right? That sinus was not strong enough to move mucus from the bottom all the way up to the opening. So really flushing and irrigating that sinus effectively is critical. This is a patient who had sphenoid sinusitis, there was persistent refractory seen as a good bony opening. And this was a patient we performed an extended sphenoid sinusotomy on. Here we're taking down the bottom of the superior turbinate, identifying a contracted left sphenoid sinusostium. Opening it up with a that you see here. Using the microdebrider to remove any redundant tissue and debris. And here, we're just taking partitions up to the skull base and making a large wide opening. This is a mushroom punch, which allows us to actually enlarge that opening a little bit further by 360 degrees. So a nice instrument to bite a different direction without having to come in and out of nose to replace the instrument. So you can see here, this sphenoid sinus tells you where the skull base is, and then we just trace that forward toward the frontal recess.
