PETER GAILEY: Welcome. And thank you for joining us for the future of facial nerve care for patients with complex parotid tumors webinar. We're glad to have you with us today and look forward to a great discussion. I'm pleased to introduce the speakers for today's webinar. Please join me in welcoming Dr. Jacob Dey, a facial plastic and reconstructive surgeon and an expert in facial reanimation.

Dr. Eric Moore is a head and neck surgeon and expert in managing complex parotid tumors. Thank you both for joining us today. And with that, I'll turn the presentation over to you.

JACOB DEY: Great, thank you. And thank you all for taking time out of your evening to join us as we discuss the future of facial nerve care for patients with complex parotid tumors. I'm Jacob Dey. And on behalf of myself and Dr. Moore, we really look forward to sharing information about this topic that we're very passionate about. We have no disclosures and no financial conflicts of interest.

Our hope this evening and with this webinar is to share information about how complex parotid tumors are thought about and managed and how their treatment can often involve involvement or injury to the facial nerve and how we approach the reconstruction of that. We also hope to highlight our innovative model of care at Mayo Clinic with our complex carotid tumor facial nerve multidisciplinary practice where we help patients with tough complex parotid tumors to both maximize their cancer treatment and to optimize their facial nerve outcomes.

An overview of our topics. We'll start by talking about parotid tumors and then give a little background/information on facial paralysis. And then we'll use a couple of cases to highlight some of our innovative approaches to treating these complex tumors and reconstructions. So with that, I'll turn it over to Dr. Moore to discuss parotid tumors.

ERIC MOORE: Thanks, Jacob. And thanks to everybody for joining us. The last century saw the majority of the development of how we modernly think-- treat and think about parotid tumors and the facial nerve within the parotid gland. The first facial nerve preservation and removal of a parotid tumor was in 1907, and it was very unlike what we do with most parotid tumors today.

It was done under local anesthesia. There was poor classification of the different tumor types at that time. And there was largely an enucleation of the tumor, recognizing that the facial nerve was nearby and trying to bluntly dissect around that. There's been-- then very rapidly after that, a couple of key recognitions. One, that that technique led to a high recurrence rate and so an interest in trying to more completely resect parotid tumors.

But also the separation, anatomically, of the parotid gland and what we today colloquially describe as the lobes, based on the fact that the facial nerve runs through the parotid gland, separated into a superficial portion and a deep portion. Those portions that are lateral to the facial nerve and those portions of the parotid gland that are deep to the facial nerve. At our own institution, about 20 years after that, was a nice description of the fact that most parotid tumors could be removed by superficial parotidectomy.

That's because the majority of the gland sits lateral to the tumor. But for those tumors that were more aggressive, those tumors that sat deep to the facial nerve, or those tumors that were known to be highly malignant, complete parotidectomy with preservation of the facial nerve was possible. The fact that the facial nerve is so intimately in play in parotid gland surgery is nicely outlined by this.

This was a study 10 years ago, looking at a decade and a half of medical, legal complaints related to salivary gland surgery. And there were 26 medical legal cases that were pulled out of Westlaw in the previous decade that involved the salivary glands and salivary gland surgery. Of those 26 cases, 9-- 16 of them involve the parotid gland, but 9 of them involved facial paralysis that occurred after parotidectomy.

And I point this out just because it's intimately important to the patient and very important to the surgeon how to identify and protect the facial nerve during even routine parotidectomy. So how do you do that well? I think it starts with both good image study and just anticipation of where the tumor is going to lie in relation to the facial nerve. So I'll show some examples of how I typically do that based on common imaging techniques and how to anticipate and predict where the facial nerve is going to sit, and what's its relationship going to be to the parotid-- to the parotid tumor.

Specifically, is the tumor going to be above or deep to the facial nerve, or is there going to be tumor at the stylomastoid foramen that's going to make identification of the facial nerve in the classic ways that we do it difficult. You need an organized identification technique of the facial nerve and then you need an atraumatic technique. So this CT scan on the left side shows a cross-section, or axial view, of the parotid glands.

And most importantly, it shows two vessels that sit basically at that 2/3, 1/3 lateral and medial junction of the parotid gland. Because you can't see the facial nerve well on imaging studies, you need a surrogate marker for where the facial nerve is going to be. And the retromandibular vein and the external carotid artery as it courses through the parotid gland are a great surrogate marker.

So I try to look at how much gland is-- or how much tumor is sitting lateral to those structures, or is the tumor sitting medial to those structures. And that gives me a rough approximation of whether it's going to be a superficial or a deep lobe parotid tumor. The view on the right just shows the facial nerve with the dissected superficial parotidectomy. And again, it shows those vessels that sit very, very close to the facial nerve.

So the retromandibular vein and the external carotid artery sat just behind the facial nerve and are a good surrogate approximator for it on the imaging studies. So this is then, again, an axial CT scan. And the parotid gland on the patient's left side, or the right side of the view, is deep to that surrogate marker, deep to that external carotid artery as it courses through the gland.

The majority of the tumor sits medial to that marker. So you can anticipate that this is likely going to sit also deep to the facial nerve. Knowing that ahead of time allows you to have a really great discussion with the patient on what's going to be involved in facial nerve dissection to remove their tumor and gives the surgeon some advanced notice of what they're going to have to do to approach the tumor and how they're going to have to manage the facial nerve.

And then how do you identify the facial nerve during parotid surgery? This is a review for most people, but it always is-- bears repeating to point out. The facial nerve, you can go ahead and advance the slide there, comes out of the stylomastoid foramen. And that stylomastoid foramen is not visible, typically, during parotidectomy. But what is visible is the tympanic ring mastoid tip groove.

So that green arrow there is showing the junction of the tympanic portion of the temporal bone and the mastoid portion of the temporal bone. And that tympano mastoid groove, which you can see and feel during parotid surgery, leads directly to the stylomastoid foramen. What's the significance of that? Advance the slide there. That ring and that groove is going to be a great approximator for the course of the facial nerve.

So as the facial nerve comes out of the stylomastoid foramen, go ahead and advance the slide there, it has to course across the mandible to get to the mid-face and innervate the muscles of facial expression. So that tympano mastoid groove and the parotid gland directly anterior to it is a great approximator for where the facial nerve is going to sit during parotidectomy.

Again, in this patient, you can see the sort of depression up by the ear between the mastoid tip and the tympanic ring. And if you draw a line directly anterior to that depression, that approximates the course of the facial nerve trunk. How do you identify the facial nerve during parotidectomy? Well classically, you do trunk dissection and then follow the nerve anterograde out through the parotid gland.

But sometimes you're not able to do that because of where the tumor sits. I'll show you some examples of that. And you have to perform retrograde dissection so you have to find the facial nerve, most commonly the inferior division, as it courses over the facial artery and vein at the notch of the mandible. That's a good place to identify it distally and then follow it retrograde back to the trunk.

Or you can follow the frontal branch, or the zygomatic branch, back to the trunk and get to the facial nerve that way. And finally, sometimes when the tumor completely surrounds or encases those structures, you'll have to identify it within the mastoid bone or intratympanic identification. For classic trunk identification, we teach find that tympano mastoid suture line or groove.

That gives you the rough horizontal, or superior/inferior location of the facial nerve trunk. Identify the tragal pointer, which is a portion of the tragus which forms sort of a triangular point which points right to, again, that tympano mastoid groove typically and leads you to the trunk as it exits the stylomastoid foramen. Find the digastric muscle because where the digastric muscle inserts into the tympanic ring then that gives you the depth.

You can go ahead and advance there. So here's a classic example of a tumor that's sitting in the deep lobe but that you can still use those techniques to find trunk and dissect anterograde. So we've identified the trunk on the right side at that tympano mastoid groove where the trachea pointer points and we followed that anterograde out through the parotid gland to lift the parotid gland up.

And then we're seeing the pes anserinus or the superior and inferior division that courses directly over the course of the tumor. Most parotid gland tumors are benign. Identification of the facial nerve correctly and with those techniques allows you to see the relationship of the gland-- the gland and the nerve and the tumor. And then most of the time, you can bluntly and carefully dissect the tumor off the nerve, or the nerve off the tumor in this case, and preserve it quite nicely.

Here's another example of identification of the trunk. Lifting the tumor off the trunk and the inferior division and the pes anserinus with the parotid gland with atraumatic technique, allowing you to preserve the facial nerve carefully. And this is the total superficial parotidectomy again. Where the tumor and the gland have been dissected off, the nerve and the superior and inferior division, leaving that basically pristine and untouched with careful blunt technique.

But careful identification of the facial nerve is the key to that. Here's a case where it might be a little more difficult to dissect in the classic trunk fashion. So this is a deep low parotid tumor. Again, from this axial scan, we see it sitting deep to the external carotid artery and retromandibular vein as they course through the gland. I wasn't able to identify the trunk because the majority of the tumor is set directly on top of and over the trunk.

So I dissected the facial nerve out distally and followed it retrograde over the tumor. And then once I could see the entire facial nerve, could dissect the tumor off of it. Next slide. Here's an example of that. There's the tumor on the left, sitting intimately associated with the trunk. This schematic gives you a view of what we're looking here. The trunk is coursing partially over, partially under.

The tumor with the tumor surrounding it. And once we've identified the facial nerve distally and traced it back to the trunk, then we can carefully dissect the tumor off that facial nerve. Again, most benign parotid tumors and even low-grade malignancies, are not intimately associated with the trunk where you can dissect them off. And finally, here's a patient that's going to be impossible.

We'll get to this, again, later on in the talk with our case example where it's going to be impossible to identify both the trunk, or really the distal segments, very well because the tumor encases all of them. And this is a case where we might drill out the mastoid bone and identify the facial nerve intratympanically and then follow it out distally to the stylomastoid foramen to gain our bearings.

JACOB DEY: Great. So I just want to give an overview about the facial nerve and facial paralysis to kind of lay the groundwork and the foundation as we approach these cases and thinking about facial reanimation. So as many of you know, the facial nerve is a seventh cranial nerve and has very intricate and complex anatomy. It exits the skull base and goes through the temporal bone.

Sorry, it exits the brain stem at the pontomedullary junction, goes through the temporal bone behind the ear, exits through the stylomastoid foramen. And then as you saw from many of those pictures with Dr. Moore, goes through the parotid gland, dividing it into deep and superficial lobes, making its first branch point at the pes anserinus into an upper and lower division and then five main facial nerve branches.

And then it just continues to branch and branch and branch, as you can see from this diagram here. And it goes to innovate, or drive, all of the muscles of facial expression. And that's complex. There are about 20 muscles on each half of the face that help us make facial expressions and blink and move the mouth and smile. And that's one of the most important functions of the facial nerve, but the facial nerve has other functions that we don't always think about including.

Special sensory functions and parasympathetic functions. There are many sources of injury to the facial nerve. And in my practice, I see a lot of patients with facial paralysis. And the most common cause of facial paralysis is viral injury to the facial nerve, such as Bell's palsy or Ramsay Hunt. But other common causes of facial paralysis include tumors along the course of the facial nerve or tumors of the facial nerve.

And commonly those are in the parotid gland, which is the focus of this talk, or skull-based tumors. And there are many other causes of injury to the facial nerve. When there's been injury to the facial nerve, clinically that presents as facial paralysis. And this is my framework for thinking about facial paralysis. When I see a new facial paralysis consult, I like to place the patient into one of these four categories because it informs me on what their likely symptoms are and what the treatment options are.

And so I think you can take any facial paralysis patient and put them into one of these four categories. So the first category is complete flaccid facial paralysis. So all of these patients have paralysis on their right side. And so this woman has a complete flaccid facial paralysis. This is what happens after a facial nerve is initially injured. It presents as flaccid paralysis where there is ptosis of the face at rest, and it's characterized by lack of muscle movement.

Depending on the severity of that injury, it can either be complete or incomplete, which is our next patient category. Again, this is a type of facial paralysis characterized by lack of facial muscle movement, but it's incomplete. So this patient is still getting some degree of facial movement. It's just not as much as the other side. Our next patient is a good example of another category of facial paralysis, which I call Aberrant Reinnervation Syndrome, or ARS.

And so any time a facial nerve is injured, like I said, the initial presentation of that injury is going to be a flaccid facial paralysis. However, if the facial nerve remains intact or if an injured facial nerve is reconstructed, it has the ability to regenerate, which is great. But sometimes, depending on the severity and location of that injury, that recovery of facial function, that reinnervation and new axonal growth, doesn't necessarily happen in the correct way.

And that's what aberrant reinnervation syndrome is. It's patients presenting with facial synkinesis, facial muscle tightness or hypertonicity, and facial muscle spasm and twitching. It's a very bothersome subtype of facial paralysis, but a very different subtype than flaccid. And then the last category is a patient who has had injury to the facial nerve, followed by recovery, and still has components of facial muscle weakness.

So still has an incomplete flaccid facial paralysis, but also has components of aberrant reinnervation syndrome. And I think it's important to note that a patient can evolve over the course of their injury and recovery through many of these different subtypes of facial paralysis. So if a patient has a severe injury to the facial nerve, they can have initially a complete flaccid facial paralysis and then progress and recover over time to incomplete flaccid and then recover even more but maybe develop aberrant reinnervation.

So this is the framework that I use in my mind when I'm approaching patients with facial paralysis and trying to figure out what treatment options are available. So then when we talk about treatment of facial paralysis, the real-- sorry. The treatment is facial reanimation. And facial reanimation, for me, is an umbrella term. It describes numerous non-surgical and surgical treatments that we have to treat patients with facial paralysis.

Now the ultimate goal of facial reanimation is to improve facial symmetry and facial function in patients who have facial paralysis. But it's a long list of things that we have available. And this is a list that's constantly growing as we innovate and we understand more about facial nerve injury and recovery and develop new techniques to further improve facial symmetry and function for these patients.

So with that background, Dr. Moore and I will go through a couple of cases here that we've worked on together in our complex parotid tumor facial nerve multidisciplinary clinic. So that's a clinic we're very excited to have here at Mayo and Rochester where, for these patients with really complicated parotid tumors that have either caused a facial paralysis or are all wrapped around the facial nerve and are threatening the facial nerve, we can work together as a team.

So Dr. Moore as the head and neck cancer surgeon with expertise in parotid gland surgery and myself as a facial plastic surgeon with expertise in facial reanimation. And then a host of others who are part of our team. Radiologists who are specialized in head and neck radiology, pathologists who have years and a lot of experience in parotid gland pathology. Which as Dr. Moore will talk about, has many nuances to it.

Radiation oncologists, medical oncologists. Important to help me and the patient with recovery of facial function is facial physical therapy. We have a great nursing team and care coordinators and then can involve, as needed, ophthalmologists and speech language pathologists and dental specialists. So we really have the luxury here of a broad team of experts that we can call upon to help patients with these complex tumors.

And ultimately our goals are to optimize the cancer treatment, with a goal of curing the patient if at all possible, as well as maximizing facial nerve outcomes. So we're working to give each patient the best facial function possible and working as a multidisciplinary team. And kind of the magic of Mayo Clinic, I think we're able to provide really well coordinated care for patients and give them world class care and an elevated patient care experience.

And it's really, for me personally, also just fun to work with such talented colleagues in all of these areas as we approach these difficult problems. From my perspective-- so I do a lot of facial reanimation. But I think these cases are some of the most challenging cases when it comes to facial reanimation because the amount of injury with some of these tumors to the facial nerve can be extensive.

And we're not just dealing with facial nerve reconstruction but carotid bed defect reconstruction. And some of our common options that I would call upon for facial reanimation may be off the table because of the tumor. And so I think to approach these cases from a facial reanimation standpoint, you really need to have all the tools available to you in your toolbox.

And so with that, I will turn it over to Dr. Moore to go through a case.

ERIC MOORE: So there's a number of ways that the facial nerve can interplay with parotid tumors and there's a lot of different situations that can happen. And that makes treatment of parotid tumors extremely challenging and also extremely rewarding because as Dr. Dey mentioned, you have to have a whole lot of potential tools at your disposal.

And as much as we try to anticipate and predict what we're going to encounter and then plan out how we're going to adequately rehabilitate it, you can sometimes run into situations intraoperatively even, that you didn't anticipate, that can cause you or require you to adjust on the fly. But here's a case example that we treated that illustrates a whole bunch of the nuances in parotid tumor and cancer interplay with the facial nerve.

So this is a 48-year-old woman who had a history for parotid surgery for the most common carotid tumor that you can acquire, which is pleomorphic adenoma, a benign tumor in 1990 in California. One of the reasons that we tell people that they need to have pleomorphic adenoma treated, even though it's a benign tumor, is that it will slowly and inexorably grow over time.

So it can go from a small tumor to a medium sized tumor to a large tumor to an enormous tumor, if left alone. But the other reason that we tell them that they need treatment for parotid tumor is because it can transform into a malignant tumor, as we'll see here. So this patient developed a recurrent mass in her parotid gland 10 years after undergoing treatment because it was a recurrent tumor and a benign tumor and she'd already undergone previous parotid surgery.

Revision surgery is more complex. Revision surgery puts the facial nerve more at risk. She decided to slowly-- to observe her tumor over time, thinking I don't have to do anything about this because it's a benign tumor. It slowly enlarged and she didn't have any facial weakness associated with it and she was relatively non-bothered by it, except for the fact that she could feel nodules within her parotid bed.

In 2023, she underwent an MRI scan of her face because it grew a little bit more rapidly than she was accompanied to and she underwent a biopsy with a fine needle aspiration that was suspicious for carcinoma and she presented to us for treatment. We're going to see a tumor within her parotid bed on the left side, and it's multifocal meaning there's multiple tumors there, multiple masses.

That's very typical of recurrent pleomorphic adenoma. Recurrent pleomorphic adenoma most classically is thought to recur because of tumor that is outside the capsule of the tumor when it's removed. So any release of tumor outside the capsule during removal has the potential to recur as multiple masses, and so this is what it typically looks like when it recurs even as a benign tumor.

But there's heterogeneity in these tumor masses. They don't all enhance the same and look the same, which is a sign of potential malignant degeneration of some. This patient has normal facial function. No facial nerve weakness associated with this. So we think we're dealing with recurrent pleomorphic adenoma and some malignant transformation in some of those nodules.

Based on that, and with our imaging and with our treatment plan, we went to the operating room and performed total parotidectomy. During the course of that total parotidectomy, we did re-biopsy and find that we were encountering malignant transformation or myoepithelial carcinoma within pleomorphic adenoma. We anticipated possible facial nerve sacrifice because of the intimate association of the tumor nodules with the nerve.

And we anticipated that we might have to approach that nerve further up into the mastoid to get a clean margin around it. Common reconstruction options for the facial nerve that we can employ are greater auricular nerve graft or inner positional grafting. As Dr. Dey will show you, we have other nerves at our disposal also for interposition grafting. And then we want to fill in the parotid defect.

We're dealing with both an oncologic process and a cosmetic process. An ideal management of that is complete adequate oncologic removal of the tumor, management of any lymphadenopathy that may occur within the bed, complete margin negative resection of the tumor. But also then, rehabilitation of the patient's facial nerve and their contour defect to try to achieve an ideal result.

In this particular case, we're going to show motor nerve anastomosis for interposition grafting and why we chose the masseter to zygomatic branch of the facial nerve for reannimation. So dividing up the facial nerve into an upper facial nerve function and a lower facial nerve function to try to decrease some of the effect of that aberrant reinnervation that Dr. Dey called about.

We love using the anterolateral thigh for a filler graft because it gives us contourable, low morbidity of donor site tissue that we can model and mold into the parotid defect. It's vascularized so it holds up to radiotherapy and subsequent healing afterwards. And it also gives us the ability to harvest that motor nerve at the same time in one donor site defect, and then we'll show you a couple adjunctive maneuvers also in facial reinnervation.

So this is that patient's tumor as it's coming out. This whole mass is multiple recurrent parotid tumors, many of which have carcinoma, ex pleomorphic adenoma, within them. It's a conglomerate mass, impossible to completely free up her facial nerve from this mass. This is the difference between benign recurrent pleomorphic adenoma and malignant transformation.

With benign recurrent pleomorphic adenoma, you can often find a plane and preserve the facial nerve with removal of the tumor nodules. In this patient, we could not find any plane to separate the facial nerve from the tumor nodules, which is a good sign of malignant transformation. This is the bed. Sorry, Jacob. This is the bed when we're all finished, where we've resected the tumor.

We're going to point out that we have distal and proximal facial nerve edges and blood vessels that are clipped here in preparation for soft tissue reconstruction.

JACOB DEY: Right. So once the ablated portion of the surgery was done, then we worked on reconstructing. And like Dr. Moore had mentioned, we kind of approach these in two ways. One, we have a parotid bed defect that needs to be reconstructed from a facial contour standpoint. And the other is the facial nerve reconstruction and the facial reanimation.

So in this case, we're left with a total carotid defect. So a significant facial volume defect. And we're left with the need to do facial reanimation. What informs us on our decisions there. One, this patient had normal facial function going into the case. So I know her native facial muscles are intact and they're working well. And then it really just depends on our options at that point with what nerve are we left with after we've cleared the cancer and the margins?

And so in this case, we called upon one of our otologists who drilled the mastoid, identified the proximal facial nerve and the mastoid segment. And we had cleared a tumor margin on the nerve in that area. So that was my proximal-- so I had a stump of proximal facial nerve in the mastoid. And then in this case, it's a tough case. Sometimes we-- then distally, I have main trunk before pes or I have the nerve at the pes or I have an upper and lower division that are separated.

But in this case, really the tumor was extended out to where I was just left with the five main branches of the facial nerve. And so then we really have to think about the optimal way to reconstruct-- to optimize the patient's facial function. And like Dr. Moore mentioned, minimize aberrant reinnervation and facial synkinesis. And so-- and then Dr. Moore had also identified, as you can see with the clips here in the neck, vessels in the neck, teeing us up for our adipofascial free tissue transfer for carotid bed reconstruction.

So that-- I would say that is our favored approach for these cases where we're going to do nerve grafting and nerve transfers. We have a total parotid defect to fill and the patient is likely going to need radiation, post-operatively. And for a couple of reasons, like Dr. Moore had mentioned one, I feel that the adipofascial free tissue transfer, which is vascularized, holds up better to radiation than just a free fat graft.

I think if this patient did not need radiation, an abdominal dermal fat graft would be just fine and work well. But with radiation, I like the vascularity of the tissue because it really preserves the contour of the face. The other reason I like that is, as we'll get to in a few slides, harvesting the adipofascial free flap allows me, in the same location, to have a great nerve.

The motor nerve, the vastus, that I can use for interposition grafting of the facial nerve. And the last reason I like it is I feel like the vascularized tissue protects the nerve grafts, to some degree, from radiation change and damage to the nerve grafts-- potential damage with radiation. It's something that we'll talk about. We're doing active investigation and we follow patients over time and track their outcomes.

So we're really excited to see what this innovative approach holds for these patients. But I feel like, intuitively, it makes sense that if we're able to cover our nerve grafts with vascularized tissue, it's going to protect them, to some degree, from the radiation change that they will experience. So for all those reasons, we chose to do adipofascial free tissue transfer and facial reanimation.

So to do that flap, it's basically harvested very similar to any ALT free tissue transfer. So on the anterolateral thigh, relying on the lateral circumflex femoral vessels. You don't need to harvest it with a skin paddle. Sometimes we will harvest it with a really narrow skin paddle, just for ease of elevation of the flap. But really you're harvesting vascularized fat and fascia over the vastus lateralis muscle, capturing the perforators off the lateral circumflex femoral.

And conveniently, running along the lateral circumflex femoral, is the motor nerve to the vastus muscle, which you can take a segment of, as you can see here, which we did in the case, with no significant morbidity to the leg. And this is a great nerve graft for interposition grafting for the facial nerve. I think it's probably one of the best because it's a large diameter nerve that matches very well the diameter of the facial nerve.

And it's a motor nerve. It's not a sensory nerve. So its architecture on a microscopic level is set up very similar to the facial nerve, which is also a motor nerve. So we harvested motor nerve to vastus and the adipofascial free tissue flap from the thigh. And then proceeded back up to the face. So this is a photograph showing the proximal facial nerve coming out of the mastoid.

And so I did microsurgical anastomosis of the motor nerve to vastus, to the proximal facial nerve. I used 9-0 nylon sutures, and this is a collagen nerve wrap that's on the nerve to support the connection. We then went and said, which do we want to connect the interposition nerve graft to branches-- so this is an interesting thing because now we have to decide which branches in the face are we going to prioritize and which branches are we going to target for primary interposition grafting.

And the way I think about this is the most important branches, from the patient's perspective and a functional standpoint, but I want to prioritize are the facial nerve branches that are helping them blink and close the eye and the branches that are helping them smile and move the mouth. So let's say in a case like this I was able to divide up all the fascicles of this motor nerve to vastus and plug them all in and do five nerve connections to all the five main branches of the facial nerve.

Even if I could do that, I wouldn't do it. And the reason is yeah, it may look nice. It may look like I've reconstructed the facial nerve. But I can't control where the axons, as they regenerate through that nerve graft, are going to go. So I can't control if an axon that elevates the brow goes down to the mouth or not. And so if I do that in a case like this, I'm going to probably give the patient bad aberrant reinnervation and synkinesis.

And I'm taking away valuable axons from the nerve branches that I really care most about and want to target, which are the zygomatic and the buccal branches. So in this case, I identified-- Dr. Moore had teed up for me the main buccal branch here. You can see just above that a couple of zygomatic branches. So here's one smaller one and there's one just down from that.

And so we took-- so in addition to that, then we also dissected out and identified the masseter nerve. So the masseter nerve is a powerful motor nerve that I commonly use for facial reanimation. It's a great nerve because it's powerful. It has a lot-- it's a strong motor nerve and it has a lot of axons that we can use to supercharge and plug into the facial nerve.

And it happens to be easily available in the surgical field in these cases. There are some cases where there's the tumor and the parotid gland is very invasive and invades into the masseter and this nerve option is off the table. But thankfully, in this patient, it was preserved. And so I identified the masseter nerve coursing through the sub-zygomatic triangle and the infratemporal fossa and through the masseter muscle.

Identified, as you can see here, the dominant descending branch of the masseteric nerve. And that's another great nerve that we can use for facial reanimation. So now I've got primary interposition grafting from the main trunk of the facial nerve and I've got this masseteric nerve, which patients can easily use with facial physical therapy, learning to put their teeth together to trigger a smile.

And so now I've got these two new sources of innovation as we think about facial reanimation. So what I did in this case-- so this is showing the motor nerve to vastus interposition graft, going down from the proximal facial and the mastoid segment. Going up through the carotid bed defect, up over the edge of the mandible and over the masseter muscle.

And then I did an end to end anastomosis of that nerve graft to the main buccal branch. And in this case, because the patient's facial function was intact prior to surgery, I could use a nerve stimulator and stimulate these branches and watch the facial movement, which is very helpful in deciding where do I want to target the precious resource of these nerve grafts.

And so this buccal branch produced a really nice, strong smile, including movement of the commissure and upper lip. So that was the target. I also had a nice zygomatic branch here. So I again targeted these really important midfacial branches and did an end-to-side anastomosis, as you can see here, of that motor nerve to vastus, now carrying the main facial nerve axons to both buccal and zygomatic branches.

And this I feel very safe about doing and not causing significant synkinesis because there's so much redundancy and crosstalk and overlap between the midfacial branches natively that this produces, typically, a very good result. And then just to supercharge things and give the patient as much as we could, as far as facial reanimation, we connected one of the other zygomatic branches to the masseter nerve, as you can see here.

So after all of that facial nerve reconstruction, then we were able to do microvascular anastomosis. And Dr. Moore had the terminal external carotid artery, as is often available in these cases, and the facial vein available for anastomosis. And we did microvascular anastomosis and then inset this flap. And so here you can see the adipofascial ALT free flap.

And it's nicely covering all those nerve grafts. It's filling the carotid bed defect and it's well vascularized. And you can see the fat and a little bit of the fascia lata here. So it really reconstructs the bed well.

ERIC MOORE: So that is a good example of a malignancy-- a clear malignancy of the parotid gland that required facial nerve resection and then elegant rehabilitation of the patient with interposition grafts using two different nerves. And again, we have a multifocal goal here, which is what makes this treatment fascinating. We want to cure the parotid tumor so we plow all of our oncologic goals of complete tumor resection, management of perineural invasion, management of extra parotid extension, management of lymphatic spread.

Potentially, adjuvant therapy. And then also give the patient the best potential cosmetic outcome. We're going to show you another case example here. This is a patient also that has recurrent parotid pleomorphic adenoma. She had surgery many years ago. She's had slowly progressive multifocal lobular masses within her right parotid bed. No signs of facial weakness.

And FNA elsewhere showed pleomorphic adenoma. But this patient has just massive pleomorphic adenoma. She's had several different treatments of this in the past. We're going to-- we know we're going to be into scar tissue from a re-operative parotid bed. But she also has just innumerable amounts of tumor. And these patients, I talk to them about the fact that she's young.

We don't want to just leave this alone and leave it there. We're going to have to treat this at some point, either preemptively or later when it starts to progress and grow and cause mass effect. Or hopefully, unlike that other parotid patient, is transformed into malignant tumor. And we know we're going to potentially get some facial weakness out of this operation.

We're going to try to preserve as much facial function as possible, but we know there's a high possibility that we're going to get some weakness with this extensive a tumor. A common approach for this would be to wait until the tumor causes facial paralysis, then remove it and reconstruct it. But we don't really like to wait until someone develops a malignancy or until they develop the sequelae.

We'd like to do something preemptively, particularly on younger and healthier patients. And this is a very innovative approach that Dr. Dey has presented and is going to show you. But we're going to do some preemptive facial reanimation, followed by a period of recovery, and then tumor removal in six to nine months. What is the advantage of this?

We think that if we reinnervate those midfacial branches, it'll soften the blow for the patient of complete resection, leading to potential facial paralysis and then reconstruction and then having to wait for all that to take place. So we're trying to get some facial function into the midface, particularly. Preemptively so that if we go in and remove tumor and cause facial paralysis by having to remove any facial nerve and have to do inner positional grafting at that point, then we will have set the patient up for a faster recovery by doing some preemptive facial reanimation.

JACOB DEY: Great. So I wanted to talk a little bit about this because it's something that I'm very interested in and I really enjoy working with Dr. Moore on these cases as we think, what can we do to further enhance the patient's outcome? I have no question that Dr. Moore is going to do great surgery and treat the tumor and give the patient a great outcome from that standpoint, but what else can we do?

How can we push the envelope to try to give these patients, at the same time as getting good-- great tumor control, great facial function. And so that's where preemptive facial reanimation comes into play. Preemptive facial reanimation is not a new technique. It's using all the techniques that have been well described and developed and that I use regularly in my facial reanimation practice.

The innovation is how we apply it. And as Dr. Moore alluded to, it's applying it prior to the facial nerve injury. So it's useful in cases of patients with benign tumors of the parotid gland-- of the facial nerve, such as a facial nerve schwannoma. Or patients with benign tumors all around the facial nerve, like this case that we presented. And we know likely at some point along the course of that tumor and its treatment, the facial nerve is going to be injured.

So what can we do ahead of time to both, as Dr. Moore said, soften the blow. Minimize the morbidity of facial paralysis associated with treatment of the tumor, as well as to enhance the patient's recovery and shorten the time of that recovery. And so that's the thought behind preemptive facial reanimation. We're employing the similar techniques of nerve transfers, but we're employing them prior to injury of the facial nerve.

And I think, in my mind, there are many benefits of doing this in the setting of a benign tumor for patients. One is, yes. You're going to hopefully decrease the length of time that that patient has a complete, or very significant, facial paralysis. Secondly, when a patient has a facial nerve injury. If that's a complete flaccid paralysis, the facial muscle, for a period of time-- six, nine months-- is going without innervation.

And during that time, there is a degree of muscle atrophy. So if we're able to prevent that period, that downtime of the facial muscle, prevent that atrophy, perhaps we can give them a better ultimate facial reconstruction rehabilitation. So I think those are some of the reasons that we're excited about this. Some of the techniques that we use for preemptive facial reanimation, like Dr. Moore said, we're targeting those really important midfacial branches that are helping with quality of life things for patients.

Blinking, smiling, movement of the mouth, which helps with eating and speaking clearly. And common techniques that I'll use are cross facial nerve grafting and masseter nerve transfer. And sometimes, hypoglossal nerve transfer. And we're not, in these cases, targeting or plugging into the main trunk of the facial nerve. I want to preserve the current function that the patient has, but enhance it by plugging in new axons from other locations so that when it comes time to treat the tumor, their face doesn't go completely out.

They don't have a complete facial paralysis. So I'm targeting those facial nerve branches more distally out in the face and finding the high value ones to add additional axons to. And so we can harvest sural nerve from the leg and do cross-facial nerve grafting. And as shown in the previous example, we can do masseter nerve transfer to the zygomatic branch, or buccal branch helping with smile.

Or hypoglossal nerve transfer, or multiple of those options. Most commonly in my practice, I will do both cross-facial nerve grafting and masseter to facial nerve grafting. Or both, or just one of them, depending on the patient's situation and how much time they have prior to treatment of the tumor. Typically with masseter to facial nerve transfer, the time from doing that surgery before we see an effect or see the axons growing into the facial nerve musculature is between four and six months, with an average of about five months for the masseter to facial.

For cross-facial, it's a longer distance. The nerves grow slowly, about a millimeter a day. It takes about seven to nine months after that surgery before we see activity of those new axons being plugged into the face. So in this patient, we did both cross-facial and masseter to facial nerve transfer, demonstrating both options for preemptive facial reanimation.