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BackTable / ENT / Article
Facial Reanimation Surgery: Reinnervation Strategies & Advanced Techniques
Iman Iqbal • Updated May 26, 2025 • 34 hits
Facial reanimation is a delicate and highly personalized field that aims to restore movement and expression after facial nerve injury. While many cases of facial paralysis, like those caused by Bell’s Palsy, will self-resolve, some patients will require urgent surgical intervention. When surgical intervention is required, approaches range from nerve grafts and transfers to emerging procedures like electrical stimulation and transplantation of biologically enhanced nerve conduits. This article explores insights from facial plastic surgeon Dr. Myriam Loyo Li on how to evaluate these cases, when to intervene, and what surgical techniques might offer the best outcomes.
This article features excerpts from the BackTable ENT Podcast. We’ve provided the highlight reel in this article, and you can listen to the full podcast below.
The BackTable ENT Brief
• The first clinical step in facial palsy is identifying whether spontaneous recovery is likely or if intervention is needed due to causes like trauma or tumors.
• If no facial function improvement is seen in three months, MRI is recommended, and early reinnervation surgery is considered to improve long-term outcomes.
• For patients with transected facial nerves, nerve cable grafts are used in conjunction with masseteric nerve transfers to boost recovery potential.
• Fascia lata slings and similar techniques are used to manage facial sagging, particularly in elderly patients, to restore tone and support symmetry.
• In cases where the proximal facial nerve is unavailable for graft, combining the masseteric and partial hypoglossal nerve transfers can offer improved reinnervation coverage.
• In select patients, especially younger individuals, a masseteric-to-facial nerve transfer can be performed first, followed by a cross-facial nerve graft to maintain muscle health and potentially improve natural, spontaneous movement.
• New methods like intraoperative electrical stimulation and neurotrophic factor-enhanced nerve conduits show early promise in accelerating and improving axonal regeneration.
Table of Contents
(1) Evaluating Flaccid Facial Paralysis
(2) Reinnervation Strategies for Non-Recovering Facial Paralysis
(3) Optimizing Nerve Transfers in Facial Reanimation Surgery
(4) Future Innovations in Facial Reanimation Surgery
Evaluating Flaccid Facial Paralysis
Flaccid facial palsy refers to facial weakness ranging from complete immobility to partial loss of strength. The key initial step in diagnosis is determining whether the paralysis is likely to recover spontaneously, as seen in many cases of Bell’s Palsy, or if it may persist due to other causes. Clinicians also aim to distinguish between flaccid and non-flaccid paralysis, the latter often involving mixed symptoms such as spasms or synkinesis and indicating more serious disease.
Bell’s palsy patients are expected to show some recovery within six months. In rare cases, recovery can take up to nine months, most often when underlying neuromuscular issues exist. If no signs of recovery are evident by three months, imaging is recommended. Typically this includes an MRI of the entire course of the facial nerve – from brain to skull base to face – to rule out local malignant growths impeding on the nerve.
[Dr. Shiayin Yang]
Myriam, you want to just give us a definition of what exactly is flaccid facial palsy?
[Dr. Myriam Loyo Li]
Sure. When I hear you ask about flaccid paralysis, I think about weakness, like either a patient's completely flaccid and they're not moving at all, or they have some degree of weakness where they can't quite move their face with a normal strength.
[Dr. Shiayin Yang]
For our listeners, if you have someone coming into the office and you're thinking of management, just go through, how do you evaluate these patients? Then how do you determine what you're going to offer them? Let's say someone comes in, their face, they have weakness, it's not working. How does that consultation go with these patients?
[Dr. Myriam Loyo Li]
Sure. I think the first step for me is to figure out if they're going to recover spontaneously or not. Do I think this condition is going to improve on its own or it's likely to stay as it is unless I do some intervention? I guess that was probably where you were coming in with your question about flaccid paralysis versus non-flaccid paralysis. We can have people that were flaccid before but have now recovered and have spasms or synkinesis or mixed picture of weakness and coordinating movements, muscles that are co-activating what they shouldn't be.
For me, still the number one for flaccid paralysis is Bell's palsy. It's the most common cause of facial paralysis. For every one person that I see with a tumor, with trauma, with other etiology for their paralysis, I probably see 40 to 50 people with Bell's palsy. If somebody comes in and they're flaccid, usually what I'm trying to figure out is if this is Bell's palsy or something else. Then if it is something else, then do I expect it's going to recover on its own or not? Then from there, figure out a treatment plan.
[Dr. Shiayin Yang]
How long for your Bell's palsy patients do you wait? What do you tell them? When do you expect to see some type of recovery for them?
[Dr. Myriam Loyo Li]
For all Bell's palsy patients, you should see some recovery. It's not uncommon for patients to say, "I just never got better. I'm still suffering from Bell's palsy," when they have had some recovery and tone, just not a complete recovery to normal pre-injury function. For us as the doctors, as the otolaryngologist, or the facial nerve surgeons, all Bell's palsy patients should have some recovery. In general, I think the longest it should take is six months. I have had one person that took more like nine months that has been the only one outlier that I've ever seen. He has neuromuscular dystrophy. I really think that he was reinnervating before, but his muscle fibers were just not taking that reinnervation. In general, by six months, somebody with flaccid paralysis should be starting to have some movement.
[Dr. Shiayin Yang]
Just in terms of guidelines and getting some type of imaging, if they don't have any recovery, are you usually getting an MRI around that six-month point?
[Dr. Myriam Loyo Li]
Yes. Our academy, the American Academy of Otolaryngology, had an expert who put out some really nice guidelines. By three months, if there's no sign of recovery, then I'm typically getting imaging. Then, one of the pearls about getting the imaging is that we really want to image the whole course of the facial nerve. Brain, base of skull, and face. I have picked up on tumors like that before for somebody that's been told that they have Bell's palsy and they have a parotid tumor or a more anterior or base of skull tumor that wasn't picked up by a brain MRI.
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Reinnervation Strategies for Non-Recovering Facial Paralysis
In treating patients who do not have Bell’s palsy and are not expected to recover facial nerve function on their own, early intervention is essential for improving outcomes. Dr. Myriam Loyo Li stresses the importance of timely facial reinnervation, especially in cases where the facial nerve has been completely transected, such as in vestibular schwannoma or CPA angle meningioma. In these situations combining nerve reconstruction with the primary treatment is a preferred approach, particularly for cancer patients with parotid tumors.
When a significant portion of the facial nerve is transected cable grafting is performed, but additional interventions like nerve transfers (most commonly masseteric or partial hypoglossal) and static suspension can . The addition of a nerve transfer aims to enhance the chance of functional recovery, as outcomes from the cable grafts alone can be somewhat unpredictable. Static suspension, via techniques like fascia lata slings, helps to minimize the associated facial sagging and dysfunction. This approach is particularly important for older patients who may already experience age-related facial droop.
In cases where the proximal nerve is unavailable or difficult to locate, both masseteric nerve transfers and partial hypoglossal nerve transfers may be used. The partial hypoglossal graft is more selective in terms of tone restoration and is especially helpful in cases where other options are unavailable. However, Dr. Loyo Li is cautious with this procedure due to potential side effects like dysarthria and dysphagia.
[Dr. Shiayin Yang]
I guess now going down this pathway of our patients who are not Bell's palsy or who don't expect recovery, let's say you see them within the first couple months, what's your next pathway for treatment for these patients or, what do you tell them?
[Dr. Myriam Loyo Li]
If I know, the nerve has been sacrificed and it's completely disconnected and it's not going to get better on its own, then I'm typically trying to intervene as soon as possible. I really think that the faster we can get in there and bring back innervation to the facial muscles, the better the recovery will be. Sometimes I'll have a vestibular schwannoma or a CPA angle meningioma where the surgeons know that the nerve has been transected and are not expecting recovery. I'll probably intervene in those patients fast. Then sometimes my preference is always to be able to do the reconstruction for a cancer patient, like a parotid cancer patient at the same time. I do sometimes get people who have been treated in outside facilities and then we'll just try to go as soon as we can to try to reinnervate the face.
[Dr. Shiayin Yang]
Okay. I think cancer patient's a good point. I'm interested in, typically in my practice, if it's a cancer patient who has some portion of the nerve transected, trying to, either bring it, co-act the nerve together primarily if you can, but if you can't, then cable graft it. I know there's been different ways in terms of types of grafts you can use, as well as adding additional nerves, such as masseteric. What do you like to do in your practice for those patients?
[Dr. Myriam Loyo Li]
For my practice, it's rare for me to have a branch that has been transected. Most commonly, I'm being called when the main trunk is missing and it's a large segment that's missing, probably around six centimeters of facial nerve there and missing. In that scenario, while I'm still doing the cable graft and hoping to get some recovery, I will always add a nerve transfer, most commonly masseter, sometimes also partial hypoglossal, and then I'll always add some static suspension.
The reason I do that is I feel like the cable graft is unpredictable. Sure, I have seen patients where the cable grafts had some beautiful return of function, particularly in younger patients, 30-year-olds, but those are rare. I really want to give them a better chance of getting some return of function by adding the masseter-to-facial. Then I really like adding the static suspension because when they-- particularly if they went in with normal facial function and they wake up and they're paralyzed, the fact that they have the lift and the static suspension really helps decrease the morbidity of the sag and the dysarthria, the dysphagia. I tend to do fascia lata slings for the mid-face and try to leave the oral commissure undissected.
[Dr. Shiayin Yang]
Here, there's options. I'm curious, do you do temporalis tendon transfer? Do you prefer doing partial hypoglossal? Do you try to do both masseteric and partial hypoglossal? Because I think they're all valid options to use in this case.
[Dr. Myriam Loyo Li]
I think my biggest use is masseteric and a static sling because, like you said, most of these patients are older patients. They already have facial droop. I do find it takes a while for them to recover. They usually don't get great recovery of the forehead, I see. A lot of them have mid-face droops, like mid-facial droops. That lower eyelid is already being pulled down just from natural aging. Those two parts I do use a lot in my practice.
[Dr. Shiayin Yang]
I'm curious about the hypoglossal because I haven't done that. Are you just doing a cable graft to hypoglossal to the main trunk of the facial nerve or how are you deciding to incorporate that and how exactly do you do it?
[Dr. Myriam Loyo Li]
I was very cautious in using hypoglossal for a long time because I have seen people with very severe dysarthria and dysphagia from tongue weakness from hypoglossals done sort of back in the day. I really think that now that we're doing 20%, 30% of hypoglossal, it tends to have much less morbidity. Now, our head and neck cancer patients are a slightly different population. If they have a large resection, they're already missing soft tissue and muscles in the face, they definitely can have worse dysphagia. Most of the times when I'm doing reanimation for a cancer patient, it tends to be a parotid cancer. Either a squam that metastasized to the parotid or a primary cancer of the parotid.
They're not particularly having other sources of pharyngeal dysphagia or tongue weakness or things like that. I'm not a surgeon that will commonly add the hypoglossal at this stage, but I know that others are. What I think we can gain from doing this, from doing masseteric and also the hypoglossal is more tone. I think the hypoglossal will provide more tone and allow us to reinnervate other branches that perhaps the masseteric couldn't get to.
The places where I've seen myself using both masseteric and partial hypoglossal have been where I don't have a proximal nerve. The proximal nerve either is still positive or has been drilled out all the way to the mastoid and we still can't find the stump. Then I won't try to cable graft all that length. I'll use the masseter for a higher midface branch, and then I'll put a partial hypo to a lower branch. At this point, I'm trying to be efficient and fast and minimize more dissection. I will put just a cable from hypoglossal up to a lower buckle branch for the facial nerve.
Optimizing Nerve Transfers in Facial Reanimation Surgery
Patients with unchanged flaccid facial paralysis at three months typically begin periocular management, and at six months of recovery without change a nerve transfer can be considered. This transfer is most commonly between the masseteric nerve and the facial nerve. In patients with favorable prognosis, especially younger individuals, a cross-facial nerve graft may be added to enhance spontaneous movement. This often involves a staged approach, using the masseteric nerve as an initial graftin the first stage and connecting the cross-facial nerve graft later to maintain neuromuscular viability and improve symmetry.
Effective reanimation strategies function on an understanding of each patient’s functional goals, and virtual preoperative consultations have made this significantly easier in recent practice. These consultations help tailor surgical plans to patient lifestyle and while one patient might prioritize eye protection for their work, another might emphasize the importance of speech functions. The conversations that occur during surgical planning inform choices between masseteric and hypoglossal nerve transfers, weighing factors like functional demands, operative time, and morbidity.
[Dr. Shiayin Yang]
Going back to the topic we just discussed, you saw a patient, they're flaccid, the nerve is cut. What about that patient who is flaccid? They had a surgery, let's say a tumor, and they think the nerve is intact, but they can't give you a 100% yes or no answer. Let's say you're seeing this patient at three months. What do you do?
[Dr. Myriam Loyo Li]
I think our traditional teaching, or at least mine, had been to wait a year. Somebody had a vestibular schwannoma, we would wait a year. Then at one year, if there was no reinnervation, then we would intervene. I think that has really changed for me. I'm intervening at six months. There's good data from Hopkins, Kofi Boahene, this study where he would offer early intervention in six months, and then followed patients. Those that declined the intervention at six months were followed to a year.
It's a small case series, but still, nobody that had no function at six months, then went to develop it at one year. If you think about what we're doing with vestibular schwannoma, we're really going to find one branch and leaving the rest intact as it is. If there was going to be further recovery, we're not harming that further recovery. For somebody that at three months has no recovery of function, I'm already working on their periocular health. If they have developed ectropion, I wouldn't expect that they would reinnervate and it would, all of a sudden, lift the lower eyelid. I'm doing that type of interventions already. We're talking about doing a nerve transfer around six months if there is no recovery.
[Dr. Shiayin Yang]
Then can you define for our audience, what nerve transfer are you doing at six months?
[Dr. Myriam Loyo Li]
Most commonly it's a 5-7. Sometimes I'm setting a first stage cross-facial nerve graft. One of the reasons I do that is because I'm using the masseter as a babysitter and then plugging a cross-facial nerve graft as a second stage. My thought is that I'll be able to get more spontaneity of movement on the paralyzed side by using that cross-facial.
[Dr. Shiayin Yang]
Where are you connecting your masseter and where are you connecting your cross-face?
[Dr. Myriam Loyo Li]
I typically connect my masseter to the largest mid-face branch that I can see.
[Dr. Shiayin Yang]
It's typically easy, right? They're sitting right on top of each other. As you're dissecting in way and route to isolating the masseteric motor nerve, you'll find the mid-face branch that you're looking for, for the facial nerve.
[Dr. Myriam Loyo Li]
Because I never get enough length on that masseter as I think I'm going to get.
[Dr. Shiayin Yang]
Under the microscope, it can look like you have such great length, right? Then you pull it out and it's like, this is not going anywhere.
[Dr. Myriam Loyo Li]
In vestibular schwannoma, it's easy because you can trace the facial nerve more approximately and get the length like that. I wish I had tips for you, like, okay, how do you get that masseter to be longer? I suppose it would be like, sometimes I do remove masseter muscle. It's going to atrophy anyhow. I'm going to denervate it. I'll freely debulk the masseter muscle to create more space. Then sometimes I'll remove a little bit of parotid to allow the facial nerve to move a little bit more.
[Dr. Shiayin Yang]
Then with your cross-face nerve graft, where are you connecting that to?
[Dr. Myriam Loyo Li]
The traditional sense where the babysitter was first described was a hypoglossal where the hypoglossal nerve was being used early to keep the neuromuscular junction and facial muscles alive. To still get innervation to keep them moving. Then you would come back and then use a cross-facial nerve graft. You would undo the hypoglossal and put the cross-facial nerve graft.
I'm not quite doing it exactly like that. I will still leave the 5-7 connected. I will just choose one of the branches from the 5-7, and I'll plug the distal tip of that cross-facial nerve graft there. Then sometimes you'll see a little bit of the cross-innervation. You can stimulate directly where the 5-7 has happened and stimulate, like, proximal to your neuropathy, and you'll see what moves. Then you can go distally and there are other branches that are now cross that will stimulate and choose one of those. I don't have large case series to tell you like it definitely works I'm definitely at it, spontaneity.
[Dr. Shiayin Yang]
I'm curious because I truthfully haven't loved my cross-facial grafts and I'm wondering how-- because there's that argument, does masseter give you any spontaneity? I think most would say no, but I think some say you might see a little bit. There's actually been a study where they did an EMG analysis and showed that with chewing, you actually do get some activation with oral commissure excursion. Could that be the spontaneity you're seeing? I just haven't had a ton of great success with my cross-facial nerve graft. I assume you think it helps since you've been doing it.
[Dr. Myriam Loyo Li]
Yes. I think it helps, but I don't know for sure. I really do need to study it for longer. I definitely think that in my younger patients, I'm much more excited to try it. I have vestibular schwannoma patients that are 28 years old, and so I think a cross-facial nerve graft on a 28-year-old with no radiation, a very different scenario than what we were talking about just a minute ago.
[Dr. Shiayin Yang]
With our parotid patients.
[Dr. Myriam Loyo Li]
Yes. We also have vestibular schwannoma patients that are in their 60s or in their 80s. I think their regenerative potential for that cross-facial nerve graft will be different. I think I'm seeing more spontaneity of movement with adding the cross-facial nerve graft as a single stage after using the master as a babysitter. I don't know.
[Dr. Shiayin Yang]
What time point do you add it?
[Dr. Myriam Loyo Li]
I normally let them get as much reanimation as they're going to get from 5-7, and they're usually tired from surgeries, They just had a craniotomy and then--
[Dr. Shiayin Yang]
Yes, huge surgery.
[Dr. Myriam Loyo Li]
Yes. Then they just went through another reanimation. I'll just let it be as long as it's working well. When they say, "Okay, can you do something else for me?" Say like, "Well, we have that cross-facial nerve graft there and check the tunnel and look at that."
[Dr. Shiayin Yang]
Are you adding hypoglossal? Let's say they're at a year, they have great excursion, but they're still completely flaccid or not, they don't have good tone, I should say that. Are you adding hypoglossal then? Are you offering hypoglossal at a year?
[Dr. Myriam Loyo Li]
Yes. Traditionally I was not doing the masseter and the hypoglossal at the same time. That has shifted for me. Now I will offer it to patients. A lot of the patient's decisions will depend on how we present it. I feel like I'm presenting it more favorably, but I'm still a much more, I guess I will say like, I really do advocate that they undergo 5-7 at the very least. If they're looking to do less surgery and they don't want to add hypoglossal, I'll be honest, I won't put as much emphasis on why I think it's so important. Whereas I do think that doing the 5-7 at six months is really important.
If they just want to do that and they don't want to add hypoglossal, I won't say, "Your chances of having flaccidity at rest are much higher if you do this." I'll say something like, "Okay, we've discussed pros and cons and this seems like a good way to go." How you were saying, do we get spontaneity from masseter or do we not? I definitely agree with you that some of us are using our masseter to smile more than others. Just however our brain is made, however our facial structure is made, we activate masseter more when we're smiling. I think it's possible that people that do that we just are masseteric activators during smile get more spontaneity when we're reinnervating them with 5-7.
There is plasticity and the nucleus of the facial nerve and the trigeminal nerve are close by. There's probably some people that are more plastic than others. I think my favorite study for smile spontaneity is Hadlock's study with Dusseldorp where they did the spontaneity assay. They showed patients this like little funny video clip, which is really funny. It's like this little baby that's giggling. If you've never watched it, you totally should. Some of the people innervated by masseter were spontaneous.
It was a lot less than cross-facial, but a small group, if I remember maybe 20%, this is just going off the top of my head, had some spontaneity. Then I think Hopkins, Nina Lu and Kofi Boahene looked at tone for masseter. I want to say it did depend by age. If they were over 50, then they were more likely to only get-- like if they were very flaccid, they would only get a half of the week correction with masseter only. I will add some static suspension when I'm doing 5-7s for vestibular schwannoma patients where they already are very ptotic and the face is really falling off.
[Dr. Shiayin Yang]
Do you know in those patients where they found tone with 5-7, were they doing end-to-end with masseteric to facial nerve?
[Dr. Myriam Loyo Li]
I can't remember that I've read that on the paper, Shiayin, but that was my impression. They were doing end-to-end with masseter. For younger patients, I really don't see that resting flaccidity. I don't think every single person that only gets a 5-7 will end up flaccid at rest. I think there is some variation there, and I think definitely older patients are more likely.
[Dr. Shiayin Yang]
The challenge with the young patients is that it's hard to tell. Young patients tend to have more tone than older patients. I think it takes a while for that flaccid state to reveal itself.
[Dr. Myriam Loyo Li]
At the same time, that side will age a little less, right? It'll have less movement.
[Dr. Shiayin Yang]
Yes. It's truly amazing because I have a patient who had paralysis of the upper part of her face, and she had it since she was a child. The difference between the two sides is striking because she obviously was not moving that part of the face. She has no wrinkles on the one side and the other. She has these deep wrinkles. I think that topic is very interesting. You have a patient who's flaccid. There is some thought that the nerve could be intact.
I always counsel patients, this is a little bit of a tough decision because as a facial nerve surgeon, it is against your inherent belief of cutting an intact facial nerve, or it is very, very difficult to cut an intact facial nerve. At what point do we make that decision? You touched on it, but just really making this a decision with you and the patient is so important because their goals and what they want to achieve may be different than what you think is best for them.
[Dr. Myriam Loyo Li]
I think for me, if at six months, they are having no movement, then I will move forward with surgery. For me, it will definitely be a 5-7, possibly including some fascia lata suspension, possibly a cross-facial nerve graft, possibly a partial hypoglossal. I don't think waiting a year helps. I think it might harm the level of improvement that we can get. At the same time, if they have any movement, even slight twitching at six months, then I hold off because even slight twitching, I think it's a sign of reinnervation that will continue to get better with a little bit more time.
[Dr. Shiayin Yang]
Yes. It's hard because you know that the level of synkinesis they're probably going to develop. It's such a hard dilemma. I also think it's so tempting. You're like, oh, let me put that masseter in there, but there hasn't been that great data to show that it will prevent synkinesis. To me, additionally, I've had those patients who didn't want anything and they do recover. Depending where, because of how proximal that injury is with those tumors, it just takes a really long time for them to recover. Then it's hard to predict how much synkinesis are they going to develop.
[Dr. Myriam Loyo Li]
I really do think that our patients that undergo nerve transfers will have a better outcome than patients that are undergoing free muscle transfer. If somebody says, "I don't want to do an innervation, I just want to watch it," and they have no recovery, we have the backup of doing a free muscle transfer later. I think it's a little different than people who were having normal movement of the face, undergo a crani for a CPA tumor, and then have flaccid paralysis that is not recovering, to the patients that are having progressive decline or changes in fluctuations, especially like the facial schwannoma patients. I think that slow and progressive decline will do worse with reinnervation than a single injury than we are looking at reinnervating.
…
[Dr. Shiayin Yang]
I think that's such an important point because we all know that patient who is in their 70s or 80s and already in very poor health and you're trying to get them off the operating table. They have multiple medical comorbidities and we opt not to do a facial reanimation because we think, oh, this is going to recur or they don't have much longer to live. I think that's such a huge point to say, this is a quality of life and it's going to affect them significantly. Yes, I think being able to find that balance is probably something I haven't quite figured out yet. Just with more data and research and how it really helps them can be really impactful for patients, but it's definitely a hard line or a hard balance to figure out.
[Dr. Myriam Loyo Li]
I think that's one of the areas where like all of this virtual care has really helped me to try to have those conversations with patients. Before it wasn't uncommon for me to operate on somebody that I might not have had the chance to really meet and talk to before and just be evaluating the defect, how much of the facial nerve is missing. For us, around 50% of people have preoperative facial paralysis before we go in there for their cancer and 50% don't. They had normal function, but with virtual, now we've been able to connect and I learned so much about people and their like preferences and expectations.
I can remember a guy that was like a woodworker. For him, the eye protection and getting it done immediately was super important. People that had to be in board meetings and were speaking and preserving and making sure that they had no tongue weakness and no risk was a priority for them. Totally agree with you that following the patients longer and paying attention to their quality of life and the things that matter to them. Then the impact of this, finding choices, between masseter and hypo, not just reinnervated and not reinnervated and looking at length of time in surgery and other comorbidities really will help us choose better for our patients.
Future Innovations in Facial Reanimation Surgery
Facial reanimation is a rapidly changing field, but many current research prospects are focusing on enhancing axonal regeneration. Experimental applications of implantable nerve conduits embedded with neurotrophic factors, though still under investigation, may improve axonal regrowth while reducing the risk of fibrosis. Additionally, some preliminary data has shown that the use of brief intraoperative electrical stimulation may offer regenerative benefits. This electrical stimulation functions by delivering charge proximal to the neurotherapy site for a short duration, leveraging retrograde signaling to activate the facial nucleus and promote axonal sprouting. These emerging techniques underscore a growing commitment to advancing facial nerve repair through both surgical precision and biologic innovation.
[Dr. Shiayin Yang]
I'm curious because this is something that I talked about in fellowship and it's still something that I'd like to look into is have you noticed a difference in terms of, really seeing that time to reinnervation with a motor nerve versus a sensory nerve? Because commonly if you're doing a cable graft, most likely you're using greater auricular or if you can't use that, it's neural nerve, which are both sensory, but the facial nerve is a motor nerve.
[Dr. Myriam Loyo Li]
Great question. I wish I could tell you the answer to this. The theory behind it being like if we're using a sensory nerve, is that why our cable grafts are not doing as well? If we're using a motor nerve, can we get more growth through that? I think my volume is small where I can't quite separate and study that and tell you. That's the part where I think like if all of the centers are doing these super rare, highly complex surgeries, if we pull our data together, we'll be able to start getting more answers.
[Dr. Shiayin Yang]
Because that's just something that I think there's multiple unanswered questions in facial paralysis and that's definitely one of them.
[Dr. Myriam Loyo Li]
Yes. Which cable graft do you use and does it make a difference and then do you flip it so that--?
[Dr. Shiayin Yang]
Exactly. Since we're on the topic, what about how do you do your neurorrhaphy, and then do you use anything to cover it?
[Dr. Myriam Loyo Li]
That hasn't been an area where I've done a lot of research, so it might be a little outdated, but my preference is just to put nylon sutures and then use a little bit of Tisseel around to reinforce. I'm trying to put them together with minimal tension to not bunch up the accents, but rather just have them sitting or posing right next to each other and to put the sutures in the epineurium.
[Dr. Shiayin Yang]
I'm curious because we always used little vein grafts and it's now so easy to just take a little bit of the vein, in the nearby field to cover up, do your neurorrhaphy, and then cover that. Now there's newer things that have data in hand literature with Axogen. It's always curious, what is the best way? Do you have to sew it to minimize how much you handle the tissue and the potential damage? It's definitely an area that I think could use some.
[Dr. Myriam Loyo Li]
I haven't looked at their literature recently, but I think there's this balance between how can we reinforce that coaptation so that we guide those accents towards each other in a better way and so that they're not just spreading out and getting lost. Then how do we do that so that we're not creating excessive inflammation and scarring so that it doesn't make it harder for the accents to grow through that area? When I was a resident, which now is 11 years ago, they were doing animal trials at Hopkins where they were comparing different techniques and honestly, a lot of coaptation.
[Dr. Shiayin Yang]
Different neurorrhaphy techniques. Okay. Exactly. Yes.
[Dr. Myriam Loyo Li]
There was a point where you were just creating more inflammation and it wasn't truly helping. I think there's some really cool research happening looking at, could we have some sheet repair that's surrounding the neurorrhaphy and has neurotrophic factors that will promote axonal growth? It's a little bit hard to think about using that in cancer. I definitely think that how do we enhance growth in our nerve transfers? How do we enhance growth in our cable grafts is definitely such a cool area of research that is going to be getting better and better in the next decade.
Definitely, the tubules that are coded in growth factors, I think will be something that we'll be hearing more of. My center, OHSU, has been collaborating with Cleveland Clinic. They have a randomized control trial on intraoperative brief electric stimulation. We are a site that's recruiting. Not for cable grafts for cancer, but for cross-facial nerve grafts, we're using brief intraoperative electric stimulation to try and enhance growth. Hopefully, we'll have some preliminary data to support its use.
[Dr. Shiayin Yang]
Interesting. When you're putting in your cross-facial nerve graft, what are you stimulating?
[Dr. Myriam Loyo Li]
You go proximal to your neurorrhaphy or coaptation, and then you stimulate for 10 minutes. The idea is that the stimulation will go retrograde towards the nucleus, and then that will sprout for their external growth. It's based on animal data. Then there are human trials that have shown that this type of brief intraoperative stimulation improved motor repair after carpal tunnel surgery, after digital nerve repair, and even stretched spinal accessory nerves in a neck dissection. Outcomes have been like functional recovery, like hand grip and strength and shoulder strength, even like a year after the innervation. It's pretty exciting stuff.
[Dr. Shiayin Yang]
What are the outcomes are you looking at? Are you looking at clinical outcomes in terms of like how quickly are they demonstrating a tunnel sign? Are you also looking histologically when you do your second stage at the nerve? How are you guys measuring those?
[Dr. Myriam Loyo Li]
That's why the model of the cross-facial nerve graft is so exciting to study how do we improve growth through a cable graft, because we have that second stage where we can biopsy the distal tip. Electron microscopy to look at external growth at the distal area. Really, this has been Patrick Byrne's project. He really started the Cleveland Clinic, and the background data from animal data and the human trials are there. I'm hopeful that we'll find the same for the cross-facial nerve grafts. It's really exciting. We've just started this year, so we will for sure have more data and more information to share on this.
Podcast Contributors
Dr. Myriam Loyo Li
Dr. Myriam Loyo Li is a facial plastic surgeon at Oregan Health and Science Univeristiy in Portland, Oregan.
Dr. Shiayin Yang
Dr. Shiayin Yang is an assistant professor of facial plastic and reconstructive surgery with Vanderbilt University in Nashville, Tennessee.
Cite This Podcast
BackTable, LLC (Producer). (2024, November 5). Ep. 198 – Advanced Techniques in Facial Reanimation [Audio podcast]. Retrieved from https://www.backtable.com
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