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BackTable / ENT / Podcast / Transcript #198
Podcast Transcript: Advanced Techniques in Facial Reanimation
with Dr. Myriam Loyo Li & Dr. Shiayin Yang
From cable grafts to free muscle transfer, surgical treatments for facial paralysis are evolving quickly. In this episode of the Backtable ENT Podcast, Dr. Myriam Loyo Li, facial plastic surgeon at OHSU, joins guest host Dr. Shiayin Yang of Vanderbilt to discuss dynamic procedures for facial paralysis. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Initial Evaluation & Management of Facial Palsy
(2) Reinnervation Strategies for Non-Recovering Facial Paralysis
(3) Innovations in Nerve Grafts & New Techniques in Facial Reanimation
(4) Merging Machine Learning with Early Facial Reanimation
(5) Patient-Specific Considerations in Facial Paralysis Care
(6) Use of EMG in Managing Facial Paralysis
(7) Age & Timing: Nerve Transfers vs. Free Muscle Transfer
(8) Free Muscle Transfer Techniques
(9) The Art of Muscle Design in Multivector Facial Reanimation
(10) Advances in Free Strap Muscle Flaps & Future of Facial Reanimation
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[Dr. Shiayin Yang]
My name is Shiayin Yang, and I'm an Associate Professor of Facial Plastic and Reconstructive Surgery at Vanderbilt University in Nashville, Tennessee, and I have the pleasure of being the guest host for today's episode. It is my distinct honor to be able to have Dr. Myriam Loyo Li, who is a colleague and personal friend on the show. She's a facial plastic surgeon at Oregon Health and Science University. She's an associate professor in the Department of Otolaryngology, as well as the co-director of the Facial Nerve Center. Welcome, Myriam. It's good to see you.
[Dr. Myriam Loyo Li]
Same. Thanks for having me, Shiayin.
(1) Initial Evaluation & Management of Facial Palsy
[Dr. Shiayin Yang]
Of course. Today's episode, we'll be discussing surgical management of flaccid facial palsy. I guess for our listeners, first, 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.
(2) Reinnervation Strategies for Non-Recovering Facial Paralysis
[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.
(3) Innovations in Nerve Grafts & New Techniques in Facial Reanimation
[Dr. Shiayin Yang]
Which makes sense because if you have a patient who has that big of a tumor, they likely have a positive, the nerve is likely going to be positive. Especially if they're sacrificing that much of the facial nerve.
[Dr. Myriam Loyo Li]
Yes. This has been a little bit of a point of discussion for us at OHSU just because our head and neck surgeons wanted to make sure that we weren't just prolonging the surgery and making it more complicated in somebody with a very scary, advanced tumor that is likely to recur. We've been pretty impressed that, to put a cable graft to a partial hypo doesn't add a lot more time. Patients really do get reanimation. Even if they have recurrence of their cancer, they still have better function while they're having to live through that recurrence. I want to be mindful that we're not just making these surgeries for patients that are going to die of their disease, like extremely long and complicated or adding morbidity. I think it really can't be done in a way that doesn't do that, but rather it gives them more quality of life.
[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.
[Dr. Shiayin Yang]
What do you use for your cable graft?
[Dr. Myriam Loyo Li]
For a long time, we were not doing any-- I took a deep breath, right? When you asked this question, I was like, "What do we use for the cable graft?" At OHSU for a long time, we were not putting any free flaps to reconstruct the volume deficit. Even though it's large volume deficits, we were not, and it's a lateral defect. It's not in the center of your face and the patients had a lot going on. I think we were a bit of an outlier in that.
[Dr. Shiayin Yang]
I think the majority of the academic centers in the US were putting free flaps on those patients. I'm curious if you guys were shy, probably.
[Dr. Myriam Loyo Li]
Yes. I think it's a combination of both.
[Dr. Shiayin Yang]
A combination of both, okay.
[Dr. Myriam Loyo Li]
Because we weren't, then I was really being creative with the nerves around this area. I would take long radial ray or some cutaneous branches from cervical rootlets to connect or control greater aruricular. Now we really have moved towards doing ALTs. Our microvascular team is really fast. They can harvest and insert very quickly. Mark Wax has been here for a long time and has been doing that work really beautifully. We just hired Sara Yang, who's also part of our microvascular reconstructive team. They're doing that and they'll give me the nerve to vastus lateralis and then now I have a motor branch to use. That's been a really nice finesse and upgrade that we've been doing to our surgeries.
[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.
[Dr. Shiayin Yang]
That sounds awesome.
[Dr. Myriam Loyo Li]
Shiayin, that's the hard thing about facial nerve. The cases are rare, and if our outcome is how well they moved their face or how wide their smile is, it's really hard to compare outcomes like that, even with the amazing technology that we have nowadays, even with emotrics and with the dedicated validated quality of life questionnaires.
[Dr. Shiayin Yang]
It's so true. This gives you quantitative data, histologic data that you can look at. You said it perfectly. It's so hard to measure our outcomes because there are so many different factors we're taking in. Even if you as a physician thinks, "Oh my gosh, you have a beautiful smile or the face has balanced so well," the patients may not agree. Yes, I think that's really exciting research.
[Dr. Myriam Loyo Li]
As I think of it, in my ideal world, we'll be studying facial outcomes by combining different centers, and then we'd look at the clinician ratings, the objective photos, the patient perspective, and then maybe even this new area where we're bringing naive of servers to look at faces and see what they think of them.
(4) Merging Machine Learning with Early Facial Reanimation
[Dr. Shiayin Yang]
Actually, a nice thing and something that I've started looking into is how can we incorporate machine learning and AI? Because on your phone, you just have even facial recognition. It's something that Apple has already figured out, and it's something that we can easily incorporate to better study trends among patients. Then if you can do, like you said, these are rare cases. If you can pool data across the country and then have some type of machine learning or AI to process it, that can really excel our understanding of facial paralysis and our outcomes and what a physician thinks, what do patients think. It's just such a big reason why facial reanimation is such a fun topic because there's so much to do to improve our current treatment. I'm sure, in 20 years from now, the stuff we're doing is going to be very outdated.
[Dr. Myriam Loyo Li]
Why we love being facial plastic surgeons is because it's their faces and how we communicate with each other as you're sharing all this exciting stuff that you're doing with artificial intelligence. I was reminded of a patient who I did a nasal reconstruction, so not facial nerve, but she refused to change the Apple ID so that her phone would recognize her. One of her measures of success that we've done a good surgery was because her phone started unlocking and recognizing herself.
[Dr. Shiayin Yang]
That's so crazy. That's the difficulty with facial plastics is you're not the only person judging that outcome.
[Dr. Myriam Loyo Li]
Yes. The challenge and the reward, like so much of our identity, our face, and how we move and how we speak.
[Dr. Shiayin Yang]
And how we communicate.
[Dr. Myriam Loyo Li]
Yes. That's really cool.
(5) Patient-Specific Considerations in Facial Paralysis Care
[Dr. Shiayin Yang]
I guess 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]
That's another great point you brought up, because I recently just had a patient in clinic that I'm honestly struggling to figure out, where do we "start the clock" of your facial paralysis? This is a patient who had-- it wasn't a tumor, but they've had a middle-ear disease and progressive paralysis, but they have recovery. They would have these on-and-off episodes of paralysis with recovery. Of course, it's hard to remember the exact duration between episodes.
Now they're completely weak, but it's like, you have this history before of these on-and-off episodes, and it's hard not to think that it's hard to know how much of those motor implants were alive after each episode and at what point do we say, okay, this is our six-month point where we start the reinnervation. Then the other struggle is how do I cut your facial nerve if you could potentially get recovery? I think you could ask 10 different surgeons and get 10 different answers.
[Dr. Myriam Loyo Li]
Yes, and having the conversation with the patient about risk tolerance and like we being open about, we don't know, like this is how much we know and this is how much we really don't know.
(6) Use of EMG in Managing Facial Paralysis
[Dr. Shiayin Yang]
Another thing I'm interested in knowing is how often with these patients, or someone you're unsure as to the quality of their nerve, are you using any tests like EMG to see, do they have any reinnervation? Does that play any role in your practice?
[Dr. Myriam Loyo Li]
I really don't use EMG for the facial nerve much. If I don't see clinical movement, it doesn't matter if they have fibrillations or polyphasic, like even if they're showing some signs of reinnervation, they're having no movement, then that's really what I go on. I used to use the EMG more for masseter. I tended to really want to feel it even when I knew it was abnormal.
I used the EMG to confirm, yes, it is abnormal. More and more, I know if it's feeling abnormal, it's going to be abnormal. For some of the larger CPA tumors, it can be not just facial, but also the trigeminal, including the motor branch that is affected. That's the key scenario where I use EMG more to evaluate the masseteric function in an area where I think there's impairment.
[Dr. Shiayin Yang]
Is there anything specific aside from just feeling it when they're clenching? Is there any specific thing that you're like, oh, that nerve is not working as well as it should?
[Dr. Myriam Loyo Li]
Yes. I think what I've found is that I'll feel weakness in asymmetry. It's there, but it's weak. Or-
[Dr. Shiayin Yang]
In comparison to the other side?
[Dr. Myriam Loyo Li]
-in comparison to the contralateral side. Sometimes it's just like, okay, it's contracting, but not as strongly, or it'll twitch in the muscle. I think those are the things that make me think that there's been an injury. They can have reinnervation, but I don't think that reinnervation is as good as a nerve that has not been injured and had to go through reinnervation.
[Dr. Shiayin Yang]
At what time point do you-- Let's say now this patient comes to you after a year. Do you use it? Do you use EMG or nerve conduction in other ways?
[Dr. Myriam Loyo Li]
Not routinely, to be honest. In this patient that I'm unsure about, I am going to use it, but I don't think it's going to strongly change my practice or strongly change my plan. It's more as an additional tool for information, but I thought through it in my head and, is it really going to change what I'm going to do? Probably not. If it can give us an additional source of information, it might be helpful, but routinely I don't. One of the hard things with EMG is that it's a subjective thing, right?
[Dr. Shiayin Yang]
It is.
[Dr. Myriam Loyo Li]
They're going to describe this action potential for you and tell you about the abnormalities rather than like a number or a threshold or anything like that.
(7) Age & Timing: Nerve Transfers vs. Free Muscle Transfer
[Dr. Shiayin Yang]
Yes. Agreed. In terms of timing, do you have a time point when nerve transfer is not an option? What is your cutoff for patients, or does it vary? Does it vary by their age, their presentation and their etiology? How do you determine when you will do a nerve transfer versus when you're going to take the next step to a free muscle transfer?
[Dr. Myriam Loyo Li]
Yes, great question. I think we don't fully know the answer and the answer is probably a little different for every person. I definitely take age into consideration. For children are much more likely to do nerve transfers even up to a year and a half. For adults, when I'm way past that one year, I will not do it. Then when I'm approaching one year, I'll start having a conversation about either using more nerve transfers, like not just 5-7, but really also using hypoglossal.
There's some data from Dr. Lozeta in Spain that makes me think that hypoglossal might do better after one year than masseter. I talk about expectations and pros and cons and what do they want to do. If they're at that one-year mark or a little bit further out, then I start telling them that we might get some tone, we might get some few millimeters of movement. Do they want to try that or do they want to move towards a free muscle transfer?
I guess if I summarize it, it's really hard. There is no cutoff and that will be different for everybody. I think for me, in children, I will be able to give them a year and a half before I am not going to try a nerve transfer for them. Within a year and a half, I will do a nerve transfer for a child. I think for older adults, it's different. When we are past one year, I'm not excited to try nerve transfers. If we are going to do it around the one-year mark, I will advocate that we use not just 5-7 but also hypoglossal, because I think they will have a better result at that time if we use both.
[Dr. Shiayin Yang]
Then just for our listeners, why is this time important? Explain why we picked that time point.
[Dr. Myriam Loyo Li]
Yes. We think that there's a time when the neuromuscular junction is still viable to reinnervation and that reinnervation is still going to translate into meaningful movement that we see in the faces. The further out we go, the more likely we are to be unsuccessful to do a nerve transfer and get either no reinnervation or no improvement in tone or movement, or get small few millimeters of movement with some improved tone without actually having a meaningful smile. We probably want to try to get people smiling like one centimeter, and half a centimeter is better than nothing, but less than four millimeters is really not ideal.
(8) Free Muscle Transfer Techniques
[Dr. Shiayin Yang]
Yes. Really just the time in terms of trying to get that muscle reinnervated before those motor end plates die. I do agree. I think there's a difference in terms of kids and just the neuroplasticity and how much they're able to recover after these procedures, like with any other part of their body in terms of healing.
Now let's go into the free muscle transfer. I think this is an exciting area, a lot of areas for development. We'll talk about your most recent study, but in terms of the different types that are available, the most commonly known is the gracilis, which is probably the gold standard just in terms of free tissue transfer for facial reanimation, but there's been other types as well. We'll start with gracilis. It sounds like you're usually reserving this for your patients who are more than a year out for your adults with flaccid facial paralysis who've had no return of movement. Tell me just your overall, what are you using in terms of your neural input to this muscle?
[Dr. Myriam Loyo Li]
Yes. The most common innervation that I will use for a gracilis is dual innervation. I prefer doing a two-stage cross-facial nerve graft and then using the masseter. That is my most common choice.
[Dr. Shiayin Yang]
For our listeners, I assume you're using the sural nerve for your cross-facial nerve graft.
[Dr. Myriam Loyo Li]
I am. At the same time, one difference that I've noticed is that I won't harvest again for a sural nerve that has already been harvested. I know other surgeons do. I will go to medial antebrachial cutaneous if somebody has peripheral neuropathy. That's another place where I use nerve conduction. If somebody has diabetes and peripheral neuropathy, I will test their sural nerve. If it is impaired, I will use medial antebrachial cutaneous nerve. I guess I should have said that before also.
[Dr. Shiayin Yang]
I guess the question always is, how proximal do you inset your cross-facial nerve graft on the affected side? It was always like take a good branch that gives you upward excursion. You're going to down-regulate the unaffected side to give them more symmetry, but you're always in your mind like, oh, am I going to make their face-- am I going to ruin their smile on the unaffected side?
[Dr. Myriam Loyo Li]
Yes. Somehow I don't worry about that anymore. I take a good-sized branch that's in the mid-face, and there's just so much redundancy in that area. It's really a mesh more than a single nerve that's going out there. I really think of the nerves more as a mesh than like a pipe. I don't know. I'm much less concerned about giving somebody weakness on their unaffected side. I've never seen it.
I suppose if you don't have a lot of experience with cross-facial nerve graft, you want to be cautious and make sure you have a branch that is robust enough that you will have enough access to grow through this long cable graft and confirm that you have other branches around the area that are producing the same redundant movement. I think it would be hard. You really would have to take a lot to be causing weakness from a cross-facial nerve graft.
There's some exciting research that I've been following out of Brazil about cross-facial nerve grafts for direct innervation of the orbicularis oculi. In my practice, I've been moving towards a cross-facial for the free muscle and then a cross-facial towards orbicularis oculi, towards the eyelids, and I don't have enough follow-up to tell you how well it works, but I'm hoping to replicate some of the results I'm seeing coming out of Brazil where they're getting some direct reinnervation.
[Dr. Shiayin Yang]
How are you bringing that nerve? Where are you reinnervating it?
[Dr. Myriam Loyo Li]
I'm prioritizing the upper eyelid and I'm coming through the bridge of the nose.
[Dr. Shiayin Yang]
Then are you actually finding a branch to co-opt the nerve to, or are you dunking it into the muscle?
[Dr. Myriam Loyo Li]
We're doing a variation of things, which is also why it's hard to know how it works and when it works. For people who are not in the free muscle category but are still on the nerve transfer, we'll try to find a nerve branch and do the co-optation there. For people who are undergoing a free muscle, we'll try to put a branch going into the free muscle, like direct into the free muscle.
Then there is another group that has published on free platysma muscle grafts for the eyelids, which I was very hesitant to believe in. I'm just going to take a strip of muscle and I'm going to put it there and it's all of a sudden going to become alive and reinnervated? I think there is something special about the eyelids that they just have this amazing vascular supply and somehow they do better and our body biologically wants to protect the eye. That's why we get so much blepharospasm and reinnervation there. I think there's something special there. I think we need to study it a lot more before we start doing things like this that I'm talking about.
I guess my point in bringing up this several cross-facial nerve grafts in a single patient is that it is hard to give somebody weakness and the non-paralyzed side, and I'm moving towards more cross-facial nerve grafts rather than less. Dr. Raquel Baptista has been using cross-facial nerve grafts for eyelid reanimation with direct neurotization with some exciting results. We've been trying to replicate some of those findings here at OHSU.
[Dr. Shiayin Yang]
That's really cool. Definitely keep me updated on what you find. All right. You do your cross-face nerve graft, you do your first stage, and then how long are you typically waiting between your first stage and your second stage, so actually doing the free muscle transfer?
[Dr. Myriam Loyo Li]
I think it ends up being longer than six months and then closer to one year. Especially in the children, I think it ends up being closer to one year. I think we would be able to do it sooner. I think it's more coordinating and scheduling in my practice. I think six months at the earliest, I would want to check for strong Tinel's. If it's going to be only innervated through the cross-facial nerve graft, like in pediatric and children, I tend to wait closer to one year.
[Dr. Shiayin Yang]
Then you said that predominantly, most of your patients, you're doing dual innervation with a cross-facial nerve graft with nerve to the masseter. How are you then connecting those? How are you doing those co-optations?
[Dr. Myriam Loyo Li]
Great question. It's always an end-to-end for me. I try to prioritize the trigeminal and the masseter to innervate the free muscle and then find a way to incorporate the cross-facial nerve grafts. Often this will mean that the masseter--
[Dr. Shiayin Yang]
It's end-to-end masseter to obturator and then end-to-side cross-face?
[Dr. Myriam Loyo Li]
It's end-to-end for both.
[Dr. Shiayin Yang]
Okay. You're putting them both together into--
[Dr. Myriam Loyo Li]
Yes. Even though it's usually like the obturator would be a one-to-one match with the cross-facial nerve graft, I think what I'll end up doing often is I'll put the masseter there and then either I'll make it slit further down more proximally where I will then connect the cross-facial nerve graft end-to-end there, or it'll be the opposite where the masseter is closer and I'll end up connecting the masseter here and then end-to-end on the other accents to the cross-facial nerve graft.
[Dr. Shiayin Yang]
Do you ever worry about masseter overpowering your cross-facial nerve graft?
[Dr. Myriam Loyo Li]
Yes. I think for me, the priority has been getting them a smile and getting the muscle moving. I know I'm biased towards having it be successful, and so I'm biased towards prioritizing masseter. Does that come at a cost of spontaneity and cross-facial nerve graft? Probably. I don't think we truly know what is the best way to put those nerves together.
(9) The Art of Muscle Design in Multivector Facial Reanimation
[Dr. Shiayin Yang]
What are you doing in terms of vectors? There's been talk of dual vector, multivector. Many people are still just getting great results with single vector. What have you tried? What are your thoughts?
[Dr. Myriam Loyo Li]
One vector that I don't have a lot of experience with free muscle would be the lower lip. I do think that there's some really cool innovations coming up with how do we recreate that depression of the lower lip or the DLI action when we're smiling. Massanier has shown some beautiful results doing a free graciles that have both vector going to the upper lip and then a vector going to the lower lip. I've been using some static suspension, but I think we will see more and improved outcomes for the smile with lower lip considerations.
[Dr. Shiayin Yang]
Yes, there's so many nuances on what constitutes a spontaneous smile. How can you make that smile natural than what people are looking for? I think all of these different avenues are really exciting to see, what is the best way that we can restore people as best as possible.
[Dr. Myriam Loyo Li]
Just before we switch on innervation, for me, for sure, my most common one is dual innervation with cross-facial nerve graft and masseter. I do sometimes do the cross-facial nerve and the masseter as a single stage if the patient really has a strong preference. I prefer to do it in two stages. Theoretically, it makes me feel like the actions are going to be more readily at the distal to go the cross-facial nerve graft, but there is the option of doing them at the same time as a single stage. I don't think anybody knows which way is more successful.
Then for children, I tend to do cross-facial nerve graft only. I really think that they are able to get a better result for that and that it will be more spontaneous and that they'll use it more if it's based on a cross-facial nerve graft, unless it's a Moebius patient where we don't have that option.
Then for adults, I really think that the cross-masseter has completely changed my practice. In people who are nerve depleted, where I don't have the masseter anymore on the ipsilateral side, I put a cross-masseter cross-facial. It's a single sural that will have both the masseter and the facial nerves coming through, and I'll use that for the free muscle. A game changer for my people that before I was trying to do cross-facial nerve grafts on older adults in their 60s getting disappointing results, the cross-masseter has changed that for me. They are getting really nice smiles and I have five people that have had that done and I've been really surprised and impressed by it.
Another advantage of the cross-masseter is that you don't have to go as long with the nerve to go all the way to where the masseter is. If you're doing a cross-facial, you'll want to try and go as long as you can so that the co-optation of those nerves that we were discussing, like how do we put them together more optimally, the geometry is more favorable. If you're doing a cross-masseter, hopefully also with some facial nerve branches in there, I'm able to end here in the frontal incisor and then bring the obturator to it so the distance is also a little bit shorter.
[Dr. Shiayin Yang]
I also think that's important just in terms of how well and how quickly they're reinnervating, because when you're adding such additional length that the nerve has to grow across, I can't help but hypothesize that that's going to affect your final outcome.
[Dr. Myriam Loyo Li]
I think I've heard Dr. Jewett really feel very strongly about that, that shortening the grafts is going to lead to better outcomes.
[Dr. Shiayin Yang]
It's all stuff that I think also because this procedure is just more rare, that it's hard to really pull these out, determine outcomes at a single institution and what is really the best method and why there's so much variability in terms of how people are doing it.
[Dr. Myriam Loyo Li]
Yes, like rapidly evolving and then a lot of nuanced little things that conflict the outcome, but that's what makes it exciting.
[Dr. Shiayin Yang]
Yes, exactly. [crosstalk] Even when you're just building your own practice too, you're just trying to figure out what works for you. In terms of the design of the muscle and the transfer of the gracilis, there have been different ways described traditionally, a single vector, but there's also been dual vector as well as multivector. What do you routinely use in your practice and what are your thoughts on these different variations?
[Dr. Myriam Loyo Li]
I definitely started as a single vector person that prioritized the oral commissure and lifting the oral commissure to create the smile. I really have transitioned to doing at least two vectors and to inset not just to the oral commissure, but also to the middle of the upper lip to help that upper lip displace superiorly, move superiorly with the smile and increase the dental show. I think it makes the results just that much better.
I really credit Patrick Byrne and Kofi Boahene, big mentors for making that innovation and that change in the design. I'm definitely a multivector proponent. If I'm doing those two vectors, I might even add a third vector to the lower eyelid. In the lower eyelid, I was a little bit skeptical about how much contraction we would get there and how much vascular perfusion we might still have on that small little tiny third vector. The more we do them, the more we find little tiny perforators where I can even Doppler the third vector. I've been really happy with those. It gets tricky to design the length.
[Dr. Shiayin Yang]
How are you designing that?
[Dr. Myriam Loyo Li]
Yes, I'm still tweaking it and trying to make it better. I put the most important vector as the one that goes to the oral commissure, and it'll inset a little bit more laterally. Then I'll have smaller vectors that are coming closer to the anterior face of the maxilla for the second vector. Then the third vector trying to come all the way across the eyelid. I just finished writing a review that has some diagrams and intraoperative pictures, and it's going to be in press soon. I know it's Elsevier, so it must be Facial Plastics Clinics of North America. I think it'll be in press soon with some photos and diagrams.
[Dr. Shiayin Yang]
Essentially, you're trying to create that narrowing of the eye that you naturally get when you smile?
[Dr. Myriam Loyo Li]
For the third vector, I'm trying to recreate that squinting that we have with the smile so that you don't have like a wide open eye looking out.
[Dr. Shiayin Yang]
Does it help just in general with the lower ectropion?
[Dr. Myriam Loyo Li]
Yes. I find that I'm still having to do the ectropion repair. It's just that I'm using the muscle as part of the repair. Similarly to nerve transfers where I expect somebody that has a successful 5-7 to get lower eyelid contraction, they will get tone, they will get contraction. I don't expect that to correct the ectropion or lower lid malposition, similar for the free muscles. If the muscle gets reinnervation and is successful, I think we will see contraction there. I don't think this by itself will fix the position of the lower eyelid.
[Dr. Shiayin Yang]
What are you routinely doing for your lower eyelids?
[Dr. Myriam Loyo Li]
I'm very lucky that my co-director for the Facial Nerve Center is John Ng, who is the Director of Oculoplastics at the KCI Institute here at OHSU. It can be hard to get oculoplastic surgeons with their busy schedule where they do multiple small little cases to come to an all-day free muscle reinnervation, but he makes it work. He's with us to help us inset with the medial canthus, and he does most of them.
I think it's what we all do for lower eyelid, release the lateral canthus, reposition it where it needs to go, realize that it's not just pulling from the lateral canthus, but also the actual eyelid with the orbic, even if it's denervated. I used two or three vectors when I'm using the gracilis. I really think it's made my results better. One of the things I want to look at is, am I making the faces too bulky as I'm creating--
[Dr. Shiayin Yang]
That was in the next question. With three vectors, how much bulk are you getting with that in their face?
[Dr. Myriam Loyo Li]
I think one of the things that Dr. H did beautifully, and that I feel like she taught all of us, was how to make a gracilis small enough that it could fit in the face, yet strong enough that it could smile. The multivector is certainly a bigger flap. I was putting in single vector graciles that were around 16, 18 grams, and my multivector graciles at the time of inset are more like 35 grams. One concern has been, am I now going to make their faces really bulky? Their smile is going to be really wide, but is their cheek going to look really bulky? I haven't found that, but I am in the process of looking more critically, really measuring the photos and looking at that.
[Dr. Shiayin Yang]
Where are you anchoring your vectors to the oral commissure in the upper lip? Laterally, where are you anchoring them?
[Dr. Myriam Loyo Li]
Oh, the first vector or the vector that suspends the oral commissure goes to the temporal fascia, and then the second vector ends up going a little bit to the most prominent part of the zygoma. It's a little more anterior, and that becomes the pivot point for your third vector. I'm trying to end up around the maximal projection of the maxilla a little bit superiorly, a little bit anteriorly, if that makes sense.
[Dr. Shiayin Yang]
Where are you noticing most of your bulk? Is it where your second and third vector are, or is it still not traditional, above the zygoma?
[Dr. Myriam Loyo Li]
I think one of the things that I have noticed, and somehow I think this last patients that have been doing the multivector have had fuller faces, and I have not noticed excessive bulk. I think because this muscle is going to become denervated and atrophy and then get reinnervated, it's not quite as bulky as I thought it would be.
[Dr. Shiayin Yang]
It's definitely something that is challenging just in terms of figuring out the weight of it, but also trying to keep it so it's not getting scarred to the overlying skin, getting that dibbling when they smile.
[Dr. Myriam Loyo Li]
I tend to inset deep and to do all of the dissection pretty deep.
[Dr. Shiayin Yang]
To avoid that?
[Dr. Myriam Loyo Li]
To avoid that. I think the thicker I make the skin flap, the less [crosstalk] get that.
[Dr. Shiayin Yang]
What would you say is your biggest challenge with the procedure? Is there something you can identify that you really would love to improve upon it or something that you just haven't been able to completely tackle?
[Dr. Myriam Loyo Li]
Yes. I think the finesse of the muscle design and the inset. You need to be somewhat flexible and follow the perforators in the nerve pattern as it's going into the muscle. I wish I had a recipe where you would come in with a template and you just cut it to that template. I think being flexible with the perforators and then adjusting that design of where the vectors are going to come in, I think that's still the area that is more the art of surgery and the finesse that I'm working on.
(10) Advances in Free Strap Muscle Flaps & Future of Facial Reanimation
[Dr. Shiayin Yang]
I want to segue into-- we talked about different types of muscles that can be used. Previously, latissimus has been used, serratus, gracilis, but also, Dan Allen published on using the sternohyoid. Now recently you've published on using composite sternohyoid and omohyoid. The advantage of using your strap muscles is that as we were talking, the gracilis is big. It's bulky. It's also a different type of muscle compared to your facial muscles. The strap muscles are very similar in size. They're close to the operating field and then they're of similar muscle type to the facial muscles. Tell me about this. What made you venture into trying this flap? How was it? What did you think? Do you think you're going to try and incorporate it more into your practice?
[Dr. Myriam Loyo Li]
Yes. We have been doing free strap muscles for dual vector reinnervation at OHSU, and we're playing with making the omohyoid also be a third vector. It's something new that we're doing and exciting. We've been doing it for four patients that have had good movement, but that is the total number of times that we've been doing it. I should mention that I don't do this free muscles by myself. I am always doing them with a team. Lori Howell, Mark Wax, and Ryan Li helped me harvest. Really, Ryan, who is my husband, is the lead on harvesting the free strap muscles. It's sternohyoid and omohyoid.
I really learned this technique from Marc Hohman. Talking to Marc Hohman at Madigan Army Center, they were already doing it, and they had at least 10 cases under their belt, and he really encouraged me to do it. It was something that we've been thinking about for a long time. We've been really impressed and really happy with them. The sternohyoid and the omohyoid will already be covered in their fascia, so there will be no need to do dissection within the bulk of the muscle. Then once they're harvested, they're really small flaps, so they tend to be around 20 grams.
Just as we were talking about the adhesions between the muscle and the skin, these are already covered in their fascia, which should allow them to move and not adhere as much as a free raw muscle edge might. The sternohyoid has been our vector one from the oral commissure to the lateral area, and omohyoid, which is long, has been our vector two. We're mostly discarding the posterior valley, and then we're plicating it. Where we're plicating is just where we're seeing that opportunity to work on the lower eyelid.
There's no leg wound, so it doesn't affect their ambulation. I had a patient that ended up on a trip to Europe a month after having their free strap muscle, and they're strong. They're moving well and smiling. I think they need more experience. Not every patient will be a candidate. Definitely, our head and neck cancer survivals won't have the strap muscles and the vascularity.
[Dr. Shiayin Yang]
Can you explain what nerves are you using? What nerve is based off of what artery?
[Dr. Myriam Loyo Li]
Yes. I think the challenge in this harvest is that it's a very meticulous dissection with small perforators. The challenge really is the arteries and veins. We've been using superior thyroid artery, common facial vein. We've mostly been able to identify two veins, so thyroid vein was also used. The innervation, which was really your question, has been the free strap muscles have the advantage that they are already made to have dual innervation. You have ansa cervicalis and you have ansa hypoglossi, and they both innervate both muscles.
[Dr. Shiayin Yang]
Also, are you doing this as one stage? Because technically, it should be long enough.
[Dr. Myriam Loyo Li]
Oh, I haven't brought one over to the-- I haven't brought it over to the contralateral, the nerve long enough to the contralateral. I haven't done that. I've been doing them as two stages. I've done them as a single stage for a rescue for somebody who we're doing a cross-masseter. I see a lot of potential and advantages on using the free strap muscles. They're compact and small and they're already covered in the fascia.
When we're fully harvested, it's around 20 grams. We'll use the sternohyoid, which is the stronger muscle for the oral commissure, and then the omohyoid for the upper lip. You can plicate it and start using it for the lower eyelid. The challenge is in the arteries and the veins.
[Dr. Shiayin Yang]
Yes, because they're considerably smaller, I would assume. What is the team insetting them into?
[Dr. Myriam Loyo Li]
We've done both where we've gone to STA, in superior temporal artery and vein, and we've also gone to facial. We make those work. It's more the veins coming from the harvest and not injuring them during the harvest. Then the free strap muscles will come with ansa hypoglossi and ansa cervicalis. You are able to do dual innervation if you want. We have only done it in two stages. I put a cross and then we connected.
Theoretically, you probably have enough length to do it as a single stage and put a smaller cross over. We've done it at a single stage when we're doing single innervation. Because you have two nerves, it's really an ideal setting for dual innervation, and both nerves will innervate both muscles.
[Dr. Shiayin Yang]
Have any of those patients been out long enough for you to see outcomes? I realize in terms of comparing, it's too limited, but any thoughts?
[Dr. Myriam Loyo Li]
Yes. All of the four that I talked about are all moving. They're all out long enough that we know that they're having movement and excursion. I'm on the process of comparing my multivectors to the straps. Hopefully, I'll have more information for you guys.
[Dr. Shiayin Yang]
Was there any difference in terms of time to movement between just your regular practice that you saw?
[Dr. Myriam Loyo Li]
No, there really wasn't. I haven't done that many cross-masseters, and one of my straps is a cross-masseter. I was impressed that even the cross-masseters were starting to get movement within that three, four-month mark that you would expect for somebody that has masseter as part of their innervation.
[Dr. Shiayin Yang]
I think that's really cool. I think it was something that I first learned about it. I do mission trips with Dan Allen. He was talking about how he used that a lot in his practice, or he still does it in Hawaii. Just intuitively, it makes a lot of sense because they're a lot similar in size. He had done some histologic work in terms of the type of the muscle. It could be something really awesome to see if that's an evolution to something different.
[Dr. Myriam Loyo Li]
I've been really impressed and really happy with them. I know that Dr. Hohman continues to do them. It's his preference. He will always choose a strap if it's an option over a gracilis. I haven't had to abort anyone yet, but I do talk to people about that. If we don't have the proper vessels, we will have the option of going to the leg. It takes a certain type of patient to want to do something that is relatively new and innovative versus something that's tried and true.
[Dr. Shiayin Yang]
It's really hard because these patients have already gone through so much. They're just trying to get their best shot. I can imagine how it would be hard to find the right candidate for these flaps.
[Dr. Myriam Loyo Li]
I do think we're going to see more of them. Hopefully, one coming from you, Shia.
[Dr. Shiayin Yang]
I've heard that the dissection is quite tedious. I don't do that personally, but I think it would be really cool. I know we've been going for quite some time, but this has been awesome, Myriam. We always talk about it at meetings. I love hearing just the way you do your practice, how you do things differently, bouncing out ideas. [crosstalk]
[Dr. Myriam Loyo Li]
Thank you, Shia. I think we're going to get other people who do the surgeries to time in and listen. Hopefully, I'll get some feedback on how they do it and get tips from other people, because I think a lot of the things we talked about are that border between we know we have good evidence or this is how I do it. Thank you for asking my thoughts on this. This has been an awesome conversation. I could keep going on it.
[Dr. Shiayin Yang]
Yes. I'm so happy that you were able to join us today. It's hard for us to connect, just given we're cross-country. If people want to find out more about you, they can find you at OHSU. Do you have a social media account if they want to learn more?
[Dr. Myriam Loyo Li]
Yes, it's @drmyriamloyo in Instagram and then the OHSU webpage as well.
[Dr. Shiayin Yang]
Awesome. Thank you so much for joining us today.
[Dr. Myriam Loyo Li]
Thank you.
Podcast Contributors
Cite This Podcast
BackTable, LLC (Producer). (2024, November 5). Ep. 198 – Advanced Techniques in Facial Reanimation [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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