Podcast Transcript: Management of the Plunging Ranula

[Dr. Ashley Agan]
Our go-to medications. Great. Let's talk about surgery, then. We've decided we're going to take the patient to the operating room. Can you talk to us about the setup? Are there certain instruments that are really vital to being able to do what you need to do?

[Dr. Gopi Shah]
What's on the Rohan Walvekar card?

[Dr. Ashley Agan]
What's on your back table?

[Dr. Gopi Shah]
Yes, what's on your back table?

[Dr. Rohan Walvekar]
That's a good question. Again, you don't need a lot. I do have a sialendoscopy set available to me. I tell them not to open it in the beginning because I don't want to do an endoscopy if I'm not going to be able to cannulate the duct. Although the setup is pretty straightforward, a Minnesota retractor is helpful. Sometimes the Jennings mouth gap can be helpful, it's really a good instrument. It's meant for edentulous patients, but even for patients with teeth, if you use it correctly and without too much force, it can really give you nice wide mouth opening.

One of the tricks that I've used with robot cases which sometimes helps me just in better oral exposure is using single hooks or the facial retractors. I may sometimes use them to give me a retraction of the buccal mucosa just so I can get more light in, but that's just case-by-case-dependent. Other than that, Colorado tip bovie, I find that the angle tooth forceps from the sialendoscopy set are quite helpful because in terms of just grabbing the sublingual gland, but you don't have to have them. Then of course, if I do plan to cannulate the duct, then I'll usually put a stent in for the duration of the procedure just so that I can see it better.

The submandibular duct is so closely and intimately associated with the sublingual gland. It's important to note that. Anything that can help you identify the submandibular duct as you kind of manipulate the gland and flip it over and stuff like that is important because otherwise, you'll go through it. One of the things we didn't talk about in preoperative evaluation and the consenting is the lingual nerve paresis. That's a real thing. It can happen.

You have to be a little familiar with the floor of mouth anatomy to be able to make sure that you don't injure the nerve. It rarely gets injured. The sublingual gland peels off very nicely from the floor of the mouth, but again, it's important to note that you should talk about lingual nerve paresis. I think those are the basic things. I definitely have a bipolar on board. Don't necessarily need to have a harmonic. Harmonic is usually always on my cart, but for these procedures, you don't really need one. That's pretty much it.

[Dr. Ashley Agan]
When you stent the submandibular duct, do you just regular lacrimal probes or do you use the—

[Dr. Gopi Shah]
How do you cannulate?

[Dr. Rohan Walvekar]
Yes, great question. If you want me to talk about how I would approach this case, okay, as far as intubation is concerned, I'll think about the mouth opening that I have available to me. Generally speaking, I prefer not to do nasal intubations, they're just too traumatic, but if I absolutely need to, I will consider it so that I get enough space to work. Otherwise, a standard oral intubation, a tube to the other side, I'll usually use one of those joker retractors or smile makers or buccal mucosa retractors, whatever you'd like to call them, to help just keep the buccal mucosa retracted, a bite block in place is usually good enough to be able to give me exposure of the floor of the mouth.

Then the next thing I'll do is examine the papilla. If the papilla is, on palpation, I can see the papilla nicely, then there are two types of dilators you can use. Actually, three types of dilators. You have a Marchal Dilator system, which is a rigid dilator system created by Francis Marchal. It goes through a set of seven dilators, and the first two are very helpful, the 4.0 and the 3.0 just to cannulate the duct. After that, I feel sometimes the Marshall Dilator system is really difficult to get through because you have to keep cannulating the duct like five, six times to be able to get the right amount of dilation to be able to put the scope in.

Barry Schaitkin from Pittsburgh created this dilator called the Schaitkin Dilator system, which is a set of five fluted dilators. Those are very nice as well. You have to get through fewer dilators to be able to do the job to able to cannulate the duct and do an endoscopy, but again, I think there is some value in the 4.0 dilators that the Marchal Dilator system brings to the table. I tend to use the Schaitkin Dilator systems because, again, once you cannulate the first time, it's very easy to just get through two or three of them and you're done.

Then, of course, you have the Guidewire system. Cook Medical USA has a guidewire and a bougie system which is very good. You can just pass the flexible tip guidewire and then just serially dilate with the Cook dilators. Generally, if you dilate to a number four or five, I would say number five or six, you can pass a 1.3-millimeter endoscope into the duct. That's what I would start the procedure off with. If I can't see the papilla, well, I can't cannulate it easily, I'll just let it be. Because I know that the ranula is changing the anatomy where I can't cannulate it.

I've proven later on that it actually turns out to be true. Once the ranulas decompress, the sublingual gland is out, I can see everything, and then it's much more easier to cannulate the duct and just make sure that the patency is there. If I can do it ahead of time, then once I'm dilated, I'll do a quick endoscopy, just a quick diagnostic endoscopy, and then replace the endoscope with a 1.2-millimeter stent and just put a loose stitch in it with a 4-0 nylon stitch just to keep it anchored there for the duration of the procedure.

There is a specific advantage to putting the stent in, but I can talk about that later as well because I know I've been talking for a while, so if there's anything else we need to talk about on this part of the procedure, let's definitely answer those questions.

[Dr. Ashley Agan]
The stent that you're talking about is your stent that you developed, yes?

[Dr. Rohan Walvekar]
Yes. I mean, I use my stent. There are other stents available. Schaitkin has a stent through Hood Labs. My stent is also developed and manufactured by Hood Labs, which is a very nice company based in Pembroke Massachusetts. It's a small company, but they're very responsive. You can also use infant feeding tubes, but again, you can even leave a Cook catheter in place if you'd like. The reason why I put the stent in is because it has a flange, it has a way to anchor it to the floor of the mouth, then I don't have to keep worrying about the stent or whatever I put in the duct falling out every few minutes.

[Dr. Ashley Agan]
I like your stent because on the Hood website, it has a video for how to sew in the submandibular duct stent, and it's got a video for the parotid stent, which is very well done and it's very helpful. I've left in the lacrimal probes as a "stent" to help me identify it, and it's just like five minutes in, it's like half an hour, I'm like trying to put it. It's just like, okay. Yes, it gets frustrating. The stent is very helpful.

[Dr. Gopi Shah]
Is your stent, how long is it? Is it pretty much the length of the entire submandibular duct?

[Dr. Rohan Walvekar]
Yes, I think it covers the submandibular duct length and so obviously also the parotid duct length. It has two ends to it. One is specifically designed so that it lays flat on the floor of the mouth and the other end is perpendicular to the stent itself. The other end has a perpendicular flange, which will nicely seamlessly lay flat on the buccal mucosa. It's a double-headed stent. That's what the patent was around. Whichever end you need, you just cut off that end and then you can use the stent. It becomes really helpful that you don't have to pull out two stents for the parotid and the submandibular. You can pretty much use one stent for two purposes.

[Dr. Ashley Agan]
Yes. That's nice. Once you got your stents, and that's just helping you know where your duct is so that you don't injure it. Right?

[Dr. Rohan Walvekar]
Yes. There's another advantage to that, Ashley, which I'd like to point out, is that when you try to remove the sublingual gland, you have to make a floor of mouth incision. If you don't know where the stent is, then you tend to make that incision a little bit off the-- like the dome of the floor of the mouth where you expect this submandibular duct to be. What it results in is you'll have just a very small amount of mucosa, then to sew back together at the end of the procedure.

Now that you know where the stent is and you have a visual and a tactile way of identifying it, you can actually make the incision on the middle of the floor of the mouth right over the stent because then that gives you a lot of floor of the mouth mucosa to work with to put things back together.

[Dr. Ashley Agan]
Yes, that makes sense.
[Dr. Gopi Shah]
On sialendoscopy for the plunging ranula, what do you expect to see? Because I'll be honest, that has not been traditionally routinely part of my plunging ranula or ranula management in the OR.

[Dr. Rohan Walvekar]
I don't expect to see anything, any pathology, but I do expect that, when I try to do the endoscopy before I decompress the ranula, that I'll have more resistance to doing the endoscopy. Then after the ranula is being decompressed and the sublingual gland is being removed, you can pretty much get to the hilum of the gland. That's like an obvious anatomical stricture that happens because of the presence of this excessive fluid in the floor of the mouth or just abnormal sublingual gland.

The other thing is that the main reason for doing the endoscopy is to make sure that the patency of the submandibular duct is intact at the end of the procedure. You don't want to inadvertently have injured the submandibular duct and not know about it. It's, again, a matter of weighing the risks and benefits. If you find that you're pretty confident about the submandibular duct being intact, then I wouldn't necessarily try to cannulate a papilla that is not lending itself to easy cannulation.

[Dr. Ashley Agan]
How long do you usually give? You said, "I'll give myself some time, and if it seems like it's not in a good place, the papilla doesn't want to work with me today to cannulate." How much time do you usually give yourself?

[Dr. Rohan Walvekar]
That's a good—

[Dr. Ashley Agan]
Is it like a 10-minute decision because you're the expert on this or-- Because sometimes we're like 20 minutes, 25 minutes in, and it's like, "God bless. I don't know if I can do it."

[Dr. Rohan Walvekar]
No, 10 minutes is too long. If I'm doing a ranula, then-- There's two different scenarios. If I'm doing a ranula and I can't cannulate it, I'm done. Within 30 seconds, I'm moving on to doing the ranula removal, sublingual gland excision, and then I'm going to come back to the submandibular duct as something that I just want to make sure that I can do at the end. If I can't, then I'm going to say that, yes, we just do the ranula excision and not unnecessarily traumatize the submandibular duct.

For sialendoscopy cases, I will spend some time on it. I will try to cannulate the duct. I spend at least a few minutes on it before I would say that this is really not happening. I try to think about people who advocate that, and I think about Barry Schaitkin. He has been my mentor forever, and he always says that slow down and try to cannulate the duct. Because if you do cannulate the duct, it saves so much trouble for the patient.

I'll give myself a few minutes and try a few different techniques, like maybe trying different dilators or maybe just injecting around the papilla or sometimes painting the area with methylene blue, anything I can do to make sure that I can cannulate the duct. If those things don't work, then I'll move on to a papillotomy.

[Dr. Ashley Agan]
Are you wearing loupes or do you like a microscope?

[Dr. Rohan Walvekar]
Yes, I wear 3.5X loupes. They really serve me well. I think the microscope in my hands is very restrictive. I feel like there's a lot of open component to what we do with transoral surgery, and so the microscope can sometimes be challenging to use. Those people who do use the microscope do it well, and both their hands are free and it really is an advantage in many ways to use the microscope.

[Dr. Ashley Agan]
Moving on to removing the sublingual gland, so now that you've identified your submandibular duct, then what comes next? Specifically, when we were talking about the anatomy of the floor of the mouth earlier, do you go looking for the lingual nerve so that you can protect it or—

[Dr. Rohan Walvekar]
This is a great question. We are talking about essentially how do you remove the sublingual gland, how do you approach this? Once you make your floor of mouth incision, know that you're going to have some layers of minor salivary glands before you get to the submandibular duct. Once you make your floor of mouth incisions, I almost try to peel off the mucosa and go towards the lateral aspect towards the mandible. When you do that, you start seeing a very nice plane develop between the mucosa and the sublingual gland.

I try to start there to be able to see that nice, what we call in Pittsburgh flim-flam. That's that nice fibro-fatty tissue. That's how I was trained in Pittsburgh and brought it to LSU as well along with my other colleagues from Pittsburgh. Flim-flam is always a good thing. You get into that space between the mucosa and the sublingual gland laterally. Then anteriorly, it's important to get deep enough where you are seeing the submandibular duct to the midline, towards the tongue, and you basically go down to identify your mylohyoid muscle. Then you peel that back and connect it to your lateral dissection.

Now you have to make a commitment also to cut the sublingual gland at some point. Remember that the sublingual gland sits in the sublingual fossa, but the minor salivary gland comes over the submandibular duct. Once you've identified the submandibular duct, whatever is over it, you just make an incision and push it laterally. Now you have basically an incision towards the midline, you have a dissection laterally, and you where your floor is. Then you start peeling the whole thing back.

The important thing here is that you have to expect the lingual nerve branches to come. How are they going to present to you? They're going to present to you in a way that they come from lateral to medial towards the duct. If you keep that in your mind, you'll be able to see them much more easily. There is a lot of vascularity here. You'll see some pretty big bridging veins that come from the middle of the floor of the mouth and towards the posterior lateral aspect of the floor of the mouth, so expect that to happen. When you do see those, I stop, take the bipolar, make sure I really cook them well before I take all of it out.

The suction, like a Pynchon, like a pediatric Yankauer suction, is a really good tool to be able to push into this space once you find it over the floor of the mouth and to just do one swipe and dissect your sublingual gland all the way to the back. The last part of this is that you will see a lot of this just come together very nicely as you do it. At some point, the sublingual gland, if you look at those illustrations from our anatomy books and you see the deep portion of the submandibular gland and how it creeps over the mylohyoid muscle and then they show this sublingual gland just in front of it, in reality, that's not how it is. They're almost together.

When you want to make that posterior cut of your sublingual gland, you have to look for change in texture of the glandular tissue that you're cutting. You'll clearly see that the submandibular gland is much more integrated than the sublingual gland. It has a different color to it. It is much more globular and rounded, and then you can basically make a cut at that point and take out the entire gland. It's a big piece of tissue to remove the entire sublingual gland.

[Dr. Ashley Agan]
I'm glad you brought that up because it is hard to tell. It's this blob and you're just going and going and hoping that you see that submandibular gland and then you see mylo. Like you said, they're not that common, but I think for the one or two plungings that I've had in the last couple of years, I think one of them, I was like, "Oh, there's a defect in the mylo. Okay, that's cool. We got some saliva out." We're still like, "Okay, where do we take this? Where does the gland stop?" Sometimes that decision-making can be tricky because it's hard to tell the difference in the textures of the gland, I think, grossly.

[Dr. Rohan Walvekar]
Absolutely. I have a publication that we did with transoral use of robot for sublingual gland excision. Again, I think it's overkill. I think you don't need a robot to remove the sublingual gland. In some cases, if you really have problems with access, it could be an advantage. The point I'm bringing is that there's a video in that publication, which is really nice because it shows you the posterior extent of the sublingual gland and where you need to cut it off.

[Dr. Ashley Agan]
Very cool. You're peeling it from anterolateral posteriomedial direction? Correct?

[Dr. Rohan Walvekar]
Yes. Then you have to know your limits. Your limits are going to be, the floor of the mouth is going to be your lingual nerve first, and then your mylohyoid muscle, because it'll be on the mylo. Your most medial limit is going to be your submandibular duct, and your posterior limit is going to be your submandibular gland, the superficial portion. Then the lateral aspect is the mandible. Once you put that in your mind, then it becomes a lot more easier to make a decision about where to start and where to stop.

[Dr. Ashley Agan]
Then, as far as management of the ranula itself, you mentioned earlier it's a pseudocyst, so it doesn't have a thick wall or capsule in the way that other cysts might. What do you do for that part of it?

[Dr. Rohan Walvekar]
Great question. Once the sublingual gland is removed, 90% of the time, the ranula will decompress because it'll just be right there, it's all connected. All you have to do is just decompress the fluid and you're done. Sometimes when the fluid doesn't decompress, I'll use a hemostat, and I'll basically try to explore that space and try to pop into the ranula, and I'll just decompress it.

Worst case situation—

[Dr. Ashley Agan]
And just massage the external component.

[Dr. Rohan Walvekar]
Massage the external thing and just use a transoral dissection to just get into that space and just open it, just let it all decompress. Then worst-case situation, if it doesn't, then you go externally, take a thick 18-gauge needle, and just aspirate what you can. The important thing is that it's going to go away over time. Theoretically, if you just remove the sublingual gland, the body will resolve the pseudocyst over time, but you don't want it to take weeks for that to happen, and that's why we purposefully decompress the pseudocyst.

It either decompresses on its own, and you remove the sublingual gland or you purposefully make a transoral dissection through the mylohyoid muscle, you just point towards the thing and just open it up like you would open an abscess. I would put patients on postoperative antibiotics and steroids because it is a traumatic procedure and you don't want them to get secondarily infected. A lot of them will continue to have some amount of swelling in the neck, and you have to do a lot of reassurance to tell them that it's going to go away.

[Dr. Ashley Agan]
How do you like to close your floor of mouth incision?

[Dr. Rohan Walvekar]
Just 3-0 vicryls. Again, it's important now that you don't have the sublingual gland in place that you make sure that you don't either injure the lingual nerve while you're making the closure and also, don't injure the submandibular duct.

[Dr. Ashley Agan]
At the end, you do like a quick look at your submandibular duct. Again, if you were able to cannulate it, just take a look and make sure it looks good.

[Dr. Rohan Walvekar]
Yes. I just do a quick endoscopy and make sure that it's all fine, but that's not a necessary component. It always makes you feel better if you could do it. I have to tell you that there was one patient who I did recently and who came to me from another state for management of a plunging ranula. Everything went okay except for the fact that we couldn't decompress all the cyst fluid.

In the weeks that followed, it was challenging to know that this fluid is taking its own sweet time to go away, and I really had to counsel myself and the patient that this is going to happen the way it's meant to be. Sure enough, it did, but you have to invest in that thought process. That's what I wanted to say even if you've done this many times.

[Dr. Ashley Agan]
How long would you wait?

[Dr. Rohan Walvekar]
It took about two and a half weeks. Not terrible but still—

[Dr. Gopi Shah]
It's like post-op swelling, right?

[Dr. Rohan Walvekar]
Yes, kind of.

[Dr. Gopi Shah]
I would have been sitting thinking the same thing, though. Is there ever a reason for these to ever go in the neck anymore or do we have enough data where it's just like, no, you got to take the sublingual gland out and if you can pop that pseudocyst, great, then we're done, or is there ever a reason to anything transcervical over in these?

[Dr. Rohan Walvekar]
I don't think I can conclusively tell people who do a transcervical approach that they're doing the wrong thing, but I can't imagine why somebody would if there's an alternative because it's a mess going through the neck. The best part about doing the transcervical approach is you're not burning any bridges other than removing the sublingual gland. It's also the easiest access to the most problematic area.

My answer to this is I don't have a statistic for it, but based on my personal experience and what makes logical sense to me that you would do the transcervical approach first, understanding that if things by chance didn't work, which would be I would say less than a few percent of transcervical, maybe something totally different and you missed the ball on this, then you can always come back through the neck later. That's how I approach talking to patients and colleagues about what are the chances of this coming back and all of those things.