KATHRYN VAN ABEL: All right. Today we're going to be talking about superficial parotidectomy. It's one of the most common surgeries that we do during your residency training and beyond.

The indications for superficial parotidectomy are many. We approach this area when we're looking for tumors within the parotid gland itself, when we're looking to see if there's any spread of tumor from something else, such as a skin cancer in particular. However, the most common reason that we do a superficial parotidectomy is when we're trying to remove a tumor from the parotid gland itself.

The most common tumors within the parotid gland are going to be benign. We traditionally think of 80% of the tumors within this gland as being benign, 20% being malignant. The most common tumor that we remove from the parotid gland is a pleomorphic adenoma, and we're going to be reviewing the resection of a pleomorphic adenoma in the following case.

As with many cases, preparation is key. We want to think about the monitoring that we do for facial nerve dissection. This requires placing a four-lead facial nerve monitor. There is data that placing a facial nerve monitor does not improve the safety of the operation, and it's always important that the surgeon operates based on their understanding of anatomy and not necessarily based on the feedback given to them by a facial nerve monitor.

However, when using a monitor, it is imperative that you understand how it works. We typically place four leads. These need to go through the muscles of facial expression, so not just through the skin. We place the red near the lip, so think red for lip, blue for eye.

Purple goes on the chin, and you can think of this as a Purple Heart award, so it goes down by the heart. And then orange is the only one left, so it goes up on the forehead. You have to place two leads separately from-- two leads also need to be placed separate from the face, and these are considered your grounding leads.

There's a green and a white needle. These should be separate and not touching each other. Typically we place these in the shoulder, and these will be inserted into your facial nerve monitor box, which we'll show you shortly.

With all of these, we typically wrap at least one loop and then apply a Tegaderm over the top. This allows for a failsafe. If someone were to tug on the wire, then we would know that it wouldn't pull the needle out first. It would just pull the wire loop.

Each of your leads should be placed into the corresponding color coordinated part on the box. And then the green and the white lead should be placed accordingly so that you can get good stimulation. Next, we have to set up our nerve monitor, which is being shown here. You need to make sure that it's set up for the lead facial nerve monitor, each of your muscles is giving you proper feedback.

Then you can go to your monitoring section or monitoring tab at the top of the box, and you want to look and make sure that it's set up at 1 milliamp and 100 microvolts. Then when you tap on each lead, you'll see feedback in that specific muscle. So you can see here that all of our leads are functioning properly.

Next, we mark out our incision. This is going to be a preauricular incision with a modified facelift approach. It's important that you think about right angles, a right angle underneath the ear, a right angle at the hairline, and a right angle where it would come back to form your neck incision. The neck incision should be made two finger breadths below the mandible, thinking about where the angle of the mandible is and where your external jugular vein is.

Next, we inject 1% lidocaine with 100,000 epinephrine, taking care to do this in the subcutaneous area, not too deep within this subcuticular tissue. The difference is that we want to make sure that our skin doesn't bleed, but we don't need it down in the soft tissue where we'll be dissecting through. Often you'll be doing cases for a free flap, where you want to make sure that your external jugular vein is kept safe. To avoid puncturing the vein, you can just skip over the area where you see your vein.

Next, we begin with our prep. Again, preparation is key. It's hard to do your operation if somebody's hair is in the way. So we're going to start with placing a wide paper tape over the ear on either side, making sure that it connects on the forehead and has some contact with the skin. If you carefully peel this back, you'll see that this pulls all of the hair out of the way, and then you can protect the ear to make sure that it's safe.

Next, we do a standard prep with Betadine, extending this all the way down to the collarbone to ensure that you're able to do a neck dissection, if necessary, and extending over to the midline. Remember after your scrub, to do your paint. This is done with the same area in mind. Dry and remove your towel carefully to make sure that you don't contaminate the wound.

Next, we'll begin draping. The person who typically lifts the head, and then your scrub tack will be able to place the towels underneath this for their head drape. The head drape gets draped around and they consider where you prep to, so make sure that you prep a little bit a larger area than you think you need. So that way, if the drape slips a little bit, you know that you're protected.

The next step is squaring out your surgical field, taking care to prep all the way to the side and all the way down in case you need to do a neck dissection. When you place the drapes, there is a sticky part that you want to extend down to the head rest, but not the head itself so you can move the head side to side during surgery.

Next, we'll begin with our incision. You want to make sharp right angles at each of your corners, keeping your knife perpendicular to the skin. When you make your postauricular incision, you lift your ear lobule out of the way, and again, right angles at the infra-auricular portion and the postauricular portion.

Next, we're going to place double-prong skin hooks and then try to identify our parotid fascia. This is underneath this mass, so you want to be looking for this layer as well. Keys to this step are good retraction of the skin upwards, away from the wound, and then the back traction that your assistant's providing or you're providing with your index finger, and then the counter traction with your thumb within the ear. You want to keep your tips up until you get over the top of the parotid gland, and then some providers continue with SNPs and some go with spreads. I think it's nice to use a spread so that you can look down to see if you can find your masseter muscle.

Next, we're going to start working underneath the ear to try and find our great auricular nerve. Once you find the nerve, you're going to follow this superiorly towards the ear, dissecting up and laterally so that you're able to dissect the entire course out up to the ears and protect the postauricular branch. Next, we're going to ensure with this facelift incision that we have adequate exposure. It's important that you're over the entire parotid gland.

And in this area, you want to be looking for your external jugular vein. And at this part, is nice to be able to cut sharply to divide this sternocleidomastoid muscle and keep that muscle intact and down. And that's why it's nice to have your great auricular nerve exposed so that you can cut here with confidence. Once you have adequate exposure, you're going to use at least three fishhooks to give you proper retraction.

The pre-tragal tunnel is important, and it's important to do a wide spread, making sure you get over the top of the cartilage. You want to be able to feel with your finger down to the junction between the cartilaginous and bony ear canal, and if possible, down towards the tympanomastoid suture line.

No surgery is without bleeding. It's important to know how to control this. If it's in an area that you can't safely bipolar, you can simply place a towel. Now we'll begin with identifying our posterior belly of digastric.

You want to keep your posterior branch of your great auricular nerve safe and in view while you're doing this part. You can use cautery to separate some of the tissue from in front of the ear, making sure to protect your great auricular nerve. You want to palpate the angle of your mandible and think about where that position is to find your posterior belly of the digastric.

You want to think about the projection of the muscle between the mastoid tip and the hyoid bone. Place your finger with the pad up towards the angle of the mandible and your fingertips should be on the posterior belly of the digastric. Here you can see the posterior belly coursing appropriately from the hyoid to the mastoid, right underneath the angle of the mandible. Then we can start dissecting back up along the posterior belly of digastric towards our mastoid.

Now we have our pretracheal tunnel and our posterior belly of digastric and we can start dissecting through the soft tissue, between these two points. Typically, we like to use blunt dissection, and you want to cauterize only if you know that you're up and away from the nerve.

We want to use a mosquito and some good retraction here to start working bluntly through this tissue. You want to spread and only take tissue that you can see through, so thin tissue, which is not going to be the nerve. Your assistant should always bipolar parallel to your tips and pull away slightly from the tissue underneath to ensure that they don't pass point or accidentally cauterize anything underneath the area that you're presenting to them. Similarly, with the scissors, you want to bring your scissors in parallel to the mosquitoes and ensure that you can see the tips on both sides so you know what the blades of your scissor are cutting through.

As we work through this tissue, we're going to work on a broad front, ensuring that we don't dig ourselves into a hole so that we have the best chance of finding the nerve and protecting it. Many people talk about whether to leave some parotid tissue or to try and dissect all the way behind it. It's OK to start marching your way anteriorly through the parotid tissue to find the nerve. And if you need to, you can take the remainder of the tissue afterwards.

When dissecting out the main trunk of the facial nerve, you have to think about your landmarks. The most common landmarks we use are the tragal pointer, which is the medialmost point of the tragal cartilage. It's the pointed end of the cartilage off of the external auditory meatus. The nerve exits the foramen approximately 1 centimeter deep and 1 centimeter inferior to this point.

The second landmark people talk about is the gastric ridge. This is where the posterior belly of the digastric attaches to the mastoid tip. The facial nerve will run at the same depth below the skin surface and bisect the angle between this muscle and the styloid process.

Next is the temporal mastoid suture line. This is actually the most precise landmark for the facial nerve, as it leads medially, directly to the stylomastoid foramen, where the facial nerve will exit. The next landmark that you can use is to do retrograde dissection to get yourself back from one of the peripheral branches to the main trunk of the nerve. And finally, one can work from the mastoid, so drilling out the mastoid via mastoidectomy to find the main trunk of the nerve and then follow this out into the soft tissue of the parotid gland.

Once you've found the main trunk of the facial nerve, you want to identify the pes anserinus. This is where the main trunk of the facial nerve branches into the upper and lower divisions. So you place your mosquito onto the mastoid tip and rock on the mastoid tip so that you don't put pressure onto the nerve itself. As you do this, you're going to lift up and out, and peek underneath the bridge of tissue you create to try and identify that pes anserinus. You can see that the upper and lower divisions are now visible.

Then, depending on where your tumor pathology is, you'll either dissect out the upper or lower divisions first. You want to do this by bringing the tips of your mosquito along the top of the nerve, and then coming up and out laterally, away from the main bunch of the parotid tissue, allowing your assistant to bipolar and cut, as we've discussed. With each step, you continue following along the main trunk of the nerve and along each of the major branches, working your way from the most peripheral section towards the central section of the parotid tissue.

You want to make sure that you can see your nerve down. We often tap with the bipolar to see whether or not we get any facial twitching or feedback from the facial nerve monitor. One of the critical techniques in parotid surgery is tension-countertension as you dissect out your nerve, and making sure that you don't put pressure on your nerve and injure it while you're dissecting along it. By placing a finger on the proximal part of the nerve and pulling it towards you, and having your assistant using their retractor to provide you some countertension, you can use your mosquito and rock on your finger as your fulcrum to dissect out the nerve.

Next, it's important to palpate your tumor and always keep it in mind as you're doing your dissection. You never want the tip of your mosquito to ever go into the tumor accidentally. You always want to understand the relationship of the tumor to the nerve underneath, and using your fingers as a guide, it can really help you do this.

You can see here that we're dissecting underneath the nerve, so I'm being very careful to keep the tips of my mosquito away from the tumor itself. But again, following our good parotid dissection techniques, using tension and countertension, trying not to fulcrum on the nerve itself, using my finger to provide back tension, keeping my tips away from the tumor. And in this way, we can follow out the nerve, which fortunately in this case, is running underneath the tumor.

Also in parotid surgery, you'll notice that despite our best efforts, the nerve often has a mind of its own and is anastomosis in patterns that are unique to the patient itself. So you always have to follow the nerve and make sure that you connect from the main trunk or the pes to the periphery outside of the tumor. You're going to work your way down along the nerve to try and identify each of the remaining branches.

So working our way inferiorly, we can see areas that are tinting. And once we know that we've dissected out each of those branches, we can turn our attention to the inferior division. It's typical to exchange places with your assistant at this point so that you're standing at the furthermost part of the top of the head and your assistant is below you to the right.

As we dissect the inferior division down, you always have to work around your retromandibular vein. The nerve can go both under and above this vein, and it's important to understand that relationship, to pause and take time to investigate as you go around this vein. Sometimes you can use a vascular forceps to pick up the vein and ensure that you keep the nerve in your sights the entire time.

It's often that we have little blood vessels that go over the nerve, and sometimes it's hard to understand how to manage these. Typically, we try and avoid bipolaring right on the nerve. And so you can grasp this and bring a clip in, making sure you clip away from the nerve fascicles to stop the bleeding. If you're ever nervous about this, you can simply wait, apply pressure, and most bleeding will slow down or stop.

After we've dissected out the superior and inferior division, everything will be pedicled on the mid-face branches. You want to make sure that you still dissect out any large branches until you can see them go all the way from your pes or your main trunk to the periphery outside of the range of your tumor. You can see that there's a three-dimensional landscape that you're operating around, and you want to make sure that you adjust the angle of your dissection to that landscape, both coming up in front of the masseter muscle and then going down and transversely as you go over the top of the mound of the parotid tissue.

Now we're holding the parotid gland in the tumor in between our fingers. So you take it from your assistant and you work horizontally through that tissue until you find the duct. You'll clamp this, and you can cut the part that goes towards pathology and then tie off the duct to prevent any infection.

It is not unusual to do a superficial parotidectomy and not find the duct. You don't need to go looking for it, unless you're doing the productivity for chronic infection. In that case, you should look for the duct and ensure that you like it. Remember that several buccal branches will be closely adherent, as in this case, to that duct, and so it's important that you've dissected out each of these branches and make sure that you keep them safe.

This completes the superficial parotidectomy. You can now see that we have a nice network of nerves well exposed. You then irrigate and remove any remaining blood clots and blood products from the wound. You can cauterize with bipolar cautery to ensure that you have good hemostasis, remembering to avoid cauterizing or thermal injury to the nerve.

So to review our landmarks, we have our pes anserinus, our inferior division, our superior division, our buccal anastomotic division, the retromandibular vein, which here is going underneath the inferior division and the marginal mandibular nerve. We've got our posterior belly of our digastric coming from the hyoid up towards our mastoid tip. We also have where our pre-tragal dissection was and our tragal pointer. Out laterally, we have our great auricular nerve. You can see there is our angle of our mandible, just for reference.

Now we'll remove all of our tractors. We'll remove our fishhooks and we will place a drain. You do this by dissecting underneath the skin out towards the hairline. Make a single stab incision into the skin. We can then pass a mosquito through this and then join this with a second mosquito and allow it to draw the second mosquito into the proper location.

The drain is then passed through the skin. Make sure that your drain hole is wide enough to allow the drain to come easily out, but not so wide that it will slip out and not function properly. We then place a drain stitch with an O silk suture. You want to do this by grabbing a decent amount of skin so it doesn't come out through the skin, tying an air knot, and then affixing this with a surgeon's knot to the drain, making it snug enough so that it won't come loose, but not so snug that it kinks the tubing.

I like to do this just at the first part of the taper so that way the knot is not so loose that it allows the thicker part to come out through the skin. Typically, do two knots and do this in the Roman sandal technique, where you pass the suture around the back a second time. You pass the drain tube underneath the skin. And then using a heavy Mayo scissor, trim this to fit your wound appropriately.

Next, we begin with closure. Everybody closes their wound differently. I like to use 4-0 Vicryl and close each of our points first. You want to make sure that you take the same amount of tissue on each side and try and line up our right angles. So we have a right angle here in the skin. You can mark this with a small nick at the beginning of your procedure, but most of the time you can see this if you look carefully for it.

We always do a single interrupted suture, burying the knot. I like to snug it down and then pull the stitch toward myself to get the knot to lay down in the deep position. And then we do four knots, and your assistant will cut down right on the knot to try and bury the tail. Next, we're going to close the postauricular point. We do this in the same fashion.

One thing you need to take care of is not to squeeze too hard with your forceps on the skin you're grabbing, especially in someone who's at high risk for keloids. You can cause trauma to the skin and a worse outcome for their scar. This is done in the same fashion. We'll pull the knot down, do a total of four knots, and then cut.

Next, we'll close the triangular portion of the incision, which we always place above the tragus. Again, you want to be careful not to squeeze this tissue too hard. It's easy to do. You certainly need to grab it, but be sure not to squeeze too hard. It's also why we used a tooth forceps, so it doesn't apply a continuous large surface area of pressure onto the tissue.

When you're closing, you want to place enough stitches so that you provide strength to the wound, but not so many that you strangle or injure the tissue. So we'll work in by having the different segments of the incision and then closing this until we can't get an instrument between them.

If you place a stitch and you don't like how it brings the tissue together, if the sides are mismatched, you should cut out the stitch and replace it. Everybody has to replace stitches every now and again.

This is an important part of closure. It's important that you stretch. This incision out to its full length so that you adequately close and appropriately close each side of the incision. It's not uncommon for us to have bunching of the skin in this area. And I believe that with proper closure, we can avoid this for our patients. They often collect debris here and it's not very nice to look at.

So having an assistant who can really pull that skin forward for you to make sure that you get this lined up properly will help, and it will help your patient. You're often closing this by yourself without much assistance. But if you ask your scrub tech to help you with this, it will certainly be feasible for you. Then we continue with having our incision and closing until we can't easily pass a forceps between the two knots. And I recommend always using a forcep when you're closing and trying not to close with your fingers, to avoid needle sticks.

Next, you want to blot dry and keep the blood out of your field as you apply your Dermabond. This is the part that your patient's really going to see, and so if it's messy with blood and Dermabond, they're going to notice that. However, often you can't avoid a little bit of blood under your Dermabond. You want to keep it from dripping, again, because this is what your patient's going to be looking at and that Dermabond stays on stays with them for about two weeks.

Next, you want to make sure that your drain tubing is working. And that will complete your procedure.