E36 Masterclass with Todd McMullen On Thyroid Nodules
Listen to this podcast on SoundCloud
Chad Ball 00:15
Welcome to Cold Steel, the Canadian Journal of Surgery podcast, with your hosts Ameer Farooq and Chad Ball. The goal of the CJS podcast is threefold. The first is to highlight the best research currently being completed by Canadian surgeons. Second is to offer educational topics for both surgeons and trainees alike. And most importantly, the third goal is to inspire discussion, thoughts, creativity and career development in all Canadian surgeons, we hope you enjoy it.
Ameer Farooq 00:50
Dr. Todd McMullen is a scientist and endocrine surgeon at the University of Alberta in Edmonton, Alberta. In this episode, we talk to Dr. McMullen about a topic that is sometimes a pain in the neck for trainees, thyroid nodules. Dr. McMullen gives us his approach to nodules, how it works them up, a brief overview of how he does his thyroidectomies, and post-op calcium management. We hope you enjoy.
Chad Ball 01:16
First of all, thank you very much, Dr. McMullen, for joining us on Cold Steel CJS podcast. It's a real pleasure to have you and I'll say out of the gate and in all disclosure to our listeners, I've known you for a very, very long time. I think we knew each other before we even knew we knew each other just growing up in Edmonton and working in various establishments over the years. It's great to have you on, thank you.
Todd McMullen 01:40
Happy to be here, Chad. And yes, we do have a few stories between us going back a few years now.
Chad Ball 01:46
We'll try and keep those out of the podcast for the good of all, so to speak. For those of the country that are listening that might not know you, as well as I do. Tell us where you grew up, tell us where you did your training, and what that pathway was like.
Todd McMullen 02:05
I grew up in, pretty much, exclusively in Alberta, but not in one center. We did move around a little when I was younger. My family were farmers and in the oil patch, like so many people in Alberta. So we did move to different places in small town Alberta where the oil patch was growing in different places. As I entered into university, I started at the University of Alberta where I did a PhD in biochemistry. At that time, I was leaning a little bit more towards the research career. I actually went to Virginia, I had fellowship and did some work at the University of Virginia, in the medical school there, doing some research. And then I was working in New Jersey, actually just outside New York, with a pharmaceutical firm. I had a job with a pharmaceutical firm for a little while and at that point, I made the decision I wanted to move a little bit closer to the personal and the human side of research. I felt that the industrial elements of it were a little bit more about budgets and I wanted to change gears. So at that point, I applied to medical school. I went to medical school, actually, in Toronto. So I did my initial medical training in Toronto. Then did residency in general surgery in Edmonton. I came back to Edmonton it as it has an excellent reputation for getting your hands on a lot of cases. So I came back to Edmonton and that was definitely the case. And following along that line with heavy case volumes and exposure. I chose a fellowship in endocrine surgery in Sydney, Australia, where they have they have a fantastic fellowship. The TS Reeve Fellowship in endocrine surgery. I went there for a year and then came back to Edmonton to practice.
Chad Ball 04:00
That's great. There's no doubt the Reeve Fellowship, I think everyone within general surgery knows about that fellowship. Tell us what that was like. Maybe, your perception to train as a fellow in Australia compared to maybe if you had say, stuck it out in Canada, the US for your fellowship training.
Todd McMullen 04:00
I think the centers that offer endocrine surgical training in Canada, the US or Australia are all excellent. What I liked about Australia was obviously the fellowship itself was well established, they had outstanding preceptors and they were dedicated, as most excellent fellowship programs require, they were dedicated to the fellows both in terms of an academic sense, but also giving you that that ability to teach you how to operate. In Australia, they've got a little bit of a different system compared to Canada. It's more of a dual system with private and public. The benefit as a fellow in that environment is that the surgeons have a lot more access to operating time then typically they do in a Canadian center. Would be as an example where most surgeons work at maybe 1 or 2 sites, but in Australia they will often work at 3 or 4 different sites. So they're operating a lot more and you are along for the ride. And when there are that many cases to do, because there's an opportunity to operate almost every day, your volumes are exceptional. I think it's really tough to imagine a fellowship program that can match the volume, and the breadth of experience that I received in Sydney. It was fantastic. Sydney is a gorgeous city and obviously, they had a big program with 3 dedicated endocrine surgeons, and they had a dedicated endocrine pathologist who was fantastic. And so again, that element of the sheer number of cases as well as the academic setup made it fantastic. It was a one year fellowship, so they encourage publications, you're able to do everything in one year.
Chad Ball 04:18
That sounds great. It's amazing how frequently the guests that we have on the podcast talk about the quality of fellowship being linked to overall operative volume. I think we know that intuitively. Even as residents. But it is so critical, there's no doubt. What drew you, Todd, to the field of endocrine? What did you like about it?
Todd McMullen 06:28
Again, most surgeons in their career, they look back, what are the things that influenced them? I had a mentor in David Williams, who was more traditionally head neck oncology trained general surgeon. He did a lot of thyroid work as well as work in the oropharynx. And he had introduced me to thyroid surgery, and obviously because it had an oncology piece, it fit in with a little bit of my research background. So that was, I think, definitely a plus. I saw the oncology elements of thyroid surgery, and I was very interested in that element of it. It's technical, there's some very interesting technical pieces to thyroid surgery. And there's some smaller procedures as well as bigger ones with neck dissections. With my endocrine practice, it is definitely a full endocrine practice. So I do adrenals, I do neuroendocrine tumors. There's everything from a thyroidectomy to the radiobiology of the treatment of neuroendocrine tumors, and lutetium therapy or Gallium-68, the new diagnostic work we're doing. So it had a breadth to it. Again most, I think, surgeons look for a bit of variation, small and big. So that's what took me there. I can link my research, I was in general oncology research. So that's the path I chose.
Chad Ball 07:57
You've touched on your research a few times already and that's how a lot of us in the country certainly think of you, as a busy researcher, in a lab as well. I was curious if you could run us through the evolution of your basic science or your laboratory side of things. In particular, as that's evolved, what some of the stresses have been, what some the pleasures have been? And, as you and I were just talking about before starting, maybe the commercialization aspect, good and bad, of that?
Todd McMullen 08:28
Yeah, so research has always been something that interests me and I looked at a clinical career as a way to try to blend a little bit of clinical practice with a research program. The research I worked on for an oncology company in New Jersey was something on interleukins and looking at metastatic disease. It was a very natural, organic growth into thyroid cancer. Why does it spread? What are the mechanisms that drive lymphatic metastasis. That's where I moved to. And most of my research is very, mechanistic, it's benchtop work. Lots of genetics, looking at why tumors spread to lymph nodes, and of course, thyroid cancer is an excellent example of that, but it applies to other cancers as well. As I've gone further on, I found more fundamental mechanisms that apply not just to thyroid cancer, but other endocrine and other non endocrine cancers. The challenges I think, aren't hard to see. When you are trying to balance both the clinical and research career, you've got to put time in both of them. And being a surgeon when you work weekends and nights, and trying to manage a lab, at the same time trying to get funding in a super competitive environment where everybody has a great idea. And you're competing against PhDs with big labs who've got a lot of time, a lot of trainees, you've got to be so focused and dedicated to what you do. You have to love what you do or you won't survive. I think if I had to pass one thing on to the trainees that look to my experience, and they look to careers in research and surgery, I say, as long as you love what you do, you'll find the time. I don't want to make it sound like you can't do a surgery, because there are some great things about surgery, you can block off days of the week and things to do it. But you know, you have to be dedicated to it for sure.
Ameer Farooq 10:39
Could you tell us a little bit about the whole commercialization piece of your work?
Todd McMullen 10:46
That's a challenge too, but something that I'm very interested in. I learned early on that as an academic, in a lot of the manuscripts you write, you're trying to sell an idea. But in commercialization, you're trying to sell a product. And there are a whole bunch of steps between create, trying to fine tune an idea and then developing a product from that. I've learned, my opinion, I've had some excellent experience. And again, mentors in the business field that have helped as we've moved through the commercialization aspect of it. And certainly in Alberta, which I don't think most people would recognize as having a huge healthcare industry, there are there are absolutely opportunities for commercialization in their programs to help people bridge that gap between the funding gap. Between taking your idea, and those research ideas, and then scaling it up and testing it in a way that, when you have a product, it's ready to go, it's tested, it's going to work every time and I have a lot of respect for industry. What healthcare industry and how there are so many different things that you just don't think about, whether you're a consumer or a scientist, in industry, there's no room for error, you're not allowed to make any, there's no mistakes. No, you don't cut corners. It's got to work, it's got to work every time. And so, I've learned a lot about the commercialization piece. It is a bit of a challenge in Canada in some respects compared to some of the larger centers in on the West Coast or East Coast of the United States. But having said that, it can still be done. You've got a good idea, people will come to it. There is funding for it. There are a lot of fantastic people that I didn't realize, a lot of philanthropists that aren't looking to make money, they're just looking for that good idea, they want to make a difference. Those people are out there and those are the people that you need to help you along the way.
Ameer Farooq 12:49
Given that at some point in my life, I'm going to write that little quiz. So I wanted to talk about the the ever-present incidental thyroid nodules, which seems to be a hot topic on on exams. I wanted to take a step back and just have you talk to us a little bit about, how big of a problem is this whole incidental thyroid nodule on a population health level. And I'm sort of thinking of some of the studies out of South Korea where they showed that we've just been picking up exponential numbers of these incidental nodules without really a change in mortality from thyroid cancer.
Todd McMullen 13:32
That's an excellent question. And it again, blends into a lot of the questions that researchers like myself are trying to answer. What's that perfect marker for identifying genetically, or on a fine needle aspiration biopsy? What are the the genetic signals or things that indicates, this is going to be a problem for a patient? Or what isn't? So you're absolutely right, that magic chemical or protein hasn't been found yet. So now we have to rely on population studies. I think it's very clear now that we have increasing incidence of thyroid nodules and it's probably in large part due to the increased use of ultrasound and the sensitivity of ultrasound. When I trained, I trained to use ultrasound, the machines were somewhat bulky and didn't provide the resolution that now handheld, very small for sounds that many physicians carry in their office. And certainly I do all my own ultrasound in my office. I find a very high number of nodules that are probably, your right, not clinically relevant. So I think, to your point, it's very clear now that a lot of thyroid nodules are not clinically relevant. We don't have to use the old paradigms where nodules meant surgery. And I think that, in the last year, and there have been excellent articles, you're right, there was the big study out of South Korea, because they have a very large screening program involving ultrasound and thyroid. They're probably the most intensive ultrasound use in a population in the world. So that's how that came to be. But the similar studies have been done in the United States and Canada, for sure. I think that we do have to revise our approach to thyroid nodules, especially the small nodules. And you're starting to see that, you're starting to see less surgery, more active surveillance, even for thyroid cancers themselves.
Ameer Farooq 15:37
I want to come back to that in a little bit, but let's say you get the common exam scenario, or frankly, real life scenario that many general surgeons face around the country. Let's say you have a 50 year old female who, unfortunately had to meet Dr. Ball one night on the trauma service, and was incidentally found to have a 2 cm thyroid nodule on a CT scan. How do you approach that patient?
Todd McMullen 16:06
Well, absolutely. Once Dr. Ball has done his work and made that patient safe for me to see, again, you're right, it's absolutely a common scenario. Despite all the advances in genetics and gene chips, the history and physical can go a long way to determining whether that nodule is going to have a detrimental effect on that patient or not. Step 1, of course, is the history of the nodules. Is it something that came on very quickly? The personal history for the nodule, is it something that's grown very quickly? Is it something they've recognized, perhaps a while ago, but didn't think anything of it? Obviously, in this case, we're assuming it wasn't growing quickly. The things you'd want to know about, any difficulties with swallowing, a change in their voice. The voice change is actually something that's very important and very specific in indicating a potential aggressive malignancy. So that's very important to ask. You also want to ask about their family history of thyroid cancer. There's some excellent studies looking at familial relationships and in terms of having siblings, first degree or second degree relatives, with thyroid cancer. There's a known increase in risk, especially for first degree relatives, so siblings, their mother, their father, for example. Depending on the number, it can be anywhere between 2 to 5 times higher risk for thyroid cancer for those patients. I guess the final thing that everybody knows about of course, thanks to Chernobyl, would be radiation exposure. That's a common theme. I've had many patients, more than I would have ever imagined, that come from Europe and years ago, were concerned about exposure to radiation as a result of that event. Of course, there's been other events around the world since then. But radiation exposure may also lead to an increased risk of thyroid cancer, there's lots of studies on that. Although what's very interesting is that there's not a very clear dose response rate in terms of the amount of radiation you receive. Obviously it is important but what's equally important, and perhaps even more important, is how old you were when we were exposed. If you're exposed at a young age to radiation, that may be a particularly higher risk for cancer. And those are the historical features. Of course with the physical exam, if they don't have any voice changes or otherwise fine. You want to assess it for fixation. Most benign or even relatively indolent thyroid cancers would be mobile, relatively soft nodules. It's the hard fixed nodule that is the most concerning. And so from that point, for the purpose of the exam, so anybody that's practicing for their exam. Whenever it does happen, which hopefully this will pass soon for you guys in fifth year. An ultrasound is still an excellent, or is an excellent modality and getting even better at discriminating between benign and malignant neoplasms. And that's a big change in my practice, that's something I use a lot more, I rely more and more on the thyroid to a so called PI-RADS imaging scoring system. So it's an imaging and reporting data system just like BI-RADS for breast. It's becoming more and more, even in the last 2 years, more and more useful discriminating benign from malignant neoplasms. You can even use that to decide whether you're going to choose to biopsy and I certainly do in my practice. Now you will see some variations depending on the volume of practice and different scenarios, but for me when I ultrasound, I use the TI-RADS criteria, I assess its risk for malignancy and I don't always biopsy nodules, even if they're 2 cm. If I think that they look, they have a really low score on the TI-RADS system. You have to be careful for an exam setting. Obviously that's a little bit of a deviation. I think most people might think to that it's appropriate and reasonable to biopsy 2 cm lesion after you do your ultrasound. But for me, because I see so many nodules, and I think a lot of people have multiple nodules, looking outside of this particular case, it's not unreasonable to use ultrasound to stratify risk, and I think you'll see more of that in the future.
Ameer Farooq 20:36
Can you talk a little bit about what features you look for on ultrasound? Because I think that's becoming increasingly important, as you say.
Todd McMullen 20:44
Absolutely. Not to put the listeners to sleep by listing off the TI-RADS scoring criteria. But I think the major features, the things that you have to look for, would be, the most relevant things on an ultrasound report that you want to look for. Things like micro calcifications, that's a really important one, it's one of the biggest predictors of malignancy. You want to look at irregular margins. If it looks like it's irregular, or lobulated. Those types of features are definitely linked strongly to malignancy. Taller than wide is another one for sure. And hypoechogenicity. So if it's very hypoechoic and looks a lot darker than the surrounding thyroid parenchyma, when you're scanning with your ultrasound. If you put those together, you've got a very high risk of malignancy.
Ameer Farooq 21:38
I'm actually curious, do you put a TI-RADS score on your consult notes? If you see someone in the office and you do their ultrasound, do you quote a TI-RADS score?
Todd McMullen 21:48
So traditionally, before, well about 2 years ago, when I started using it exclusively, I wasn't putting scores on, but now I am. For trainees, I would say this is important. The way that college looks at things and this is a very specific point, for medical legal reasons, if you're using ultrasound to stratify, and you're deviating from what the standard of care may be, and that, of course, is a moving target, it's not an unreasonable thing to be very detailed in your documentation. And even getting a separate ultrasound report from one of your local ultrasound sites that provide that level of detail, because you want to be able to go back. No, I didn't biopsy because my TI-RADS score was very low. If you don't provide that detail, if that did end up being a cancer, then that might be a problem if you don't show that you took the proper steps to stratify it as best you could.
Ameer Farooq 22:51
Alright, so moving on from the history in the physical and the ultrasound, what are your next steps in working up? Let's say a nodule that seems indeterminate on ultrasound. What are your next steps?
Todd McMullen 23:10
In most cases, so unless they had no risk factors, no reason to be concerned on physical exam. In most cases, with a nodule 2 cm in size, especially somebody 50 year old, she's 50 year old, relatively young. That's a long time for something to change. Obviously, the fine needle aspiration biopsy, which would be done under ultrasound guidance, that's the standard now. I don't think anybody does it without having an ultrasound probe on the nodule at the same time. You get much better sampling when you have the probe on, you can look for the nodule, make sure you properly sample it. You would do the FNA, absolutely.
Ameer Farooq 23:55
Any other investigations you do? Let's say, TSH or technetium?
Todd McMullen 24:00
Oh, sure. So of course, obviously, I made the assumption, perhaps a dangerous one, that she was not hypo or hyperthyroid, but absolutely for exam purposes, you want to assess whether they're thyrotoxic. Of course, the thyrotoxic module is much less likely to be malignancy, you may not choose to do a biopsy in that particular circumstance. That's the only time I would order a technetium uptake scan would be if they were thyrotoxic, if their TSH was suppressed and they didn't recognize that. Which would be unlikely, but it can happen if they're just mildly suppressed, for example. But other than that, I don't routinely order, for example, CT scans for thyroid nodules or even for thyroid cancers unless there's other features of it, if it's much more aggressive, but that's your basic workup.
Ameer Farooq 24:58
Gotcha. I think this segues nicely into talking about, let's say you get your FNA result back, you're given all these different things back. AUS, FLUS, all these things that confuse trainees to no end. Can you walk us through the Bethesda classification for nodules?
Todd McMullen 25:21
Sure, the Bethesda criteria is fantastic and I think it was overdue. That standardization has really helped with surgical planning. And I think it's also helped the pathologists in terms of helping address the variability between reports and the nomenclature that is such a challenge. When you would have different pathologists report using different terminology that made it a little bit difficult for you as a surgeon to plan, and so the Bethesda criteria, which is basically a numbering system, I through VI, it assigns a risk of malignancy depending on what the pathologists decide. A I is basically a non diagnostic scan, or no sorry, non diagnostic biopsy. So you'll have to redo that. So it means you don't have enough cells to make a proper assessment. And then the rest, the remaining II through VI, go from benign through to malignant. So benign is II, and that means your risk of malignancy is less than 5%, essentially. It's very low risk of malignancy. And at that point, obviously, you don't have to think about surgery. For III and IV, that's where there's a lot of confusion for trainees. And I'll be honest, this is probably, if you looked at pathology papers and for thyroid, there's a very healthy stream of publications on a monthly basis looking at cellular atypia. And that's a level III, a diagnostic category III, where you just have some atypia, or you have a follicular lesion of unknown significance. So in those circumstances, the pathologists still feel confident they don't see enough, for example, nuclear grooving, or architectural atypia, within the nucleus of the thyroid cell that they're assessing on the cytology. They don't see either a number or in the nature of what they see, to call it cancer, but they do see some irregularities compared to just a normal boring, what should be benign thyroid cell with a small tiny nucleus and homogenate, they may see a bit of atypia, but they're not sure. So then those cases, they'll call it atypia of unknown significance or follicular lesion of unknown significance. The current guidelines, and there's variations on variations on this of course, but I won't get into the details, usually you can repeat the FNA. Whereas for Bethesda class IV, we're going up higher, that's a follicular lesion where they see some, again, cellular atypia. But because they can't sample as you know, psychology, they're really looking at mostly nuclear features and some other small architectural features, they can't really see where the sample came from. They can't determine if it's a malignancy. In those cases, when they call it a follicular lesion, or follicular neoplasm, the guidelines would suggest a surgical approach and a thyroid lobectomy to address whether or not that's truly a malignancy. Where they can look at the entire specimen, including the capsule. For V and VI, V is suspicious for malignancy. And the reason V and VI are a little bit different is that, if you look at the studies, which have been validated over the years, there have been large trials, looking at lots of patients in different centers. Suspicious for malignancy, that's around a 70% chance of malignancy. So then, the guidelines are whether you do, again, a lobectomy, or total thyroidectomy, depending on the size of the nodule. Then, of course, VI is pretty much 98%, 99% chance that it's malignant. I've only seen, I think, in my entire career, one case where it had been called a VI. And in the end, it wasn't malignant. It's very rare for them to miss that. And generally, the Bethesda criteria are fairly accurate and have been very well validated. Especially for your II, V and VI, you can hang your hat on those numbers.
Ameer Farooq 29:41
Just to be clear, if you have say, a follicular neoplasm, are you sending these people for a lobectomy? Or do these people get a total thyroidectomy? Can you walk us through that a little bit?
Todd McMullen 29:56
That's going to be patient and surgeon dependent. If we were talking about this case, for example, the 50 year old lady that had this incidental thyroid nodule found and we went through the process and it was biopsied, and the pathologist called it a Bethesda IV. Then, if they had no other nodules, textbook would say you could consider them for a surgical, just a thyroid lobectomy, just a straight up lobectomy. Now, the choice between, again, if you look at the thyroid guidelines, the 250 pages, they might even be longer than that, I can't remember. The very large American Thyroid Association guidelines, the use of lobectomy for diagnostic or even for known cancers, there's sort of a range in there. So for diagnostic purposes, just about everybody does a lobectomy, there's no question. The only reason I would do something more involved than a lobectomy for somebody where it's not diagnosis cancer, but it's just a Bethesda III or IV. would only be if they had some other concomitant thyroid disease. If they had lots of other thyroid nodules, it was causing compressive symptoms, if this was a cold module in the context of them having Graves' disease and they had Graves' disease with thyroid nodules, for example. You may choose then to do a total thyroidectomy because you're addressing 2 different problems and they will want one surgery. But from just a pure diagnostic standpoint, a lobectomy is usually what you would. That's the standard answer.
Ameer Farooq 31:40
But let's say you have a 33 year old woman, incidental thyroid nodule, her TSH is normal, she has a 2.5 centimeter nodule, with a couple of nodules, two 1.2 centimeter nodules on the contralateral side, would you offer that? I think you may have already kind of alluded to this, but let's say them having some nodules on the other side, would that make you more or less likely to do a lobectomy?
Todd McMullen 32:10
Again, this is very much a patient specific question. And the other element that comes into it is their age. This is a relatively young patient that you've just described. The likelihood that they will need Synthroid or thyroid hormone replacement after doing a lobectomy increases with age. So if somebody really wants to stay off thyroid hormone, and I have no reason and no concern, based on my ultrasound assessment of those nodules on the other side, and I was concerned for whatever reason of the larger nodule on the contralateral side, just the one side, I would still perform the lobectomy. So as long as those other nodules are low risk, and they don't have any other disease, and they're not concerned about a malignancy risk, and they're happy to follow those nodules, because they will need to be followed, then a lobectomy is fine. So you can see it's very complicated, the decision for a lobectomy versus a total thyroidectomy will depend on, how many nodules on the other side, how old the patient is. How concerned are they about following it? Some patients, the concept of having another biopsy, and when I do the biopsies, I'm being honest here, the patients don't tend to complain about discomfort. But if they come from other centers, they do often, there may be circumstances where the biopsies are quite painful and for whatever reason, I know why, patients, if it's uncomfortable, they don't want to go through it again. Some patients are very anxious about more biopsies. So they just say, well, if there's multiple nodules, they know they want the whole gland removed. I am definitely becoming more conservative because the literature, I think is really important, there's more evidence for the detrimental effects, and the somewhat poor quality of life for some patients that are on thyroid hormone replacement. So I think trying to keep as much native thyroid tissue as possible is a first principle and you'll always do your best to try to do that and minimize a surgical risk. Does that answer the question? I hope, it's a bit long winded.
Ameer Farooq 34:19
That was fantastic. Although, we always like the black and white answers. But general surgery and life in general isn't in black and white. So I think that was a fantastic, nuanced approach to this. I was hoping that you could briefly describe how you do your thyroidectomies. And in particular, talk about some tips for identifying the recurrent laryngeal nerve.
Todd McMullen 34:49
Okay. So I'll give a little bit of historical context because I think it might be relevant there. Obviously, you try to do the smallest possible incision. And typically, the lower you are on the neck, most people cosmetically are happy with that. The majority of my patients are younger and obviously they're a little bit more concerned about the cosmetic elements of a neck incision. So those are the general principles. Once I enter the neck, and this is pretty similar, I don't do them with a robot or endoscopically, not yet anyway. I've looked at different techniques, going through the bottom lip there, there's some fantastic videos, I haven't tried any of these yet. But doing the traditional thyroidectomy, once you divide the skin and the platysma. The skin incision, I will try to make very small, but the mobilization on the inside, in terms of the subplatysmal flaps, dividing the strap muscles of the midline. I make sure I do that quite extensively because you'll need that flexibility as you move the incision around. When I release the thyroid capsule, and that is to say, to roll that lobe out of the tracheoesophageal groove, you're going to need to address the middle thyroid vein and its tributaries. And then it becomes a choice. Now I'm going to walk you through what I do, there are different ways to doing it. Some people, once they release the thyroid, or once they deal with the tributaries of the middle thyroid vein, then some people will look for the recurrent laryngeal nerve. I usually don't do it at that point. What I will do is take the superior pole and inferior pole vessels next, so after the middle thyroid vein, it's the superior pole and inferior poll vessels, then continue to stay on that thyroid capsule. And I mean close to the capsule. Even after doing as many thyroids as I didn't fellowship, I think it took about 3 more years in practice, before I really honed my surgical technique to really stay as close to the capsule as possible, and do everything you can to preserve the blood supply to the parathyroids, which I think is probably the more challenging part of the operation. Obviously, you don't want to cut the recurrent laryngeal nerve. But I think the more challenging technical piece is preserving parathyroid function. And certainly the rates of injury, in terms of hypoparathyroidism versus recurrent laryngeal nerve injury echo that. In high volume centers, recurrent laryngeal nerve injuries aren't 1% to 2%, they're probably much less. So I think that's important to know. But hypoparathyroidism is still 1% to 2%, even in high volume centers. So anyway, you staying on that capsule really tightly. What I do is I go down to the prevertebral plane. So this is something, I think it's very important, I go right down to the prevertebral plane, identify the esophagus and then come up and visualize between the trachea and esophagus, the tracheoesophageal groove. The nerve will always be there. So I always tell the resident trainees, especially as they're getting further along in their training and have done more and more, make sure they get down to that prevertebral plane. Then come up and visualize, with the trachea superiorly and the esophagus posteriorly, they should be able to identify that small couple millimeter region of the tracheoesophageal groove, the nerve will be there. Now it may be distorted by the nodules, some thyroid nodules can be posterior, the tubercle of Zuckerkandl, which is that little outpouching that sort of extends laterally into the tracheoesophageal groove, is an excellent landmark. So you can use that because you know the nerve is close. Hopefully it's underneath it, but it doesn't have to be. Sometimes it runs anterior to it. And be aware of nerves that bifurcate or even trifurcate. Some of the most difficult cases I've had, where nerves actually trifurcated because the more anterior branches are the motor branches, the ones that actually modulate the vocal folds. And the posterior branches are to the esophagus. So they don't have as much of an influence on their voice, but the anterior branches do, so you have to be very careful. You stay in that capsule, come down to the tracheoesophageal groove. You've landmarked it between your trachea and the esophagus there. And then you just use capsular release, and then it's just time. It's just that careful layer by layer. I use McCabes. I tell the residents, always point the McCabes in the expected direction and just do small openings. At that point, once you find the nerve, I do trace it at that point fully right into the cricothyroid muscle releasing that thyroid capsule as you go. I don't think there's ever been, and I sometimes spent a long time finding a nerve that was ultimately a long way from the thyroid, and I easily could have taken out the thyroid without even looking for the nerve, but I'd never do that. I always look for the nerve and finish my capsule release and then divide the tissue and ligament of Barry. Sometimes I use a lot of ligature device. That's just my personal tool. I'll put a wet dental right under the ligature device so I can get as close as I can, to make sure I don't leave any thyroid behind.
Ameer Farooq 39:59
Do you use any adjuncts like nerve stimulator?
Todd McMullen 40:03
Excellent question. The technology when I started was not great. I don't use it now, unless it's a very difficult, reduced scenario. And I do lots of scenarios with advanced metastatic disease or locally invasive disease where I have to or explore or release the nerve. I traditionally, because of my volume, I've always felt comfortable in most cases, not using nerve monitoring. And in the rare case I do use it, it's usually the third or fourth time in, for somebody that's had unfortunate recurrence.
Ameer Farooq 40:47
Gotcha. I did want to ask you about the lateral mini incisions for thyroidectomy. Because I've seen that you've done some research on that as well. Is that something that you do and can you tell us a little bit about that?
Todd McMullen 41:04
Yeah. That's a technique I learned in Sydney. And that was something that they had worked on extensively was the the lateral incision. The idea of that approach is that you can use a smaller incision. The goal, again, is to make your skin incision as small as possible. So the lateral approach allows you to find the nerve quickly. Whether it's for parathyroid surgery, for example, or if you're going to do a minimally invasive hemithyroidectomy and you want to do a really small incision, you can use that lateral approach because there's less manipulation, you find the nerve. But you have to be very, very experienced, because you do come on the nerve very quickly, very quickly. So you have to know your anatomy very well. It's not something that I would do, you wouldn't do that, the first thing you would teach. It's something that you only do once you have a better, or an excellent, understanding of the anatomy. Because you don't have the exposure that you do, obviously the incisions are smaller. So you don't have that context. You have to know exactly where you are at all times. It's a nice approach, absolutely. I don't, again, do it quite as often as I did in Sydney. It works better for patients with smaller necks, smaller nodules. Once the nodule are getting higher or larger than 3 or 4 cm, I do tend to go with the midline approach.
Ameer Farooq 42:34
Right on. I did want to ask a question that perhaps is aimed a little bit more towards junior trainees who might be listening to the podcast. That's about postoperative calcium, because I think we've all been there, the middle of the night getting calls about calciums in a postop thyroid patient or the patient that's having some oral numbness. Can you talk about what your approach is for these patients from a postoperative standpoint, particularly with regards to the calcium?
Todd McMullen 43:04
Sure. I think the fun part about this is that, if 1000 surgeons were to listen to this part of the talk, I'm sure there would be 1000 different comments on my approach versus other surgeons. My personal approach, and again, that's why I want to preface these comments, is that it's highly variable among lots of high volume surgeons, excellent surgeons. They do different things, even in my own center compared to what I do. But what I do, because a lot of my patients are from up north, they are from geographically disparate regions where they're not always close to a hospital. My approach has been to first, I think everybody would get a postoperative PTH, usually within an hour or so of surgery. You get it in the recovery room, usually before they go to the day surgery unit or to their inpatient unit, if you're going to keep them overnight. Once that PTH is there, I look at the PTH number and I look at the calcium. For patients where for some reason, the parathyroids aren't working, or you've inadvertently removed some or all of them, which of course, obviously almost never happens. But obviously, where they don't work, they may be left behind but are not working properly. Under those circumstances, the PTH will be undetectable and for patients that really have very little parathyroid hormone, usually even within an hour surgery, their calcium will drop very quickly and precipitously. So for patients that have low PTH and very low calcium, I immediately start vitamin D, and supplemental calcium. Again, there's multiple different ways you can give it, I just use TUMS because it's easy to chew, and it's something that most patients don't mind taking large volumes of. The hospital pills, calcium pills, are large, hard to swallow and not very palatable. On the other end of the spectrum, if their PTH is normal and their calcium, most calcium levels will decrease a little bit during surgery, even just part of the physiologic response to surgery, but if it's in the normal or close to normal range, I won't start vitamin D. But I give everybody usually 2 weeks of calcium postop just on spec. So I'll give them 1 g BID for 2 weeks. So usually it ends up being 2 pills, twice a day, for 2 weeks. Everybody. In particular for Graves' patients, even if their PTH and calcium levels are near normal, for reasons that I don't fully understand, but it is documented in literature, they're more likely to experience the symptoms of hypocalcemia, even with small decreases in calcium levels. So that helps to ameliorate those concerns for the patients. I do a lot of patients with thyrotoxicosis. So I found that that's very valuable there. And I only use Rocaltrol or vitamin D, supplementary vitamin D when their PTH is undetectable. So then you will titrate that up. The way pharmacologically to give Rocaltrol capsules is every 6 hours. But usually, I don't give it 4 times a day. At most, I'll give it twice or 3 times a day for people that perhaps have profound hypercalcemia, but that's generally rare. Most of the time, I just give BID Rocaltrol for a couple weeks until their parathyroid hormone levels recover.
Ameer Farooq 46:33
So, are you keeping people overnight and then checking their calciums? Or is that PTH and calcium that you get initially enough for you to go on and potentially discharging people home?
Todd McMullen 46:45
For 90% of people, that's all I do. If their PTH and calcium levels are quite low at the time, or just in the immediate postop period, I may order repeat bloodwork in about 6 hours. Not a repeat PTH. I just order a calcium level just to see how low it's going to go. Most patients, I don't keep overnight anymore. Most patients go home the night of surgery. Some patients I'll keep overnight, we have a short stay unit where they can go home first thing in the morning. But most patients will leave the same day before midnight. And I will only get repeat bloodwork if I think their calcium is, if their PTH is undetectable and I'm worried that they will have problems with hypercalcemia.
Ameer Farooq 47:33
That's perfect. That's exactly the kind of overview I was looking for. I did want to ask you about one more thing before we wrap this up. And that is the role of lymph node dissection, because that's another thing that sort of seems to come up. Are there any scenarios where you are doing a prophylactic lymph node dissection? In my mind, I think that's sort of in the medullary thyroid cancer, and correct me if I'm wrong. And who are you doing a therapeutic dissection on, as well? Can you talk a little bit about that?
Todd McMullen 48:11
Well, the easiest one, is the therapeutic. I think there would be very little debate among surgeons around the world if there are palpable lymph node metastases or if there are substantial deposits of disease on ultrasound that are greater than 1 cm that are clearly visualized. I think there's no question about the value, under those circumstances. Prophylactic dissections are still highly variable. Even in my experience in Alberta, which is quite fun, you'd think Edmonton and Calgary would be similar but it's like there's a magic line in Red Deer. Things happen north of Red Deer different, and south of Red Deer can be different. So even in Alberta, there are different approaches. And it depends a lot on the local tumor board and in the Cross Cancer Institute, where our tumor board is, it's not just the surgeon [inaudible] for myself or that my patients and I will make the decision, it's the consideration of what the tumor board will want. In my center, even microscopic, that is to say less than 1 cm deposits of thyroid cancer, if identified on ultrasound, would be considered reasonable to carry out lymph node dissection. That's not always the case, depending on the center. So for me, in working in a center where we're a little bit more aggressive in the use of lymph node dissections, prophylactically or otherwise. I will do prophylactic dissections for patients that have abnormal lymph nodes on ultrasound, even if they're relatively small. If they do not have, and I ultrasound them myself, every case, both at the time of clinic and then at the time of surgery, which hopefully isn't too far apart. But that, unfortunately can vary certainly in our current COVID-19 scenario where some patients are having to wait longer for surgery than I would like. When I do ultrasound them at the time of surgery, if I do see abnormalities in the lymph nodes, based on their morphogenic, what they look like on ultrasound, either in terms of size or morphology, I will intervene with a prophylactic dissection. If I don't see anything, I typically do not, unless it's a really high risk scenario. If there's a patient with a very large, 4 or 5 centimeter, primary tumor and I'm concerned about multifocal disease, where I think they have multiple deposits within the thyroid. There's evidence for intrathyroidal spread in some cases. Under those circumstances, I will perform a prophylactic lymph node dissection on level VI. So I'm sorry, I wish I could make the answer black and white for you. But there's a bit more gray area there too.
Ameer Farooq 51:14
You've been listening to Cold Steel, the official podcast of the Canadian Journal of Surgery. If you've liked what you've been listening to, please leave us a review on iTunes. We'd love to hear your comments and feedback, so, feel free to email us at [email protected], or connect with us on Twitter @CanJSurg. Thanks again.