Hello, and welcome to Scrubbing In, a podcast powered by Specialty Care. I’m Todd Schlosser and today my guest is Dr. Mark Li, the Chief of Neurosurgery at Lehigh Valley Health Center. In this conversation, Dr. Li and I discuss a lot of topics ranging from how he got into neurosurgery to how imaging has changed the way neurosurgery is done. I think you will particularly enjoy his top three different areas of innovation that have helped revolutionize neural surgery, but for now, enjoy Scrubbing In with Dr. Li.


Todd Schlosser:            Thank you for joining us here on scrubbing in today. I am on location at the Lehigh Valley health network with-

Dr. Mark Li:                  Dr. Mark Li.

Todd Schlosser:            You beat me to it. Dr. Mark Li, who is the Chief of Neurosurgery here, and I like to start off the podcast with this question and that is simply what was it that drew you to have a passion to work in health?

Dr. Mark Li:                  I don’t know about health care in general, but I can tell you a story about a neurosurgery, which is what I ended up doing.

Todd Schlosser:            Oh, awesome. Yeah, let’s do that.

Dr. Mark Li:                  So I actually went to medical school not intending to be a clinician. I went to medical school to do research. I had come out of a graduate school program getting my PhD in chemistry.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  And I thought that having some contact with the biological sciences would help me in research. So I went to medical school fully intending to be in a lab somewhere and at the very end of my medical school, clinical rotations, I had to do a neurology rotation, which nobody wanted to do. No offense to the neurologists-

Todd Schlosser:            Sure, I mean you are one now.

Dr. Mark Li:                  Well I’m a neurosurgeon.

Todd Schlosser:            Well, okay.

Dr. Mark Li:                  So I happened to do a neurology rotation at a very small hospital within our medical school system. And the two neurology directors of that rotation took one look at me and they realized that I probably wasn’t going to be a neurologist. So they sent me down to the OR where there was a neurosurgeon named Marx Bowens who was at that time, probably in his late 50s, early 60s and the first day he said, “Come on in, scrub in and help me do this tumor.” So for the next six weeks-

Todd Schlosser:            Is before you had any sort of general surgery residency?

Dr. Mark Li:                  I was not a resident yet. I was a medical student.

Todd Schlosser:            Oh, okay.

Dr. Mark Li:                  And for the next six weeks, he let me first assist him in almost every case that he did and got me interested in neurosurgery.

Todd Schlosser:            Wow.

Dr. Mark Li:                  I changed my entire study plan and I eventually applied to neurosurgery residency.

Todd Schlosser:            Okay. So let’s sort of unpack a lot of that. That’s an awesome story though. And that’s, I mean, he obviously didn’t have to do that.

Dr. Mark Li:                  Correct.

Todd Schlosser:            Yeah. He just out of the kindness of his heart or wanted, wanted to pass on his passion for neurosurgery.

Dr. Mark Li:                  I think so. And he must have seen something in me that sparked that dynamic.

Todd Schlosser:            Yeah. Well, and the neurology folks saw it too, and that’s why they passed you off. But, so you went to Caltech and got your PhD in chemistry, is that correct?

Dr. Mark Li:                  Correct.

Todd Schlosser:            And then you went to Harvard Medical.

Dr. Mark Li:                  Correct.

Todd Schlosser:            And that’s when you had that experience right? When you were there at Harvard, did that add any time to your studying of medicine at Harvard or was it just the regular medical program because did you change from a research focus to a neurosurgery focus, and does that change require that you spend more time there?

Dr. Mark Li:                  No. No. The school timing was the same. While at Harvard I did a postdoctoral fellowship and medical school kind of at the same time.

Todd Schlosser:            Oh, okay.

Dr. Mark Li:                  So I was fully entrenched in research at the time.

Todd Schlosser:            Yeah. Okay. So then you shifted to neurosurgery?

Dr. Mark Li:                  Yeah.

Todd Schlosser:            So how did you choose the residency you ended up in?

Dr. Mark Li:                  So there’s a match system in residency training. Every applicant applies to the intended positions and it’s just like trying to get into college. You apply to the programs that you think you’d be interested in.

Todd Schlosser:            Right.

Dr. Mark Li:                  They interview you and then there’s a rank list where each of the applicants ranks their number one choices.

Todd Schlosser:            Right.

Dr. Mark Li:                  And each of the programs ranks their number one choices and there’s a computerized match that allows you to go to whichever residency program that you end up in.

Todd Schlosser:            So you sort of pick your favorite, they sort of pick their favorite candidate, and then the computer sort of assigns the schools based upon …

Dr. Mark Li:                  Correct. Correct.

Todd Schlosser:            That’s a pretty good system.

Dr. Mark Li:                  It’s a great system. It’s a little surprising sometimes when you wake up one day and you find out you’re going-

Todd Schlosser:            Oh, I’m moving.

Dr. Mark Li:                  Yeah. And so in my case I moved to New York.

Todd Schlosser:            Yeah. And so you went from I’d imagine Boston to New York.

Dr. Mark Li:                  Yeah.

Todd Schlosser:            And then you were in New York for about, was it …

Dr. Mark Li:                  Six years.

Todd Schlosser:            Six years. Okay. Doing your neurosurgery residency. I’ve seen residency times vary. Is that a common time for a neurosurgery residency?

Dr. Mark Li:                  Yeah, neurosurgery residency is somewhere between five and eight years, depending up specialty training, depending on how much research you do in the middle of that training.

Todd Schlosser:            Sure. So you finished that residency and I think you stayed in New York for a few years after that.

Dr. Mark Li:                  Three years after that.

Todd Schlosser:            Three years and then you ended up here. So how did you end up at Lehigh Valley?

Dr. Mark Li:                  I was recruited here actually by the former CEO of Lehigh Valley Health Network Elliott Sussman, who wanted somebody who was a little bit younger, I think maybe somebody to bring some of the newer technologies in neurosurgery to this area.

Todd Schlosser:            And that was 2003?

Dr. Mark Li:                  2001.

Todd Schlosser:            2001 okay. So you’ve been here for a good number of years.

Dr. Mark Li:                  I think this is my 18th year.

Todd Schlosser:            So were you recruited in as Chief of Neurosurgery?

Dr. Mark Li:                  I was recruited in as Chief of Neurosurgery. Probably too young for the job but-

Todd Schlosser:            Well you can say that now with, you know, hindsight being 20/20, but I’m sure at the time you felt like you were ready for the challenge.

Dr. Mark Li:                  I was a little apprehensive, but probably ready for the challenge.

Todd Schlosser:            Okay. Yeah. Well, I mean clearly you’re ready for the challenge because you didn’t wash out in a year.

Dr. Mark Li:                  Right? I’m still here.

Todd Schlosser:            Yeah, they kept you on. So you did something right.

Dr. Mark Li:                  For better or worse, I’m still here.

Todd Schlosser:            So you did mentioned while we were sort of setting up and having a chat beforehand that this is a trauma one center and it’s a stroke designation center. What was the-

Dr. Mark Li:                  So we are a level one trauma center.

Todd Schlosser:            Level one trauma center.

Dr. Mark Li:                  And a comprehensive stroke center.

Todd Schlosser:            Okay. So what are the qualifications to be able to get those classifications?

Dr. Mark Li:                  So for trauma there are several qualifications including resources. There have to be both sub-specialty clinical resources that are available almost immediately within 30 minutes.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  OR resources and the ability to do certain types of cases. The the ability to take care of certain types of patients, especially the sicker ones.

Todd Schlosser:            Sure.

Dr. Mark Li:                  And we were actually the first level one trauma center designated in the state of Pennsylvania.

Todd Schlosser:            Oh wow.

Dr. Mark Li:                  And because we happen to be next to a very large interstate, we have a large population of trauma patients and we continue to be very, very busy.

Todd Schlosser:            So it was a lot of that, I’d imagine trauma, that’s people who are having severe brain hemorrhages, things like that that are happening and they have to get here as fast as possible. They have to be worked on as fast as possible. Is it those kinds of situations?

Dr. Mark Li:                  Correct. So we as neurosurgeons, we see mostly traumatic brain injury and traumatic spinal injuries.

Todd Schlosser:            Yeah. I’d imagine like people from accidents, like car accidents or you know, we have an amusement park across the way.

Dr. Mark Li:                  Yeah. Car accidents. Falls.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  We see lots of hunting accidents in the during deer season.

Todd Schlosser:            Oh wow. Yeah, I didn’t think about that.

Dr. Mark Li:                  We see annually we always see one or two people falling out of deer stands, you know, significant injuries just from daily life.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  But mostly blunt traumas from auto accidents.

Todd Schlosser:            Yeah. So, and a lot of those, I have a little bit of experience in that, a lot of those can cause your brain to bleed.

Dr. Mark Li:                  Correct.

Todd Schlosser:            And then that bleeding causes pressure and that that can obviously severely damage the brain and ultimately end in that patient expiring.

Dr. Mark Li:                  Correct. That’s the one issue that we try to mitigate as neurosurgeons is the secondary injury to the brain from raised pressure. And that raised pressure is usually because the brain starts to swell in response to the primary injury, which can be just a contusion or you hit your head and then there’s a bruise and that bruise starts to bleed, or it can be a more severe bleed. But that’s the reversible and treatable causes of injury that we’re trying to mitigate.

Todd Schlosser:            Right. Surgeries like cardiovascular surgery have been going on much, much longer than neurosurgery have. So like they’ve had much more time to innovate and work on surgical techniques and I’ve seen that neurosurgery seems to have like a quicker pace of innovation and that this may just be anecdotal because I haven’t talked to every neurosurgeon.

Dr. Mark Li:                  So you may be surprised to find out that neurosurgery is older than cardiac surgery.

Todd Schlosser:            Really?

Dr. Mark Li:                  So the first documented, well-documented series of human neurosurgical cases was Victor Horsley and that was right around the time of Lincoln. So it’s been around for a while.

Todd Schlosser:            Yeah. Yeah.

Dr. Mark Li:                  Now the field was in its infancy for a long time.

Todd Schlosser:            I feel like it sort of got ramped up around the computer age, is sort of the way I sort of see it, which I’m fine to be wrong about, but I’d love for you to educate me on it.

Dr. Mark Li:                  So I think one of the interesting things about neurosurgery is that because the brain is housed in a closed container.

Todd Schlosser:            Sure.

Dr. Mark Li:                  I.e. the skull.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  It was always very difficult to see inside that box.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  Right? So for the longest time until we had good imaging, it was just a guess as to where a lesion was.

Todd Schlosser:            Sure.

Dr. Mark Li:                  So if you look back at the old nurse surgical literature, Harvey Cushing, who was a famous American neurosurgeon who operated in the 1920s, many of those early neurosurgical procedures were explorations to try to find a problem.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  And those explorations were negative as many as 30 to 40% of the time. So it really wasn’t until the advent of the cat scan, which came out in about 1975 that we were able to see inside that box before we violated the box.

Todd Schlosser:            Sure.

Dr. Mark Li:                  And that changed the whole thing. So you’re right, the computer age, the age of technology really allowed us to marry preoperative views inside the brain, to then directing the technology to be able to effect change within the brain.

Todd Schlosser:            Sure. Are we seeing innovation come out I think since the 70s with cat scan technology sort of pick up the pace as it, I’m assuming when you mentioned it was in its infancy for a long time, you sort of see that infancy ending in around the 70s when cat scans allowed you to look in but not violate the box of the skull?

Todd Schlosser:            So is innovation ramping up since then and what are some of those innovations that you think has changed the field of neuroscience?

Dr. Mark Li:                  Yeah, I think there probably has never been a more exciting time to be a neurosurgeon. We have technologies that allow us to, I think there are three different areas of technological innovation that have really helped with neurosurgery. The first is just magnification in seeing, viewing. So microscopes and micro instruments have allowed us to operate much smaller with much more delicacy than we were able to operate before.

Todd Schlosser:            Sure.

Dr. Mark Li:                  And that’s just purely because we can make magnify things and we can see them better.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  We can also think about the functional consequences of what we do and we can monitor what the brain is doing or what parts of the brain are doing at the time of operation. So that neuro-physiologic monitoring and the ability to actually, instead of just seeing the organ, actually assess function while we’re operating to stay away from important function, has really changed our ability to intervene.

Todd Schlosser:            Do you mind if I ask you about that a little bit?

Dr. Mark Li:                  Sure.

Todd Schlosser:            Okay. So, and I’m assuming, and correct me if I’m wrong, but when you’re operating on someone’s brain, it’s very delicate obviously, because you don’t want to permanently impair their speech, so what sort of things, or their ability to move, those kinds of things. So what kind of precautions do you take to make sure you’re not impacting their speech center of their brain, or their movement center, or any other center?

Dr. Mark Li:                  So it’s very interesting, if you talk to neurosurgeons a generation or two ago, there was sort of this idea that we don’t like to operate on the left side of the brain because the left side of the brain is where speech was or speech is.

Todd Schlosser:            Sure.

Dr. Mark Li:                  And the left side was sort of a no fly zone.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  Because it was unpredictable where in the left frontal lobe speech was. But as we’ve gotten better, and better, and better, at localizing, we’ve been able to intervene much more, leaving speech intact. So the first way that that was done was in the 60s, mid 60s to early 70s, people started to do procedures while patients were awake and speaking. Right?

Todd Schlosser:            Yeah. Yeah.

Dr. Mark Li:                  And everybody’s heard of being operated on while you’re awake.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  So awake craniotomies were a great way of monitoring speech. But as imaging technology got better and better, we were able to actually functionally image the brain and light up areas that were important in speech preoperatively. So we didn’t have to do as much awake craniotomy.

Todd Schlosser:            So is the patient awake and you have electrodes attached to their scalp just sensing those areas or how does that go?

Dr. Mark Li:                  Actually to get a functional image of the brain. It’s just an MRI scan.

Todd Schlosser:            Really?

Dr. Mark Li:                  And so the patient goes into the MRI scan and they’re asked to do a certain series of tasks and it’s a very interesting technique where you do a task, and it can be a motor task, it can be a thinking task, it be a visualization task, whatever that task may be.

Todd Schlosser:            Right.

Dr. Mark Li:                  So for speech it would be trying to generate some language, and they do a scan for a certain amount of time, and then you clear your mind, and you don’t do that task for a certain amount of time. They can subtract the blood flow images between the two and it shows where the blood flow is increased for that particular task. And that-

Todd Schlosser:            That’s very interesting too.

Dr. Mark Li:                  That is the area that is activated during that thought task.

Todd Schlosser:            So based on blood flow alone.

Dr. Mark Li:                  Based on the change in blood flow to a certain area of the brain. And it turns out that that’s highly correlated to the area of neuronal activation, which is how we map that area on an image, and then we can use that map to stay away from it.

Todd Schlosser:            Awesome. So then you don’t have to do as many awake-

Dr. Mark Li:                  Correct.

Todd Schlosser:            Neurosurgeries?

Dr. Mark Li:                  Correct?

Todd Schlosser:            Yeah.

Dr. Mark Li:                  We can also map motor areas for example that way. And then we can combine that with inter-operative mapping where we actually stimulate the motor area, verify that that’s where the motor area is, and stay away from it. So those are called motor mapping cases. We do quite a few of those as well here.

Todd Schlosser:            So you also mentioned that Lehigh Valley Health Network is a comprehensive stroke center and I’d imagine that has its own, requirements to get that designation. So what are some of those requirements?

Dr. Mark Li:                  So a comprehensive stroke center is the highest designation of stroke center.

Todd Schlosser:            Okay.

Dr. Mark Li:                  The designation comes with the ability, again, like trauma, to provide the spectrum of care to stroke patients, and that includes the rapid diagnosis of stroke, and the rapid intervention for stroke, including some of the newer things like intra-arterial TPA, which is a clot-busting technique.

Todd Schlosser:            So stop the stroke before it happens.

Dr. Mark Li:                  Try to dissolve the clot before it has a chance to completely destroy the brain that that is cut off from blood, the blood supply. Also do interventional procedures in order to stop aneurysms from bleeding, or to glue vascular malformations, and then also to treat the sicker stroke patients and try to get them through that episode so that we can salvage as much brain as we can.

Todd Schlosser:            Yeah, well, because much like trauma, strokes can cause a part of the brain to just sort of be there one day and not the next. Right?

Dr. Mark Li:                  Correct.

Todd Schlosser:            So you want to make sure that you can salvage as much of it as possible so their quality of life is as high as possible.

Dr. Mark Li:                  Right. Minimize any further damage, salvage as much as we can. And in this day and age, I think the exciting part of stroke work is that we can reverse some of these strokes if we can bust the clot or we can open up the blood vessel with an interventional technique. You’ve heard of cardiac stenting, for example.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  We don’t stent arteries in the brain, but if a brain artery becomes clogged, the interventionalist can drive a catheter into that clogged artery and suction out the clot, or put a clot-busting drug into that clot, dissolve it, and restore blood flow. And that has proven to be a miraculous way to treat strokes and we can take people who would have gone on to have severe disabilities,, reverse the blood flow issue and they can be relatively normal.

Todd Schlosser:            That’s awesome. That’s truly amazing. So you’re able to go remove the clot, extract it, or just dissolve it. And as the blood flow returns to the brain, they regain maybe not all function that they lost, but they get some of it back?

Dr. Mark Li:                  In fact, so it can be partial, but we’ve had several patients who’ve had full restoration of function and go back to being themselves.

Todd Schlosser:            Yeah, I’d imagine, and again, correct me if I’m wrong, a lot of that has to do with the time that that section of the brain was at a loss of blood flow?

Dr. Mark Li:                  Correct. And that’s part of the designation as a comprehensive stroke center. We have to demonstrate that we can intervene within a very short amount of time because time is of the essence when it comes to these kinds of issues.

Todd Schlosser:            So I’d imagine to get both the level one trauma center and those sort of designations, you have to be on the front lines of what’s new and what’s cutting edge. So what are some of the cutting edge things that are coming down, sort of the neurosurgery sector?

Dr. Mark Li:                  I think the ones that pop into my mind are, I think functional neurosurgery is an area that is extremely exciting, is probably still in its infancy, but will become a very important area of neurosurgery that gains much more traction in the next generation. Functional neurosurgery is surgery in order to alter or restore function.

Todd Schlosser:            Okay.

Dr. Mark Li:                  And the surgery that you’ve probably heard of is surgery for Parkinson’s disease and the tremor. So in those surgeries, we’re not cutting anything out.

Todd Schlosser:            Right.

Dr. Mark Li:                  We’re actually putting an electrode deep within the brain-

Todd Schlosser:            Deep brain stimulation.

Dr. Mark Li:                  To stimulate. And that stimulation actually restores function. Well, it turns out that there are also procedures that are on the horizon that modify function. So there are techniques to stimulate parts of the brain that may end up influencing mood, for example. So there are some trials out now that are looking at stimulation for severe depression or OCD. There are stimulation concepts to help with seizures as well, and these are all in their infancy, but I think functional neurosurgery is a very exciting area.

Todd Schlosser:            So that deep brain stimulation can impact things like mood, and I guess like you mentioned OCD. So that’s, I mean I realized that that was housed in the brain and I didn’t realize we were at the place where we could focus in on it like that.

Dr. Mark Li:                  So there have been some small trials on using stimulation to counteract OCD symptoms and they’ve actually been quite successful.

Todd Schlosser:            That’s awesome.

Dr. Mark Li:                  So let’s talk a little bit about endoscopic surgery and minimalist keyhole surgery.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  I think the one big area that that has really taken off in the past ten years is minimal access surgery and minimal invasive surgery and this includes using rigid telescopes or endoscopes in order to operate. So we can operate now through very, very small openings and effect the same sort of results that we were able to do before only with big openings. And that has improved quality of life for patients. It’s shortened the recovery time for patients. And that’s really been a big leap forward for us.

Todd Schlosser:            Excellent. So let me close with one final question and that simply would be if you were talking to someone who is considering residencies, and their specialization, if you will, what would be your sales pitch to get them to take on neurosurgery?

Dr. Mark Li:                  My first sales pitch would be to say that you got to do what you love.

Todd Schlosser:            Sure.

Dr. Mark Li:                  And I tell all of the younger residents this, that if you are not truly in love with that specialty-

Todd Schlosser:            Yeah, whatever it is.

Dr. Mark Li:                  Whatever it is.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  Be careful.

Todd Schlosser:            Yeah.

Dr. Mark Li:                  I think neurosurgery is the greatest specialty around of course. It requires a level of precision, and a level of care that I think is much higher than many other surgical specialties, mostly because we operate on an organ that doesn’t recover well. So other surgeries operate in ways where their organs can heal. The brain doesn’t heal very well.

Todd Schlosser:            Right.

Dr. Mark Li:                  So if you like being on the edge, if you like doing something that is highly technical, highly specialized, and has no room for error, this is the field for you.

Todd Schlosser:            It is very high stakes, it seems.

Dr. Mark Li:                  It’s high stakes and most of us love it, most of us love that aspect of it. We thrive on it, and if you are that person, please consider us.

Todd Schlosser:            Well and clearly a lot of those people exist because you are one yourself but you also have quite a few that work underneath you here at Lehigh Valley Health Center.

Dr. Mark Li:                  Yes we do.

Todd Schlosser:            So thank you so much, Dr. Li, for doing this episode with us. We really appreciate it.

Dr. Mark Li:                  You’re welcome.

Todd Schlosser:            Thanks.