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BackTable / VI / Podcast / Transcript #156
Podcast Transcript: Percutaneous Lung Biopsies: The Basics
with Dr. Fred Lee
We start off Part 1 of a 2 part series with Dr. Fred Lee discussing Percutaneous Lung Biopsy Technique, with tips and tricks to help your daily practice. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Having a Dedicated Lung Biopsy Nurse
(2) Lung Biopsy Technique
(3) Preparing Lung Biopsy Specimens for Pathology
(4) CT vs. CT Fluoroscopy for Lung Biopsies
(5) Doing Biopsies at End-Expiration
(6) Choosing Biopsy Trajectory
(7) Post-Biopsy Follow Up
(8) Percutaneous Lung Biopsies vs. Bronchoscopically Electromagnetic Navigated Biopsy (ENB)
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[Dr. Christopher Beck]:
Ladies and gentlemen, welcome to the BackTable Podcast, your source for all things in the vascular and minimally invasive. If you are a new listener, welcome. For all of our regular listeners, welcome back and thank you for listening.
[Dr. Christopher Beck]:
Today, we're going to be discussing percutaneous lung biopsies with blood patching. Today to help us with that discussion we have [Dr. Fred Lee]. Dr. Lee is chief of abdominal intervention at the University of Wisconsin. Dr. Lee recently helped publish a paper on this topic in JVIR, I think it was the September Edition. For our audience if you'd like to follow along, feel free to hit the pause button and check out this paper, or just feel free to soldier on and then catch the paper on the back end. Fred, welcome to the podcast.
[Dr. Fred Lee]:
Thank you very much, Chris. It's wonderful to be here.
[Dr. Christopher Beck]:
If you would, would you just go ahead and introduce yourself to the audience and talk a little bit about your background and what your current practice looks like?
[Dr. Fred Lee]:
Sure. I'm a radiologist at the University of Wisconsin and I'm a professor of radiology, biomedical engineering and urology. And my practice is approximately 50% diagnostic and 50% intervention with a focus on percutaneous interventions in the chest and in the abdomen. I do a lot of biopsy work and I also do a lot of tumor ablation, both in the chest, abdomen and pelvis. That's primarily my clinical practice. My research interests are primarily focused around ablation and some other percutaneous interventions throughout the chest, abdomen and pelvis as well.
[Dr. Christopher Beck]:
They're like lung biopsies, right?
[Dr. Fred Lee]:
Exactly.
[Dr. Christopher Beck]:
All right. One thing that I want to talk about before we actually get into the paper, although it is within the paper, but I just wanted to talk about your technique of the lung biopsy. And I'll just let you take it as an open-ended question and describe it, but there are a couple things I do want to drill down on.
(1) Having a Dedicated Lung Biopsy Nurse
[Dr. Fred Lee]:
Sure. So we've been doing lung biopsies at the University of Wisconsin for as long as I've been here, which is about 30 years, and one of the things that we thought about in great detail is that lung biopsies can be both very dangerous and also very important for the patient. And so we feel like it's important to get this right.
Lung biopsy is not something that you want to dabble in, you want to do it real well. And so along those lines, we thought about every aspect of the procedure from what patients we're going to do to how to manage complications, and tried to drill down and understand how to do it better in each of those little sub areas.
In our practice, we do a lot of lung biopsies. We have a dedicated lung biopsy nurse named Marcia Foltz, who's really fantastic. And we have an intake service which is primarily Marcia with some other help. And our referring doctors will directly call Marcia with many cases, otherwise they run into us in the hallway or they message us through the electronic medical record system as the broad intake.
And then what happens is, like many of your practices I'm sure, the patients get screened by one of the radiologists that do lung biopsies and if they're appropriate they're then put on the schedule. So I'm sure that's very similar to virtually everybody's practice. I think one of the differences though, is that Marcia is dedicated to CT-guided procedures. That's all she does. And lung biopsies make up a very large percentage of her practice, probably about 50% of her practice.
So at Wisconsin, we will do lung biopsies two to three days a week with a few other patients scattered in on the off days, so to speak. I'd say that our average is around 10 to 15 lung biopsies per week, sometimes less, sometimes more, but something around that range. And so we're very busy. We have about seven or eight physicians that perform them and all of us do a high volume of these procedures.
So we're very used to doing it. We have very similar technique and standards and we try to standardize anything that we do when we do lung biopsies, so everything from how we do local anesthesia to how we obtain specimens. We try to standardize this as best we can. There are some minor differences as there are in every practice, but we really do have an eye on standardization because if you don't standardize what you do, it's hard to improve in a systematic way. And so that's how we do it.
[Dr. Christopher Beck]:
Well, one, I just wanted to take a beat and recognize how fantastic it is to have someone, it sounds like Marcia, a dedicated RN to all your CT-guided procedures. I think that speaks to the volume of what you guys are doing. Go ahead and talk about what I think you're about to launch into, is the actual technique of the procedure and as far as... Actually, I'll leave it open-ended, the technique of the procedure.
(2) Lung Biopsy Technique
[Dr. Fred Lee]:
Sure. Before I get into that, I do want to reiterate exactly what you said that having a dedicated nursing resource is really important. Marcia knows all the indications for the procedure, she knows all the referring physicians, she attends every procedure as well. And so if something is going haywire, she's a really good canary in the coal mine and can warn physicians that something's going wrong or something along those lines. So a very, very valuable resource.
In terms of the procedure itself, I'm a firm believer in trying to do things the same way if at all possible every single time you do it. I liken a little bit to what my buddy Louis Hinshaw always says about his golf swing, he said, "If you can get it exactly the same every time, then your chances of success go way up." So I try to do this in a similar fashion if at all possible.
And one of the things that I do is that I will turn the patients so that I'm delivering the needle from the top to the bottom, rather than putting a needle from the side, if at all possible. Now, it's not always possible for various reasons, but if I have my druthers, I try to put the needle in from the top down. So I think that's one thing that I personally try to standardize.
The other thing that I think we don't think about enough sometimes as interventionalists is local anesthesia. And I spend a lot of time making sure that we have adequate and excellent local anesthesia. And how I particularly do it is I use lidocaine with epinephrine and we buffer it with a little bit of bicarb.
And the reason that I use lido with epi is multifold one is that, of course it lasts longer and so patients tend to have less pain in the recovery area and maybe are a little less distressed if they were going to have some pain. That's number one.
Number two is that lidocaine with epi is a vaso, it causes vasospasm. And especially when I'm going between ribs, I want to inject the lidocaine with epi ahead of myself and try to spasm the intercostal vessels down so I'm less likely to hit them. I don't have great data that this decreases the incidence of damaging the intercostal artery or vein, but I think it probably does. As I said, I haven't done a controlled study on this, but I think it probably does a good job in that.
The last point I want to make with local anesthesia, and if you read the paper you'll see how we do this, is that I tend to do a two needle technique. Some people will put the guide needle right down to the pleura surface and inject lidocaine through the guide needle. I don't like to do that as much. I personally believe that if you take a second needle, I usually use a spinal needle in a large patient or an inch and a half needle in a smaller patient.
I put an extension tubing on it. And so I have a closed system. And with CT fluoro, I rapidly put it down in to the inner space just a millimeter or two short of the pleura and inject a fairly high volume, five or six ccs of lidocaine with epinephrine right on the pleura to cause this concavity and in the pleura as it's pushing into the lung. And in that way, I'm certain that I have excellent anesthesia and the patient's not going to feel it when I pop the needle through the pleura and into the lung. That's how I go ahead and do local anesthesia.
[Dr. Christopher Beck]:
I just wanted to take a second and recognize that I know exactly what you're talking about, in that when you're administering the anesthesia, you get that lenticular fluid interface between the pleura and the lung surface.
[Dr. Fred Lee]:
Exactly.
[Dr. Christopher Beck]:
And so you're talking about getting maybe a 25 or a 22 gauge spinal needle down, or maybe the short needles that come in the biopsy sets.
[Dr. Fred Lee]:
Yes.
[Dr. Christopher Beck]:
Administering five to six MLs of 1% lidocaine can with epi, right? I just wanted a quick summary.
[Dr. Fred Lee]:
Yes, that's exactly right. And if you do it and you're very close to the pleura surface and you inject enough lidocaine, you have that lenticular shape of the pleura and what that tells me is that I have adequate anesthesia in the intercostal space. What I'm trying to avoid is the patient feeling pain when you place the needle through the pleura into the lung and taking a sudden deep breath, because if they do that, I worry about lacerating the surface of the lung. And of course, then you're going down a pneumothorax pathway, et cetera.
[Dr. Christopher Beck]:
Sure. Sure. Okay. And then once you have the lidocaine down and it's time for... Before you get into the actual technique of it, can you talk about the needle selection size and why you guys choose that needle?
[Dr. Fred Lee]:
Yeah. So if you look in the literature, there are papers that do lung biopsies with needles of various sizes, even up to 14 gauge, which seems very extreme to me. In our practice, we uniformly use a 19 gauge introducer with a 20 gauge core biopsy. However, the data is pretty good for even a 17, 18 set in terms of pneumothoraces and other complications.
The cut point is probably in the 17, 18 gauge range with larger needle sizes having higher complication rates and smaller needle sizes probably having a similar complication rate to that 17, 18 gauge size. So I think anything larger than that is probably not advisable. We tend to go smaller and we have very good results with smaller needles.
The biopsy size is important and is becoming more important in the era of personalized medicine where we're not just necessarily getting a biopsy for histopathology anymore. There's genetic testing and all kinds of other things that are required by our specimens. And this requires larger numbers or larger sizes of specimens, which is a different topic altogether, but something to keep in mind when you're doing biopsies.
(3) Preparing Lung Biopsy Specimens for Pathology
[Dr. Christopher Beck]:
Sometimes a closer relationship with your pathologists and your referring docs on, not just understanding that you're doing a biopsy, but understanding the point of the biopsy, and then what you're trying to accomplish from it can help sort out those things on the back end. I know that in our practice, we started putting our biopsy samples in two different formalin containers. And for whatever reason, that was helping our pathologists sort through and save a little extra tissue for a molecular genetic testing. But sorry, go ahead, Fred. Keep going.
[Dr. Fred Lee]:
Yeah. That's exactly right. And that's one of the roles that Marcia plays in our practice is she screens all the patients and contacts all the referring physicians for exactly what they're going to be testing for and where the specimens go. There's nothing worse than throwing specimen in formalin and then realizing you needed fresh tissue-
[Dr. Christopher Beck]:
Oh, yes. [crosstalk 00:14:19]
[Dr. Fred Lee]:
... or vice versa, right? That's a really bad mistake to make. So having someone screening for that on the front end is really important in my opinion.
[Dr. Christopher Beck]:
For sure. And then also one of the things I noticed about the paper, do you guys have pathology in the room or a cytotechnology in the room for assessment of either adequacy or whether or not you're in a non-necrotic part of the tumor?
[Dr. Fred Lee]:
Back before maybe 2014 or 2015, we did a large number of fine needle aspiration biopsies. Essentially we just don't do that anymore in the chest, primarily because of this molecular testing and things that's needed and specimen adequacy. And so when we changed our practice, at the time when we were doing FNAs, we did have a Cytotec in the room. Once we changed our practice over to core biopsies, we no longer had a technologist or a pathologist in the room.
I know that some practices are doing a touch prep or some rapid testing of core specimens. I mean, that could be helpful. There's some data that decreases the overall diagnostic rate of the final specimen. I'm not sure how true that is, but there are some papers that have mentioned that as a possibility. So we just tend to put the cores right in formalin with no monkeying around and try to get the maximum amount of tissue that we can from the biopsy specimen.
One of our major limitations is that, as you can see from the paper we go after really small nodules. A very large proportion of our nodules, maybe 20, 25% of our nodules are one centimeter or smaller in size. In fact, last week I did a five millimeter nodule. So this is becoming increasingly frequent and your ability to get great specimens from those really small nodules can be really tough. And in our practice, I think virtually every practice, your diagnostic rate drops somewhat as the nodules get smaller.
Even though our rate is lower, it's still pretty good. In this paper, as you can see when you read it, the diagnostic yield is somewhere around 87% for nodules that are a centimeter or smaller. And so you can still do a really good job with small nodules if you have really excellent technique, but you should expect your diagnostic yield to drop slightly as the nodules get smaller.
[Dr. Christopher Beck]:
Fred, actually, I had a little bit of pushback from some of my referring docs about... My practice, mirrors yours in many ways, including not having pathology in the room for a touch prep review for adequacy, but at least my explanation was that if you're talking about a five millimeter needle, really anything under 10 millimeters, I mean, where are you going to put the needle?
I mean, presumably you've put it in the optimal spot and there's not a lot of wiggle room in terms of making it any better when you're down to lesions that small. And so I told him it didn't create a situation where I'd be able to change the procedure in a way that was meaningful to increase my diagnostic yield. We've actually also moved away from using cytopathology and just have moved to all core biopsies of basically all pulmonary nodules and masses.
[Dr. Fred Lee]:
Yeah. I think more and more practices are doing it. Even from an efficiency standpoint it's a big advantage, but I have to say that there have been some attempts in the technology world to give some immediate feedback to you that you actually did hit the nodule, and that would be wonderful if that is the case.
It would be nice if we could do it in a way that is very fast, doesn't steal tissue from our final diagnosis, so to speak, and is something that we can do in the room. But even though there have been some attempts at that, nothing has really bubbled to the top at this point. So you inventors out there get working. We need something like that.
(4) CT vs. CT Fluoroscopy for Lung Biopsies
[Dr. Christopher Beck]:
One of the things I wanted to switch gears a little bit and talk about is just questions in general about... I mean, you guys clearly do a high volume. I feel like I'd be remiss if I didn't just pick your brain a little bit on some of the optimization methods for doing lung biopsies. And I just have a series of...
You can either make 'em quickfire or throw away questions, but one of the questions that was mentioned in the paper, or maybe tangentially was CT fluoro versus CT just regular. I don't know, standard CT guidance. I think that I know what fluoro CT is, but now I feel like the line is a little bit blurred in that there are some places that I've been where I can't say they had a pedal next to the CT scanner.
But they certainly have software where the patient goes in, it does a quick three slice series that maybe covers a centimeter or two centimeters of the lung and that feels in the vein of CT fluoro, but may not qualify CT fluoro, but can you talk a little bit about how CT fluoro and just standard CT changes or doesn't change your practice much?
2
[Dr. Fred Lee]:
Sure. This is a complicated topic. And I think we have to also throw in CT navigation using historical data sets too, because that's another method that looks like it's becoming increasingly adopted. So conventional CT intervention was started back in the mid 1970s by [John Haga 00:19:37]. It hasn't really changed all that much.
That's the method where we'll place a needle, walk out of the room, do a small diagnostic scan generally with a short Z-axis, figure out where our needle is, walk back into the room, make corrections and walk back out of the room, et cetera. This can be very laborious. For a small lung nodule, this can take a tremendous amount of time.
As you noted, the lung is moving and even though we're pretty careful to get all of our scans in end-expiration, which I would urge people to do because it's the most reproducible phase of respiration and it's also the longest. Even with that, the nodule can be all over the place and you can find yourself chasing a small nodule all day, depending on how much patience you have.
And so that has not changed since the mid 1970s and the primary reason that people state for using that is that they get no radiation exposure, no personal radiation exposure to the physician. And so that has some validity. I can't criticize that.
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
In our practice we've taken the opposite tact, and we've done two things. First is that we have really embraced CT fluoroscopy as a semi-real time technique. So there are two methods of CT fluoroscopy. One of them is real time CT fluoro, which is similar to conventional fluoro, but with CT, and there are extremes of this where people will put their hand in the x-ray beam and push the needle into the nodule while holding down the pedal. And that is true real time or near real time technique.
That can cause some extreme radiation exposures to the patient and the physician, depending on how long you stand on the pedal. And we have some trainees with really heavy feet, and so I think radiation exposure can be very high if you do that. Then there's the second technique, which is the hybrid technique, which is some people call intermittent fluoro, we'll call tap mode, there's other names for it in which just as you described, every time you step on the pedal, you get a limited series of images that are projected very quickly onto the screen.
And for our particular system, which is a GE system, we have three images: top, middle, bottom. You can vary the slice thickness depending on the situation and the size of the nodules you're going after, et cetera. And we will limit the stepping on the pedal until the patient is in expiration.
And again, I have to give kudos to my nurse, Marcia, who's really good at looking at the patient and even those irregular breathers and patients that belly breathe and things, she can figure out when the patient's in end-expiration and she signals to me to tap on the pedal.
[Dr. Christopher Beck]:
Sounds great.
[Dr. Fred Lee]:
Really, I mean, having her in every procedure makes things so much easier. So we will tend to use the tap fluoro and that will really limit the radiation exposure to you and the patient, and I would urge you to do that. There's another hybrid version of that that is even less radiation and is a little less cumbersome than walking in and out of the room. And that is to do the tap fluoro technique, but take one step behind a screen when you do it.
It's not as fast as being right at the patient's bedside, but if fluoro radiation is worrying to you, then that is a way of getting zero radiation. You can also stand lateral to the CT scanner where there's excellent shielding and get no radiation as well. So those are two ways if the radiation concerns you which I think CT radiation is very misunderstood.
And for those people that are willing to do a test procedure, for example, which is maybe a thousand times more radiation than a lung biopsy, no radiation is the best of course, but I think it's important to put it into context versus other procedures that interventional radiologists do. And lung biopsies with really good technique, with low MA, most of the time you only need 10 MA.
At 140 KV you'll get more bang for your buck in terms of image quality at 140 KV and at low MA your radiation exposure is very low and you can make it zero with slight modifications using shielding or stepping to the side of the CT scanner.
[Dr. Christopher Beck]:
Well, I'm glad I asked that because one of the things that comes to mind whenever I'm talking about CT fluoro is that heavy footed approach where someone steps on the pedal, reaches their hand into the gantry and adjusts the needle. That's what I always picture.
But I think it's good to point out that you can have the pedal, you can bring the pedal off to the side of the CT. I've seen people do it with a screen. All those things can really minimize that, which I think is the main argument against CT fluoro versus conventional CT where you walk out of the room as the radiation exposure.
[Dr. Fred Lee]:
Exactly.
(5) Doing Biopsies at End-Expiration
[Dr. Christopher Beck]:
And you also talked about another thing I wanted to bring up, and I was going to bring it up in the context of moderate sedation versus local. It sounds like you guys do at moderate sedation for everything, but making it a point to do your biopsies on end-expiration, I think that's a good practice to get into.
I think sometimes there's room for variation where if you happen to... Sometimes lesions can pop into a better area if you happen to use a different breath-hole. But I think end-expiration tends to create the most reproducible location of a lesion.
[Dr. Fred Lee]:
Absolutely. And you can use respiration to your advantage, as you were saying. If you need to pull the nodule down to you a little bit, just have 'em take a very small breath and hold it. My issue is that when we start giving little sedation to patients, it's very hard to get a reproducible breath hold. And also it is...
Getting back to the balloon analogy again, puncturing a patient during inspiration is like filling a balloon and then sticking a needle into it. And I would rather have a deflated balloon and stick a needle into it with less pressure in the lung. I think it probably decreases your pneumothorax rate as well. But again, something we haven't proven, but we suspect.
(6) Choosing Biopsy Trajectory
[Dr. Christopher Beck]:
One of the other things that I wanted to bring up was the trajectory at which you picked to biopsy the lesion. One of the most challenging lesions, for me personally, and I've seen it bugger up to my other partners, are those lesions that it's towards the lung base, you have a small lesion that contacts the pleura, but I wouldn't say is pleura-based.
And I feel like for whatever reason, it's those pleural-based nodules. Sometimes even it's a shorter distance to get to, but there's something about those lesions that can be a little bit more difficult. I haven't, in my own opinion, but I was wondering if you had any specific advice on that in particular and why maybe they tend to give us a little bit of grief.
[Dr. Fred Lee]:
Oh, Chris, I'm so glad you brought that up because those are the ones we all hate to see, the lower lobe nodules which tend to move more, and the ones that are on the pleural surface. The tendency is to directly puncture those, which I think is a mistake. I personally... Because what happens is that even if you're successful puncturing it, it's a little bit like you have a marble, for example, something hard on the surface of a soft background lung.
And so I think it's a little bit hard to actually puncture the nodule, number one. And number two, the tip of your needle is right at the pleural space. And when you pull your stylet out, oftentimes air rushes in and you end up with a pneumothorax, and then of course you start going down that whole slippery slope.
Generally, for smaller nodules at the lower lobe on the surface, I personally tend to take a slightly longer path and I'll puncture through some parenchyma to try to stabilize the needle and get me a little away from the pleural surface when I do my biopsies, because what you don't want is when you're doing exchanges of the stylet for the biopsy needle because every time you pull the stylet out, you're going to introduce air and it can progressively drop the lung if tip of your needle is in the pleural space.
And so I like to be in the lung parenchyma if at all possible, but I know exactly what you're talking about. We all groan when... In fact, we all accuse Marcia of putting those patients on our day and somehow I personally think that I'm being targeted by having those doctors on my table.
[Dr. Christopher Beck]:
Sure. Your excellence is being targeted. Marcia thinks that you…
[Dr. Fred Lee]:
But all my partners feel the same way. For some reason, I think it probably evens out, but I like to go through parenchyma for those. And in general, for biopsies, you want the shortest path, but that's the one exception that I'll make is lower lobe, small service nodules. Those things can be really painful. Those are not fun.
[Dr. Christopher Beck]:
I agree. And for the same reasons that you say that... I sometimes think that whenever you just don't have a whole lot of needle purchase within the lesion, even if you manage to just nail it. For a small lesion, you just have such tenuous access and then you're trying to biopsy and that part when you're actually taking the biopsy, it's a little bit of blind leap of faith that the needle stays in position.
If you use certain types of needles, you may actually be just biopsying the pleural surface, which I think sets you up for a pneumothorax and so I agree. I think the technique of anchoring your needle with a little bit of a longer throw in that situation makes sense.
[Dr. Fred Lee]:
There's one other technical point I want to make, because this is a little trick that I think can be really helpful. Most of you out there, I would guess, have CT scanners that can tilt the gantry. And our system, we can tilt up to 20 degrees and we're fortunate at UW that we have a Big Bore CT scanner. And when you have a large patient in a Small Bore CT, you can find yourself working in very tight quarters. And you're concerned about contaminating needles and hitting the stylet on the CT, et cetera.
And this is exacerbated when you tilt the gantry. It decreases the amount of working space that you have. And so for those of you that are purchasing CT scanners, you should really think about a Big Bore CT. We have an 80 centimeter Bore CT and even though it's only 10 centimeters more than the typical diagnostic scanner, which is generally 70 cm, it makes a huge amount of difference because the patients tend to kind of spread out and you get disproportionately more room at the top where you generally tend to do most of your work.
Tilting the gantry. Now, this is a little trick that really helped me get between ribs, because it always seems that that nodule that looks so ripe and juicy for the picking on the diagnostic scan, when you put the patient into the scanner in the position you want to do your biopsy, somehow that is always directly behind a rib. And that just seems to be the luck of the draw more often than not.
And so the way I think about it is that you need to tilt the gantry either toward you to come from the patient's top or away from you to come toward the patient's bottom, so more feet up. And the way I decide which way to tilt the gantry is that I scan through the nodule, and so I scroll from the top to the bottom and I say to myself, "Is the nodule end-to-end expiration? Is it closer to the top of the rib or the bottom of the rib?" If it's closer to the top of the rib, then I will tilt the gantry toward the patient's head. So I'm coming from the top down. I hope that makes sense. It's-
[Dr. Christopher Beck]:
No, no it does.
[Dr. Fred Lee]:
Yeah. That's how I choose my obliquity. And it's just really simple. You just scroll through and decide if the nodule is closer to the top or the bottom and then tilt the gantry that direction. I usually start with 10 degrees and that almost always opens up the rib space. If that doesn't work, then try 15 or 20 degrees. And I guarantee that that will take care of almost all of those nodules that are hiding behind ribs.
I prefer to tilt the gantry than trying to deal with it via respiration, because as we noticed before, or as we discussed before, I find that once you give a little bit of conscious sedation, trying to get the patient to take a reproducible breath just goes out the window and it becomes really difficult.
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
Then you find yourself chasing a nodule, which is never a great situation.
[Dr. Christopher Beck]:
Is there ever any concern when you hit the under surface of the rib or even nodules that are just behind a rib, but there's a little bit poking out underneath the rib... Is there any concern that when you're really hugging the bottom of the rib for an intercostal bleed or... For me, I'll just say that I know that it's a calculated risk. I know it can happen and I know it's a higher risk when I'm really hugging the under surface of the rib.
But sometimes when you're talking about very small lesions, I just feel like sometimes we don't have a lot of options that are open to us when you're trying to angle the gantry to give yourself a little bit more wiggle room, or you're trying to mess around with breath hold techniques, which can arguably end up in its own rabbit hole of its own.
[Dr. Fred Lee]:
Yeah. This is one of those things that every time you put a needle under a rib, you say a little prayer that there's not an intercostal artery there or in particular, an aberrant intercostal artery that you're going to lacerate. And every time I get away with it, I'm shocked, knock on wood. I think the rate of damage to the intercostal arteries is surprisingly low in the literature considering how aggressive we've become with our patient selection.
And I mean, think about it. How often do you turn down a procedure because, geez, I might have to go under the rib so I shouldn't be doing that. I mean, that's... I think radiologists are getting really good at this procedure and are taking on all kinds of cases in patients with nodules pretty much anywhere in the lung and we get away with it, and I think a lot of it is luck.
And when you hit an intercostal artery, I don't think you should generally blame yourself because for every time you come under a rib and hit an intercostal artery there are maybe 200 times where you didn't, and so I think it's just... Hitting an intercostal artery is just bad luck in my opinion, more than it is technique. And as you know, in elderly patients, as you start getting out more lateral away from the posterior part of the thorax, the position of the intercostal artery becomes more unpredictable.
And as people get fatter and more elderly, there are plenty of intercostal arteries that are running right down the middle of inner spaces. And so I shake my head and admire all those that are getting away with it. And I feel bad for myself and for others that that hit 'em on occasion and I'm just not sure that we have a great way of seeing it every single time and avoiding it every single time. And generally the information that we get from a lung biopsy is so important to the patient's journey going forward that we have to accept those small rates of complications that we're going to get.
(7) Post-Biopsy Follow Up
[Dr. Christopher Beck]:
Yep. I totally agree. My next question is regarding the post-biopsy follow up. So you have an uncomplicated patient, no pneumothorax after the biopsy and the patient's feeling well, how long do you keep those patients? And what's the imaging after the biopsy?
[Dr. Fred Lee]:
I'll answer that first by explaining our practice and then maybe touching on what's happening around the country and around the world, because I think this is something that's changing a little bit. In our practice, in an uncomplicated lung biopsy, we will send the patient to recovery for one hour with a biopsy side down. And assuming that everything is fine with the patient, we will get a chest x-ray in one hour post procedure.
If that chest x-ray shows expected findings, and what I mean by that is, as you allude to, sometimes there'll be a small post procedure pneumothorax that we are fine with. It's not something that we're going to bother intervening in. And as long as the chest x-ray is concordant with that, you don't see a very large pneumothorax or the patient's not symptomatic, then we'll hold the patient for another one to two hours and discharge them.
So a total of two to three hours and one chest x-ray is our routine. Now, for me and I think my partners it's fairly similar if patients are in the intermediate situation where they have a pneumothorax, it's maybe just a little bit bigger than you might expect, or there's something about the patient that's bothering you a little bit, then what we'll do is get another chest x-ray an hour after the first chest x-ray and very carefully compare those.
And we're fortunate in that our thoracic reading room is right around the corner and our thoracic radiologist, Chris Meyer is on this paper and is one of them and he's fantastic. In fact, Chris is the one that taught me about the blood patch when he was at Indiana. They were using the parenchymal blood patch as well.
[Dr. Christopher Beck]:
[inaudible 00:37:08].
[Dr. Fred Lee]:
And we'll go talk to Chris or [Jeff Keeney 00:37:14] or one of our great thoracic radiologists and they will very carefully compare the chest x-rays. Because I have a rule that I will not discharge a symptomatic patient or a patient that has a changing chest x-ray. And I want to see a stable chest x-ray at least one hour apart before they'll hit the door, if they have an x-ray finding.
And so there can be up to three chest x-rays postprocedure if you're monitoring a known pneumothorax or complication and you want to be sure that it's stable. But after about two or three chest x-rays, I'm thinking to myself, "Maybe I should throw them back on the scanner and do a pleural blood patch. I mean, I don't want to fool around this forever."
[Dr. Christopher Beck]:
[crosstalk 00:38:00]
[Dr. Fred Lee]:
Yeah, exactly.
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
And some of my partners are more willing than others to follow intermediate-sized pneumothoraces. I tend to be a little bit more on the side that I just don't like to look at it, and so I tend to aspirate it and put a blood patch in if it's starting to bother me.
[Dr. Christopher Beck]:
Okay. That's fair. So for the routine patients who are doing well, it's one hour in recovery, biopsy side down, chest x-ray at the one hour mark, and then an additional one to two hours of recovery, then out the door.
[Dr. Fred Lee]:
Right. And that's our practice. I just want to be sure that people know that this is not dogma necessarily-
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
... and that there are people that are investigating even no chest x-ray after a routine uncomplicated lung biopsy that showed no pneumothorax after the procedure on the scanner. Some people are shortening the follow up time. I think we're in the middle of the extremes that are practiced around the country, but I think everybody needs to hang on because I think this is an evolving topic.
[Dr. Christopher Beck]:
I agree. Right now, and just for lack of having a better answer to it, our practice is a post-biopsy x-ray at one hour, and then no matter what that shows, we'll still keep them for a post-biopsy X-Ray at three hours then out the door after the three hour if it looks good and that's... People just do things differently and I can't say that...
One of the criticisms in that way, is to always think about how many of those three hour films where we're finding a delayed pneumothorax, which does happen, the delayed pneumothorax does happen, but it's how many of those are we intervening on? When you have an asymptomatic patient who's sat-ing well, those are few and far.
And one of the things that we keep going back to, some of our younger partners, we routinely say, "We should be treating the patient, not the pictures." But we are also trying to standardize a practice across a wide breadth of practitioners. And so we're just trying to find something that works for everybody's practice and that's the challenge for us.
[Dr. Fred Lee]:
I think that practice sounds great. I mean, there are extremes to both sides where people are keeping patients four or five hours afterwards, and there are some other extremes where people are not getting a chest x-ray and just watching patients for a short period of time and sending 'em out the door. And I think there's arguments to be made both ways.
And I think this is going to be evolving over years and I have the feeling that... My gut sense is that we'll follow exactly what you're saying and that as the data is coming out that longer follow ups and more imaging is probably not adding that much. And my guess is we're going to be doing less over time. But as I said, I think this is an evolving concept and I don't think that there's no standard that's out there that we have to meet at this point.
[Dr. Christopher Beck]:
Sure. Agreed.
(8) Percutaneous Lung Biopsies vs. Bronchoscopically Electromagnetic Navigated Biopsy (ENB)
[Dr. Fred Lee]:
There is one other topic that I think we should touch on, and that is the role of percutaneous lung biopsies versus the bronchoscopically electromagnetic navigated biopsy. And I think there's not a ton of literature comparing the two techniques, but they are somewhat competitive and I've noticed that many more patients in our center are getting ENB first before the patients are sent to us.
And I think, if you look at the literature, the diagnostic yield rate for an ENB biopsy is 75% maybe. There's some different numbers out there in the literature, but I think it's around that. And when you ask people, pulmonologists especially, why they're going first to ENB versus percutaneous biopsy, I think you'll get a variety of answers.
One is that for some reason, which I don't really understand, ENB is considered non-invasive, whereas what we do is considered invasive. And I find that difficult to reconcile in my own mind because putting someone under essentially general anesthesia and putting a scope all the way down their trachea and into their bronchi and out to the periphery lung, that seems pretty invasive to me compared to what we do. I mean, we're-
[Dr. Christopher Beck]:
Right.
[Dr. Fred Lee]:
I mean, to me, it's even a little bit controversial, the use of conscious sedation. I mean, there are many practices that don't use conscious sedation at all, and I think do a great job. I would say that virtually every patient that we do, that we can get adequate local anesthesia doesn't even really feel what we do to them. And the conscious sedation is more for them to hold still and to be less anxious during the procedures and maybe to help control coughing. I don't really understand that argument that well.
The second is that I've seen in the literature several times where it's been referred to that the highly invasive percutaneous lung biopsies have a very high pneumothorax rate and therefore we should be doing ENB first because the pneumothorax rate is lower. And I think in this paper, we addressed that a little bit.
[Annie Zlevor 00:43:12] who's, again, the primary author on this paper, did a bit of a literature dive. And it turns out that even though that is true to a point, the pneumothorax rate is generally greater in percutaneous series, the intervention rate is no different.
So in our series, for example, as we noted earlier, we only put chest tubes in at about 2% of patients, whereas in a lot of the ENB series, they're putting in chest tubes up to 4% of the time. So I don't really get that argument either. Now, there are areas where ENB does a better job than we do and vice versa.
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
A very small peripheral nodule is probably our area and central airway-based lesions are probably ENB areas, but there is this large area of overlap that I think we need to study and try to understand better, which technique is better for one versus the other. Because I think in the absence of data, we're going to find ourselves fighting a tough battle that is going to be patient access-based.
Who sees the patient first and what the referral patterns are at a particular institution rather than evidence-based. And so I guess I would urge the listeners out there, if you have a practice where you can study this topic to go ahead and do it.
It's something that I think we're going to be studying sometime in the future too, and try to really get this a little bit more standardized so that this doesn't become a... I mean, it becomes a patient distribution issue rather than a fight between specialty issues, because I really don't think we should try to get into that personally.
[Dr. Christopher Beck]:
I agree. And I think the evidence-based patient-centric approach, it's hard to argue against that. I will say one of the other arguments I've heard for ENB is when they're doing the nodule biopsy, a lot of times our interventional pulmonology guys, they say that we can sample the lymph nodes at the same time. And so they'll make an argument for lymph node staging.
And one of the other things that they're very upfront about is that... This is what they're trained to do, and they think these procedures are fun. And so we have a healthy competition with us and the interventional pulmonologists, but I will say that as of late in the last couple of years, I feel like we've been getting the nod more and more as their samples are coming back less and less adequate for genetics and molecular testing.
[Dr. Fred Lee]:
Yes.
[Dr. Christopher Beck]:
But I agree that I think that hopefully some people will settle the answer in terms of deciding which is best for that area of overlap, those mid range lesions, where I think both teams, interventional pulmon and interventional radiology are doing a good job.
[Dr. Fred Lee]:
Yeah. I agree with you. I mean, I think an evidence-based approach is going to be better and maybe it's just because I'm getting older, the intensity of turf battles seems to be going down. I think I'm fortunate practicing at University of Wisconsin where, I mean, we have a very collegial medical staff and we just don't have those fight-to-the-death turf issues here.
And I'm not sure if that's a reflection of what's happening nationwide and worldwide, but I think maybe it's more a reflection of just everybody being really busy and plenty of work for people to do. But I have to give a nod to our interventional pulmonology group. Scott Ferguson leads that and they are great collaborators and I think they would be open to an evidence-based approach. We just need to get that evidence out there, which is not really available the last time we looked at all the literature.
[Dr. Christopher Beck]:
Sure. Which was September of 2021, when the paper came out?
[Dr. Fred Lee]:
Sure. I'll just say a few months ago, Annie did a pretty deep dive into the literature. For those people that are listening, and there's been some paper published last month, I'm sorry, okay?
[Dr. Christopher Beck]:
Sure. Right.
[Dr. Fred Lee]:
We're all busy.
[Dr. Christopher Beck]:
All right, guys, that concludes part one of the Lung Biopsies podcast. Stay tuned for part two.
Podcast Contributors
Dr. Fred Lee
Fred T. Lee Jr, MD is a professor of Radiology, Biomedical Engineering, and Urology, The Robert A. Turrell Professor of Imaging Science, and the Chief of Abdominal Intervention at the University of Wisconsin.
Dr. Christopher Beck
Dr. Chris Beck is a practicing interventional radiologist with Regional Radiology Group in New Orleans.
Cite This Podcast
BackTable, LLC (Producer). (2021, September 27). Ep. 156 – Percutaneous Lung Biopsies: The Basics [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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