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BackTable / VI / Podcast / Transcript #157
Podcast Transcript: Percutaneous Lung Biopsies: Pleural & Parenchymal Blood Patching
with Dr. Fred Lee
In Part II of our Lung Biopsy Series Dr. Fred Lee and Dr. Christopher Beck discuss Pleural and Parenchymal Blood Patching to prevent Pneumothorax, including results of the recent JVIR article from Sept 2021. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Parenchymal Blood Patch Technique
(2) Introduction to Pleural Blood Patch Technique
(3) Advice for Trainees Doing Lung Biopsies
(4) Pleural Blood Patch For Pneumothorax
(5) Efficacy of Pleural Blood Patch
(6) Complications of Pleural Blood Patching
(7) Arguments Against Blood Patching
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[Dr. Christopher Beck]:
Ladies and gentlemen, welcome to the BackTable Podcast, your source for all things endovascular and minimally invasive. If you are a new listener, welcome. For all of our regular listeners, welcome back, and thank you for listening.
(1) Parenchymal Blood Patch Technique
[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. All right. So let's talk a little bit about the types of blood patches in the technique of doing blood patches. So would you just talk about like first a differentiating feature between what's mentioned in the paper between parenchymal blood patch versus pleural blood patch?
[Dr. Fred Lee]:
Sure. So, this can be a source of confusion because the naming is somewhat similar, and I want to make sure that we're really clear. So a parenchymal blood patch is what we do in virtually every case, and the reason behind it is to try to lower our pneumothorax and other complication rate. And a parenchymal blood patch is very simple. It's just injecting autologous blood drawn from the patient's IV, as you're withdrawing the introducer needle after the specimen has been obtained. So that's a parenchymal blood patch, and that's performed in virtually every patient. In this study, we mirrored what has been shown in the past that if you do that, you do decrease your complication rate and your chest tube rate.
So we're pretty sure that it is a very valuable sort of prophylactic preventative measure, and we do it now routinely. At the beginning of the study period, we didn't do it routinely. There are a few of my partners that were a little slower to adopt the technique, and it was kind of nice because we had a built-in comparative group between blood patching and no blood patching, and as expected, complications are lower if you blood patch. So that's a parenchymal blood patch and it's routine and it's preventative and it looks like it's effective. And that's been shown in literature before.
[Dr. Christopher Beck]:
So parenchymal blood patch, for summary, is through the 19 gauge introducer needle, 5 to 10 mL’s of the patient's blood as you're pulling out the needle?
[Dr. Fred Lee]:
Exactly.
[Dr. Christopher Beck]:
So at the very tail end of the procedure, it takes 10 to 20 seconds. You're just adding a little bit of blood as an introducer needle's being pulled out?
[Dr. Fred Lee]:
Exactly. So once I'm getting near the end of the procedure and I've taken my last or second to last core, Marsha's watching and she starts drawing blood from the patient's IV. If the patient has a saline infusion, when she withdraws the blood, she discards the first couple of cc's, so you're not just injecting saline, you're injecting whole blood. She usually draws maybe, it depends on the depth of the lesion. If it's deep up to 10 cc's, if it's superficial, maybe three, four, or five cc, something like that. And then as you're withdrawing the needle, you have to get the rate exactly right. You want to inject as you're pulling back and you would like to inject the bulk of the blood at the pleural surface if, at all, possible.
So you have a good feel for how far the needle’s in, and so you assume, okay, the nodule is three centimeters deep from the pleural surface. So when you get near the three centimeters, then you inject the bulk of the blood. The idea is just that the whole blood will go into the airspaces and clot. And then it also fills the track as you pull the needle out, and this should, in theory and now I think in practice, reduce the air leakage that you get from the puncture site. So it's a really simple procedure, it doesn't take any extra time, and it's just really routine. The only caution I would say is that patients will sometimes, if you forcibly inject the blood and the blood goes into the airways, they can get some coughing from irritation of the airways, and even I tell patients, they occasionally get a little bit of homolysis from it.
So I just warn people ahead of time. Sometimes if I'm going to do a big blood patch, Marcia will give a little extra fentanyl right before I start injecting. And that's usually all that's necessary for the blood patch. So routine simple, fast, we do it in every case, and I'm pretty sure that it decreases complications.
[Dr. Christopher Beck]:
And you guys always use the IV site for what you're using moderate sedation, or do you sometimes if that IV's not good, do you do like a butterfly and stick at another side? Or are you always able to get it from the IV?
[Dr. Fred Lee]:
I would say about three quarters of the time we can get it straight from the IV. On occasion, it's up against a valve or it's a small vein or something like that, we're not able to adequately draw it. But I would say probably about three quarters of the time we can get it straight from the IV. Our nurses that place those IVs are aware that we're going to try to draw from it, and so they do look for a reasonable size vein in the holding area when they're putting the IV in at the beginning.
[Dr. Christopher Beck]:
Sure. Are there any situations where you agitate the blood or do you just take it, basically the nurse takes her syringe, gives it to you maybe at a sterile syringe and then you administer along the track? Or do you put it on a three-way stopcock and have another 10 cc syringe for agitation? Or it's just straight from her syringe, Marcia's syringe, to your syringe to body?
[Dr. Fred Lee]:
So I've seen several different practices around the country and around the world and how they do it, and everybody is a little bit different. For example, at UCLA, they let the blood clot. They figure that a blood clot is just as good as whole blood that ends up clotting in the lung parenchyma. And that there's certainly some validity to that, I would assume. I do it in a very simple way. And what I'm trying to do is decrease the open needle time when the needle's in the lung parenchyma, and also I try to do a wet-to-wet transfer of the syringe to the introducer needle. And so the way I do that is that I will pull the stylette back and then Marcia drips the blood onto the stylette, and that through a capillary action, the blood then travels down the stylette into the hub of the needle. And then when you pull the stylette out, she continues to inject a drop or two, and then screws the Luer lock syringe directly onto the introducer needle. And we don't have any exposure of air to the lung parenchyma with that very simple technique.
[Dr. Christopher Beck]:
Excellent. I will say that I am a big fan of the blood patch technique. And so for those listening, me and Dr. Lee here may be victims of confirmation bias and just talking about a procedure that we very much like and think is a great adjunct to lung biopsies. But for some reason, I got in the habit of agitating mine. Like I just take a 10 cc syringe and an empty 10 cc syringe, and sometimes my nurses will draw the blood ahead of time. And so it's nice to break up some of that clot that if I go to inject, can kind of get hung up and then I have to use a little extra force. And so it helps for a smoother introduction of the blood. And sometimes I don't know why I do it other than that old habit, and I'm used to doing it with gelfoam, but I don't know if it adds anything. So it's was just curious how you guys do it.
[Dr. Fred Lee]:
Yeah, it makes some sense, especially if the blood was drawn a little bit ahead of time. Usually with fresh blood, she'll draw it right from the IV, hand it to me, and I'll put it right in.
[Dr. Christopher Beck]:
Sure.
[Dr. Fred Lee]:
But if it's been drawn earlier, and I think there is some rationale to allow the blood to kind of partially clot, and if you agitate it, you can distribute it throughout the syringe better and it probably injects better. So I think there is some rationale for that as well. No data, but our rationale and as you know, many of these small technique points are a matter of opinion, not a matter of fact.
[Dr. Christopher Beck]:
That's right. That's right.
[Dr. Fred Lee]:
So we all have to understand that just because we do it doesn't necessarily mean it's right. But as long as you have success, more power to you.
(2) Introduction to Pleural Blood Patch Technique
[Dr. Christopher Beck]:
Right. A small amount of Voodoo and everyone's technique is okay. So we talked about the parenchymal blood patch. Now, can we switch gears? And you discuss the technique of the slightly different pleural blood patch?
[Dr. Fred Lee]:
So the pleural blood patch is a salvage technique. And I first got the idea for the pleural blood patch back in the early 2000’s when I was speaking to a thoracic surgeon about bronchopleural fistulas. And he explained to me that some of the postoperative fistulas that the thoracic surgeons encounter after thoracotomy can be cured essentially by a large volume pleural blood patch. And how the thoracic surgeons do it is a little different than how we do it, but they have a preexisting large chest tube in patients. And they'll inject up to like 500 cc’s of the patient's blood into the pleural space in an attempt to really seal a suture line that might be leaking.
So having heard that from one of my thoracic surgery colleagues, I thought that this may be applicable to lung biopsies. And so back in 2011, we published our early experience doing this primarily with a fine needle aspiration lung biopsies. And we found that it was successful, especially when you compare to simple aspiration. So we compared simple aspiration of a pneumothorax versus aspiration plus a pleural blood patch. And we found that the need for a chest tube was down when you combined aspiration and pleural blood patching. Now, what pleural blood patching is in the context of a lung biopsy is it's a salvage technique, and what it does is in most cases, it prevents you from having to place a conventional chest tube.
And the reason I was interested in this is primarily, I have to say that I have a touch of laziness in me, and I realized that every time I had to put a chest tube in a patient after a lung biopsy, the next day was quite a hassle. I mean, you're checking chest x-rays, and you're doing extra rounding on patients, and you're clamping chest tubes, and eventually you're pulling chest tubes and more chest x-rays and more monitoring of patients. And that became very user intensive, so to speak. And so in an effort to decrease my own efforts in this area, I thought there has to be a better way. And an ounce of prevention, of course, is better than the pound of cure. And so the next time I had a patient on the table, I tried this technique with just a smaller volume of blood than what the thoracic surgeons were doing, and lo and behold, it worked.
And based on that single first attempt at it, mean a couple of my partners started doing it a little bit more routinely, and I think we were able to prove in 2011 that it probably works. And so since then, it's become a stalwart of our practice. So I can describe this in a little detail if you're interested in hearing it, Chris.
[Dr. Christopher Beck]:
Yeah, no, for sure. And that's one of the things that I thought was... I thought this was one of the very strong points of the paper is that with the pleural blood patch, you may still have post biopsy pneumothoraces, but if you can treat those with an aspiration and a pleural blood patch, then you can decrease the rate at which you'll... Basically, those patients can still have the same throughput as someone who just has a very tiny pneumothorax that doesn't require an intervention. So, yeah, no, please describe the pleural blood patch.
[Dr. Fred Lee]:
Yeah. Your comment is exactly right. In most of the patients that get a pleural blood patch, they don't even realize that we blood patch them, and they had the same experience as somebody that comes through just for a conventional uncomplicated biopsy. And so that's a very appealing thing. I mean a patient with a chest tube sitting in the hospital is generally not a happy patient, and the physician that's checking chest x-rays and clamping and pulling chest tubes is generally not a happy physician. And so I think we can solve two problems at once if we can really decrease our chest tube rate. So how we do this, and the way I think about it is a couple fold.
The first is that all of us have had that situation where you go to do your lung biopsy, you pop your needle into the lung, either into the nodule or shorter than nodule, and suddenly the lung deflates on you. And that is like a sinking feeling. It's usually the first case of the day, and everything goes downhill from there. And so that is a nasty little situation. Blood patching works so well in that particular situation, because what happens is once you cause a pneumothorax, it's very difficult to get an adequate biopsy of the lesion, primarily because there's no surface tension between the pleural surface and the lung. And so the lung can move like crazy with respiration and with manipulation. And if the pneumothorax continues to accumulate, the lung can continue to collapse, and it's virtually impossible to hit the lesion and to wedge your needle into the nodule.
And so what happens is if I'm doing a biopsy and I cause a pneumothorax, I just pause for a minute, I put in a five-French multi-side hole catheter, I use a centesis needle, and I'll describe the technique in a minute. I hook it right to wall suction, reinflate the lung, and now you're back to the native situation. So you can just go ahead and finish your biopsy. In fact, sometimes the lung deflates so fast that your needle falls out of the lung and is kind of dangling in the pneumothorax. That's no problem. I just pull the needle back into the subcutaneous tissues, and when I reinflate the lung, generally, the orientation of the nodule and the needle is as it was originally. And so oftentimes I can just now re-advance the needle right into the nodule without any other changes or manipulations.
And so that re-expansion, I find, has been very useful. It saves me a ton of time chasing nodules and inadequate specimens. And patients that I'm worried about with maybe a persistent or a growing pneumothorax, all that is just solved by putting in a centesis needle or re-expanding the lung, and finishing your biopsy.
(3) Advice for Trainees Doing Lung Biopsies
[Dr. Christopher Beck]:
I wanted to just drill down on that for some of our younger listeners or trainees or people who are just fresh out of practice, and for some reason, don't have a lot of experience doing lung nodule biopsies, but I've seen some of my partners get really frustrated with lung nodule biopsies. And that's one of the real sticking points is that I think CT gives you an illusion of like that the lung is the static creature, but once you have a pneumothorax in play, everything is kind of out the window in terms of how that lung parenchyma is going to respond to your needle. And so I see my partner is still trying to drive it into a collapsed lung and they can't understand why the lung keeps moving or the needle is not where they would expect it. And so I just wanted to have everyone just take a beat and recognize that it's a very, very dynamic process, even without a pneumothorax, and when you add a pneumothorax, it's a difficult hurdle to overcome and pushing forward with a biopsy.
[Dr. Fred Lee]:
Absolutely. I completely agree. The analogy that I think about is that you're trying to put a needle into a deflated balloon and you're chasing it around, it's moving all over, it's flopping around in the chest. Patient might be in distress. Some pneumothoraces hurt on occasion, especially maybe with patients that have adhesions or something and you're pulling on the lung. And so now you have a patient that might be a little shorter breath or having pain, you're chasing a nodule, there might be some bleeding in the lung. I mean, everything's going to hell in a handbasket. And instead of trying to continue with the biopsy, just put in a centesis needle, I just hook it right to wall suction with a five-French centesis needle. You can't develop really high, negative pressures in the pleural space, it's usually just enough to re-expand the lung and collect any air that continues to leak during the procedure. Never had a complication with it. So yeah, just do it before you start to chase lung nodules.
So that's kind of the first thing that I keep in mind when I'm doing lung biopsies and things start to go wrong. This is a really nice solution to kind of get you back on track and just basically into the routine of doing procedures like you always do. One of the details about placing the Yueh centesis needle that's very important, and I have a picture of this in the paper that I think you should look at for any listeners out there, if you're going to do this technique. And that is that when you put the Yueh centesis needle in, it's a very small catheter, it's a multi-side hole catheter, but make sure you put it in at a fairly shallow angle with respect to the surface of the lung. That's so that when you re-expand the lung, the centesis needle doesn't poke the lung surface, which can be painful and distort the anatomy that you're trying to hold stable. To put it in at an oblique angle so it folds up nicely in the pleural space when the lung re-expands.
So that's just a small detail, but I think it's important to make sure that you're going to decrease your complications with the pleural blood patching and with the centesis needle.
[Dr. Christopher Beck]:
Does it make any difference if you direct the Yueh needle towards your actual presumed site where there's a hole in the lung or towards the site where your introducer needle punctured the pleura?
[Dr. Fred Lee]:
Well, that's something that we don't know for sure.
[Dr. Christopher Beck]:
Okay.
[Dr. Fred Lee]:
The way I think about it is that the blood patch that we're going to put into the pleural surface distributes itself fairly evenly over the entire surface area of the lung. And I'll get to this in a moment, but when you do do the blood patch, you lay the person down so that the biopsy side is down. And that helps decrease leakage from the site of the puncture, but I think it also allows the blood to pool near the puncture site. And so my guess is it probably doesn't matter, but it's not something I know for sure.
(4) Pleural Blood Patch For Pneumothorax
[Dr. Christopher Beck]:
Okay. I get the feeling that you were about to launch into how the actual pleural blood patch component.
[Dr. Fred Lee]:
Right. Okay. So assuming that you had a pneumothorax while you're doing the biopsy, at this stage, I've introduced the Yueh centesis needle into the pleural space, I pre-expanded the lung, and performed the biopsy. So as one of my old professors said, "You had the complication, don't let that stop you from getting a diagnostic yield, too" And so go ahead and do the biopsy. If you create more of an air leak, you have the thing under control because you have a catheter in the pleural space. So you're good to go. So at that point, once I finish the biopsy, I'll still blood patch, do a parenchymal blood patch, as we described before, because you want to try to stop the air leak if, at all, possible.
And so I have to admit that I'm a little bit more generous with my parenchymal blood patch in the face of a known pneumothorax. And so maybe instead of injecting three or four cc's in the tract, I'll inject seven, eight, nine cc’s in the track, something along those lines. And I try to stop the air leak if possible. So now I'm in a situation where I've done a parenchymal blood patch, the biopsy needle and the introducer are out, and I'm left with a Yueh centesis needle in the pleural space, hooked directly to wall suction, and the lung is back reinflated. And so at this point, many people in the past would consider that an aspiration and they just pull the Yueh centesis needle and put the patient biopsy side down and take their chances. And that's what we used to do. But now what I'll do is through a three-way stopcock, I'll place a three-way stopcock on the Yueh centesis needle. One of the three way ports is to the patient, one of the three-way ports is to the wall suction, and the third is what I'm going to do my pleural blood patch through.
And the way I do that is very similar to the parenchymal blood patch. Instead of though five cc's, Marcia will draw more blood. And the median volume in this study was 30 cc's, but I have to admit that our numbers have been inching up over time, and maybe it's that old American adage, if a little is good, a lot's better.
[Dr. Christopher Beck]:
Right.
[Dr. Fred Lee]:
And we couldn't actually prove that more blood is better, but I don't know. I kind of figured it's not worse, so what the heck?
[Dr. Christopher Beck]:
It's still not as much as the half a liter that your cardiothoracic colleague was dealt again.
[Dr. Fred Lee]:
Exactly. I have to laugh is that one of the reviewers for the paper when we told them that we pulled out even 100 cc’s or 50 cc’s, they were shocked at this high volume of blood that is coming out of the patient's veins. And I said, "Geez, if you only knew what the thoracic surgeons had to, you wouldn't have criticized me for it in the paper." But anyway, so I think our blood patches are so much less extreme than what the thoracic surgeons are doing. You pull out maybe... I do generally about 50 cc’s now. So Marcia will pull 50 cc’s, I'll put the Luer lock syringe on the three-way stopcock, and during this whole time that you're prepping the patient for the pleural blood patch, everything, you leave them on suction, because just having the whole opposed to the chest wall probably does some good, too, and now we want to add some blood as well. So there's no reason to not continue suction during this entire time.
So then I'll hook the syringe to the three-way stopcock and then when we're all ready and everybody's ready, I'll change the three-way stopcock and inject the 50 cc's of blood right in the pleural space, pull the stopcock, bandaid on, patient side down. And then I leave them on the CT scanner for 10 or 15 minutes, do a quick check scan to make sure that the lung has stayed inflated, and if that's good, they go right to recovery. And we do the same couple hours with a one hour chest x-ray to make sure the lung stayed inflated and then the patient gets discharged. So many times, the patient doesn't even know that they've had a pleural blood patch, much less a parenchymal blood patch, which every patient pretty much gets. This can be really fast.
I mean, I figure it takes you an extra 5, 10 minutes, something like that. And if you have the equipment ready... We have a little box that has all the connectors and tubing and all that stuff, because that seems to be the biggest holdup. When I decided I needed to do it, somebody's running around the room, trying to like, where did I put that three-way stopcock? And where did I put that centesis needles? So I would advise you to have a little kind of pneumothorax box with everything that you're going to need. We have a separate chest tube box, too, with everything that we need, if we're going to put in a chest tube. And that way you're doing a little bit less scrambling, and I think that the procedures go a little faster that way.
So that's how you do a pleural blood patch. It's really fast, it's simple, and it works like 80%, 85% of the time, especially in patients that don't have emphysema. It works virtually every single time. I think in our paper, it only failed once in a patient that did not have emphysema. So it's a very effective procedure and it saves you all... you guys know about clamping, chest tubes, and looking at chest x-rays, and being bothered the next day. And man, I'll tell you, it feels really good when you discharge the patients and you don't have to worry about all that extraneous work on the day following.
(5) Efficacy of Pleural Blood Patch
[Dr. Christopher Beck]:
I totally agree. And that's to say nothing of the patient experience and to improve how fast they get out of the hospital. The longer you're in the hospital, the more things that can happen to people, especially in the days of COVID. So yes, I echo that sentiment. And that's one of the things I wanted to point out in the paper is that of the patients you did that on, and I don't remember the in, but of the patients without emphysema, work in all but one. And I think the overall rate, and you can correct me if I'm wrong, Fred, but it was five out of six, or 50 out of 60 patients who were able to do the pleural blood patch went on to have no additional intervention, and they just got discharged same day.
[Dr. Fred Lee]:
Yes, that's exactly right. It was over 80% of the patients the blood patching resolved the pneumothorax without the need for a chest tube. And our numbers would have been better, I think. Our overall pneumothorax and chest tube numbers would have been better except there were something like one and a half... Our overall chest tube rate then is 2.5% or so. And that number is one of the lowest in the literature. And it would have been around 1%, but it turns out that back in the early parts of the study earlier in our practice, some of my partners and me too, I'm guilty of this as well, when we had one of those new authorities that the lung just dropped when you touched it kind of thing. And everybody that does lung biopsies know what I'm talking about. They would just put a chest tube in.
And so, as we were just learning about blood patching, there were still some people that were sticking in chest tubes in that situation. And I think that if we first tried a pleural blood patch as a salvage procedure, I think our chest tube rate would have been down around 1%, which is, I think, by far the best in the literature. And if you use a 19-gauge introducer, 20-gauge needle, I think most people's practice will be very similar to ours.
[Dr. Christopher Beck]:
That's great. So one of the things I wanted to ask about in the 60 patients who you guys did the pleural blood patch, is it always in scenarios where the biopsy is still in progress or being done? Or were there ever circumstances where you do the biopsy, you do the parenchymal blood patch, and so everything's out, and then you say, oh, I think sometimes just inherently you either have a symptomatic pneumothorax or a pneumothorax that you just have the feeling is larger like the little tiny postbox in the pneumothoraces that we sometimes see? So I guess my question is, in some of those patients, the 60 patients with pneumothoraces, were some of those patients included patients who have already completed their biopsy and the parenchymal blood patch had been done?
[Dr. Fred Lee]:
Yes to all the above. The pleural blood patch is really versatile and we use it all the way from the minute you start... In fact, I have to digress for one minute to tell you a quick story, because this is really funny.
[Dr. Christopher Beck]:
Sure.
(6) Complications of Pleural Blood Patching
[Dr. Fred Lee]:
So we had a fellow who's not going to be named, and he was very aggressive with local anesthesia and a couple of times dropped the lung before we even started the biopsy. We have a name for that, but it gives away his name, so I'm not going to name it.
[Dr. Christopher Beck]:
That particular procedure's now named after him?
[Dr. Fred Lee]:
It is exactly right. Yes. And I have another partner who's spectacularly good, and even one time when he was a fellow, he went even further. He dropped the lung and managed to inject lidocaine into the lung parenchyma in the same patient. So we named that after him also. Yeah, they have their own complications named after them. Anyway, getting back to when we use pleural blood patching, it can go all the way from those particular situations where we drop the lung during lidocaine administration, all the way to a delayed pneumothoraces in patients that come back a day or so after the procedure, after they've been discharged with a delayed pneumothorax. And what happened at our place a couple of times is that patients that had had a lung biopsy, maybe a day or two earlier, had gone home, were doing okay, maybe had a coughing fit, drop their lung, came to the ER, and our emergency room colleagues put a big surgical chest tube into them.
[Dr. Christopher Beck]:
Oh, wow.
[Dr. Fred Lee]:
And that was really nasty. I remember one particular patient was really large around 300 pounds, and what I found out about this, I want you to go see him on the floor, and he had like a three or four-inch cut in his chest to get down to his chest wall, to put a surgical chest tube in. And he's glaring at me. He was not happy with what had happened. And I'm like, geez, I wish they would have told me, because I could have slid a tiny little tube in there and taken care of it. In fact, patients that come back to the ED with delayed pneumothoraces, we give them a trial of a pleural blood patch. And I think I personally have salvaged like four or five patients with delayed pneumothoraces and haven't needed a chest tube.
So they come to the ED with a delayed pneumo, bring them up to CT, do a pleural blood patch, watch them for a couple hours, then send them back home. And knock on wood, I don't think that we've had a patient that's come back a second time in that situation. So we use pleural blood patching all the way from when our fellows dropped the lungs during local anesthesia, all the way to delayed pneumothoraces that happened days afterwards.
[Dr. Christopher Beck]:
In the scenario that if you had a delayed pneumothorax and say it was a posterior approach, and so you're bringing them back next day for a pleural blood patch, would the approach be to have the patient supine, anterior stick with the Yueh, and then reinflate the lung and that it administered the pleural blood patch that way? Or would you make any effort to put them in the prone position and have the Yueh needle a little bit closer to the access site? That kind of goes back to that earlier question. I suspect I know the answer.
[Dr. Fred Lee]:
I have to admit that I don't make any particular effort to get the needle close to the puncture site.
[Dr. Christopher Beck]:
Got you.
[Dr. Fred Lee]:
Just assuming that the blood's going to distribute itself fairly uniformly. Now, when you look at a chest x-ray after you do a blood patch, it's really hard to tell that you did anything. Sometimes with a 50 cc blood patch, you might see a tiny little pleural fusion or something. So I have to assume that there's this tiny little rim of blood, very thin, that's surrounding the entire lung. And I'm hoping that gravity will bring more of the blood to the puncture site, but I'm not 100% sure that that's true. So I personally don't make much of a specific effort to get the blood near the puncture site.
[Dr. Christopher Beck]:
Okay. And so going to the paper, in one of the statistics that struck me was that, and you can correct me if I get any of these numbers wrong, but blood patch versus no blood patch, in your sample, it was 5.7% of patients who had a blood patch did not have any complication requiring an intervention. So you may have a pneumothorax, you may have a tiny pneumothorax, but then that new pneumothorax goes on to either be asymptomatic or not enlarge on a chest x-ray, and so no future intervention. So 5.7% with the parenchymal blood patch. And then if you did not have a blood patch, then closer to 14% having a complication that required an intervention, is that right?
[Dr. Fred Lee]:
Those numbers are correct. And this was a result... I have to admit that one of the reviewers... No, I think it was Dan Sze, who's the editor of JVIR, pointed this out to me that in one of the reviews that we had the opportunity within our sample to differentiate what happened to patients that had parenchymal blood patching versus those that didn't have parenchymal blood patching, because our series included some of the early cases where we didn't routinely use a parenchymal blood patch. So it was kind of serendipitous. And honestly, Dan had to point that out to me. I didn't really put that together, that wasn't in the original version of the paper. And so we went back with our revision and we looked and that's exactly right. I was gratified to see that patients that did have a parenchymal blood patch had a lower rate of complications than those that did not.
And this was one more confirmation that blood patching does work, and this has been proven in other studies as well. In fact, I'm not sure that a negative study on this topic has ever been published. And it would have been a little embarrassing if the opposite has been true, because honestly, I didn't know the answer when Dan had pointed out that I had failed to include that in the first version of the paper. But fortunately, it lined up as the previous literature had suggested it was going to be, and in our own experience, too. Thank goodness.
[Dr. Christopher Beck]:
Right. And I think there was a paper in 2000, maybe it was four or five years ago, there was another paper in JVIR talking about parenchymal blood patches and decrease rates of pneumothoraces that required an intervention. But that's one of the things I did want to like drill down on for the patients, is that you may still have the small pneumothoraces after your lung biopsies. So our practice is kind of a microcosm of what you guys had earlier on in your practice in that I, and maybe a couple of other partners will do blood patches very routinely. In fact, now 100% of the time for our lung biopsies and in some of the other partners do not. And some of the CT techs will say that, "Oh, you're still getting about as many new authorities as your partners" but I said, "But how many are we actually putting the chest tube in?" And I'm like, pay attention to that.
And certainly our numbers aren't as large as your numbers, so I think it's harder for them to see the bigger picture, but I'm highly confident that the number of chest tubes that I've put in since I've started putting in, or since I've started doing blood patches has gone down. And I think I stopped. I started doing it two years into my practice, as soon as that JVIR article, and I think it was '17 or '16 came up.
[Dr. Fred Lee]:
Mm-hmm (affirmative). I think your experience is a reflection of ours too. And I have to laugh because [Annie Zlevor 00:36:33], who's the primary author on this paper, she's a medical student here at University of Wisconsin, very talented. And Annie said to me, a couple of times, "The numbers are pretty convincing. Why do you have some patients that did not have a blood patch and some that did?" And it seems like it should be really obvious. And I think your observation is very valid. There's two things, one is there's the noise of the large number of pneumothoraces that are not even really a complication. I mean, they're an observation by imaging only, and those nobody really cares about.
And so when I look at a pneumothorax rate, that really doesn't mean anything to me. What is important obviously is their rate of the need for additional interventions. And based on that, I think the parenchymal blood patch has really shown its value. The second observation that I just have to laugh when you're explaining your practice, because ours is very similar too, and this is what I was explained to Annie when she was asking why we have some people doing this and some people not doing it. And it's a fundamental human condition that it is very difficult to change what people do. And people have a way of justifying what they do. They have an internal confirmation bias. And even in the face of pretty good evidence, it's hard to get people to change their practice. That's just the human condition, I think.
And so, in a way, it's good because you have kind of internal experimentation going on. And if you find one is better than the other, ideally, you'll vary and kind of move your practice more towards that. And that's what happened in our practice is that my partners are very evidence-based, and when they saw some of the results of parenchymal and pleural blood patching, to their credit, every single one of them has switched over and now does parenchymal blood patching and pleural blood patching as a standard.
(7) Arguments Against Blood Patching
[Dr. Christopher Beck]:
That's great. So to bring up the counterpoint, are there any downsides to doing either parenchymal... Let's just start with that. Are there any downsides to a parenchymal blood patch? And I'll let you take it from there, because I was going to start listing things that were just kind of straw man, but go ahead.
[Dr. Fred Lee]:
Yeah. And I think straw man is probably a good word to describe kind of semis or pseudo arguments that have been used against doing a blood patch. It takes you an extra minute or two, which in the context of a complicated lung biopsy is probably a very small amount of time. There have been other methods to, I shall say plug the hole, so to speak, after you do a lung biopsy, and virtually every one of these has proven to be effective in one way or another. So for example, people inject saline in the tract, they'll put gelfoam in the tract, there'll be fiber and plugs, they'll be put in the track, all kinds of things. Almost anything you can think of has been placed in the track, and I think virtually, every one of these papers have been positive.
So there's probably nothing magic about blood. I like it because it's a liquid when you inject it. And so it goes through a 19-gauge introducer needle very easily, and then eventually, it becomes a solid as it clots and fills the airways preventing an air leak. So I think it's kind of an ideal solution to inject, but it's not the only solution. So I don't want to put it out there that any of the other techniques don't work because I think they all do. There is maybe a theoretical risk of increased infection. Again, probably a straw man argument, the infection rate for lung biopsies should be near zero in your practice and in my practice. Maybe it's slightly higher for pleural blood patches, but knock on wood, I've never had to come back and drain an empyema or anything like that in a patient that we did a pleural blood patch in.
I think this is one of those rare techniques in the history of human medicine, where it makes sense, the data seems to be following it, and there's not much of a downside.
[Dr. Christopher Beck]:
I mean, it basically belongs to the patient, you're taking out, administering a different area, there's no cost to the patient, there's no real added time to the procedure. You're getting so much bang for your buck that I don't want to call it a no brainer, but I think if you're aware of the literature, it's maybe another way to put it, it's quite compelling to at least add to your practice or consider adding?
[Dr. Fred Lee]:
Absolutely. One thing that I have heard in terms of pleural blood patching, and maybe this was in the context of a surgical chest tube and open thoracotomy, and some sort of lung resection with a big stable line, is that it is maybe theoretically possible that you could have more adhesions in the pleura after a blood patch. I guess that's true. In fact, Dan asked me whether our surgeons have noted more adhesions when they go to do vats or robotic thoracotomies, and really, they haven't mentioned anything to me about it. I have to admit that we don't pull them or anything, but they have not really complained that this is a significant problem when they go to do a subsequent procedure. So I think that might've been something that's leftover from the surgery days and the very large volume blood patches in the context of a 30-French tube, and staple lines, and major surgeries, and things like that. But I think for us, that's not really a downside.
[Dr. Christopher Beck]:
We also do not pull our cardiothoracic surgeons, but they're of the ilk where they would let us know immediately, if all of a sudden, they were like, oh, we're getting these tons of adhesions, their particular docs, I feel like they like what they like. And so I feel like as soon as they had had there was something different about a lung biopsy and like they're getting added adhesions, they would let us know very quickly. I feel like even if we had one adhesion, I'd hear about it and our whole practice would be like, we'd have to change. Even that's an over-exaggeration, they're a good bunch. All right. Well Fred, thank you very much for coming on the podcast. We really appreciate it.
[Dr. Fred Lee]:
It's my pleasure. It was great to talk to you, Chris.
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 28). Ep. 157 – Percutaneous Lung Biopsies: Pleural & Parenchymal Blood Patching [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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