Transperineal Prostate Biopsy: A Practical Guide to Procedural Success

[Dr. Aditya Bagrodia]
All right, now we've done our equipment, we've got the ultrasound probe, we've got a freehand device. I think the one that you've created and optimized, Matt , if I'm not mistaken, has probably been the one that's most commonly used. We've decided to do this either fusion, cognitive fusion, or MRI fusion and now it's D-day.

Juan, I know you to be a very thorough guy. Walk me through in gritty detail what this looks like from the patient walks in the room, even made with prep, enemas, all that kind of good stuff, and maybe I'll just pepper in some questions here and there, some clarification, we'll get Matt's input also.

[Dr. Juan Javier-DesLoges]
Going back to when I said we were doing about 50 minutes in the OR now we do in about eight minutes and before I even bring that patient into the room, I mean we did an in-service with the nurses with PowerPoints, reviewed everything that I specifically wanted in the room. The patient walks in, he puts a gown on, he gets himself in position with his legs and the stirrups, we use paper tape to tape the scrotum up. We then shave the perineum but not the median raphe as I impress upon the residents. Then we use the Betadine stick. We don't use any wet prep to prep the perineum. In terms of an enema, originally everybody got an enema, now I just do it if they have a history of constipation. In terms of antibiotic use, when we were first doing them, everybody got Keflex or Ancef when they're in the OR. Then when I became an attending in July, I just said, "I'm just not going to give it anymore and see what happens based on the Lancet oncology publication," and nobody got an infection. I selectively will use antibiotics for somebody who's got an external catheter, somebody who's got a history of recurrent UTI, or if they had a perianal fistula or even a perianal fistula repair. Any of those high-risk patients will still give them some antibiotics.

Now we're getting ready for the biopsy. I have the nurses mix up the lidocaine. I borrowed this from Matt here, but we do a combination of 1% lidocaine mixed with basically an equivalent amount of normal saline. It comes out to about a half percent of lidocaine with some sodium bicarb to take off the acidity of the lidocaine. I do a skin block.

[Dr. Juan Javier-DesLoges]
I don't know if you know this, but we recently just switched our spinal needle. Before I was using, I think it may have been a minute, like a 22 spinal needle or something like that, but it was so flimsy. It would dive off in different directions in the perineum. I think we recently switched to either 20 or 18. That kind of stiffer longer spinal needle to just go after the levator and bolus the tract before the muscle in the muscle behind the muscle.

Again, that's something I learned, it's like a plug for the AUA course even though I promise I'm not actually lecturing at it. That's what I learned there and I've used it and it's worthwhile for me.

[Dr. Aditya Bagrodia]
We get our blocks in and I don't know if the rest of the listenership would have these concerns, but that was certainly a big first anxiety hurdle for me to get over. I can say in my experience that the patients are doing perfectly fine, of course just like a transect muck or whatever here. Again, you might have somebody that doesn't get perfectly anesthetized and I think you can just add in a little bit more, just inject a little bit more local. Okay, good.

A wheel with a 30-gauge inject some of the track, then get to the levators and that's again going to be your hand movement more kind of right-left than so much of a rotation. Is that correct? Okay, good. We've anesthetized the track. We have gone and either done a fusion with our software or planning on doing a cognitive fusion and now the 14 or 16 gauge metallic sheath needle goes in. Is that right, Matt? Is this what you do?

[Dr. Matt Allaway]
Yes. The precision body, I prefer to call it, is more like a trocar more because the design doesn't have the dimensions of a coaxial needle. It's a 15 gauge trocar with an inner lumen of only 18 gauge. It provides extreme stiffness because you're asking it to shift in these various positions but not bend or sway. The tip is a diamond cut because it's just got to be barely sharp enough to pop through the skin, but once it's deep in the tissue, you don't want it to be like a coaxial needle that has sharp sides to it, because as you're shifting medial to lateral, up and down, you don't want to theoretically be slicing through any tissue and result in a hematoma. That locks into that space. I call it the perineal scruff.

If you have a dog, you grab the dog by the scruff and again, shift it all over. We're anchoring the scruff and we're moving the scruff and gliding over the fascia of the pelvic floor muscles in concert with the probe in the rectum actually distorting the prostate to position your trajectory exactly the way you want to fly into the prostate. That would be a simple way of describing it. It's obviously a little bit more dynamic and it takes a little practice.

[Dr. Aditya Bagrodia]
Got it. Ideally, when you get your coaxial trocar in, where do you want the tip of that trocar to be?

[Dr. Matt Allaway]
You don't want it to be in the muscle, you want it to be in the subq tissue, but the track that Juan describes from the skin to the pelvic floor, you're creating a lidocaine tunnel. The access trocar sits in the lidocaine tunnel and shifts in any position. You don't want the needle to be in the muscle. It's going to lock it and could potentially do some damage, I would predict, but just sitting there probably, it varies from patient to patient based on perennial thickness, but it's going to be a few CMs from the pelvic floor.

That's really useful real estate because that's like you're flying your plane into the prostate, you use that little bit of space to use the bevel of your needle and glide into the prostate. Unlike transrectal, which is once you commit, I mean, as soon as the biopsy needle exits the needle guide on transrectal, you're committed to tissue, but not with this. With this, you have the opportunity to visualize your trajectory and say, "Okay, I'm going a little lateral, I'm going a little anterior." Then you add a little secondary hand motion and anchor in the capsule at the right location.

[Dr. Juan Javier-DesLoges]
I think this is where there's probably differences in attachments, which is where I think Aditya is talking about. The nice thing about the precision point of the perennial logic is the trocar needle is hubbed with the skin. When the needle comes out, you can see the tip of it right at the edge of the ultrasound sometimes. I think that that is the point that Aditya is asking about is that we actually use a much longer metal needle sheath. It's about 13.8 centimeters.

Again, I had gone through several iterations to see what was the appropriate needle length or biopsy needle sheath that I needed to use. Our needle tip, the trocar needle, it's just the tip of the ultrasound because if it's in too far, you can't shift up and down. If it's out too far then you're out of the skin. The way that the precision point's set up, it's perfectly in place because its hubs are so close.

[Dr. Aditya Bagrodia]
Okay. It sounds like no matter how you get there, that needle right at the tip of the ultrasound is what we're shooting for. Is that about right, Matt?

[Dr. Matt Allaway]
Yes, and Juan brought up a good point that I try to teach people. I've always used the 20-gauge, six-inch spinal needle for the very reason that Juan brought up because the 22, which is what we use for transrectal, it's so flimsy. It's flying all over the place and sometimes you lose track of it. We're now doing a cadaveric dissection to show in great, great detail exactly what we're trying to accomplish with the block. Because I think there's some misconceptions out there. They talk about the subapical triangle. That's confusing, Juan, isn't it? It's almost suggesting that the block is done right under the urethra. You're doing a space ore.

I actually used to include that part in my block, but now I only do it if I need it. I do what's called a tap test. Before I start my biopsy, I divide the prostate into four quadrants, it's called a tap test. The patient's laying there and you're watching their eyes and you mimic with your spinal needle, you mimic where you're going to go with your biopsy needle and you tap the pelvic floor. Right posterior quadrant, I tap medial and then I come out and tap lateral, don't say anything to the patient, you just watch their eyes, and the eyes never lie.

If they feel any pain, they can't hide it because transperineal cannot be done without a proper block. Transrectal can, I did almost my whole career, I pretty much did half of my biopsies without any local because they don't feel pain. I do the tap test and then if they feel something on the tap test, then I already have my spinal with the lidocaine and just add a little and then wait a minute and then recheck the tap test. Plus that also gets you comfortable with the anatomy to see how you're flying in and check your alignment and make sure you're pointing, shooting correctly.

[Dr. Aditya Bagrodia]
Yes, that's great I think you're ready to go, right? You can assess things with a relatively smaller gauge needle and re-anesthetize or anesthetize further, should it be required. I actually spoke to Juan about this just last week. One of my earlier ones I actually had difficulty visualizing the prostate on one of the hemiprostates and he had a couple of good pieces of advice that it's always absolutely mandatory to do a rectal exam. You could have some residual stool in there that can obscure the imaging, make sure that you have plenty of lubricant between the cover or sterile condom or whatever you may use and the probe and then also a significant amount between the probe and the rectal wall. I think Juan's adopted a technique of actually injecting a lidocaine jelly syringe just to really maximize the amount of lube because some of the anatomy, I feel like seeing that little slip of muscle lateral to the apex can be a little bit more nuanced than transrectal. Any tips and tricks in that department, Matt?

[Dr. Matt Allaway]
Yes, we call that the rectal slurry. What I do is I stopped doing enemas. Okay, completely. I've never regretted it. Now one out of 50 cases, you got that guy, he's loaded with poop. That's a disaster. Okay, but maybe 1 in 50, 1 in 60. For those I actually just do a dam lavage with a 60 cc catheter tip syringe and just go to town. Because if you can't see what you're doing, you're just going to struggle.

The enemas don't really help that much in my opinion. I think Juan's got a great idea. If the guy's got a history of constipation, if he'll admit to it, then maybe I should do that. Now I don't put the rectal slurry in every time. What I do is I go in with the probe first and if I've got a beautiful look and I can push my probe parallel to the floor and straight down and still see the prostate, I'm good. Just get started. If there's a bit more stool in the way, then I pull the rectal slurry, which is about 40 ccs, and squirter in there and it pushes the poop out of the way. Rectal gas, now that's going to make your experience really frustrating. I find that the guys with enemas, if anything, had more gas. Gas is a killer. I always keep an 18-front red rubber catheter in the room. I don't open it for every case. We call this “fracking for gas”. I like it because it's controversial, fracking for natural gas. It sticks with people.

You take your probe out, you stick the red rubber catheter in the rectum and then you put your probe in underneath the red rubber catheter and you can see it on your axial array. Then use the tip of your probe to steer that red rubber catheter into the gas pocket to the actual gas. You're putting it through the poop, which is the shale rock and you're depositing it in the gas pocket of natural gas and venting it and you can actually hear an audible when you're done too. It's like, "Yes."

Then leave your probe in and then slide the red rubber out and deposit it on a chuck that I place underneath the patient on the floor because you're going to get lube, some blood, some other nasty stuff and to make your turnover of the room faster, keep a little chuck on the floor and lay the catheter on the chuck because sometimes these gassy fellas gas will re-present, especially in the cases you're doing in the afternoon. I find out that the gas load is nasty. I'm a urologist, I like urine, but I don't like this stuff. The afternoon is where you probably need the catheter a little bit more than the morning cases.

[Dr. Aditya Bagrodia]
All right, hey, I think that does show that there are some tips and tricks that all of us can take away, but definitely super helpful just to maximize getting a good look at the prostate, which is kind of what the whole experience has preceded on. Okay, so we've got it in anesthetized. We've got our trocar in at the tip of the probe and I do want to be respectful of everybody's time here as we approach an hour, but essentially different styles out there, but a little bit of a different way to think about the prostate more anterior, mid, posterior, lateral medial and then if they've got a longer prostate, a bit more work to get to the base. Are those your basic mapping biopsies plus targets?

[Dr. Juan Javier-DesLoges]
Yes, going back to our original way that we were doing it and how we've evolved over time. Originally the way that our program was doing this transperineal, it was just a straight U-shaped medial-lateral layer tier, medial-lateral mid-halfway through the prostate medial, lateral posterior. As I was starting to do more of them, I followed it and then I was starting to look at my outcomes and I was like, there's something off here. Then I just realized that I think I'm missing the base of the prostate. Then I started looking at all these different types of templates because there's really no agreed template. It's basically what people have talked about in their experience.

Now what I do and what I have the nurses set up for is a 16-systematic template biopsy where we do that standard U-shape configuration. Then I watch the needle in real-time and I determine am I getting all the way to the base of the prostate to capture the base of the peripheral zone? If I don't feel that I am, or if I'm a little unhappy with posterior biopsies, then I'll do those extra four cores.

Then for the ROI, I do basically the UCLA penumbra where basically one or two in the middle of the lesion, then just the shadow of the lesion with another total of four biopsies. That's the way we do them. I generally try to do the ROI first, in case you do get one of those hematomas that blocks your visualization. I've had one really bad pelvic hematoma I think in the 200 that I've done. Outside of that, that's my basic system for doing them.

[Dr. Matt Allaway]
This discussion of templates I think unfortunately would require more time than we have because this is where the wild west is. You've got a lot of gunslingers out there doing transperineal and we really haven't agreed on what's ideal. For me, as I tried to pioneer this, I can't screw this up. What I did was I used the grid saturation data to guide me initially. Those are the ones with the grid stepper, taking 50, 60 course craziness, but that's always considered like in the PROMISE trial, that was the gold standard on not missing cancer.

We started looking at all these different templates, Ginsburg, this preceded music and all that and the U-shaped thing. Ginsburg was a good one. It's almost like a modified barzel. Then we just started tweaking. We went from Rosen columns to sectors. What we found little known to us, there was an Italian researcher running the same play. We both were like, "What is the sweet spot?” How can I get the best cancer detection with the least amount of core? What is that number now? I'm talking about no MRI. You've got no MRI, you just got a clinical suspicion. The number was 20. Dr. Pepe in Italy does exactly 20. Now everybody looks at me and they're like, "Oh man, you're crazy. That's too many cores." I think you have to bespoke it a little bit and look like Juan said, you just have to watch how you're flying in and appreciate where did I hit and where did I not hit.

I do think that we've got to get this template thing organized. We've got to come to some understanding because if transperineal does not increase complications with more cores and the patient tolerates more cores, why not grab a core between the ten and two o'clock position anterior because actually, we find a lot of cancer anterior medial Ginsburg template, which is the one used in Europe. It includes that area too. I always grab samples in that area. Again, it's a long discussion.

I think the most challenging thing for urologists is transitioning from transrectal to transperineal. It doesn't match. They take their little box with their jars and they're like, "Well, okay, which one's apex medial then?" It's apples and oranges. You've got to rethink the whole template, and that's where it comes to reading your music. I think you should pick a template that's good.

In the MRI world, I think we can adjust the systematic sampling, but even there, it's a little bit wild west right now. My goal is that every patient comes in and I can look them straight in the face and say, "I sampled that prostate and if there's something there, I found it." I think the overall cancer detection should be about 70%. That includes all PI-RADS, all players, and I think it should average about 55% clinically significant if your template is done properly. That's what I've found. That's based on, I've done over 2,500 cases myself, I've participated in up to 5,000 total, and I've looked at data that's made me just quite sick to my stomach, so many cores of data. This is an exciting area and I think you guys being at the academic level can really contribute to this aspect of the whole biopsy.

[Dr. Aditya Bagrodia]
The music analogy and the finesse totally resonates as well. The first ones I did, under supervision of course, it's just like, "Okay, good, I can see the anatomy. I can see where we want to inject our blocks. I can clearly even familiarize myself with a new way of describing the process." It's not like the base, mid, apex, needle, and lateral. Now, we're talking about posterior middle, interior middle, lateral, and so on and so forth.

I think there's a learning curve. Maybe on round one I can identify the prostate reliably and biopsy it and not have things like skeletal muscle or adipose tissue, which I think sometimes people in their early days have, or a lot of fibromuscular stroma or so forth. It is a process and it is a little bit more nuanced perhaps than the transrectal approach. We've got an ultrasound. That's mandatory. We've got an actual biopsy gun, whether that's a disposable or reusable. Is anything else even required at this point?

[Dr. Juan Javier-DesLoges]
I think you need a needle sheath. You don't want to stick the patient 20 different times. I know that there's a couple of groups out there that have looked at the disposable angiocaths. I'm a little hesitant to use it. When I was a resident, I saw that when you re-shoot the needle through a plastic angiocath it can actually shear off the plastic. We use a metal biopsy needle sheath similar to what Dr. Allaway does. I think that's the minimum. Do you actually need the attachment? I think you could make an argument for not using it. It makes it go much faster though when you have an attachment there.

[Dr. Aditya Bagrodia]
I feel like for people that think about this all the time these mundane things are not something you spend time thinking about. Explicitly, you're talking about like a 14 gauge metallic needle. You've got your ultrasound probe in the rectum, you're going to place that at the ten and two o'clock position and try to get it to just set the apical most aspect of the prostate. Does that sound about right?

[Dr. Juan Javier-DesLoges]
Yes, 16 gauge probably I think.

[Dr. Aditya Bagrodia]
16 gauge. You get that in there and then basically, you're going to take your biopsy gun, secure that needle in some type of position, which is challenging, I think we can all attest to that, then take your course. That's bare minimum. Now, you can do it in the OR. You don't have to necessarily worry about your blocks. I think of course if you could do a block that would be maybe better for the patient but that's the basics. Is that true?

[Dr. Matt Allaway]
Yes, and I think you just mentioned the block. We've talked about the anxiety of those first cases under straight local. The block here is distinctly different from a block for transrectal. A transrectal block injected at the base of the prostate, the old Mount Everest sign is approaching the hypogastric nerves. The transperineal block is a combination of mostly pudendal nerve and hypogastrics.

The hypogastric nerves live underneath the pelvic floor muscle. They're between the pelvic floor muscle and the capsule of the prostate at the apex. All your pudendal branches then splay out in the subcutaneous tissue. They tend to be in higher concentrations, intimate with the muscle. The training, I think, on learning how to do this right, not being too medial, being more lateral, understanding the nerves that you're blocking is part of this whole training concept. It's really not just about poking the prostate through the perineum. Yes, that's going to reduce infections, but I was working with a group in Michigan and their pathologist said, "Our cancer detection dropped when we switched to transperineal." I said, "Wow, really?" I dug in deeper and they were using a grid stepper and they didn't even realize it, but they were basically biopsying the transitional zone. A bad transperineal biopsy could yield potentially lower cancer detection than a transrectal, for that reason. The training is the biggest monster for us to tackle.

As Juan mentioned, you've got these hands-on courses, but there's no phantom in the world that simulates the feel of the perineum. There's no way to learn this other than being in the room with the urologist and walking them through it. I decided to tackle this at an industry level, which means I've got to try to convert the US and the world into this technique. These people, they've been practicing, some of them for a couple of decades. We can't wait for the residents to be matriculated through their training programs to make this movement happen. That's going to take 20 years. That's really the big challenge. I think the key thing is proper training and support because sometimes we have to be there side by side with urologists for 15, 20 cases before they're ready to fly on their own. That's a big commitment and no courses or PowerPoint presentations can make up for that hands-on experience.