Podcast Transcript: Contemporary Surgical Management of BPH

[Dr. Aditya Bagrodia]
All right. Fantastic. I must say that I've used the rolling ultrasound in our clinic and it's pretty user-friendly. You can get the information that you need at the point of care, which is clearly nice. Okay, great. Understood that the size isn't the only fork in the road but perhaps it gives us a reasonable place to start. And maybe the smallest sliver of the pie is going to be large prostates. So let's start out with large prostates. A, how do you define that?

[Dr. Claus Roehrborn]
That was a heavy debate amongst the BPH guideline committee members: what is large? And some people, even the peer reviewers of the guidelines said, "Give us guidance. Give us numbers." And we refuse. Because some people can resect a 60 g prostate, some can resect an 80 g prostate, some can resect 100g prostate and we don't restrict that. So what is large is a little bit in the eye of the beholder. We suggest that large for most doctors starts at 8 0g. Because I really doubt that many of our current trainees can resect 40 or 50 g of tissue safely. Why would I say 40, 50? Because that's the transition zone tissue you want to resect if you're faced with an 80 or 90 g prostate. That's how much you want to resect. And most of them can't. So to me, large starts at 80. Anything above 80, either I want to sit there for 4 hours and do a KTP laser, which is still incomplete, or I do a bipolar TURP and I'll do it all myself with no trainee involved to do it quickly, or I just go to the category large prostates, which starts at 80 and goes to the 100 g or 200 g and 300 g.

And in that category, the best choices right now are no longer the open prostatectomy either retropubic, the old Millin approach, or suprapubic, but the best choices are either a robotic assisted laparoscopic enucleation, which 90% is done transvesical. Only 10% is done retropubically, opening the capsule. It's just the robot is not really well suited to do it, and you'd have to release the bladder, like for a radical prostatectomy, so there's a lot of reasons not to do it. It's a transvesical robotic assisted laparoscopic, which works extremely well. Sizes 80 to infinity. Now, there are 20, 30, 40, 50 places in the United States where there are real experts who can do holmium enucleation or a thulium enucleation, and this is the same thing. The sky is the limit. They enucleate prostates from 80 to 150, 200, 300 g.

What happens, though, is after a robotic enucleation you put the prostate in the bag and you take the bag out and if the prostate is 100 g or 200 g takes the same time. The morcellation, as you know, takes longer. So you enucleate transurethrally 250 g or so, the morcellation time takes longer. So maybe this is a detriment for HoLEP in 200 g, 300 g and the benefit of the robotic assisted enucleation. But then again, there are patients who had prior surgery or have reasons not to do a laparoscopic surgery for whom only the transurethral approach is applicable.

We have found in our training program and others have found that if you have a busy training program and the residents do a lot of robotic radical prostatectomy, the learning curve for a simple prostatectomy is fast, efficient, and they learn to do it safely. I love, love the idea that our residents leave here and if they are seeing a 200 g prostate, they know what to do and they have a tool to apply to that patient. So that's the story on the very large prostates. 80 g and above for me, and for others maybe 100 or even 120, but for me it starts at 80.

[Dr. Aditya Bagrodia]
Yeah, I think that's really helpful to help start the discussion. I'll ask you to comment on two things as it pertains to bipolar TURP. Why exactly is there a size cutoff if you're not going to be contending with the same fluid disturbances, post-TUR syndrome, when it comes to a bipolar TURP?

[Dr. Claus Roehrborn]
I suppose, theoretically, there is none. Now, that depends a little bit on how your setup is. In the 1980s studies were done on body temperature changes with irrigation. If you commit yourself to use body temperature saline irrigation for a bipolar TURP, I suppose you can keep on going. If you don't do that, then eventually the core temperature decreases, the longer you resect with room temperature normal saline, and eventually this becomes an issue. The patient becomes hypothermic and, as you know, coagulation parameters change and the patient doesn't do as well. But if you go with the warming, I presume you can keep going.

An argument against that is as follows: If you follow basic geometry and you calculate the inside surface area of a bowl or of a ball, the prostate ultimately becomes like a bowl, right? The opening is towards the bladder neck and the rest of it is this bowl-shaped configured prostatic capsule. The more you resect the larger the surface of that bowl gets. It's just the inside surface of what a ball would be on the outside. And it becomes harder and harder to stay oriented and to be good about your hemostasis. Particularly for trainees. They pretty soon get lost if the prostate is 60, 80, 90, 100 g in size and it's just harder and harder to execute this fully.

Secondly, if you have a very large prostate and you resect that, you have to do a lot of coagulation at the end. And you do all this coagulation and the patients oftentimes, 10 days, 14 days later, they shed this surface scab tissue and they start coming to the emergency room with fresh bleeding. So I must say that there are practical reasons, teaching reasons, training reasons, and also health reasons that I wouldn't do it. If I can do a robotic assisted enucleation in 90 minutes time, then I don't want to be there for three hours of general anesthesia time and approximate that effect with a bipolar TURP.

[Dr. Aditya Bagrodia]
Yeah, I wholeheartedly agree. Certainly in the bladder cancer world, I would say that a properly done transurethral resection of a bladder tumor is a case that requires a technical skill set and all TURBTs are not the same and similarly all TURPs are not the same and I appreciate you highlighting that. Last comment before we shift on from the large prostate world is you mentioned a four hour KTP. I think this is something that's an easy trap to fall into when it comes to doing KTP prostatectomy: you ablate for some amount of time, regardless of prostate size, you take a look from the veru into the bladder and say, "Yes, nice, good looking channel. Let's call it a day." And clearly you're going to be making a return trip here. Can you talk a little bit about what your number that you have in your head in terms of energy per gram so that when you look over at your KTP machine, you've got so many watts or joules or kilowatts--I can't even remember the unit anymore--and you say, "Yeah, I think I've done a good job."

[Dr. Claus Roehrborn]
The problem is that many surgeons who use KTP, they don't know the size of the prostate, so they are going in sort of blinded and then they start vaporizing and then they are saying, "Okay, now I'm done." And when you look back then with an imaging study, cross-sectional imaging, you realize that was just a very surface layer and he didn't really get to the bulk of the prostate. We see this all the time. Unfortunately, the kilojoules, that's what the unit is that we measure--kilojoule energy that is applied-- is not recorded by the device. The company, Boston Scientific, doesn't really know how many kilojoules each doctor applies for each treatment. I keep it fairly religiously and if I go in for, let's say, a 50 or 40g prostate, I want to end up with 200 kJ. And I would say that 200 kJ should ablate approximately 20g of tissue. I can do that, if I stay on the laser and I use about an energy of 150W or 160W, I can do that in approximately 20 minutes.

So these are my yardsticks. The time that the laser is on, and not that I'm looking around or the trainee's looking around, but the time the laser is on, the energy that I use, which ranges from 80 to 180, so I shoot for 160 as my top power setting, and then the total energy would be 10 kJ equating about a gram of tissue. That also happens to be a gram of tissue ablated by that laser per minute if you are efficient and if you know how to do it. If you are only in there and you turn the laser on and you are too far away, you don't create bubbles, you don't ablate the tissue, then all bets are off. I don't know how much tissue is ablated, maybe very little. So a well-trained, well-experienced KTP laser resectionist can do a gram a minute, and a 40 g prostate 200 kJ would be appropriate. I would probably do 300 kJ for a 60 g prostate.

[Dr. Aditya Bagrodia]
Okay, fantastic. I'll just try to briefly summarize. Large prostates, we're looking at bipolar TURP, can be technically challenging, comes with fluid and temperature changes, potential bleeding risks that are considerations. KTP prostatectomy, I think you need to be committed for the long haul to really get a good job and serve the patient well. Then you've got the simple prostatectomy, probably most frequently done via a minimally invasive approach with the benefit of avoiding an enucleation step, and of course conversely it is a transabdominal surgery. And then lastly HoLEP, minimally invasive option, technically challenging, limited to certain areas of expertise, and then the morcellation step. So that's really helpful I think, just to unpackage how to think about those. Maybe before we jump into more average size prostates and symptom, patient preference, anatomical considerations, I would ask you suprapubic tube at the time of surgery in patients with retention, is that something you do pretty reflexively? If you could just offer a thought on that.

[Dr. Claus Roehrborn]
Yeah, that's an unresolved issue in research in LUTS and BPH, and just as there is no answer for the detrusor hypocontractility, there are really unclear indications for it. I use a suprapubic tube in patients where I suspect that there will be a problem post-op with the resumption of normal urination and a voiding efficiency of greater than 50%. How do I do that? Well, I get my idea, my gestalt, from the phenotype. Is the patient young? Is the patient old? If he is already fairly old, does he have a high retention volume, is the voiding efficiency only 20, 30%, what does the bladder look like on ultrasound or on the MRI? Is it already heavily trabeculated? Does he have diverticular is there evidence for long standing obstruction? All of this would lead me to say, "Well, I put an SP tube in as a bladder retraining tool and let the patient come to a point where maybe his voiding efficiency improves to 70 or 80% and then take the tube out."

Every single factor changes it a little bit. For a patient has a lower retention volume and is younger, I would be less prone to do it. If I look inside and the bladder wall looks good and there is not too much in the way of trabeculation, I would be less inclined to do it. If I look in during the surgery and I realize the prostate really is visually obstructing and the lateral lobes are really compressing the urethra, oddly enough, I would be less likely to put an SP tube in because I'm thinking, "Well, this patient I can convert from a high retention volume to a low retention volume just by unobstructing him." The biggest risk is clearly an octogenarian with a high retention volume and a modest sized prostate and when you look in you see this heavy trabeculation with these fibrous strands run through like sails and diverticular everywhere and you realize the prostate isn't even that big. Then you know you are in trouble, and that patient gets an SP tube. Because to convert that patient to a normal urination would be very difficult.