CT Guided Percutaneous Renal Mass Cryoablation - Daniel Watson

December 13, 2019

Daniel Watson and Alan Burns present their collaborative approach in favor of percutaneous renal mass cryoablation for renal masses. To date, Dr. Watson and Burns have done 207 of these procedures. The mean age of the patient is approximately 69 years and the mean size of the lesions is about 2.3 centimeters. Dr. Watson suggests a 85% cure rate with this procedure.  


Daniel L. Watson, MD, Urology Specialists of the Carolinas, Charlotte, North Carolina, USA.

M. Alan Burns, MD, Mecklenburg Radiology Associates, Charlotte, North Carolina, USA.

Read the Full Video Transcript

Daniel Watson: I really wanted to bring Alan, Dr. Burns, with me because our experience with this started in 2008 and we've done all these cases together. I don't think I'd feel comfortable doing them alone. I don't think he'd really want to do them alone either. So our experience has been... The whole series has been all of us together.

I'm sure most of you guys out there are urologists, so you've probably had a day where you've been in the OR, you've done a couple of da Vinci prostatectomies and your second one had came from outside and he hadn't seen the ultrasound. You cut in the guy's bladder, he's got a big median lobe. You dig that out, it takes an extra 15 minutes, and you've got to reconstruct the bladder neck and you get to the office and you're late.

You've got 20 patients to see and the last patient on your schedule is a new discussion for a renal mass. And you walk in the room, you're 45 minutes late. The guy's sitting there, he's got two daughters and one, of course, is a nurse. And you bring them out and you show him the CT scan and he's got a two centimeter posterior renal mass it enhances.

So you go over the films and you start talking to them about options. And obviously you can survey or you can observe these lesions, they're all T1As. They grow one to two millimeters per year. However, the family's like, "Dad has a cancer in his kidney, we want it treated." You're not going to do a radical nephrectomy on the guy, but you could do a partial nephrectomy. And I started doing robotic surgery in 2004 and I've done somewhere between 1500 and 2000 prostates. And I've done a lot of partial nephrectomies as well. But I can tell you that I'm very selective in who I want to do at da Vinci partial nephrectomy on. And it's not a guy who's 75 with a posterior mass. I just find it's very difficult to flip the kidney in men, the fat's really sticky. It's a very difficult case. And so if you want to do a partial for this guy, I'm thinking he's going to get a flank incision, which is obviously a much more morbid procedure.

So along came percutaneous renal mass cryoablation. So this guy is a perfect candidate for that. We can go to the next slide. We started doing these... Oh, I got that. We started doing these in 2008. I had seen a patient who had gone to one of our academic centers in North Carolina and she had Von Hippel-Lindau disease, had had two open partial nephrectomies, had incisions that met in the middle and met in the back. And she came back to see me and she had a three-centimeter lesion and wanted to know if there was a way to treat her without having to cut her open again. So that was the first case we ever did and it worked out real well and we did it together.

To date, we've done 207 of these patients. The mean age is around 69 years. There we go. The lesions range from... Actually the mean size's about 2.3 but the range is anywhere from a centimeter to 3.8. But as Alan's going to show you, the one that was 3.8 was probably more like five centimeters. Our complications we've had, when I wrote this slide we'd had two perinephric hematomas that we admitted for observation. Last week we had another one, so now we're at three. None of those people have required any intervention, like an embolization or a rush to the OR for a nephrectomy. And going forward and looking at our data, when I talk to these patients, I've been quoting them at 85% cure rate with percutaneous cryoablation. Looking back at our data for our 207 patients, we're at 97%. So 201 out of 207 patients. A cure to us means on followup, renal mass protocol, CT scans, the lesion that we treated does not enhance.

We've been very pleased with it. If you get involved in this type of treatment, the patients do great. We do it under local with a little IV sedation. We don't do them in a surgery center because we don't have a surgery center because we're in North Carolina. That's a CON state. We do them in the CT scanner in the hospital. Virtually a hundred percent of them go home. They spend about an hour in the recovery area. If they don't develop bad pain, which usually means they're having a hematoma, they go home. I send them home on like 10 Lortab. Most of them never take a pain pill. They come back two weeks, they couldn't be happier. Six months later you get their followup CT, the thing doesn't enhance. And I mean, it's just a great, great procedure for these patients.

Unfortunately for us, the reimbursement's not great. Medicare pays us $452. I found out recently there's another code, 77013, that is a CT guidance code that can bump that up another 190 bucks. The other problem for this is that Medicare won't pay for two surgeons, so he and I can't bill together. So his office, we just bunch them together. He bills five cases, I bill the next five cases. This is not a home run. We're not going to get rich on this. But when you do these cases and you see how well the patients do, I think it makes it worthwhile. Now Alan's going to show us a couple of cases.

Alan Burns: So that's our started standard set up. We use conscious sedation, patients do well. This is just an example of one of our typical cases. Patient had a GI stromal tumor that was resected, had neuroendocrine tumors in the pancreas that were resected, came back with a small lower pole lesion that looks pretty straight forward for cryoablation, but the ureter is really very close. Sitting within a centimeter is too close. If you ablate that you'll get a stricture. So we brought him in and tried to displace the ureter with a needle and just push some saline in.

We were unsuccessful so we brought him back again. Dan took him up to the OR, put in a ureteral stent. We perfused the kidney with normal saline and actually worked very well. You can see right here is the ice ball. The ice ball is low density and you can very accurately tell where your ablation zone is. It's right up to the level of the ureter but not touching the ureter. And then on the six-month follow-up, the image was fine. So there was no hydronephrosis and no tumor enhancement.

Daniel Watson: We added more saline going through that. 

Alan Burns: Yeah, through the whole. It really worked very well. So this is the larger lesion that we've done. It's 3.8 centimeters one direction, but it's probably five, cranial-caudal. We used five cryo needles and created a huge ice ball. Thought that for sure we hit ablated this lesion completely, but when we pulled out the needles, the patient bled. She complained of pain and has this 10-centimeter hematoma.

She's one of those two that Dan referred to. She did well with conservative therapy and I guess went home the next day or so. The other problem with large tumors is that they tend to recur. So when she came back, she had a small recurrence here, it's about 13 millimeters. So we treated it like we would any other, and put in a couple of cryoprobes and ablated what was that recurrence in the tumor bed and she's done well.