Chatting to Professor Henning Olsen, a Urologist with decades of experience in managing this renal condition.
DPS PUJ obstruction
[00:00:00] Welcome to Discover Paediatric Surgery.
Andrew: My name is Andrew Grieve and I look forward to being your host today on this exciting episode. We are lucky to have Professor Henning Olsen today with us is a pediatric urologist from Denmark. And I can never pronounce his Hospital properly Aarhus, aahurs, but Aarhus, I definitely haven't got it.
Henning: No one gets it right.
Andrew: So Professor Olsen has two interests in life. The one is Urology and the other is sailing. But sadly today, we're going to talk a little bit about Urology and maybe next time it's about sailing. Thank you for [00:01:00] joining us. We appreciate your time. Sayo Henning. I mean, we'll just jump in we're going to talk about pelvic ureteric Junction obstructions and obviously in children. I mean in the first world
there's obviously a lot of antenatal diagnosis of hydronephrosis does your unit get referred all the patients with this antenatal diagnosis for review or do you only see those that's end up having a problem later in life.
Henning: Well it depends on and if they came from the local area, that means something like 500,000 we will see them and then they come from from outside of the country, which or referral area is something like three and a half million.
They are seen in local hospitals and the prenatal diagnosis made there. And in case of a bilateral hydronephrosis, they come up [00:02:00] the questions and and often with bilateral hydronephrosis they are born in our Hospital. Unilateral hydronephrosis are born very normally and and get the follow-up after a schedule which we have in Danish Pediatric Society in the Danish Urological Society.
It's very clear schedule how to handle these kind of of patients. So it's just in case in case of off bilateral hydronephrosis, then then they have to be referred to us.
Andrew: So they're very early. Okay, do you ever get involved in antental counseling for these these parents?
Henning: Well, if we talk about infra-vesicle obstruction means urethal valves.
We are involved. Yes, because this is in some cases involve some some questions about continuing [00:03:00] the pregnancy and then the prognosis and what kind of surgery has to be done. And what's the prognosis after surgery? And what did what in general the parents have a very little understanding of course what the problem is and then they need some some discussion.
Andrew: Just to give us an idea.
I mean how many kids with hydronephrois that's noted antenatally, how many of those kids eventually come to surgery? Is it the majority of them or is it quite infrequent?
Henning: No, it's is very infrequent, well not very but it's in the around 25 to 30 percent. We are very conservative in especially unilateral hydronephrosis.
Andrew: And and I mean, you know, obviously there's a massive differential diagnosis for hydronephrosis. Do you know what portion in your unit eventually end up actually having a pelvouretheric junction obstruction out of all the antenatal hydronephrosis patients.
[00:04:00] Henning: The majority the vast majority is UPJO (ureteric pelvic junction obstruction) . Of course it is, okay.
You see reflex is is the next common cause of a kind of hydronephrosis but it's not so pronounced but in if you get trained in a way of looking at ultrasound their many, you know the AP diameter and they have calluses and then anything else but if you look at the ultrasound of a kidney in many cases you have in your mind.
Well, this is real hydronephrosis. This is some guy we are going to operate on and this is a guy there's probably kind of reflex or something like that. And this is very subjective and it's not objective at all, but it's based on you know experience and you cannot describe it. Hmm. You see [00:05:00] if you see a patient with an appendicitis you make up your mind in the first very first moment when you see the patient; this is appendicitis have going to
I'm going to operate right? Is it true?
Andrew: Yes, you get a feel for it.
Henning: Then you start out making all you know the evaluation and then in check and and so on but at the end; you will operate because you have seen it just in the very very first moment when you just open the door look at the child and then you know it okay, that's it.
It's never right?
Andrew: yes you are right it's almost like an art you get a feel for it.
Henning: a clinical view. You cannot describe as you cannot use it for however studies. It's not it's not something you can use for anything. Just your personal your personal, you know experience.
Andrew: Yeah. Any what exactly is a pelvoureteriec junction obstruction. How does it develop [00:06:00] what sort of the physics behind it?
Henning: Well, personally, I do not know what it is and I do no less while time is going and I but in principle of distortion of normal architectures and it's it's fibrosis dysplasia something in between and it's rather
hyperplasia than an atrophy and in it, It's a growth failure. And that's why because it's a growth failure. That's why only 30% needs an operation because the child is growing and in many many many cases. This condition will resolved spontaneously by Nature.
Andrew: Okay. And then how often do you see extrinsic causes of of puj [00:07:00] obstructions?
Henning: What what's an extrinsic you mean?
Andrew: Something like a lower from the vessel?
Henning: Is this extrinsic? My my question is? How many normal children have an aberrant Crossing accessory vessel to the lower kidney pole and be logical think yeah, the is sending the pelvic region and upwards and end in the ascending process.
For all children lose some of the vessels and get some new vessels upstairs. Hmm. I have some always thought it's it's it's a developer knows personal [00:08:00] question. And there's a reason why we see the crossing vessels accessory vessel, whatever you want to call is yeah. See this later in life. And it's very rare than you are operating on a very young child you were you see a Crossing vessel?
You see this what you would call an intrinsic obstruction are high insertion of the pelvis or whatever. It's I think it's a bit different.
Andrew: Yeah, yeah.
Henning: Accessory vessel.
Andrew: Okay, so it's not necessarily causing the problem. It's more that it's you know an Association.
Henning: Of yeah, it's some point of time.
It's the cause for the symptoms. Yeah. Okay. If you have that they have here they Crossing vessel and you have a hydronephrosis [00:09:00] and they drink a lot of whatsoever. They do. The ureter will Kink over the the accessory vessel and then they get symptoms and vomiting and pain and the symptoms which are caused by this Crossing vessel.
Of course, they are. Okay. Otherwise on these guys. You see a lot of fibrosis. Hmm. a lot of fibrosis around the the upjo and you can release this fibrosis. But essentially we will be back on this and when we come to the to operation, How to operate these think when you operate on a hydronephrosis you should always do and dismembered pyeloplasty, but we can get and go back to this later.
Andrew: Yeah, we'll discuss a bit more in detail later. I mean you mentioned a little bit about some of the symptoms that these [00:10:00] children present with. I mean, obviously those are to diagnosed antenatally have regular routine follow-up, but those that aren't diagnosised antenatally, and we obviously see more of those than you do. You mentioned some of the typical symptoms, but maybe we can just go through those again and what are some of the things that they present with?
Henning: Well, one thing an older nurse in our department is observed is that they start to thrive after release the hydronephrosis the newborns again their bowel movements changing and something is happening because when you're born with a hydronephrosis, you don't know what pain is because you are born with your just developed with this pain.
It is pain. What is pain? Pain pain is something you; you find [00:11:00] out when you are born and perhaps it is before you are born, and it's something which is intermittent. But if your constant pain it's not a pain. It's just a condition just life is these poor children? They just they live that this condition and that's it.
They think life is like this. Okay, we have to find out and later in life they get the symptoms such as to the crossing vessel. As, as I mentioned they did they vomiting and and the pain and this lasts for some of them half an hour others of them two days. Some of them were avoiding vomiting and when the vomiting the loser lot of
fluid and losing lot of fluid means reducing urine [00:12:00] production, reducing urine production resolves the problem with the kidney and then then then then the the symptoms disappear.
Henning: The essential difference between these two kinds of children is that that many of the children with Crossing vessels and intermittent
symptoms have nearly normal differential function of the kidney, but the young ones they might from the beginning have a decreased differential function in their kidney.
Andrew: Okay, thats an interesting facts. Yeah. Do you see a lot of urinary tract infections in these this group of patients?
Henning: no, no, once in a while?
The same as haematuria, the same is true for stones. We see more and more I think. [00:13:00] okay, the older ones all the patients are but rarely in the young ones. But but you have to ask people about them from from the from Turkey or from the Eastern Asia they have much more Stones there in even in hydronephrosis children.
Andrew: Yeah. Okay. Yeah, I think it's um, there might be some genetic predisposition as well.
Henning: Yes genetic or environment the you can speculate about what what's the reason is?
Andrew: Hmm. Do we see these more common in males versus females left versus right or most then bilateral? What's your experience in your cohort of patients?
Henning: Bilateral is about 15%. 10- 15% not more. In small [00:14:00] children It's more on the left side.
Both groups can say and then both male and females. Okay, whether there are more males in the end the accessory vessels. All right, let's look where we are. We have a database about these these guys and it's obvious that the more males 55% males and females in the older group
Andrew: Okay, so, All right.
So you mentioned that your kids with antenatal diagnosis of hydronephrosis obviously have a regular screening program and then they get referred to you only if there are problems. What some of your investigations of kids with suspected pelvoureteric Junction obstructions? What's things you guys look at?
Henning: Well, if you have a unilateral hydronephrosis as you know, we do [00:15:00] it about 7 to 10 days after birth because they kidney function is not fully developed. It's better after six weeks. We do it after 7 to 10 days to get some kidney function and when when when they start drinking and voiding, okay, if we have a case of bilateral we do the ultrasound already.
Prenatal diagnosed children, we do the ultrasound the day of birth just to to avoid that we are overlooking cases of infravesical obstruction. Okay means it's the walls but we will always repeat this study day 7 and then we will do depending a bit on what we find out about the four weeks old.
And then again at it three months. The nuclear studies are postponed always to four [00:16:00] to six weeks due to the development of the nephrons that takes at least four weeks to get some some proper answer from the nucleus studies. And so we wait for this time and it depends of course, how much is this very rare that you think that you need to operate or do some relief just after birth in that upjo. It's very haven't seen this. Yes. I don't think so. Yeah.
Andrew: Okay. Can I can I ask I mean there's you know initially when you know people started talking about doing antenatal ultrasounds in their neonates for this condition they used to always to talk about the size of the pelvis.
And you know, did it have some baring on surgery and outcomes in those things and my impression is has been a bit of a move away from that. Do you [00:17:00] still find it important to see the size of the pelvis in these kids in these neonates?
Henning: Well, we look mostly because of what communication courses we look most of all of the intra-renal.
anterior-posterior diameter of the pelvis the external part of the pelvis is so far not of Interest (right) does this is just Nature's Way of defending the kidney against the against the possible obstruction while the intra renal APD diameter has been shown that it has some significance on the
on the prognosis and we use AP diameter of 12 millimeters when the we call the case a hydronephrosis the radiologist the call hydronephrosis after AP [00:18:00] diameter of 10 millimeters. Both of us might be right, but but it has something to do with a follow-up. In most cases, you don't have this question.
But if you have an AP diameter of seven millimeters, let's see seven millimeters. So we will make one ultrasound after four weeks and if this is true still true, we will not do anymore. We will redo not do a nuclear study we will just leave the child and that's it. Okay. So we will not make any further investigations.
We will call this hydronephrosis.
Andrew: I guess it's more of a screening tool then. Yeah. And we've been using MAG-3 as our nuclear study. Are you using the same? Yeah, Can you maybe just go through what some of the principles are behind the [00:19:00] MAG-3? What are we looking for? And what makes it useful in puj obstruction?
Henning: The MAG-3. It's a renography. It's a it's it's both renography, and it's scintigraphy. For us the most important part of it is the the the scintigraphy part of the examination; that means to find out the differential function and something which is very important. You have to look
at the pictures these nuclear medicine guys are doing especially in a newborn child. If you have a right-sided quite large hydronephrosis, the liver is very close and the background in this examination can be quite active close to the liver and make it gives you some misinterpretation, especially [00:20:00] in large kidneys and enlarged kidneys.
Henning: You have to be very careful on their interpretation of the differential function. And where they place; especially when the function is down to 20% or something of that the look carefully at this pictures not just at the curves and then tracing their but look at the pictures. Look what's going on there. And where have they drawn the lines. Because the lines in the MAG 3 they draw on the picture is subjective
assessment of the nuclear medicine and not not the truth. Yeah, so be careful be careful there. With regards to the washout. Well In smaller children, we don't rely if you have a normal curve. Normal curve means [00:21:00] like a Gaussian distribution if you remember this from your statistics, this is a normal curve.
Henning: but but if you are at normal curve, you cannot interpret this as an obstruction, even if it goes up after half an hour or something like that. It depends on the size of, the size of the pelvis. If you have a bath tube on one side and just then one normal wash hand wash on the other side and you have the same amount of nuclear activity in both of them.
No matter what if the if the drainage is the same; the activity will sustain in the large system for much longer than the other system. This does not mean that there's an [00:22:00] obstruction. Okay. So quickly the same the same drainage on both sides.
Andrew: Right right
Henning: Therefore the disease side needs to drain much more volume to get rid of the activity.
Okay. Be careful interpretating large systems with the halftime or anything else?
Henning: Forusemide might might help you a bit. If you get a kick after furosemide you can be quite sure that there is not very much obstruction. Obstruction is not absolute. It's not a complete obstruction. It's a obstruction is a degree of obstruction if there is obstruction.
There Is no established washout time the literature regards to children in contrast to adults. In adults you have established [00:23:00] washout times you should rely on but but in children there's no literature about the the the real washout time. The preferred washout time. They're not good studies on their own pace.
Andrew: Okay, so we just bear that in mind obviously when we interpret the MAG-3 tests. Have you been using or you're tempted to look at MR urography with gadolinium?
Henning: We have been tempted a couple of years ago, especially because the the MRI urography was was kind of way of to estimate the differential function in the kidneys, but a few years ago in Denmark, we had Scandal about the gadolinium with some adult patients.
And with insufficient kidney function they get a lot of fibrosis and symptoms after gadlolineium in a very [00:24:00] few patients, but you know how things are once you have this story in the newspapers, then it will hang on and since then it has been forbidden to do to any kind of these gadolinium, especially not in children.
So this is not an option anymore. We use MRI for without gadolinium for some some reasons if you have unclear Anatomy for for any kind of dilation of the upper urinary tract, but not a routine. No, of course not.
Andrew: Okay. Okay, so I mean obviously once you've made the diagnosis and then done the nucleur studies and those things obviously at some stage we need to decide
whether we either going to watch the patients or we going to consider offering them surgery. When do you make that distinction? What kind of things are you looking at to make that decision?
Henning: Well [00:25:00] you have some Nordic guidelines, which define when the kidney function is deteriorating and when we are suggested to
to do surgery.
We do operate when the differential function on follow-up decreases more than five percent.
Henning: If there is a huge progress on ultrasound and then you might recall the statistics from Great Ormond Street. If you have an AP diameter of more than 35mm to 50mm in the intra- renal pelvis. Then we find the indication we discuss the indication for surgery.
[00:26:00] Andrew: And on your first MAG-3 if there's a big difference in differential function between the two kidneys. Would you consider it then or would you still watch them to see what's happening?
Henning: This is an ongoing discussion. If you our limit for normal differential function is 40%.
In Copenhagen it is 42% and somewhere else might be something else. This is yeah, there's not going to be really really clear where it should be done. We follow always the children. If you are born with a differential function you have a hydronephrosis , hydronephrosis. Significant...