25 th Anniversary State-of-the-Art Expert Discussion With Ralph C. Cohen,MBBS,BMedSci,MS,FRACS,on the Advances of Surgical Practice in Pediatric Urology

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Ralph C. Cohen, MBBS, BMedSci, MS, FRACS

Dr. Ralph C. Cohen is Clinical Professor of Paediatric Surgery and Urology at the University of Sydney. He has worked for the last 20 years in the Department of Surgery, The Children's Hospital at Westmead, Sydney, Australia.

 He trained at the Adelaide Children's and The Royal Children's Hospital, Melbourne, Australia, at The Hospital for Sick Children Great Ormond Street, London, United Kingdom, and The Hospital for Sick Children, Toronto, Ontario, Canada.

 He has a wide range of research interests, which currently include minimally invasive surgical procedures using animal models both for teaching and for development of innovative techniques. He has published 75 articles in peer-reviewed journals and given 120 presentations at national and international meetings.

 He is a Member of the Court of Examiners for Paediatric Surgery, Royal Australasian College of Surgeons, Past President of the Pacific Association of Pediatric Surgeons (PAPS) for 2011–2012, Past President of the Australian and New Zealand Association of Paediatric Surgeons (ANZAPS) for 2012–2013, and a Member of the Executive Committee of the World Federation of Associations of Pediatric Surgeons (WOFAPS), Asia/Pacific Regional Representative.

 He has been married for 42 years, and he and his wife have four children and five grandchildren.

Dr. Cohen, thank you for taking the time to visit with me today. I was hoping we could talk about the progression of minimally invasive urologic procedures. When did you first see urology starting to change from open procedures—pyeloplasties, reimplants, nephrectomies—to the acceptance of minimally invasive urologic procedures, excluding cystoscopy, in children?

It would have been in the mid-1990s, and it started with pyeloplasty and treatment for vesicoureteral reflux. Craig Peters published the first article in 1995 on laparoscopic pyeloplasty, which, as you know, is one of the more common operations in urology. Following that report, a series was published in 1999, and that was really the start of the application of laparoscopic surgery to a major urological problem in children.

There has also been a significant change in the treatment of vesicoureteral reflux. Along with the nonoperative treatment, the minimally invasive interventional approach has been the application of injection techniques, which can be credited to Barry O'Donnell and Prem Puri in Dublin in the 1980s. More recently, we've seen the development of the laparoscopic intravesical pneumovesicum and extravesical techniques for ureteric reimplantation. However, these techniques have been slow to gain momentum, probably due to the fact that the conservative approach and the injection techniques have been more widely applicable.

Do you think that these advancements were drawn from the adult side, or do you think it was more pioneering in terms of the pediatric urologists?

I think it was probably initiated more in the adult, as most minimally invasive surgery (MIS) has been. As the instrumentation downsized, it has become more applicable to children.

However, there has been pioneering work in children. There is no doubt MIS is more difficult in children due to their smaller size and the fewer numbers of pediatric cases, which make it difficult to maintain and develop the necessary skills. Despite these hurdles, we have increased our application of MIS across the whole range of urological problems—pelviureteric junction obstruction, nephrectomy, more recently partial nephrectomy for duplex systems, and extravesical/intravesical ureteric reimplants. I think that these are the main areas in urology where MIS has been applied over the last 10–15 years with some success.

You mentioned that Craig Peters was the first person to do a laparoscopic pyeloplasty, but there must have been others who were pioneers at that time that continued to push or refine the technique.

Of course. In Australia, Hock Tan has been one of the pioneers in pediatric laparoscopic urologic surgery, and published one of the first series of laparoscopic pyeloplasties, confirming that it could be generally applied and with good success.

I would like to mention that we have a responsibility to be somewhat cautious about minimally invasive surgical approaches in terms of, what benefit is it having to the patient over a standard open operation? Currently, there are only a few well-constructed randomized controlled trials comparing open and minimally invasive techniques that confidently support the minimally invasive technique to be superior to the open technique.

For example, if you consider the open retroperitoneal and minimally invasive approaches to duplex kidneys, the laparoscopic approach to remove the nonfunctioning upper moiety is certainly achievable. However, it takes on average, according to published series, 4 or 5 hours to do that operation. This procedure can be done open in about an hour and a half.

So we need to consider all aspects of the procedure. Are the anesthetic time and duration of the operation important in children? Certainly, but are they less important than the cosmesis, than pain relief, than length of stay in the hospital? All these parameters need to be carefully assessed in randomized controlled trials before we can really say we are offering our patients a better operation by a minimally invasive technique.

Do you feel that these same arguments should be made with regard to the injection techniques as well?

So the question you are raising is the benefit of artificial substance injection over, say, conservative treatment, antibiotics, and monitoring for renal function and urinary infections. There are studies showing that the injection technique is more expensive and offers little in the way of benefit in some patients in terms of recurrent urinary infections or preservation of renal function over conservative treatment. So, yes, all these techniques have to be assessed. Ultimately, our expectations should remain that at the end of the day we provide the best option for the care of our patients.

Let's talk a little bit about the robot. The adult urologists have really been the surgical specialty pushing the robot, correct? For example, robotic prostatectomy, I believe, is well accepted and considered almost the gold standard in some places. It seems that we are starting to see more pediatric urologists using the robot. Is that your impression, as well?

Well, Dan, I just happen to be sitting here in my office looking at a picture of Craig Peters (from the Boston Children's Hospital at that time) and myself taken here at the Children's Hospital at Westmead in 2005. I invited Craig to come and show us how to do robotic pyeloplasties. He very kindly agreed to come over, and I was able to borrow a Da Vinci robot from the distributor here in Sydney. Together we did the first robot-assisted laparoscopic pyeloplasties on two children here at The Children's Hospital at Westmead.

It was a fascinating experience to see how that technology affected the operation, particularly in terms of the ease of suturing. As we all know, the rate-limiting step in a lot of laparoscopic surgery is the intracorporeal suturing and tying knots. I was very impressed by how the robot facilitated this and made it so much quicker and easier.

But then again, its cost was about $3 million at that time, and another half a million dollars a year to maintain it. In adult surgery, prostatectomies are a common procedure, with large numbers, and so you are able to get the experience, maintain your skills, and justify the costs.

In children, the use of the robot is often hard to justify, in terms of the types of surgery we do and the numbers of patients that could potentially benefit. Many surgeons, including enthusiasts like John Meehan in Seattle, would agree that you have to be selective with this type of technology to justify its use in pediatric surgery. Many of the cases we can do just as well by standard laparoscopy, and with much less cost to the system.

Even in adults, there is literature showing that with the radical prostatectomy using a robot, the outcome measures are not significantly improved over standard laparoscopic or even open surgery. So my caveat on all this is that we have to be very careful about rushing into applying new technology to our patients without a clear understanding of the benefits for the patient.

When you look at pediatric urology since 2000, what has set the minimally invasive approach on its path, besides just the innovative surgeons? Is it certain instrumentation, surgeon commitment, patient demand, or any combination of those?

This is a complex and very good question. I think initially it was the instrumentation, the downsizing from the adult instrumentation, which was a major step forward for its application to pediatrics. Then, like any new technique, there was a phase of great enthusiasm, and everything had to be tried. Eventually, the pendulum will start to swing back, and it becomes evident that the new techniques are not really providing a benefit in some operations, but is obviously superior in others. Ultimately, those operations that benefit from MIS become clearer, and the application continues. That is a natural process that you expect with any new technology.

I would like to mention an important aspect in particular for pediatric surgery, urology, and MIS: how to ensure that we can maintain our skills in the numerous conditions where we have limited opportunities to do a particular procedure in a minimally invasive way because of the infrequency of the disease or diagnosis? What we have established here in Sydney is an animal laboratory with porcine models for training of our surgical trainees, and consultants, to maintain and improve their skills, even for common operations. We use these same facilities to work on developing and refining new operations. I think we have a great responsibility to think of novel ways that are effective in pediatric surgery and urology to maintain and develop our MIS skills, and simulation is one way of doing this prior to clinical application.

I think you are exactly right. Over the last few years, there has been significant focus on the development of simulation models. There are some really delicate lifelike simulation models now that are just coming into mainstream, where people are starting to recognize that they can be used in the way you just described, and move a little bit away from the live animal models, which can be quite costly.

Yes, costly, and different parts of the world have different rules. For example, in the United Kingdom, they cannot use animals. Regardless, whatever method of simulation that is being used, we need to harness that in pediatric surgery and urology.

Another important aspect in pediatric surgery is the ethical issue of how you start to do an MIS operation you have never done before? Maybe you have seen it in a video at a meeting, or talked at length about it with someone that has performed the procedure. How do you ethically start doing this new operation, and how do you consent the parents? You have to tell them that there is a very good open operation that has a 95% success rate. However, I would like to do the same operation via a minimally invasive approach, but that I have never done it this way before. It's not just the surgeons; it also involves anesthesia, nursing staff, and the hospital management as well. How do they protect themselves legally if something goes drastically wrong? I suppose the point I am trying to emphasize is the difficulty of credentialing in the era of MIS. We don't want to stifle advancement, but it is something that every hospital and surgeon must deal with.

Perhaps in the future it will be simulation or lab animal models, like we are talking about, that prove proficiency in that model before they are credentialed.

The advancements being made are amazing. As the software programs improve, there may be a computerized software program of a laparoscopic pyeloplasty that you can objectively score and determine when someone is adequately trained to do a minimally invasive procedure independently. There are a lot of possibilities.

I do not know what it is like in the United States, but in Australia, we do not have a good standardized approach.

We do not either. I think that this is something that, as academic faculty training residents, fellows, and students, is part of our responsibility. We are going to need to figure out how to do that. As we move forward, it is going to have to be a more structured evaluation that proves competency, rather than just saying they spent 6 years doing one thing and now they are competent.

In Australia and the United Kingdom we now have “safe working hours.” What this means is that the residents can only work 50 hours a week, whereas when you and I were residents, we were working 80–100 hours a week. I believe that the shorter working hours leads to a decrease in the continuity of care in some cases. This includes the inability see how the patients progress after surgery, and the residents miss out on surgical cases. So the overall surgical experience is significantly diminished. This loss of exposure has an impact on their ability to safely perform complex laparoscopic surgical procedures.

I completely agree. I would like to move the conversation in the direction of more of the technical aspects of minimally invasive urology. Recently there has been a substantial interest in single-site or natural orifice translumenal endoscopic surgery (NOTES). Pediatric urology had one of the first successful procedures that was done with NOTES if we consider injections for vesicoureteral reflux. Are there other procedures that you envision in urology that are going to be amenable to either a NOTES or a single-incision approach?

That is an interesting question. The NOTES concept worries me a little. The basic principle of creating a hole in the stomach, the rectum, or, in a girl, the vagina to perform an intraabdominal procedure creates a situation where the risks potentially outweigh the benefits. As I look at it, the main benefit of doing that is going to be cosmesis and postoperative pain, but there are numerous possible downsides, including the risk of intraabdominal infection, the technical aspects of operating in small-size body cavities, and the increase in the time it takes to do the procedures. So I think, quite frankly, that these risks outweigh the potential benefits.

Given what we can currently accomplish via NOTES, I agree.

Regarding single-incision laparoscopic surgery (SILS), this already has applications in cholecystectomy and in appendicectomy. In my experience, I think it makes it technically a little more difficult, and the trade-off, once again, is that you have one 4- or 5-cm incision through which you put all your instruments, as opposed to three or four 3-mm or 5-mm incisions.

I think we need to be careful that cosemesis does not become the overall guiding principle of how we choose a technique and apply it to children. Cosmesis is important, but more important is the fact that the operation can be done in a reasonable time and with safety.

I think you are right. There are certain areas where SILS is going to be of benefit, and that is appendectomy and maybe cholecystectomy. But it has to follow the tenets of MIS—it has to be as good of an operation as you can do open, it has to be as safe as you could do it open, or laparoscopically in this case, and there needs to be a clear cosmetic benefit.

I am not sure that we are accomplishing the latter, and it is probably at the expense of prolonged operative times.

We must not forget the importance of prolonged anesthesia. It is clearly being recognized recently as a significant issue in neonates, with regard to the brain and the potential adverse cognitive effects. In the field of pediatric surgery neonatal surgery is the pinnacle of advanced laparoscopic MIS. We must give consideration to decreasing the anesthesia time, or we may be opening a whole new can of worms for our patients by having 4-hour operations that we could do in 2 hours. We have to be very careful about what we are doing and question ourselves, not just go ahead doing these operations because we can and ignore the potential risks we may be generating for our patients in the future.

Yes, and those risks may not appear for 5 or 10 years, postsurgery.

Exactly. Accomplishing these goals, maintaining the skills, and perfecting operations with regard to technique and operative time require large numbers of patients. If we cannot get adequate numbers of patients to develop skills, then we have to look at other ways, which likely involves simulation.

These minimally invasive technique issues exist for pediatric surgery and urology; the same basic principles need to be adhered to and assessed.

So with regard to MIS, I think we have seen a shift where our colleagues are starting to accept the fact that this is more mainstream. For example, fundoplication. I think most people agree now that the laparoscopic fundoplication would be considered the appropriate route for a child that had reflux. Do you think the same thing has held true for urology across Australia, the United Kingdom, and the United States? Or is MIS urology still kind of on the outside looking in, so to speak? In the United States, we have pediatric urologists, and some pediatric surgeons do some urology. It is not like in Australia and the United Kingdom, where the pediatric surgeons are the pediatric urologists, right? So in your environment, is MIS for pediatric urology pretty much accepted across the specialty now?

I would say that some centers do more than others. Here, in my department, for example, we have only just recently had general pediatric surgeons with an interest in urology doing laparoscopic pyeloplasties. So it has been in the last 2 years we have started doing them with any sort of numbers. And the reason for that is, I think, because we have had people who have been at a stage of their surgical life where they have found it difficult to change over, and with the younger people coming through, they have been keener to adopt the minimally invasive approach. So just from that point of view, it has only been a recent uptake. But throughout Australia, I would say the laparoscopic approach for urology has not taken on as widely or as keenly as in general pediatric surgery.

I think that is the same in the United States. They are gradually moving towards more MIS, but they are a little more hesitant. I do not know if it is due to training in terms of how the urologists are trained in pediatric urology or if it is a cultural thing. Like you said, perhaps it is something that needs a generation to change?

Yes, I think that is right. The older surgeons find it more difficult to accept. For example, if we are going to take a kidney out, just doing a lap nephrectomy, which is often a fairly simple minimally invasive surgical procedure, but even that people have had difficulty accepting because they say, “Well, it can take me 2 hours to do that, or I can do it in 45 minutes through a dorsal lumbotomy.”

Right, through a tiny 3- or 4-cm incision through a dorsal lumbotomy.

And with a good cosmetic result. And the patient goes home in a similar time frame, and the pain problems are similar to a minimally invasive approach. So there has been a bit of a resistance in urology, I think, to achieve general uptake of minimally invasive surgical techniques for those reasons.

Another factor that I think needs to be considered is does urology have a dominant procedure to build upon. For example, pediatric surgery has appendectomy, pyloric stenosis, and fundoplication, all very common andthat allow the surgeons to develop their MIS skillset. This may not exist in urology?

That is right. Twenty years ago, I would do about three or four ureteral reimplants a week for vesicoureteral reflux. Presently, I would be lucky to do three in 3 years. And this is occurring around the world. The treatment of vesicoureteric reflux has changed. For the most part it is no longer a surgical disease.

So, if you are only doing one per year, how do you maintain your skills to do an extravesical or an intravesical minimally invasive reimplant? It will remain difficult.

Is there anything else you would like to comment on in terms of the changes we have seen in pediatric urology over the last 25 years?

The only other area to mention would be the antenatal diagnosis of urological problems—pelviureteric junction obstruction, posterior urethral valves, and multicystic dysplastic kidneys, to name a few. They can now be diagnosed so much more accurately and reliably antenatally. This has opened up doors for us in terms of fetal surgery. There are some surgeons starting to consider ablation of posterior urethral valves via fetal surgery. Whether that will translate into improved renal and bladder function in those children postnatally is hard to know at this early stage.

It is going to be part of the future. Even now, postnatally, those infants who are diagnosed antenatally with pelviureteric junction obstruction have better preserved postnatal renal function. These children previously would have turned up 3, 4, 5 years of age with a urinary tract infection, an ultrasound showing pelviureteric junction obstruction, and a poorly functioning or in some cases nonfunctioning kidney. Those kidneys have benefited from antenatal diagnosis, whereas they would have previously been lost.

Would you include fetal shunts in this discussion?

This is another controversial area. Often by the time posterior urethral valves are diagnosed antenatally the kidneys are already badly affected, so the vesicoamniotic shunt will be unlikely to prevent renal impairment and dysplasia but may assist in lung development. All of this is dependent on the timing of intervention. Additionally, shunts can become blocked and misplaced.

For sure, this is an area that needs to be mentioned in the overall conversation of advances in pediatric urology. It holds significant potential for further research and advances.

Any other thoughts?

No. I think we have covered it pretty well, Dan. It has been an enjoyable chat. A lot of these are my personal opinions and views about things. These may encourage other people to comment in a controversial way, or in agreement. That is one of the purposes of the Journal, to encourage discussion. It is what makes medicine and surgery so interesting, to have these opposing discussions and ideas. I think it is really important, and the Journal does that very well.

I completely agree. I want to thank you for taking the time for this interview. It has been a great visit, and one that I am sure the readership will enjoy reading as much as I have enjoyed doing.

Thanks very much, Dan.