Lower urinary tract obstructions (LUTO) are rare anatomic defects. In this video series, experts from the Center for Fetal Diagnosis and Treatment and the Division of Urology at The Children’s Hospital of Philadelphia present a complete overview of the disorder — from diagnosis, through possible prenatal treatment, delivery, postnatal management and long-term follow-up care.
Tracey Partington, Mother: So the pregnancy had gone very well until Heath and I went in at our 20-week appointment.
Heath Partington, Father: We had gone in for this joyous … just trying to find out the sex of the baby … and we saw the picture of the giant black thing in the middle that was, that always caught your eye.
Tracey Partington, Mother: The black circle was his bladder that had been overfilled over some period of time due to a blockage in his urinary tract.
Heath Partington, Father: Our local doctors weren't aware of some of the things they can do. So it was a very sad day. We didn't know we had as many options as we did.
Tracey Partington, Mother: To think that one teeny, weenie, little, extra flap of skin or a not-quite-large-enough opening in a urethra can wreak so much havoc on a baby, on a pregnancy, on internal organs.
Mark P. Johnson, MD: When a family first learns about the diagnosis of lower urinary tract obstruction, they ... many times they're very confused and obviously have lots and lots and lots of questions.
N. Scott Adzick, MD: "Can something be done before birth to help the baby?" They've usually read things on the Internet. They may have gotten some information from the physicians who have referred them.
Michael C. Carr, MD: And they really, obviously need answers to what's going on and what ultimately can be done to help their fetus.
Stefanie Kasperski, MS: The Center for Fetal Diagnosis and Treatment offers unparalleled services for families with lower urinary tract obstruction.
Mark P. Johnson, MD: It's really our job to tell them not only what the diagnosis is, but explain all the different components, all of the changes that occur that result in injury to the kidneys, abnormal growth to the lungs, and try to put it in terms they can understand.
N. Scott Adzick, MD: And in highly selected circumstances, treat before birth and quite effectively.
Minor Abnormality: Major Consequences
Mark P. Johnson, MD: Lower urinary tract obstruction, or LUTO as we many times refer to it, is an obstruction of the urethra, the tube that connects the bladder to the outside world.
Michael C. Carr, MD: It's really a ... almost a minor anatomic abnormality, but the consequences of it are profound.
Stefanie Kasperski, MS: It is a very rare anomaly.
Mark P. Johnson, MD: That only occurs in about 1 in 5,000 to 7,000 births.
Stefanie Kasperski, MS: They are usually felt to be sporadic conditions with no increased recurrence risk.
Mark P. Johnson, MD: Obstructions to the urethra actually come in many different forms. There can be a flap of tissue in the urethra that is called posterior urethral valves and probably has to do with the development and completion of that simple tube that's the urethra. There can be a complete obstruction where the tube of the urethra just never connects and that's a urethral atresia. And then there's a really kind of unusual subpopulation of fetuses that have just a very constricted narrowing in the mid-portion of the urethra that just results in a very high-restricted ability for the urine to pass.
Michael C. Carr, MD: The more significant the obstruction and the earlier that it occurs, the more profound the effects on the fetus.
Mark P. Johnson, MD: It's important for the families to really understand the relationship between urine production and amniotic fluid.
N. Scott Adzick, MD: Most of the fluid around the human fetus is fetal urine. The fetus pees into the amniotic space and then gets rid of this fluid by swallowing it and it's absorbed and goes back to the mother so this is circulation going on.
Stefanie Kasperski, MS: We know that amniotic fluid is very important not only for the baby to move prenatally, but that then promotes lung development.
Mark P. Johnson, MD: With lower urinary tract obstruction, one of the problems is the baby is unable to maintain sufficient amniotic fluid volume, and as it ingests and digests the amniotic fluid, the volume of amniotic fluid drops. And at a certain point, the amount of amniotic fluid around the baby is so low that it can start to predispose to the complications of interfering with lung growth, and we refer to that very low amniotic fluid level as oligohydramnios.
N. Scott Adzick, MD: And if the oligohydramnios is there for many, many weeks, the lungs are extremely small.
Mark P. Johnson, MD: And they never develop those small branching airways. They never develop the necessary number of air sacs to survive.
Stefanie Kasperski, MS: So the absence of amniotic fluid will result in pulmonary hypoplasia or underdeveloped lungs, which is actually the cause of death in complete lower urinary tract obstruction.
Michael C. Carr, MD: When you have LUTO, it's causing the obstruction and obstruction leads to increase pressure.
Mark P. Johnson, MD: Because the pressure gets so high in the bladder as it's trying to empty itself, the urine that's produced in the kidney can't be pumped down through the ureters into the bladder.
Michael C. Carr, MD: Back pressure put upon the kidneys can irreversibly affect them.
Stefanie Kasperski, MS: The kidneys are basically the world's most productive recycling system where all the proteins and electrolytes that our bodies want to reabsorb, get reabsorbed and all the waste products get excreted.
Michael C. Carr, MD: So if you have obstruction at a critical time point with the kidneys developing, that leads to what we would say … renal damage.
Stefanie Kasperski, MS: Renal damage from long-standing obstruction means that the kidneys are not able to perform that recycling function and are essentially excreting all of the electrolytes and proteins into the urine.
Michael C. Carr, MD: These are conditions that, you know, a fetus is born with, or is developing with, and, you know, our goal is to try to make as normal as possible what, for some reason, wasn't developing normally.
Learning Your Baby Has LUTO
Stefanie Kasperski, MS: The diagnosis of lower urinary tract obstruction is typically made at the time of an ultrasound evaluation.
Michael C. Carr, MD: Normal prenatal ultrasound screening is generally done in the mid-second trimester.
Tracey Partington, Mother: Unlike a typical ultrasound where you see black, which is fluid around the baby, there was no fluid around the baby. All of the fluid was in his bladder and it was enormous.
Michael C. Carr, MD: Clearly, if there is something abnormal that's recognized with respect to the kidneys or the bladder, the sooner that we can see those families and the sooner that we can do imaging of that fetus, the better off we think that we are.
Stefanie Kasperski, MS: Prenatal diagnosis as well as evaluation of fetuses with LUTO really requires a multidisciplinary team of specialists.
N. Scott Adzick, MD: Our team, of course, has great expertise with the medical issues, but it goes way beyond that. It's sort of, we spin a huge safety net to deal with all the needs of the family.
Stefanie Kasperski, MS: That family receives support not only from a medical perspective, but also from a family perspective.
N. Scott Adzick, MD: We want the families to just be concerned with the medical issues and not all the other support-related sorts of issues.
Stefanie Kasperski, MS: The goal is to provide families with the information that's needed for that particular family to make an informed decision about their fetus and about their pregnancy, whether that be potential in utero treatment or whether that be letting nature take its course.
N. Scott Adzick, MD: When they come to see us, we do a comprehensive diagnostic evaluation.
Mark P. Johnson, MD: The key steps are to confirm that the baby is a male.
Stefanie Kasperski, MS: A lower urinary tract obstruction in the context of a female fetus typically reflects a cloacal abnormality, which is a much more complex anomaly that will actually not benefit from in utero intervention.
Mark P. Johnson, MD: It's important to confirm that there are no other major birth defects or abnormalities that would alter the survival or long-term outcome of that baby.
Stefanie Kasperski, MS: So fetal carrier typing — either through an amniocentesis or CVS — is very important to document normal fetal chromosomes. We also perform an ultrasound and an echocardiogram.
N. Scott Adzick, MD: To assess the urinary tract obstruction and to also make certain that there's nothing else wrong.
Mark P. Johnson, MD: We need to make sure there's no major cardiac anomalies or other organ systems involved, but we really, really have to look at the urinary tract carefully. We have to look at what does the bladder look like. Is it showing the characteristic thickening of the muscle walls? We have to look at what are the ureters doing. Are they dilated?
Michael C. Carr, MD: If you begin to see that the kidneys look, on ultrasound, whiter or brighter than is normal, that tends to suggest that there may be underlying abnormalities.
Mark P. Johnson, MD: The key thing we look for are the presence of cysts on the outer part of the kidney because a presence of cysts inevitably means that there's irreversible damage in the kidney and there is no way to salvage that kidney. Lastly, we need to study the renal function by serial urine samplings.
N. Scott Adzick, MD: A bladder tap, usually serial bladder taps, two, three times over days to assess the fetal urinary composition.
Mark P. Johnson, MD: We can take that urine and send it to the laboratory and look at different electrolytes and protein markers. The more stuff that's in the urine, the worse the function of the kidneys.
N. Scott Adzick, MD: In some cases, the kidneys are already destroyed and there's nothing we can do about it.
Mark P. Johnson, MD: But what we learned over the last decades is that you really have to drain the bladder more than once because the first time you drain the urine from the bladder, that represents urine that may have been there for days or weeks and is really, doesn't reflect the ability of the kidney to function.
Michael C. Carr, MD: And so if you get rid of that first amount of urine and also look to see how rapidly the bladder would refill with urine, that potentially could tell you that the kidneys were actually working OK, and if there was serial improvement in the electrolytes that would tend to be a good prognostic factor.
Tracey Partington, Mother: In order to be eligible for the shunt procedure, there still had to be good remaining kidney function at that time.
Mark P. Johnson, MD: The results of the ultrasound, the confirmation of normal carrier type, and the results of the urine testing will really determine whether or not that baby has a chance of benefitting from intervention or whether intervention won't help.
N. Scott Adzick, MD: There are some cases where we simply can't help, where the damage has already been done, where we're too late to do anything about it.
Stefanie Kasperski, MS: And in those cases, families might choose to take the pregnancy to term with potential palliative care, or families might choose to end the pregnancy.
N. Scott Adzick, MD: The family has the information that they need. They have the counseling they need. They have the support that they need. They know that they have done everything possible to try and give that baby the best possible chance.
Stefanie Kasperski, MS: Families look to us, look to our medical team and to our expertise at the Center for Fetal Diagnosis and Treatment to be able to guide them in terms of what this anomaly means for their fetus. Whether or not there are options for prenatal treatment and what the risks and benefits of those options are.
The Option of Prenatal Intervention
Mark P. Johnson, MD: The problem with urethral obstruction in LUTO is that the urine can't get out so the bladder fills and enlarges.
N. Scott Adzick, MD: If you could decompress that urinary tract, decompress the bladder, give the urine another route to get out into the amniotic fluid, then you could avert the problems with the lungs, avert pulmonary hypoplasia, and avert the renal damage.
Michael C. Carr, MD: And that's the whole genesis of considering shunting of the fluid or the urine that's in the bladder back into the amniotic space, reconstituting that so that ultimately lungs can develop normally.
N. Scott Adzick, MD: A shunt tube provides a passageway for the urine flow to go from the bladder, which was otherwise completely obstructed, out into the amniotic space. It allows the amniotic fluid to come back, it allows the lungs to develop, decreases the pressure on the developing kidneys, and hopefully preserves renal function.
Stefanie Kasperski, MS: In utero intervention does not mean a cure. It cannot reverse the renal damage that is already present.
Mark P. Johnson, MD: It's just a temporary treatment and the real work starts after birth.
Stefanie Kasperski, MS: The multidisciplinary consult takes place to really educate the families about both the risks and the benefits of in utero intervention.
Mark P. Johnson, MD: When we really go into great detail about the shunt procedure.
Heath Partington, Father: Here's what you can expect. Here's your percentages of this happening or the other thing happening.
Mark P. Johnson, MD: We talk about our experience with long-term survival and outcomes.
Heath Partington, Father: Is he immediately going to need a kidney transplant? Is his bladder going to work at all?
Mark P. Johnson, MD: And we also talk about the potential risks to the mother and to the fetus of this procedure because it is an invasive procedure.
Heath Partington, Father: That meeting, you know, it's one of those meetings, it's a decision point in your life which you'll remember forever.
N. Scott Adzick, MD: Choices are theirs and whatever families decide to do, whatever the mother decides to do, is carrying a baby with LUTO, that's going to be the right choice for her.
Fetal Shunting: A Closer Look
N. Scott Adzick, MD: With complete absence of fluid around the fetus, sonographic assessment is not as precise.
Mark P. Johnson, MD: Part of the procedure many times, is to expand the amniotic space and that's called an amnioinfusion, where we actually put fluid into the amniotic space to create enough of a fluid pocket to allow us to do this deployment of the shunt.
Heath Partington, Father: If you pictured a completely deflated football with your kid inside it and him trying to stick a needle into the football without hitting the kid inside.
Tracey Partington, Mother: Because the baby had his fists up here by his face, there was a little spot over, between his hand and his face where they could get that needle in. I think what amazed me most throughout the entire process was the amazing teamwork that took place between the ultrasound technician and the physician, whether for a bladder tap, or the infusion, or the actual shunt procedure.
Mark P. Johnson, MD: To place a shunt, we do that in the operating room.
Stefanie Kasperski, MS: In utero shunting is performed as an outpatient procedure in the SDU which is our Special Delivery Unit. Moms will arrive and will be prepped for the procedure and will receive anesthesia services.
Mark P. Johnson, MD: The patient gets sedation and is comfortable through their IV. We use local anesthesia so they're numb and they don't feel the procedure. The sedation that mother gets is transmitted across the placenta so the baby does get some of that sedation as well. We numb the skin and we make a tiny 5 millimeter incision through the skin and then we direct this needle — that will eventually be used for passing the shunt through the maternal abdomen — through the wall of the uterus, and into the fluid space immediately next to the fetal abdomen. Once the tip of the needle is in appropriate position between the pubic bone and the umbilical cord, then it has to be carefully inserted through the fetal abdomen and into the bladder. Once in the bladder, the bladder will start to leak fluid around the needle so you have to move swiftly, but you have to move very precisely. The shunt has to be loaded into that needle. The shunt itself comes in the double pigtail configuration.
N. Scott Adzick, MD: So there's a curlicue end on the outside of the abdominal wall and one on the inside of the bladder.
Mark P. Johnson, MD: It has to carefully be straightened out so it can be passed into the needle. It's a plastic that has memory and so it will recoil to its original configuration once you're outside the fetal abdomen. You now have to again pull the sheath back a bit, turn it at an angle away from the fetus, and then push the other pigtail out into the amniotic space. So the hope is that it will lie flat against the fetal abdomen.
After the shunt is placed, mom comes out to her room on the Special Delivery Unit where we watch her for, usually, about eight hours. She gets antibiotics before the procedure. She'll get an additional dose of antibiotics after the procedure. We usually have them return five to seven days after the shunt is placed to look at shunt placement.
N. Scott Adzick, MD: To make sure that the shunt is functioning, to make sure that the bladder is decompressed, making sure that the amniotic fluid volume is in the normal range so that the kidneys can develop and the lungs can develop.
Stefanie Kasperski, MS: Once the family has come back for a post-procedure check-up and there are no complications, we start discharge planning.
Monitoring the Pregnancy
N. Scott Adzick, MD: It's important to work closely with the referring physician group particularly if the family comes from far away and many of our patients come from around the U.S. or actually, around the world.
Mark P. Johnson, MD: They return home to their referring physicians. We usually give them a phone call and talk about any issues or concerns we have as well as send them [referring physicians] a detailed letter of things that we would recommend they look for.
Stefanie Kasperski, MS: As well as a referral to a pediatric urologist who would be able to evaluate that particular child postnatally.
Mark P. Johnson, MD: Subsequent ultrasound surveillance is really up to the discretion of the obstetrician — whether it's weekly or every other week — just to make sure the shunt is in place, it's functioning appropriately and the baby is maintaining amniotic fluid volume.
N. Scott Adzick, MD: Lots of things can occur, principally, technically, to the shunt.
Mark P. Johnson, MD: That shunt can migrate. It can migrate into the abdomen in which case now the urine empties into the abdomen, or it can migrate out into the amniotic space, or out of the bladder into the abdomen and it would no longer work. So the reason that you want to place that shunt as low in the bladder as you can, is because as that bladder collapses down with successful drainage, the shunt will stay in place and has a much, much lower risk for being displaced or becoming obstructed.
Michael C. Carr, MD: In some situations, you know, the fetus may grab the shunt and literally pull it out.
Michael C. Carr, MD: We found that shunt displacement occurs in about 40 percent of cases.
N. Scott Adzick, MD: And so communication between our group and that referring physician group is extremely important.
Delivery Options for LUTO
Mark P. Johnson, MD: Generally, these pregnancies are managed at home, but many patients will choose the option to come back and deliver in Philadelphia because of the depth of expertise with care of babies with anomalies.
Stefanie Kasperski, MS: The Special Delivery Unit here at The Children's Hospital of Philadelphia is really one of its kind in the country, as well as in the world.
N. Scott Adzick, MD: Only babies with birth defects are born there. Everything is built around the mother carrying a baby with a birth defect.
Mark P. Johnson, MD: Timing of delivery is based on a number of factors.
N. Scott Adzick, MD: We want the baby to stay inside the mom for as long as possible — to get as close to term as possible — because the last thing we want is a baby with comprised lung and kidney function to be born prematurely.
Mark P. Johnson, MD: These pregnancies tend to go into labor between 35 and 36 weeks.
N. Scott Adzick, MD: Unless there is a maternal indication for a cesarean section or that sort of thing, usually these babies can be born in the usual way, vaginally.
Mark P. Johnson, MD: Through the delivery process, there's pressure put on the chest to help clear fluid from the lungs, and it's much safer for the mother to have a vaginal delivery, and it's beneficial to the baby as well.
Stefanie Kasperski, MS: So the family is able to spend time with their child, but their child has access to all the multidisciplinary services that are needed to care for them.
Postnatal Surgical Repair
Mark P. Johnson, MD: Once these babies are born, there's really a transition of care to other multidisciplinary experts.
N. Scott Adzick, MD: Neonatologists are baby doctors who specialize in newborns who are sick and in premature babies. And it's important that the family get input from the neonatologists to figure out what they're up against when the baby is born.
Mark P. Johnson, MD: Do they need extra help with oxygenation, the issues of prematurity?
N. Scott Adzick, MD: A baby with small lungs who can survive, for instance, might be in the intensive care nursery for quite some time for respiratory support, ventilator support, things of that sort. The principal follow-up though, will be urologic and renal function based, and the urologist has a great breadth of expertise on all problems urologic with children.
Michael C. Carr, MD: We provide some perspective about what the family should expect in the short run and also long term.
Mark P. Johnson, MD: They need to do studies of kidney function. They need to do studies to look at the anatomical relationships of how do the ureters connect into the bladder. Is there going to be a problem of reflux that needs to be addressed?
Michael C. Carr, MD: Once the baby is born, one factor that really becomes important is to understand how the kidneys are working. And in order to do that, you're monitoring the urine output, and also that you're assessing what's called serum creatinine, which is a reflection of how the kidneys are working. And in addition, of course, we do imaging of the kidneys with ultrasound again, to see if things look different than they did even before the baby was born.
Mark P. Johnson, MD: Trying to figure out what's going on, will then allow them to counsel the family about treatment options.
Michael C. Carr, MD: The whole focus is on trying to establish drainage of the bladder and it really depends upon what it is that's causing the obstruction. In certain situations like valves, we have to somehow incise the valves, so rid that outlet obstruction that's present.
N. Scott Adzick, MD: It can be as simple as the baby undergoing cystoscopy through a scope, scope tube that goes through the urethra to where the valves are in fulguration or removal of that valve tissue so the baby can void normally, to a more complex arrangement where it's important to decompress the obstructive bladder through a vesicostomy, through a hole in the belly wall to which the bladder is sewn to allow urine to drain, and sometimes there can be quite complicated urologic reconstruction.
Michael C. Carr, MD: In terms of what one has to do with the urinary tract, a lot of that depends upon longer term follow-up to make sure that over time the dilation remains stable or gradually does show some improvement, and most importantly that the kidney function — that the renal function — maintains itself as well.
Hope and Health for the Future
Mark P. Johnson, MD: One of the key issues for families is, OK, if we have a successful shunt and we're able to drain the bladder in the urinary tract so that, you know, we get good lung growth for pulmonary function after birth, how do these kids do after they're born?
Michael C. Carr, MD: What was recognized in some of these boys that had valves is that they really didn't have the ability or the awareness that their bladder was full.
Mark P. Johnson, MD: Sixty percent of these kids that were treated in utero were able to spontaneously void on their own and the rest of them either required occasional use of the catheter to completely empty the bladder or they were catheter dependent.
Stefanie Kasperski, MS: Long-term outcome studies that we have done have shown that most of those children that were prenatally treated have acceptable renal function but, 30 percent also have progressed to renal transplant.
Mark P. Johnson, MD: These are children that don't have normal urinary tracts and will always be at risk of further kidney injury either because of reflux or because they're much, much more at risk and susceptible to infections.
Michael C. Carr, MD: There are changes that can occur over time that unless you're really tracking them and following them, you may not recognize which can then ultimately lead to damage to the kidneys.
Heath Partington, Father: He's at increased level of hurting his kidneys if he gets infections. He is on an antibiotic.
N. Scott Adzick, MD: These babies may require long-term follow-up for their kidney function. Usually respiratory issues are more black and white at the time of birth.
Mark P. Johnson, MD: Half of them have some type of respiratory symptoms long term, low incidence of asthma. Most of them have a higher frequency of reactive airway disease. So they get colds and upper respiratory infections more often and commonly than other kids.
Stefanie Kasperski, MS: While that certainly can be a challenging time, most families and most children will report to us that they're doing well and they're adjusting and dealing with the challenges of daily life.
Tracey Partington, Mother: Michael now is 18 months old. He is running, no longer walks, he just runs.
Heath Partington, Father: If you looked at him today, you wouldn't know on the surface that there's anything wrong with the kid. I mean, he eats like a tank.
Tracey Partington, Mother: He's just a crazy, high-energy boy. He's really independent, but continues to be very, very happy. So to have been able to go through this really critical situation and come out on the other side as healthy as he is, he's just so fortunate.
N. Scott Adzick, MD: We now have a whole cohort of what were unborn patients with a previously, completely fatal diagnosis who have been helped by what we and others have done before birth.
Stefanie Kasperski, MS: The natural history of lower urinary tract obstructions is quite diverse.
Michael C. Carr, MD: We continue to learn and now I think we have a much better perspective on things, understanding what happens in terms of how the kidneys are developing, what happens to the lungs.
N. Scott Adzick, MD: For lower urinary tract obstruction, we can select which fetuses will benefit and we can help them in most circumstances.
Stefanie Kasperski, MS: There are lower urinary tract obstructions that are associated with normal amniotic fluid volume, maybe due to an incomplete obstruction, and those at this point are not candidates for in utero intervention.
Mark P. Johnson, MD: So one of the studies that's presently underway, is to look at the natural history of the outcomes in these children that have obstructed uropathies but have normal amniotic fluid volume to determine whether there might be benefits for intervening in those cases as well.
N. Scott Adzick, MD: A clinical effort at the current time is to attempt before birth to directly treat posterior urethral valves.
Mark P. Johnson, MD: Fetal cystoscopy where we can actually look inside the bladder, try to identify the source of the obstruction and potentially treat it.
Michael C. Carr, MD: And then not have to leave a shunt in place afterwards.
Mark P. Johnson, MD: I think the future is bright for families with this disorder.
Stefanie Kasperski, MS: The families that the Center for Fetal Diagnosis and Treatment really serve as the inspiration for each and every one of us.
Mark P. Johnson, MD: That's what it's really all about. It's about the amazing families that teach us what we need to know to offer hope for future generations.
Topics Covered: Lower Urinary Tract Obstruction (LUTO)