>> LOWER URINARY TRACT OBSTRUCTION, OR LUTO AS WE
MANY TIMES REFER TO IT, IS A OBSTRUCTION OF THE URETHRA,
THE TUBE THAT CONNECTS THE BLADDER TO THE OUTSIDE WORLD.
>> IT'S REALLY A ... ALMOST A MINOR ANATOMIC ABNORMALITY,
BUT THE CONSEQUENCES OF IT ARE PROFOUND.
>> IT IS A VERY RARE ANOMALY.
>> THAT ONLY OCCURS IN ABOUT 1 IN 5,000 TO 7,000 BIRTHS.
>> THEY ARE USUALLY FELT TO BE SPORADIC CONDITIONS WITH
NO INCREASED RECURRENCE RISK.
>> 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.
>> THE MORE SIGNIFICANT THE OBSTRUCTION AND THE EARLIER
THAT IT OCCURS, THE MORE PROFOUND THE EFFECTS ON THE FETUS.
>> IT'S IMPORTANT FOR THE FAMILIES TO REALLY
UNDERSTAND THE RELATIONSHIP BETWEEN URINE PRODUCTION
AND AMNIOTIC FLUID.
>> 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.
>> WE KNOW THAT AMNIOTIC FLUID IS VERY IMPORTANT NOT
ONLY FOR THE BABY TO MOVE PRENATALLY,
BUT THAT THEN PROMOTES LUNG DEVELOPMENT.
>> 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.
>> AND IF THE OLIGOHYDRAMNIOS IS THERE FOR
MANY, MANY WEEKS, THE LUNGS ARE EXTREMELY SMALL.
>> AND THEY NEVER DEVELOP THOSE SMALL BRANCHING AIRWAYS.
THEY NEVER DEVELOP THE NECESSARY NUMBER OF AIR SACS
TO SURVIVE.
>> 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.
WHEN YOU HAVE LUTO, IT'S CAUSING THE OBSTRUCTION
AND OBSTRUCTION LEADS TO INCREASE PRESSURE 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.
BACK PRESSURE PUT UPON THE KIDNEYS CAN IRREVERSIBLY
AFFECT THEM.
>> 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.
>> SO IF YOU HAVE OBSTRUCTION AT A CRITICAL
TIME POINT WITH THE KIDNEYS DEVELOPING,
THAT LEADS TO WHAT WE WOULD SAY RENAL DAMAGE.
>> 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.
>> 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.