>> THE VARIOUS SURGICAL OPTIONS FOR SINGLE VENTRICLE
DEPEND INITIALLY ON HOW MUCH BLOOD FLOW THERE IS TO
THE LUNGS, AND IS THERE OBSTRUCTION TO THE BODY.
>> THE STRATEGY FOR SINGLE VENTRICLE CAN REALLY BE
DISTILLED DOWN TO A PLUMBING PROBLEM.
>> THIS IS NOT AN OPERATION THAT CREATES A NORMAL HEART.
>> WE CAN'T FIX THE HEART.
>> WE CANNOT MAKE ANOTHER PUMPING CHAMBER.
>> WHAT WE DO SURGICALLY IS REARRANGE THINGS,
CLOSE HOLES, MAKE CONNECTIONS--
>> SO THAT YOU CAN HAVE BLOOD GOING TO THE LUNGS AND
BLOOD GOING TO THE BODY WITH ONLY ONE PUMPING CHAMBER.
>> BUT THAT ISN'T THE SAME AS A NORMAL HEART.
>> BY REROUTING THE PLUMBING,
WE NORMALIZE THE CIRCULATION.
>> AND THAT PROCEDURE THAT DOES THAT IS CALLED
THE FONTAN OPERATION.
>> AND THAT OPERATION IS COMMON AMONGST ALL
THE SINGLE-VENTRICLE PATIENTS.
WHAT IS DIFFERENT BETWEEN THESE VARIOUS CATEGORIES
IS WHAT IS DONE IN THE FIRST FEW DAYS OF LIFE.
>> IT REALLY BOILS DOWN TO HOW YOU'RE GOING TO GET
BLOOD FLOW IN AN UNOBSTRUCTED FASHION WITHOUT
ANY RESISTANCE TO EITHER THE BODY OR THE LUNGS.
>> IN CATEGORY 1, WHERE THERE'S OBSTRUCTION OF BLOOD
FLOW TO THE BODY, ONE WILL HAVE TO UNDERGO
A NORWOOD-TYPE OPERATION TO ALLOW FOR UNOBSTRUCTED BLOOD
FLOW TO THE BODY.
>> AND THE PRINCIPLES OF THAT OPERATION ARE TO
CONNECT EVERYTHING SO THAT THE ONE GOOD PUMPING CHAMBER
HAS TO PUMP TO THE BODY.
SO YOU HAVE TO CONNECT THE ARTERIES TO THE LUNGS
AND THE BODY IN SUCH A WAY THAT ALL OF THE BLOOD GOES
OUT TO THE BODY WITHOUT ANY OBSTRUCTION.
>> THE AORTA IS USUALLY TOO SMALL,
SO WE CORRECT THAT BY PUTTING A PATCH ON TO
ENLARGE IT.
>> AND THAT'S DONE BY CONNECTING THE PULMONARY
ARTERY, WHICH COMES FROM THE RIGHT VENTRICLE,
TO THE AORTA AND THEN USUALLY PUTTING A PATCH ON
TO FINISH THE CONNECTION OF THOSE TWO BLOOD VESSELS
AND ENLARGE THE AORTA.
>> IN ADDITION, YOU HAVE TO PREVENT BLOOD FROM BACKING
UP INSIDE THE LEFT SIDE OF THE HEART,
SO YOU HAVE TO CUT OUT THE PARTITION BETWEEN THE TWO
UPPER CHAMBERS OF THE HEART.
AND THEN THE THIRD PRINCIPLE OF THE NORWOOD OPERATION,
OR THE FIRST-STAGE OPERATION,
IS TO PROVIDE SOME RESTRICTED BLOOD FLOW
TO THE LUNGS.
>> WHAT WE CALL PULMONARY BLOOD FLOW,
AND WE DO THAT BY PLACING A SHUNT,
OR A SMALL TUBE, FROM ONE OF THE SYSTEMIC ARTERIES,
OR ARTERIES THAT GOES FROM THE HEART TO THE BODY,
TO THE PULMONARY ARTERY.
>> THAT IS ENOUGH FLOW THAT YOU CAN GET ENOUGH OXYGEN IN
THE BLOOD STREAM BUT NOT SO MUCH FLOW THAT YOU HAVE
RESISTANCE PROBLEMS, BECAUSE THAT RESISTANCE IS WHAT
PREVENTS YOU FROM DOING ANY FURTHER SURGERY.
>> IN OTHER FORMS OF SINGLE VENTRICLE,
SUCH AS TRICUSPID ATRESIA OR PULMONARY ATRESIA,
YOU HAVE BLOCKAGE OF BLOOD GOING TO THE LUNGS.
>> IF ONE FALLS TO THE CATEGORY IN WHICH THERE'S
OBSTRUCTIONAL BLOOD FLOW TO THE LUNG,
THEN ONE WILL NEED A SHUNT.
>> SO IF THE PULMONARY ARTERY IS TOO SMALL
OR DOESN'T FORM OR ONE OF THE VALVES THAT LEADS
TO THAT ARTERY DOESN'T FORM, THEN YOU NEED TO SUPPLY
BLOOD FLOW TO THE LUNGS.
AND WE USUALLY DO THAT THROUGH THE FORMATION
OF A SHUNT.
>> THE IDEA BEING TO CONTROL HOW MUCH BLOOD GOES
TO THE LUNGS BUT ALLOW BLOOD TO GET TO THE LUNGS
TO MIX IN THE HEART.
>> IN CATEGORY 3, IF NATURE HAS ALLOWED FOR SUCH,
IF THERE'S ADEQUATE BLOOD FLOW TO THE BODY
AND TO THE LUNG--
>> YOU MAY HAVE A SINGLE VENTRICLE WITH NO BLOCKAGE.
>> THERE ARE CHILDREN WHO HAVE A TYPE OF SINGLE
VENTRICLE WHERE THERE'S UNRESTRICTED BLOOD FLOW
TO THE LUNGS AND NO OBSTRUCTION TO THE BODY.
IN THAT SITUATION, IF YOU WERE JUST TO LEAVE THAT
AFTER BIRTH, THESE CHILDREN WOULD GET MORE AND MORE FLOW
TO THE LUNGS BECAUSE OF THE RESISTANCE DROPPING,
AND THEN THEY GO INTO HEART FAILURE.
AS THAT HAPPENS, THE BODY TRIES TO PROTECT ITSELF
BY CREATING A HIGH RESISTANCE IN THE LUNGS.
AND THAT, OF COURSE, IS THE WORST THING YOU CAN HAVE
FOR SINGLE VENTRICLE BECAUSE IT PREVENTS YOU FROM DOING
THE FINAL OPERATION, THE FONTAN OPERATION.
>> ONE THING THAT WE CAN OFFER TO INFANTS IS TO PUT
A BAND AROUND THE PULMONARY ARTERY WHICH IS JUST
A LIGATURE THAT IS PLACED AROUND THE PULMONARY ARTERY
AND THEN TIGHTENED DOWN AND ALLOWS,
THEN, RESTRICTION OF BLOOD GOING TO THE LUNGS SO THAT
BABIES GET ENOUGH BLOOD AND HAVE ADEQUATE OXYGENATION
BUT NOT SO MUCH THAT WE FLOOD THE LUNGS OR DAMAGE
THE LUNGS BECAUSE OF EXCESSIVE PULMONARY
BLOOD FLOW.
>> THE BANDING PROCEDURE TO LIMIT BLOOD FLOW
TO THE LUNGS IS A SURGICAL PROCEDURE.
ALTHOUGH PEOPLE HAVE STARTED DEVELOPING BANDS THAT
ARE ADJUSTABLE, THEY'RE STILL TYPICALLY PUT IN BY SURGERY.
>> THERE ARE SOME CHILDREN WHO HAVE WHAT IS BASICALLY
A PERFECT BALANCE BETWEEN THE ARTERIES TO THE LUNGS
AND THE ARTERIES TO THE BODY IN SUCH A WAY THAT THEY HAVE NO
OBSTRUCTION OF FLOW TO THE BODY,
BUT THEY'VE CONTROLLED HOW MUCH BLOOD GOES TO THE LUNGS
WITH SOME NARROWING AT SOME POINT
IN THE PULMONARY ARTERY.
>> AND THAT GROUP OF PATIENTS CAN ACTUALLY HAVE
THEIR FIRST HEART SURGERY WHEN THEY'RE OLDER,
USUALLY AROUND FOUR TO SIX MONTHS OF AGE.
>> HE PREDICTED THAT JOSEPH PROBABLY WOULD NOT NEED
THAT FIRST SURGERY.
>> BECAUSE OF HIS MAKEUP, THE BLOOD WAS ACTUALLY
MIXING VERY WELL, WHERE ACTUALLY HE DIDN'T HAVE
TO GO THROUGH THE FIRST-STAGE OPERATION.
>> THAT GROUP WILL STILL REQUIRE TWO HEART SURGERIES
TO GET THROUGH THE PATHWAY OF PALLIATION FOR SINGLE
VENTRICLE, BUT THEY'RE LUCKY.
THEY GET TO MISS THE NEONATAL PROCEDURE.
>> SO THEREFORE, THERE ARE EITHER TWO OR THREE
SURGERIES THAT ARE NECESSARY,
DEPENDING UPON THE CATEGORY THAT YOU FALL INTO.