Download - Presentation 2
Aortic arch surgery at the Austin
Two interesting cases in two weeks
Overwhelming at first
2 similar casesboth are young patients, from WA
prior dissecting Type A( ascending aorta) aneurism, repaired in WA
complicated-leak around the graft, pseudo-aneurysm formation along the aorta
otherwise stable
Their Aorta's( rougly)
Why travel from WA?
Experienced surgical, perfusion and
anesthesia team
3 different ways for open thoracic aorta
surgeryTotal deep circulatory arrest-can have bad neurological outcomes
Retrograde blood from (via SVC) to brain while while ascending aorta is open
Antegrade, uninterrupted blood supply to the brain throughout the surgery-very good outcomes
Initial setupInduction, very similar
to cardiac cases Pre medication with morphine, diazepam
Large peripheral iv line.
9 Mac swan-sheath, VIP Pa catheter with continuous cardiac output
4 lumen cvc
methlypredisolone at induction
3 Art lines to monitor circulation
to various parts of the body
Stages of the surgeryPut patient on bypass
Isolate the inominate, left common carotid, left subclavian in a sequential manner, connect them to a graft to supply the brain-antegrade perfusion
Hypothermia and circulatory arrest(for organs below the aortic arch) when aorta is opened
repair of aorta by EVITA graft
Putting patient on bypass
Slightly different from usual
Retrograde perfusion from arterial cannula in right femoral artery
Venous drainage from SVC
both are redo sternotomies-access to heart difficult
ONCE CPB IS ESTABLISHED
The heart is ejecting less blood, making the operating field more accessible
Body temp can be decreased for organ protection
Problems when flow is reversed in an abnormal aorta
flap can block flow
or blood can flow into the pseudoaneurysm
WHEN THAT HAPPENED
then all three art-lines lost their pressure readings and colour doppler of the aorta showed no flow into subclavian artery
decrease venous drainage into pump, allow heart to fill and eject blood normally
ventilate when heart ejecting blood to lungs
once heart started ejecting
centrifugal pump for ante grade
perfusion below arch
Establishing cerebral perfusion
The inominate, left subclavian and right brachiocephalic are ligated and attached to a graft in a sequential manner
Arterial supply to the brain via a side arm from the graft
Brain perfusion always maintained
The vessels are clamped and connected to the graft one at a time
There are numerous collaterals when each vessels is clamped
Once the graft is completely anastomosed, the main pump supplies 10ml/kg of blood to the brain
Graft
graft
Main pump supplying brain
OTHER MEASURES TO PROTECT THE BRAIN
AND DETECT ISCHEAMIA
Cerebral oximetry
another topic by itself....
hypothermia
Thiopenthone
Next.....
Aortic cross clamp in distal arch
Cardioplegia ( custodial) from venous cannula
deep hypothermia
then circulatory arrest below the arch
Followed by opening the aorta
Then actual repair
two devises were used-EVITA stent, and elephant trunk graft
EVITA stent
deployed by a guide wire placed earlier in the femoral artery
Can open up like an umbrella and form a watertight seal at the junction of the pseudoaneurysm
TOE used to confirm if femoral guidewire is in the the true lumen
Issues once aorta is repaired
rewarming 35 C for 20 mins
coming of bypass
dealing with coagulopathy associated with CPB and hypothermia
bleeding
BOTH PATIENTS HAD VERY GOOD POST OP
OUTCOMES