Aortic Arch Flashcards
Most common location and agents causing mycotic aneusrysms of Arch
- Lesser curvature of aortic arch or
- Opposite the visceral vessels in the abdomen.
typical organisms are
a. E.Coli, b. Salmonella c. Streptocci
“called myocotic because of grey, slimmy color”
List common vasculitis and aortitis
previous chest radiation for Hodgkins dsiease or breast malignancies (radiation induced vasculitis is associated with severe calcification and porcelain aorta) Takayasu Giant cell arteritis (Hortons disease) Polymyalgia rheumatic Behcet's Kawasaki Buerger's Logains Ankylosing spondylitis Reiters Rheumatoid arthritis
List brain protective features for all patients
Systemic Hypothermia (Temperatures can change...) Head packed with ice Mannitol in prime and after arrest EEG silence Alpha-stat pH control Magnesium sulfate Membrane oxygenator Closed circuit bag venous reservoir Routine cell saver device Co2 into the field
What is brain protection specific for retrograde perfusion
Superior vena cava cannula inserted
Snared below azygous vein
Flow rate at 300 to 500 ml/min
Pressure < 25-35mmHg to avoid cerebral edema
What is genetics behind Marfan
Autosomial dominant with variable penetrance occurs in 1 in 5000
mutations in Fibrillin 1 expression - on chromosme 15
more then 100 mutations have been identified
Describe genetics and features of Loeys-Dietz syndrome
Mutations in TGF beta receptors 1 and 2
Phenotype of Hypertelorism (wide spaced eyes) bifid uvula (cleft palate) generalized arterial tortuosity widespread vascular aneurysm
surgery receommended at 4 to 4.2cm cm
What are features and Genetics of Ehlers-Danlos
Heterogeneous connective tissue disorder that involve skin and joints and can cause hyperelasticity and fragility
Cardiac involvement (vascular) is an autosomial dominant inherited disorder of connective tissue resulting from mutation of COLA31 encoding type III collagen.
25% of patients less then 20 year old die
80% before the age of 40
facial features: thin, propensity to bleed, translucent skin
What is benefit of selective antegrade cerebral perfusion and Mild (28-30degrees) systemic hypothermic circulatory arrest for aortic replacement
ACP and mild systemic hypothermic circulatory arrest can safely be applied to complex aortic arch surgery up to 90 minutes
Unilateral ACP offers at least equal brain and visceral organ protection as bilateral ACP and maybe advantagous in that it reduces embolism arising from surgical manipulation on arch vessels.
Describe Crawford classification of TA
type I most or all of the descending thoracic aorta and upper abdominal aorta
type II most or all of the descending thoracic aorta and most or all of the abdominal aorta
type III distal or less of descending thoracic aorta and any involvement of abdominal aorta
type IV most or all of the abdominal aorta below the diaphragm
Where is the artery of Adamkiewicz
T8 to T12
List techniques to provide spinal protection to thoracic aortic surgery
Circulatory arrest Selective cooling of epidural or subarachnoid space Reimplantation of intercostals CSF drainage Perfusion of distal aorta -Left heart bypass - Gott Shunt
List surgical strategies for all type of descending thoracic aneurysms
Heparinzation of 1mg/kg
Permissive mild hypothermia (32 to 34 degrees nasopharyngeal)
Reattachment of segemental arteries (especially T7 to L2)
perfusion of renal arteries with 4 degree C crystalloid
sequential aortic clamping when possible
What additional stragetgies can be performed when dealing with Crawford type I or II
CSF drainage
Left heart bypass during proximal anastomosis
selective perfusion of celiac axis and superior mesenteric artery during intercostals and visceral anastomosis
How do you accomplish CSF drainage
18 guage catheter into the 2nd or 3rd lumbar space
intra-op pressure kept at 8 to 10 mmHg
Early post op keep pressure at 10 to 12 mmHg
12-15 mmHg when it is confirmed they can move their legs
Describe benefit and set up for left heart bypass
provides the greatest benefit and allows time for reimplantation of vessels
beneficial in pts with poor cardiac reserve because it offloads the left ventricle
Left atrium/Left inferior pulmonary vein to left femoral artery or distal descending aorta Bypass flows of 1500 to-2500 ml/min Allow heart to eject Monitor brain saturation Target a distal MAP of 55 to 65mmHg
