Aortic dissection questions Flashcards
What is surgical management of acute AI complicating dissection
Complicated by AI 75% of time, valve repairable in 85% of cases
Options
aortic valve repair (commisural resuspension) ascending aorta tube graft
valved-conduit
stentless free sytle
aortic valve-sparing
What is definition of aortic dissection
acute event in which blood leaves the normal aortic channel through an intimal tear and rapidly dissects between the inner and outer layers of an aortic media to produce a false lumen
classified as acute < 14 days and chronic > 14 days
What is incidence and natural history of aortic dissection
0.5 to 3 per 100 000; 85% are undetected
Coronary involvement in 11%
AI is found in 75% ; the majority are type A
Survival of type A is 43% at 1 month; 39% at 1 year; 33 % at 5 years and 27% at 10 years
50% of patients with type A dissection dies are in first 48 hours
Describe malperfusion syndrome
End organ ischemia due to compromise of the lumen of a branch artery by compression due to a false lumen, shearing off, or thrombosis. a. renal 25-75% b. limb 25-60% c mesenteric 10 to 20 % d. coronary e. spinal/cerebral
What is operative and long term survival post dissection
Acute type A operative mortality is 20%
Survival is 55-75% at 5 years; 30 to 65% at 10 year
What are treatment options of 28 year old male with trauma and transected aorta
Open repair via thoractomy with tube graft or end to end is gold standard approach
Endovascular stent grafting is more common and likely becoming the gold standard
What are advantages to endovascular stenting of traumatic aortic injury
Avoidance of thoracotomy No aortic cross clamping shorter hospital stay Shorter length of intubation lower incidence of spinal cord ischemia lower peioroperative morbiditiy and mortality less need for systemic heparinazation shorter length of ICU stay.
Describe 3 possible approaches to addressing the aortic valve at the time of dissection repair
1) Resuspension of the aortic valve commisures to the aortic wall before replacing the ascending aorta
2) valve sparing aortic root replacement with attachement of the valve inside the aortic graft and reimplantation of the coronary ostia
3) aortic root replacement with a mechanical composite graft or stentless porcine aortic root bioproshesis and reimplntation of the coronary ostia
Post type A aortic dissection repair
1) What do you do about the persistent flow in the false lumen
2) 2 months later patient develops left leg weakness and loss of sensation without signs any signs of ischemia?
3) An angiogram is done for the problem above and shows that false lumen is smaller? fewer lumbars and that the left renal artery is poorly visible?
1) No further operation on the aorta is needed: Accept the presence of persistent flow
2) spinal ischemia (loss of flow in the lateral part of the spine that is perfused via the false lumen. as the false lumen closes)
3) fenestration of the abdominal aorta (including origin of the left renal artery. could
58 year old man with medically treated type B dissection.
What is risk of developing an aortic aneurysm
What kind of follow up would you suggest
What are the indications for surgical repair in chronic dissection
1) 25% of the patient will develop an aortic dilation at 5 years. The risk increases to 45% if blood pressure is not controlled.
2) CT scan and MRI at discharge and 3 month, and then 6 months if aortic changes or Marfan every 12 months
How do you manage the distal anastomosis of an aortic dissection
Distal anastomosis has to be fashioned so that both true and false lumina are perfused if anastomosis is at the level of the distal dissection.
A wedge is performed in the septum which is then secure with sutures. If an anastomosis is beyond dissection or there is no flow to false lumen then a standard anastomosis is performed.
What surgical technique for coarctation is prone to aneursym repair.
What are 4 strategies that can be employed to reduce risk
1) lateral patch aortoplasty with dacron (or gortex) commonly used for coarctation repair predisposes to development of aneurysms oppose the patch
2) distal perfusion via femoral vein (or pulmonary artery)
distal perfusion via left atrium
distal perfusion via Gott shunt (ascending aorta to femoral artery)
use of cardiopulmonary bypass and profound hypothermic circulatory arrest
What is the main pathologic features and pathogeneis of IMH
Hemorrhage into the aortic media without an intimal tear.
Possible related to rupture of the vasa vasorum
What is natural history of IMH and what is recommended surgical treatment
About 1/3 with ascending aortic IMH progress to classic aortic dissection with intimal disruption, propagation of the dissection pane and risk of rupture or branch vessel compromise
Surgical approach is the same as for acute ascending aortic dissection with emergent dacron graft replacement of ascending aorta.
List 5 indications for early surgical intervention for type B dissection
Contained aortic rupture (hemothorax/hemomediastinum) uncontrolled hypertension uncontrolled pain branch vessel compromise aneurysmal expansion (> 5cm) Malperfusion
