Aortic dissection Flashcards
Layers of the aorta
Intima
Media
Adventitia
Most common site of tear in the intima
Right lateral area of ascending aorta
This is under the most stress from blood exiting the heart
Stanford system
Type A- ascending aorta, before the braciocephalic artery
Type B- descending aorta, after the left subclavian artery
DeBakery system
Type I- begins in ascending aorta and involves aortic arch
Type II- isolated to ascending aorta
Type IIIa- begins in descending aorta and only involves section above the diaphragm
Type IIIb- begins in descending aorta and involves aorta below diaphragm
Risk factors
Male sex
Smoking
HTN- most important risk factor
Poor diet
Raised cholesterol
Procedures or conditions that increase risk of dissection
Bicuspid aortic valve
Coarctation of the aorta
Aortic valve replacement
CABG
Turners and Noonans syndrome
Conditions that affect connective tissue so increase risk of dissection
Ehlers-Danlos Syndrome
Marfan’s Syndrome
Presentation
Ripping/ tearing chest pain
HTN
Difference in BP between the arms
Radial pulse in one arm decrease or absent
Diastolic murmur
Focal neurological deficit
Chest and abdo pain
Collapse
Hypotension as the dissection progresses
Diagnosis
ECG/ chest xray exclude other causes
CT angiogram initial investigations to confirm diagnosis
MRI angiogram provides greater detail but takes longer to get
Transoesophageal echocardiography for unstable patients too risk to take to CT scanner
Management
Surgical emergency
Analgesia e.g. morphine
BP and HR controlled- usually beta blockers
Type A surgical intervention
Open surgery to remove section of the aorta with the defect in the wall
Replace with synthetic graft
May need to replace aortic valve during procedure
Type B surgical intervention
Start with conservative management and bed rest
Reduce BP with IV labetalol
Thoracic endovascular aortic repair with catheter inserted via femoral artery
Insert stent graft into affected section of descending aorta
Complicated cases may require open surgery
Complications
MI
Stroke
Paraplegia
Cardiac tamponade
Aortic valve regurgitation
Death
X-ray finding
Widened mediastinum
