Type A aortic dissection repair
An emergency operation to replace the torn ascending aorta before it ruptures or starves organs of blood.
Why it's done
- Stanford type A dissection involves the ascending aorta, wherever the tear started. It's a surgical emergency.
- Untreated, early mortality has classically been quoted as around 1–2% per hour in the first 48 hours, from rupture into the pericardium (tamponade), acute aortic regurgitation, coronary occlusion or stroke.
- Classic picture: sudden tearing chest pain going through to the back, a blood pressure difference between arms, a new early diastolic murmur. CT aortogram confirms it.
The steps
- Cannulate safely: Often through the axillary or femoral artery, because the ascending aorta is torn.
- Cool: The patient is cooled to protect the brain and organs.
- Circulatory arrest: Pump flow to the body is stopped so the arch can be opened. The brain is usually perfused selectively through the head vessels.
- Resect the tear: The torn segment is removed and the layers of the aortic wall are reinforced.
- Replace: A tube graft replaces the ascending aorta, often with the underside of the arch (hemiarch). The valve is resuspended, or the root replaced if it's involved.
- Extend if needed: In selected patients the arch and proximal descending aorta are treated too (frozen elephant trunk).
Risks
- Operative mortality is high, often quoted around 15–20%
- Stroke
- Kidney failure, gut or limb ischaemia from malperfusion
- Bleeding
- Later surgery on the remaining dissected aorta
Recovery
Longer ICU and hospital stays than elective surgery. Lifelong blood pressure control and regular CT surveillance of the rest of the aorta.
St George's Cardiothoracic Surgery Society, City St George's, University of London.