Happy Topic Tuesday my friends! I hope you are all doing well this wonderful morning. For today’s post I wanted to share compare and contrast some different surgical approaches for the treatment of an acute Type A aortic dissection.
First a quick anatomy review - remember that type A aortic dissections are anything that involve the ascending aorta meaning the part that travels upward from the heart- it does not matter how far down the aorta the dissection involves for it to be considered a type A.
Note also- that the aorta has several important branches that come off at its arch supply the brain. These include the innominate artery which supplies the right arm and right side of the brain. The left common carotid which supplies the left side of the brain and the left subclavian which also supplies the left brain and left arm.
As you can imagine therefore, treatment of type A dissections will depend heavily on how far the diseases aortic tissue travels and whether or not these head vessels are involved.
The following is a great paper published by Dr. Dufendach and colleagues - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8078889/ It details some great details about different methods to repair an acute Type A aortic dissections with highly educational images:
Firstly, if a dissection only includes the ascending Aorta and stops before affecting the arch vessels that supply supply the brain, then a standard “hemi-arch” repair surgery can be done. This will involve resecting the diseased tissue up to the great vessels and replacing it with a carefully sized piece of Dacron graft. The big thing to remember about hemi-arch is that the arch vessels are left in tact here.
However, when patients develop more extensive dissections which travels up to the arch and includes the great vessels, total arch replacement is indicated. Here, the arch vessels can be disconnected from the aorta that is diseased and then reconnected to a branched graft system to exclude the diseased tissue. For total arch replacement, the body is cooled down to 18 degrees Celsius to decrease the risk of organ damage as blood supply from the aorta is cut off during repair.
Finally, for patients whose aortic dissections extends even beyond the arch and travels to the descending thoracic aorta, an elephant trunk technique may be used. Here, in addition to total arch replacement as described above, your surgeon may deploy a stented graft INSIDE the part of your aorta that travels downward behind the organs of the chest and abdomen and is difficult to otherwise reach and remove from the body. Note that this is different from the ascending aorta and arch where the diseased aorta was easily accessible and cut out. The use of an elephant trunk does two things:
Helps stabilize the dissected or dilated part of your distal aortic arch and descending aorta.
Helps facilitate a future secondary open or endovascular intervention to treat the rest of your aorta.
And that’s it for this week. I know that this topic may seem a little more advanced than what we usually discuss but I hope that seeing the images and slowly thinking about the anatomy comes in helpful. Please feel free to write any questions you have down below and let us know what topics you would like discussed in future blog posts!
Also, as a reminder for our friends near the Northeast. The annual Aortic Bridge walk will be happening Sunday September 15, 2024, 11 am Cadmen Plaza Park, Brooklyn, NY! More information can be found at http://www.aorticbridge.org/.
Until next time my friends. Stay happy. Stay healthy. Stay thinking aorta.
Adham
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