hi Patrick196,
This is a great question. As an Interventional Radiologist studying this procedure and the effects on BPH, the anatomy to me is one of the most interesting aspects.
Most men have 1 or 2 prostatic arteries supplying the prostate per pelvic half. So for example, you may have 1 artery on the right and 2 on the left. These arteries may supply distinct portions of the prostate gland, namely the center of the gland versus the periphery of the gland. In rare cases, a pelvic half may have 3 arteries.
There is some thought that the Anterolateral Prostatic branch, which is the branch which supplies the central part of the prostate, is the ideal target for PAE. There is a Posterolateral Branch, which feeds the capsule of the prostate gland, and prostate tissue to a lesser extent. This is based on literature from Pisco and Bilhim, who are from the group in Portugal that has extensively studied the pelvic arterial anatomy.
Most Interventionalists performing PAE today will try to target both branches. If only one branch can be targeted, we ideally want to target the anterolateral branch to get to the center of the gland around the urethra, which is likely the cause of the BPH symptoms. The most important thing to understand about PAE is that the anatomy is extremely difficult due to the small size of the vessels, and at this point we don't really know exactly why men with BPH symptoms improve after PAE. So we don't know if we need to treat both branches, or just one, etc...
However, in most cases, the Anterolateral branch and Posterolateral branch usually arise from a common trunk. This means that if we can put a catheter into that common trunk, we can treat both branches, and the whole prostate, from that position. If the enlargement of the prostate is caused by continued hormone exposure, then blocking all of the branches would be important.
This is an extremely intersting question which we hope to answer by prospective trials. Like you mentioned, it's possible that if there is variabilty in which arteries we embolize, this is going to translate in variable results.
Thanks for the great question. Feel free to ask anything!
Regards,
Andre Uflacker, MD
University of Virginia, Interventional Radiology