it sounds like your father had a femoral artery aneurysm
. An "Aneurysm" is a localized dilation of an artery, which can look like a bulge or a balloon on imaging studies like a CT scan
or angiogram. Aneurysms are more common in the brain, but they may happen also commonly large vessels such as the aorta
and femoral arteries. When these aneurysms grow, they are at an increased risk to pop and bleed, and when this happens there is usually no time to stop the bleeding as it is very brisk.
Hope that answered your question. Let me know if you have any further concerns.