Am I doing a post angio assessment correctly?

Hi All,
I'm new to this specialty, but also been awhile since I've had time to get back on Allnurses.com. good to see you all again. I write today because I am seeing more and more post angio cath pts on my medsurg/dialysis unit. My question to you all is this:

When a pt is brought to my unit for his/her post op 4-6 hr bedrest and assessments how should I be assessing the cath site for hematoma?
I have heard everything from keeping the sandbag on and vigorously massaging to prevent blood clots, to gently palpating to assure it's simple ecchymosis and not creating hematomas and/or bleeds to visually assessing to assure the pressure dressing remains C/D/I.

Lastly, is this assessment any different from a post angio cath vs a post stent placement? (stupid question?)

Sorry for all the mult questions, but my unit can't seem to answer me!!

Thanks!
Chloe