My husband had a Wallenberg Syndrome stroke last July.  One way they
diagnosed it was by doing an angiogram.  Not long after it was done,
he felt pain but was told it would go away.  One afternoon about two
weeks later he felt a big knot in his groin, his leg and foot felt
cold and it was paiful.  I took him back to the hospital where they
ran tests.  They said there was no blockage and
there was good blood flow.  However, since then he has continued to
have a cold leg and foot, the pain is worse, often more so when he
kneels and he is numb from about the calf down to his foot.  The
doctor said this condition was not caused by the stroke.  We are
convinced it was caused by the angiogram.  Any explanations,
suggestions, actions to take etc?

The appearance of a mass in the groin after an angiogram may be caused
by a hematoma (collection of blood leaking from the arterial puncture
site) or a pseudoaneurism (a leakage of blood from the aterial
puncture site contained within the wall of the artery).  Either one
can cause the symptoms mentioned by two mechanisms, compression of the
nearby femoral nerve, or by compression of the arterial lumen (worse
when the leg is bent at the hip as in squatting position).  Ask your
doctor to evaluate the lump in the groin with a sonogram to rule out a
femoral artery pseudoanuerism.
The mass in the groin is very likely the cause of your husbands
symptoms, and it needs to be evaluated whether or not it is related to
the angiogram (which it most likely is). A consult with vascular
surgeon might be the fastest way to get to the bottom of this problem.

Suggestions:  go to another doctor for an opinion, immediately.