Orthostatic hypotension after surgery

[Wally10]

My dad had trans labyrinth approach to remove acoustic schwarnoma.  A couple weeks after surgery he had a partial fat graft failure and wound dehiscence.  We got through that and now he has severe orthostatic hypotension one month after surgery. He has to take meds to keep his blood pressure up to be able to stand for 10 minutes at a time and suffers constant dizzines.  Been hospitalized 3x for syncope with loss of consciousness after surgery.  The surgery has ruined his life and he completely regrets it.  Has anyone else suffered orthostatic BP after surgery or graft failure?