"waiting times for a follow up appointment"

I had a stent fitting procedure in the carotid artery in my head in august/september of 2012 (this was the third in 6 years). Procedure was pain free and I recovered well but my follow up appointment has been cancelled twice and my new appointment has been moved to April. I have been left wondering if the procedure was successful. I am not sure if I should be on aspirin as well as my regular blood thinning medication and it is virtually impossible to get anyone on the phone.

I realise people are busy but a simple phone call or a letter would ease the worry

Is it too much to ask!