Hi,
I had angiogram in 1988 right before my first surgery (unfortunately!). Besides being an unpleasant and risky procedure, it also exposes a patient to large amounts of radiation. It was done partially because MRIs were not as precise as now, gadoinium contrast was not invented yet and ANs discovered then were huge and thus contained a lot of blood vessels in them. Now a plain MRI with contrast will give so much information to a neurosurgeon, that it makes angiogram expensive and unnecessary. In addition, there is MRA which is easier than angiogram but is also not done for ANs. I have been around asking for consultations for surgery No.2, but nobody now does angiogram. I have also heard it called "absurd".
I believe MeiMei and Nikki had Dr. Tamargo. They can tell you more about their experience. They do suffer from intractable headaches. Somebody who had them for 10 years after the first surgery, I can tell you that they are not the kind you can take an aspirin for and they absolutely ruin your life. If you plan to go with Dr. Tamargo, you would be well advised to ask him what he can do to prevent those headaches from happening.
Eve