When pre-authorizing abdominal aortogram with bilateral lower extremity run-off, code 75635 is used. However, no CT machine available, then surgeon intervenes with stenting, atherectomy, etc. How do we pre-authorize and get paid for intervention when we don't know ahead of time which method of intervention will be used? The hospital side is billing 75716 with intervention codes. The hospital is ONLY being paid for the 75716 and not for the intervention. We need to know how to get this correctly authorized so both the physician and the hospital are reimbursed properly. Any help is appreciated!!