E&M services within the 90 day global period in dialysis access creation and maturation: Part 2

Question: If a procedure is performed for creation of dialysis access and an unexpected need for an additional procedure is noted (venopasty of a flow limiting stricture, or branch ligation, for example) can a E&M service with supporting ultrasound be billed at the follow-up visit within the 90 global period when the patient is advised to have the second procedure? If so, would it be billed with 24 modifier or 57 modifier, or both?