Backgrounds and Purpose—To develop a scoring system to facilitate case selection for carotid artery stenting based on anatomic features.

Methods—Twelve experts comprising a multinational and multispecialty panel were convened. Delphi consensus methodology was applied over 4 "rounds" involving emailed questionnaires, private decision-making, structured interaction and explicit aggregation. In round 1 panelists proposed individual anatomic features that were considered relevant during carotid artery stenting. In round 2 each criterion was scored from 1 (straightforward) to 9 (difficult). Round 3 involved removing some factors based on individual scores to reduce the number of subsequent combination anatomies. The final round involved scoring 96 combination anatomies (representing a "full factorial" design) plus a dichotomous response, ie, whether carotid artery stenting should or should not be advised for a "novice."

Results—There were 1164 responses, providing a score for 12 individual anatomic features and for 96 combinations anatomies with good level of agreement between panelists. After derivation of mean (and standard deviation) of the cutting scores for 1152 yes/no responses a scoring system for combination anatomy was produced, comprising broad agreement bands presented as traffic light colors: red for particularly difficult anatomy, amber for moderate difficulty and green for lesser difficulty.

Conclusion—A scoring system has been developed, based on objective expert consensus, which can be used to categorise expected difficulty of carotid artery stenting and aid case selection.