Objectives The aim of this study was to seek expert consensus regarding the features that predict adverse outcomes in order to develop a dedicated angiographic classification system for femoropopliteal artery dissection. Background Dissection of the femoral and popliteal arteries is common after percutaneous angioplasty. Its classification is important. However, all current classification systems have significant limitations. Methods Delphi consensus methodology was performed over 3 rounds, using an expert panel of 17 interventionalists. Each was asked to rank dissection features with the potential to lead to acute technical failure and/or early restenosis and then which combination of features would require the placement of a metallic scaffold to avoid those outcomes. Results were used to develop a novel grading system and dissection treatment algorithm. Results Four main characteristics were identified from a comprehensive preliminary list. There was a good level of agreement between panelists from 773 responses (48 combinations). All panelists recommended scaffolding if a dissection produced a ≥50% diameter reduction (100%). Most recommended scaffolding if the dissection had a spiral shape (73%-100%), was severely flow limiting (93%-100%), or had complex morphology defined by long and multiple dissections (65%-100%). Multiple combinations of those features were more likely to receive a recommendation to scaffold. Conclusions Scaffolding of a postangioplasty dissection is recommended in the presence of significant diameter reduction, spiral shape, flow impairment, or adverse morphology (DISFORM). The DISFORM classification system has been developed as a tool to provide uniform language to standardize reporting and for discussion of dissection treatment and prognosis.
