Delphi Consensus Study Toward a Comprehensive Classification System for Angioplasty-Induced Femoropopliteal Dissection: The DISFORM Study.

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.