Achieving Optimal Outcomes in the Treatment of Venous Outflow Obstruction: An International Delphi Consensus

The endovascular treatment of venous obstructive disease has expanded significantly in recent years. However, best practices for optimal patient outcomes are not well established outside of the expert community and the evidence base is poor. The purpose of this study was to determine the level of consensus on statements regarding best practices. The study was conducted as a two round Delphi consensus. Statements for the first round were prepared by six expert physicians (round 1) and an expanded panel of 24 physicians (round 2) and sent to a preidentified group of venous experts who met qualifying criteria for each round. The statements were based on clinical scenarios covering the areas of imaging, clinical symptoms and baseline measures, differential diagnosis, treatment algorithm, indications for stenting, inflow/outflow assessment, successful procedural outcomes, postprocedure care and follow-up, and successful clinical outcomes. There were 39 and 80 statements in rounds 1 and 2, respectively. Respondent agreement was assessed using a 9-point Likert scale (agreed to disagreed) and a “cannot assess” option were used for each question. Consensus was defined as 70% respondents rating a statement 7 to 9 (signifying agreement) or 1 and 3 (signifying disagreement). The results of the first round were used to guide rewording and splitting compound statements for the greater clarity for the second round. The first round survey received a 68% response rate (75/110), and the second round received a 75% response rate (91/121). Respondents identified themselves as vascular surgeons (52.8%), interventional radiologists (33.0%), interventional cardiologists (8.8%), and other (5.5%) and represented the Americas (73.6%), Europe/Middle East (18.7%), and Asia Pacific (7.7%). Round 1 achieved consensus in 32/39 (82%) statements. Consensus was not reached in the treatment algorithm section. Round 2 achieved consensus in 50/80 (62.5%). The number of statements reaching consensus in the following areas were as follows: imaging (2/3 [66%]), clinical symptoms and baseline measures (12/24 [50%]), differential diagnosis (2/8 [25%]), treatment algorithm (10/17 [59%]), indications for stenting (10/10 [100%]), inflow/outflow assessment (2/2 [100%]), procedural outcomes (2/2 [100%]), postprocedure care (5/7 [71%]), and successful clinical outcomes (5/7 [71%]). This study demonstrated that while there are several areas where venous experts agree on the assessment and management of venous outflow obstruction, there are multiple domains where consensus was not achieved. This underlines that treating venous disease remains a controversial area and requires focused and coordinated research efforts across specialties to answer a number of unresolved clinical questions. The Delphi consensus has identified those areas in which these efforts should be focused.