While the treatment of venous obstruction has seen significant advancements in recent years, there continues to be a lack of robust evidence or standardized best practices for venous specialists to follow. This has been particularly challenging for those managing lower extremity venous outflow obstruction in their patients.
To help establish protocols to enhance clinical outcomes and guide future research, Cook Medical brought together a coalition of physicians to participate in a Delphi consensus study. The Delphi technique leverages the collective opinion of expert panel members through a systematic, multi-round process. This method, which is particularly effective in areas with sparse research, provides a structured framework in which experts can reach an agreement.
The results were published online in the October 2023 edition of the European Journal of Vascular and Endovascular Surgery.
In this study, the Delphi process was executed over two rounds. Initially, six expert physicians from the US and Europe formulated 40 statements covering various aspects of venous obstruction management. In the second round, the statements were expanded to 80 and reviewed by a broader panel of 24 physicians. The statements were then distributed to a carefully chosen group of venous experts who met specific qualifying criteria.
Statements were rated on a 9-point Likert scale. Consensus was achieved when at least 70% of respondents rated a statement between 7 and 9 (agreement) or 1 and 3 (disagreement). Feedback from the first round was used to refine the statements for greater clarity in the second round.
Results of the consensus study
In the first round, 75 out of 110 experts (68%) responded, reaching consensus on 32 of the 40 statements (80%). In the second round, 91 out of 121 experts (75%) responded, with consensus achieved on 50 of the 80 statements (62.5%).
Key areas of consensus
- Imaging: 2 out of 3 statements (67%)
- Symptoms and baseline measures: 12 out of 24 statements (50%)
- Differential diagnosis: 2 out of 8 statements (25%)
- Treatment algorithm: 10 out of 17 statements (59%)
- Indications for stenting: 10 out of 10 statements (100%)
- Inflow and outflow assessment: 2 out of 2 statements (100%)
- Procedural outcomes: 2 out of 2 statements (100%)
- Post-procedure therapies and stent surveillance: 5 out of 7 statements (71%)
- Clinical success factors: 5 out of 7 statements (71%)
The consensus study highlighted considerable agreement on optimal management practices for lower extremity venous outflow obstruction. However, it also underscored areas where consensus was lacking, notably in the treatment algorithm section.
Areas requiring further research
- Treatment algorithms
- Procedural interventions
- Approach to treating deep versus superficial venous disease
- Post-intervention anticoagulation strategies
For physicians, the Delphi consensus study helps provide valuable insights into current expert recommendations and identifies areas where further evidence is needed. By adhering to the consensus guidelines and focusing on the highlighted areas for additional research, the medical community can work toward more effective and standardized treatments for venous obstructive disease.
“In the absence of robust clinical data, practicing physicians have been left to draw parallels to venous interventions from their prior arterial interventional experience,” said Dr. Lawrence “Rusty” Hofmann, professor of radiology at Stanford Medicine and senior author of the study.
“Unfortunately, from a fluid dynamics perspective, the venous system is a capacitance system, whereas the arterial system is a resistance system. So, there is not a one-to-one translation of patient selection nor techniques. Therefore, the consolidation of the world’s experts into a consensus document is an important step forward in guiding treating physicians on how to achieve the best outcomes for patients,” he said. “Through studies like this, we can better understand the complexities of venous outflow obstruction and improve patient outcomes by developing evidence-based best practices.”
According to Bruce Fleck, clinical programs manager for Cook Medical, this consensus study marks a significant step toward establishing best practices for treating venous outflow obstruction. “Achieving considerable agreement among a global group of experts affirmed much of what we thought were best practices for this patient population,” he said. “The areas lacking consensus highlight critical topics for future research and investigation.”
About the authors
The study was conducted by a diverse team of six authors, three from the US and three from the EU, representing the specialties of vascular surgery, interventional radiology, and interventional cardiology. Their combined expertise and collaborative effort were crucial in achieving the study’s goals.
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- Black SA, Gohel M, de Graaf R, et al. Management of lower extremity venous outflow obstruction: results of an international Delphi consensus. Eur J Vasc Endovasc Surg. 2024;67(2):341–350. E-pub 2023 Oct 4. doi:https://doi.org/10.1016/j.ejvs.2023.09.044