Purpose:
Deep vein thrombosis (DVT) is a prevalent vascular condition that can lead to serious complications, including pulmonary embolism and post-thrombotic syndrome. Despite advances in endovascular therapies, the absence of a standardised method for evaluating venous recanalisation impedes consistent outcome reporting and inter-study comparisons. We developed the DVT Recanalisation Scale (DVT RS), integrating anatomical and functional criteria to provide a reproducible method for assessing recanalisation following endovascular treatment of DVT.

Material and methods:
This retrospective pilot study included 31 patients with predominantly iliofemoral DVT treated via catheter-directed thromboaspiration and other endovascular techniques. Recanalisation was assessed using phlebographic imaging acquired in multiple projections with compression manoeuvres. Four independent ope­rators (three interventional radiologists, one interventional angiologist) scored recanalisation using the DVT RS. The scale classifies recanalisation into five grades: Grade 0 (no recanalisation), Grade 1 (partial recanalisation without spontaneous flow), Grade 2A (flow with stenosis > 50%), Grade 2B (flow with residual stenosis < 50%), and Grade 3 (complete recanalisation with normal flow). A supplemental “(S)” suffix indicates use of stenting. Interobserver reliability was measured using Cohen’s k.

Results:
Interobserver agreement exceeded 90%, with Cohen’s k > 0.90 (p < 0.001), indicating excellent reproducibility based on phlebographic evaluation. While this analysis relied solely on phlebography, we recommend incorporating multimodal imaging – including intravascular ultrasound and Dyna-CT – for optimal assessment of residual stenosis and flow.

Conclusions:
The DVT RS is a reproducible and adaptable tool for standardising the assessment of venous recanalisation. It supports improved outcome reporting and facilitates robust comparisons between clinical endpoints and intravascular results. Prospective validation in larger cohorts is needed.