Point-of-care ultrasound in outpatient hematology clinic: A quick approach to evaluating deep vein thrombosis, venous reflux, and their implications for post-thrombotic syndrome Free

Background: Venous thromboembolism (VTE) is a prevalent condition frequently managed by hematologists. Lower extremity (LE) deep vein thrombosis (DVT), the most common form of VTE, is associated with serious complications, including risk of embolization, psychological distress with anxiety, and the long-term sequalae of post-thrombotic syndrome (PTS). Despite its clinical impact, PTS remains largely a subjective diagnosis, often using the Villalta scale, which lacks specificity due to overlap of findings and symptoms with other conditions. Point-of-care ultrasound (POCUS) is a widely used diagnostic tool across various medical disciplines, offering real-time, non-invasive assessments. To our knowledge, it has not been integrated into hematology clinics to evaluate DVT and venous reflux (VR) - two key contributors to PTS development.

Aims: We explored whether incorporating POCUS into the hematology clinic would be beneficial to assess LE DVT and VR status, examine their correlation with PTS as diagnosed by the Villalta Scale, and evaluate the utility of POCUS in informing PTS risk assessment and management. We also evaluated the impact of real-time POCUS evaluation on DVT-related anxiety and patient satisfaction.

Methods: Between 11/2024-06/2025, 101 patients with a history of DVT involving 125 LEs, were enrolled prospectively. Eligible patients were adults with a confirmed LE DVT history who were able to complete patient-reported outcome (PRO) questionnaires independently. Demographic data and VTE history were collected. Three-point compression ultrasound protocol was performed by trained hematology fellows to assess for DVT and VR (defined as retrograde venous flow of ≥1 second) in affected and unaffected extremities. The common femoral, femoral and popliteal veins were evaluated. PTS was diagnosed and graded using the Villalta scale. PROs included the PROMIS Anxiety Short Form, administered before and after POCUS to assess DVT-related anxiety, and the Short Assessment of Patient Satisfaction (SAPS) questionnaire was completed at the end of the visit. All patients provided written informed consent. The study was approved by the ethics committee.

Results: The median age was 62.5 years (range 18-90), with 85% over age 45. Most patients were male and White (64.4%), with a mean BMI of 29.8 kg/m². Among 101 patients, 44.6% had a history of pulmonary embolism and 20.8% had known thrombophilia (mostly heterozygous Factor V Leiden). Of the 125 LEs assessed, 75.2% had chronic DVT.

POCUS identified persistent DVT in 64% of LEs and VR in 48.8%. Extremities with DVT were three times more likely to have VR compared to those without (OR=3.26; 95% CI: 1.49-7.13). PTS was diagnosed in 61.6% of LEs (~60% mild, ~23% moderate, and ~17% severe). Moderate-to-severe PTS was present in ~45% of extremities with both, persistent DVT and VR. Although the odds for PTS appeared higher when persistent DVT, VR, or both were detected, these associations were not statistically significant. Among LEs with PTS, 80% had persistent DVT, VR, or both; whereas 20% had neither. In this group, most cases met PTS criteria predominantly based on Villalta scale symptoms rather than clinical findings. Conversely, ~67% of LEs without PTS still exhibited abnormalities on POCUS.

Following POCUS, 60.4% of patients reported reduced DVT-related anxiety, with an overall mean reduction of 6.3 points in the PROMIS Anxiety score - a statistically significant improvement. Additionally, 98% reported being satisfied or very satisfied with their care, despite the added time of ~9 minutes per extremity to the clinic visit.

Conclusions: Vein evaluation with POCUS and real-time visualization of LE DVT and VR results was quick, well accepted by patients, reducing DVT-related anxiety significantly. Persistent DVT was associated with a higher risk of VR, and both were frequently, but not always observed in cases of PTS (by Villalta scale). Importantly, some patients with PTS had no abnormalities on POCUS, while others without PTS demonstrated venous pathology, establishing a discordance between symptoms-based and objective assessment. Therefore, POCUS seems valuable to solidify the clinical diagnosis of PTS, identify at-risk patients, and enhance patient experience and engagement. Larger longitudinal studies are needed to validate these findings and assess the utility of POCUS-guided management strategy.