Rethinking IVC Filter Thrombosis Diagnosis: How Stratified Ultrasound Guidance Reshapes Endovascular Practice.

OBJECTIVE

To develop and evaluate a precise, ultrasound-based stratification method for diagnosing thrombus within inferior vena cava (IVC) filters, aiming to optimize diagnostic accuracy and guide clinical decision-making regarding filter management.

METHODS

This single-center study, conducted at the Emergency Orthopedics and Trauma Center of Shanghai Sixth People's Hospital, enrolled 323 patients from June 2023 to June 2025 who had undergone IVC filter placement and were suspected of filter-related thrombosis. Thrombus presence and characteristics within and around the filter were assessed using conventional ultrasound (grayscale and color Doppler) and contrast-enhanced ultrasound (CEUS).

RESULTS

Based on the integrated ultrasound findings, patients were stratified into distinct management pathways: Class 0 (no thrombus) was detected in 258 cases, allowing for straightforward clinical planning. Class I/II thrombi (small, low-risk) were identified in 30 patients, enabling direct and successful filter retrieval. Class IIIa thrombi (larger, manageable) were found in 9 patients; CEUS guidance permitted careful intraoperative removal. The remaining 26 patients with Class IIIb thrombi (extensive, high-risk) received tailored treatments (eg, thrombolysis treatment, catheter placement) prior to subsequent filter removal. All filters were successfully retrieved, with surgical specimens confirming the ultrasound diagnoses.

CONCLUSIONS

A stratified diagnostic approach using conventional and CEUS provides a reliable, noninvasive means to assess IVC filter thrombi. This method streamlines the diagnostic process, avoids unnecessary CEUS in clear cases, and delivers critical information for precise clinical decision-making in complex scenarios. By facilitating appropriate and individualized management plans, this approach can potentially improve patient outcomes and optimize filter retrieval workflows in emergency and trauma settings.