A new randomized controlled trial is underway to determine whether a modified access route during clot removal improves long-term outcomes in patients with extensive lower-limb deep vein thrombosis.
The study is comparing two approaches to pharmacomechanical thrombectomy (PMT), a procedure that uses a catheter system to fragment and aspirate thrombus. Researchers are aiming to assess whether targeting clots in the distal popliteal vein through modified access improves vein patency and reduces the risk of post-thrombotic syndrome (PTS), a frequent and potentially disabling complication of deep vein thrombosis (DVT).
A total of 160 patients aged 18 to 80 years with newly diagnosed whole-limb DVT are being enrolled across nine hospitals. Participants are randomly assigned to receive PMT either via the traditional ipsilateral popliteal vein or a modified route using the contralateral femoral, jugular, or tibial veins.
The primary outcome is the incidence of PTS over 24 months, measured using the Villalta scale; secondary outcomes include immediate vein patency, procedure duration, thrombolytic dosage, valve function, need for additional procedures, and patient-reported quality of life. Validated tools, including the EQ-5D-5L and VEINES-QOL, are administered at multiple follow-up points.
The AngioJet system, used in all cases, applies high-pressure jets of saline or thrombolytic agents to disrupt and remove clot material. This method has been proposed as a faster alternative to catheter-directed thrombolysis (CDT), which requires longer infusion times and carries a higher risk of bleeding.
Although observational data have supported the use of PMT, earlier trials such as ATTRACT did not show a clear benefit over anticoagulation alone in reducing PTS. Investigators in this trial are aiming to evaluate whether outcomes improve when inflow thrombus is removed early in patients with extensive thrombus burden extending from the iliac to tibial segments.
All patients receive standard anticoagulation beginning with low–molecular-weight heparin followed by oral therapy for at least 6 months. Compression stockings are prescribed approximately 10 days after the procedure and worn daily for 24 months. CDT and stenting may be used if residual thrombus or stenosis remains post-thrombectomy.
Thrombus burden is assessed using venography before and after the procedure, and patients undergo duplex ultrasound at follow-up visits. Safety endpoints include bleeding, access site complications, and all-cause mortality.
The study’s sample size was calculated based on anticipated PTS rates of 38.2% in the traditional group and 16.7% in the modified group. Originally delayed by the COVID-19 pandemic, the trial is now actively enrolling.
Researchers expect the findings to clarify the role of modified venous access in improving the efficacy of thrombectomy for extensive DVT and to inform future treatment strategies aimed at reducing long-term complications.
The authors declared no competing interests.
Source: BMJ Open