New non-invasive ultrasonic device for venous recanalization: assessment of feasibility and safety of thrombotripsy at 2.25 MHz in an in vitro model of recent venous thrombosis - 05/01/18
Résumé |
Objective |
Persistent occlusion following venous thrombosis is associated with an increased risk of post-thrombotic syndrome. Early venous recanalization may prevent this complication. Ultrasonic histotripsy fractionates soft tissue through a cavitation cloud generated by an external transducer. We aimed at testing this technique as a drug-free thrombolysis on recent in vitro clots.
Methods |
Venous thrombosis conditions were reproduced in vitro, using human blood clotting by stasis in silicone tubes (6 mm internal diameter, close to the femoral vein), in a 37°C water-bath, then mounted on a saline solution at a 25 mmHg constant pressure. The ultrasound device was composed of dual 2.25 MHz transducers centred by a 7-MHz linear probe. A single cavitation cloud was generated at a 3.2-cm depth from the device. Thrombotripsy was performed by longitudinal passages along of the whole thrombus at 3 pre-specified speeds (1; 2; 3 mm/s). Restored outflow was assessed every 3 passages.
Results |
24 occlusive successive thrombi of 2.5 cm mean's length were evaluated. Flow restoration was systematically obtained by the succession of 9 passages. An efficient flow restoration was carried out in 6 min maximum. Regardless from the device's speed, an average time of 76±17 s was necessary to obtain a 70% flow recovery (Fig. 1). A speed of 1 mm.s−1 allowed an efficient recanalization (80%±7%) after only 3 passages, corresponding to a treatment's duration of 1.5 min with the lowest variability. The cavitation drilled a circular channel of 1.7 mm mean diameter throughout the clot with a 1.5-mm thick residual thrombus coating the tube. Debris analysis found no debris>200 μm with 92% of debris<10 μm.
Conclusion |
Our dual transducers thrombotripsy device performed a fast recanalization of whole-blood thrombus without any parietal alteration or bulky debris formation. This new technology opens the field to a drug-free and non-invasive thrombolysis.
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Vol 10 - N° 1
P. 115 - janvier 2018 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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