Percutaneous thrombectomy of the acutely thrombosed dialysis graft: in vitro evaluation of four devices

Percutaneous recanalization of completely thrombosed hemodialysis grafts was simulated in a flow model. Thrombus removal was performed by 1) a Trac-Wright catheter; 2) an ultrasound-driven, oscillating probe aspiration thrombectomy (US-OAT) device; 3) an electric motor-driven oscillating probe aspiration thrombectomy (EM-OAT) device; and 4) a rotating spiral aspiration thrombectomy (RAT) device. All devices were able to restore a continuous lumen of the shunt model within 1-5 min, but residual layers of wall-adherent thrombi remained attached, particularly to the inner curvature of the shunt loop. Clot removal rate was 95% for the Trac-Wright catheter, 73% for the US-OAT device, 68% for the EM-OAT device (straight tip catheter), 88% for the EM-OAT device (angulated tip catheter), and 51% for the RAT device. Effluent particle rates for particles > 100 microns were 3.6% for the Trac-Wright catheter, 0.6% for US-OAT, and less than 0.1% for the other devices. Compared with the Trac-Wright catheter, the balance of clot-removing efficiency and creation of effluent particles favored the electric oscillating device with the angulated tip catheter, which had a slightly reduced, but still efficient, clot-removing capability and produced almost no effluent particles.