Preclinical in vivo testing of a rotational mechanical thrombolytic device

PURPOSE: To establish the safety and efficacy of the Arrow Trerotola mechanical percutaneous thrombolytic device (PTD) for restoring patency of thrombosed hemodialysis grafts. MATERIALS AND METHODS: The hindlimb model of dialysis grafts was created in six dogs. Animals had either unilateral (n = 4) or bilateral (n = 2) polytetrafluoroethylene grafts, totaling eight grafts. Grafts were deliberately clotted 48 hours before thrombolysis. Thrombolysis was performed with five different versions of the PTD constructed of stainless steel (n = 12) or nitinol (n = 26) and rotated with use of a hand-held motor drive. After thrombolysis fistulography was performed. RESULTS: Thirty-eight procedures were performed with the PTD, with 100% success. Thirty-day patency, evaluated in a subset of 15 procedures, was 100%. Complications included a single arterial embolus (2.6%) and eight device breakages (21%, all but two with the stainless steel version); none had any clinical consequences. A final modification of the nitinol device yielded 11 consecutive procedures without further breakage. No residual thrombus occurred in any procedure. Pathologic examination showed no significant injury to the vessels or neointima. CONCLUSION: The PTD is highly effective for mechanical thrombolysis in an animal model of clotted dialysis grafts. Based on this animal model, the device appears safe in its final modified form.