Laboratory Investigations[cmFragmentation of Pulmonary Emboli: In Vivo Experimental Evaluation of Two High-Speed Rotating Catheters

Purpose: To test two over-the-wire systems for fragmentation of pulmonary emboli. Methods: In 11 dogs, 22 embolic occlusions of lobar or central pulmonary arteries were performed by injection of preformed emboli through a jugular vein sheath. A commercially available device (thrombolizer) and a modified version of the impeller catheter were introduced via the femoral vein and positioned at the embolus site. Results: Catheter placement at the site of the emboli was possible. In more than half of the cases a hydrophilic or an extra-stiff guidewire was necessary. The thrombolizer did not rotate properly with its original pneumatic drive and required a major modification. When sufficient rotation was provided, both fragmentation catheters were able to clear the occluded main arteries. Side branches were partly obstructed by the resulting fragments. Recanalization led to a reduction of the emboli-induced elevation of the pulmonary arterial pressure by two-thirds. Histology of the recanalized pulmonary artery segments revealed localized (impeller catheter) and widespread (thrombolizer) periarterial hemorrhage. Conclusion: Embolus fragmentation led to a hemodynamic improvement. The impeller catheter was less traumatic compared with the thrombolizer, which was technically insufficient.