Fragmentation of pulmonary emboli: in vivo experimental evaluation of two high-speed rotating catheters

To test two over-the-wire systems for fragmentation of pulmonary emboli.

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.

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.

Embolus fragmentation led to a hemodynamic improvement. The impeller catheter was less traumatic compared with the thrombolizer, which was technically insufficient.