Percutaneous Large Bore Venotomy and Tract Creation

Abstract

We used a pig model to evaluate the pathologic changes that occur during large caliber percutaneous venotomy and tract creation such as is necessary to deliver the Greenfield vena caval filter. Four sequential dilator and four angioplasty balloon tract creations were performed on eight external jugular veins in four adult pigs. Gross and microscopic evaluations of the veins and surrounding tissue followed the procedures. Morphometric measurements based on extent and severity of pathologic changes in the specimens were graded from 0 (normal) to 3 (severe and/or extensive). We found that while either technique entailed damage to the veins, the sequential dilator method produced substantially more smooth muscle stretching and tearing and disruption of the internal elastica. There also was greater perivascular and intramural hemorrhage. These changes extended as far distally as the catheters and sheaths were advanced. While the number of experimental samples is too small to allow valid statistical analysis, our results suggest that the angioplasty balloon technique may be superior for tract and venotomy creation. Furthermore, large sheaths should be advanced only enough to maintain venous access to limit the extent of potential venous damage.