The nitinol vascular occlusion plug: Preliminary experimental evaluation in peripheral veins

Abstract

PURPOSE: To compare the nitinol occlusion plug with standard stainless steel coils for the occlusion of moderate-size peripheral veins. MATERIALS AND METHODS: The nitinol plug is a braided multilayered vascular occlusion device filled with thrombogenic polyester fibers. It is self-expanding and can be recaptured into its 6-F introducing sheath for repositioning prior to detachment. Ten occlusion procedures were performed in five dogs from a retrograde transjugular venous approach. Five nitinol plugs (diameter: 7.4 mm ± 0.5) were deployed in five femoropopliteal veins (diameter: 6.5 mm ± 0.7; mean oversizing 14.6%). Two sequential Gianturco coils (diameter: 7.4 mm ± 0.9) were deployed in the corresponding contralateral veins (diameter: 6.2 mm ± 0.8; mean oversizing 19.6%). Follow-up venography was performed at 1 month, following which the animals were killed and the vessels were explanted. RESULTS: Time-to-occlusion was significantly shorter with the nitinol plug as compared to two Gianturco coils (4.2 minutes ± 3.4 vs 25.6 minutes ± 14.1, respectively [P ≤ .03]). At 1 month all but one coil- doublet (80%) had recanalized or migrated, compared to only one nitinol occluder (20%, P ≤ .04). Histopathologic examination of plug-occluded veins showed a uniform organized matrix and underlying intimal proliferative response. CONCLUSION: A single nitinol occluder resulted in significantly faster occlusion time and significantly lower recanalization or migration rate than two Gianturco coils, in moderate-size peripheral veins.