FD-OCT and IVUS intravascular imaging modalities in peripheral vasculature

Intra-Vascular Ultra-Sound (IVUS) and Frequency Domain-Optical Coherence Tomography (FD-OCT), in vivo, intra-vascular, imaging modalities, widely used in the field of coronary disease, have been recently implemented in peripheral endovascular procedures, for procedural assessment, plaque characterization and determination of predictors of treatment outcomes. Their unique characteristics have also been used in order to provide additional features and improve the performance of re-entry devices and atherotomes. Areas covered: Present review focuses on available literature regarding these two promising imaging technologies in the peripheral vasculature, highlighting the added value produced by their use in endovascular therapy, their limitations and their utilization in new endovascular devices. Authors also provide their future perspective and the possible benefits in understanding vascular behavior and lesion characterization in peripheral endovascular interventions. Expert commentary: By providing both quantitative but also qualitative data on vessel and lesion morphology, intravascular imaging modalities offer a valid solution for endovascular treatment evaluation and outcome presentation homogeneity.

Paclitaxel-coated balloons for failing peripheral bypass grafts: the BYPACS study

AIM

Aim of the present study was to report the imaging and clinical outcomes of a prospective single-center study investigating paclitaxel-coated balloons (PCB) for the treatment of failing peripheral bypass grafts (BYPACS study).

METHODS

In total, 32 patients had their failing peripheral native or synthetic bypass graft treated with PCB angioplasty (Group PCB). Basic inclusion criteria were any significant proximal or distal anastomotic stenosis confirmed by Duplex ultrasound (DUS; PSVR>2.5) associated with significantly reduced in-graft velocities (<45 cm/s) putting the graft at risk of thrombosis. Results were compared with a similar historical control group of 24 patients who had their failing peripheral bypass treated with plain uncoated balloon angioplasty (Group PTA). Primary endpoint was binary lesion restenosis defined as >50% stenosis of the treated lesion on DUS. Secondary endpoints included freedom from target lesion revascularization (TLR) defined as a patent peripheral bypass graft regardless of restenosis but without any repeat intervention (driven by reduced in-graft velocities <45 cm/s), major amputations and graft thrombosis. Multivariable Cox proportional hazards regression analysis was applied to adjust for confounding factors of heterogeneity. Results are reported as Cox-adjusted hazard ratios (HR and 95% CI).

RESULTS

Baseline variables were equally distributed between the two groups. Median follow-up was 7 months in group PCB and 8 months in group PTA. Rates of binary restenosis were similar between the 2 groups (HR=1.08, 95% CI=0.49-2.40; P=0.84). Freedom from TLR was also similar (HR=0.97, 95% CI=0.36-2.66; P=0.88). One amputation occurred in the PCB group and 2 in the PTA (P=0.58). Four events of bypass thrombosis occurred in each group (P=0.71).

CONCLUSION

PCB does not significantly inhibit restenosis or improve freedom from repeat angioplasty after treatment of failing peripheral arterial vein or synthetic bypass grafts.