LAUSR

Although numerous new technologically advanced peripheral endovascular devices have been developed over the past 2 decades, only a few novel endovascular techniques have been described that extend indications and/or optimize outcomes. The subintimal technique is one bright example of what can be achieved using basic endovascular devices. In the June 2017 issue of the JEVT, Soga et al report a novel technique developed to avoid one of the most severe intraprocedural complications of peripheral endovascular revascularization procedures, distal embolization (DE). Although distal microembolization (eg, macroscopically invisible debris) occurs in nearly all infra-aortic arterial procedures, the incidence of symptomatic, angiographically evident thromboembolic events (macroembolization) requiring further treatment ranges from 1.6% to 3% for femoropopliteal lesions and between 3% and 7% after iliac angioplasty. Moreover, distal macroembolization occurs more frequently during angioplasty of occlusive disease, while direct stenting without predilation has been reported to reduce its risk. Besides direct stenting used in an attempt to “cage” any possible large debris that could incite clinically meaningful DE, current prevention techniques include deployment of peripheral protection devices (arterial filters), more commonly used during femoropopliteal interventions. The reverse flow aspiration with proximal sheath blockage (ReFLAP) technique, an inexpensive maneuver for primary stenting of chronic total occlusions (CTOs), uses retrograde collateral flow following low-diameter lesion predilation as a natural protective barrier from DE, as antegrade flow is obstructed by the sheath introduced within the proximal segment of the occlusion. The technique requires only standard endovascular materials used in every peripheral procedure (ie, sheath, balloon catheter, self-expanding stent, and syringe) and can be applied during both iliac or femoropopliteal procedures. In their prospective, single-center, single-arm study of 90 consecutive patients, the authors reported a high technical success rate (105 of 110 lesions), with vessel tortuosity and severe calcification as the only reasons for failure to advance the sheath. The incidence of the primary endpoint (postoperative DE or no-reflow/slow-flow) was 0%, both in native and in-stent occlusions. Interestingly, in 7 cases in which a distal protection filter was used, no macroscopically evident debris was noted. On the other hand, aspirated material such as foamy debris, small particles, and marked clots was evident in 54%, and small particles or marked clots were detected in 38% of the patients. These outcomes highlight the efficacy of the method in retrieving macroscopically evident material that could presumably incite angiographically evident and/or clinically significant DE. However, the discrepancy between the high rates of aspirated macroscopically evident material and significantly lower reported rates of angiographically or clinically evident DE indicates that captured material would be clinically silent in the majority of the cases. Nonetheless, avoiding a “debris shower,” especially in cases of diabetic microarteriopathy and critical limb ischemia where even minor loss of small distal limb vessels could influence longterm limb salvage, should be considered and certainly merits 707694 JETXXX10.1177/1526602817707694Journal of Endovascular TherapySpiliopoulos and Shammas research-article2017