Absorb Bioresorbable Vascular Scaffold in Complex Coronary Bifurcation Interventions

Treatment of coronary bifurcation lesions is common in everyday practice and accounts for ≤20% of all percutaneous coronary interventions. The treatment of these lesions with drug-eluting stents, especially when a double-stent technique is used, remains challenging and is associated with a lower procedural success and a higher rate of long-term adverse cardiac events such as stent restenosis and thrombosis. Bioresorbable vascular scaffolds may offer potential advantages compared with metallic drug-eluting stents, aiming at restoring vessel patency without implanting a permanent prosthesis, which may be especially beneficial in bifurcation treatment. This new technology could theoretically eliminate the late and very late stent thrombosis observed after deployment of metal drug-eluting stents because, at some point, the physical material that could potentially provide a nidus for a stent-related thrombotic event completely disappears. The most widely studied bioresorbable stent, the Absorb Bioresorbable Vascular Scaffold (BVS; Abbott Vascular, Santa Clara, CA), has recently been introduced for the treatment of coronary artery disease, and data are now available supporting the use of this scaffold in type A stable coronary artery lesions and more recently also in calcified coronary lesions, acute coronary syndromes, and acute ST-segment– elevation myocardial infarctions. However, the Absorb BVS has yet to be evaluated in patients with true bifurcation lesions because of inherent limitations, such as bulky profile, limited expansion capacity, and length of time for complete reabsorption. More specifically, there are concerns that the integrity of the polymeric scaffold may be compromised, resulting in strut fractures and the BVS unraveling, by common techniques Background—Although bioresorbable scaffolds offer potential advantages compared with metallic drug-eluting stents in the treatment of complex coronary bifurcation lesions, there are concerns that the polymeric scaffold integrity may be compromised. This in vivo study sought to provide insights about the feasibility of performing complex bifurcation stenting with Absorb bioresorbable vascular scaffolds (Abbott Vascular, Santa Clara, CA). Methods and Results—Twenty New Zealand white rabbits underwent stenting of the nondiseased aortoiliac bifurcation with bioresorbable vascular scaffolds using provisional (PS, n=5), culotte (n=5), modified-T (n=5), or T-and protrusion (n=5) stenting techniques. Angiography, optical coherence tomography, and microcomputed tomography were performed. Angiographic results were excellent without evidence of dissection or side branch (SB) compromise. PS optimally opened the SB ostium without deforming the main vessel (MV) bioresorbable vascular scaffolds, avoiding malapposition, and revealing a single connector fracture in 1 of 5 cases on microcomputed tomography. Culotte stenting resulted in complete bifurcation coverage with extensive segments of double-layered struts and inappropriately apposed struts at the bifurcation level in 3 of 5 cases. On microcomputed tomography, there was MV and SB scaffold distortion at the bifurcation with single strut fractures in 4 of 5 and double fractures in 1 of 5. Modified-T and T-and protrusion resulted in complete bifurcation coverage and in minimal double-strut layers at the neocarina. On microcomputed tomography, no strut fractures were present after modified-T, whereas in 3 of 5 T-and protrusion procedures single strut fractures were noted. Conclusions—Bifurcation stenting using bioresorbable vascular scaffolds is feasible with excellent angiographic results. PS with additional T-and protrusion whenever needed seems a reasonable approach. Whenever a 2-stent technique is planned, modified T-stenting appears the most promising. (Circ Cardiovasc Interv. 2016;9:e003849. DOI: 10.1161/ CIRCINTERVENTIONS.116.003849.)