Challenging treatment of in-stent restenosis in a coronary bifurcation by implantation of a bioresorbable scaffold under optical coherence tomography guidance

Abstract

A 67-year-old male patient with stable angina, hypertension and hypercholesterolemia who underwent bare metal stent (BMS) implantation in the distal right coronary artery (RCA) (Azule 3 × 9 mm) and everolimus-eluting stent (EES) implantation in the first diagonal branch (D1) (Xience 2.25 × 18 mm) and in the proximal circumflex branch (LCx) (Xience 3 × 28 mm). One year subsequent to the precedure the patient was readmitted for relapse of the angina Canadian Cardiovascular Society scale II, exhibiting a positive exercise test. The coronary angiography showed a distal-edge in-stent restenosis (ISR) in the distal RCA, extending to the posterior descending artery (PDA), Medina 110 bifurcation ( Fig. 1A). Optical coherence tomography (OCT) showed predominantly fibrolipidic restenotic tissue, with minimal lumen area (MLA) 1.95 mm 2 , minimal lumen diameter (MLD) 1.57 mm, proximal reference vessel diameter (RVD) 3.1 mm, distal RVD 2.75 mm and lesion length 21.2 mm (Fig. 1B, C).Optical coherence tomography-guided implantation of a bioresorbable scaffold (BRS) to treat the bifurcation ISR was performed through a radial approach, using a 6 french guiding-catheter. Guidewires were placed in the PDA and in the posterolateral artery (PLA), in order to protect the side branch in case of an eventual occlusion. Predilation 1:1 with a non-compliant (NC) balloon 3.0 × 18 mm (16 atm) was performed until the balloon was completely expanded in angiography. A second OCT run verified fragmentation of restenotic tissue and sufficient luminal gain to ensure adequate scaffold expansion. A poly-lactide BRS (ABSORB 3 × 28 mm) was then slowly deployed at 12 atm, holding pressure for 60 s. Proximaloptimalization-technique with an NC-balloon 3.25 × 15 mm (16 atm) was then performed by placing the proximal edge of the distal marker of the balloon at the carina of the PDA-PLA bifurcation, with an optimal angiographic result ( Fig. 1D). A final OCT pullback showed optimal apposition and expansion (MLA 5.3 mm 2 /MLD 2.6 mm; Fig. 1E), structural integrity of the device and clear access to the PLA side branch through the scaffold struts (Fig. 1F). Three-month follow-up documented an optimal clinical and angiographical result (Suppl. Video 1).Poly-lactide BRS are supposed to resorb completely [1-5], depending on the specific device and on patient/local conditions. The resorption restores vasomotion and eventually normal endothelial