Circumferential evaluation of the neointima by optical coherence tomography after ABSORB bioresorbable vascular scaffold implantation: Can the scaffold cap the plaque?

ObjectiveTo quantify the circumferential healing process at 6 and 12 months following scaffold implantation.BackgroundThe healing process following stent implantation consists of tissue growing on the top of and in the space between each strut. With the ABSORB bioresorbable vascular scaffold (BVS), the outer circumference of the scaffold is detectable by optical coherence tomography (OCT), allowing a more accurate and complete evaluation of the intra-scaffold neointima.MethodsA total of 58 patients (59 lesions), who received an ABSORB BVS 1.1 implantation and a subsequent OCT investigation at 6 (n = 28 patients/lesions) or 12 (n = 30 patients with 31 lesions) months follow-up were included in the analysis. The thickness of the neointima was calculated circumferentially in the area between the abluminal side of the scaffold and the lumen by means of an automated detection algorithm. The symmetry of the neointima thickness in each cross section was evaluated as the ratio between minimum and maximum thickness.ResultsThe neointima area was not different between 6 and 12 months follow-up (1.57 ± 0.42 mm2 vs. 1.64 ± 0.77 mm2; p = 0.691). No difference was also found in the mean thickness of the neointima (median [IQR]) between the two follow-up time points (210 μm [180-260]) vs. 220 μm [150-260]; p = 0.904). However, the symmetry of the neointima thickness was higher at 12 than at 6 months follow-up (0.23 [0.13-0.28] vs. 0.16 [0.08-0.21], p = 0.019).ConclusionsA circumferential evaluation of the healing process following ABSORB implantation is feasible, showing the formation of a neointima layer, that resembles a thick fibrous cap, known for its contribution to plaque stability.

► The neointima after ABSORB implantation can be evaluated circumferentially by OCT. ► The neointima layer does not contain metal and resembles a thick fibrous cap. ► This “de novo” cap may be used to seal a thin-cap fibroatheroma.