Author + information
- Hiroyoshi Kawamoto, MD,
- Neil Ruparelia, MBBS, DPhil,
- Tadashi Miyazaki, MD,
- Katsumasa Sato, MD,
- Azeem Latib, MD and
- Antonio Colombo, MD∗ ()
- ↵∗EMO-GVM Centro Cuore Columbus, 48 Via M. Buonarroti, Milan 20145, Italy
A 62-year-old man presenting with stable angina underwent coronary angiography demonstrating critical diffuse disease of the right coronary artery. Four sequential Absorb bioresorbable scaffolds (BRS) (Abbott Vascular, Santa Clara, California) were implanted from distal to proximal lesions in the right coronary artery following pre-dilation. This was followed by post-dilation with a 3.5-mm noncompliant balloon (20 atm) proximally and a 3.0-mm noncompliant balloon (18 atm) distally. Although angiography following post-dilation demonstrated an acceptable result, optical coherence tomography (Ilumien Optis, St. Jude Medical, St. Paul, Minnesota) clearly revealed longitudinal deformation and strut disruption of the BRS at the ostium of the right coronary artery (Figures 1A to 1D). Due to the fragility of the device and the risk of strut fracture, the current recommendation is that the Absorb BRS should only be post-dilated to a maximum of 0.5 mm greater than its scaffold diameter, which we adhered to by post-dilating the scaffold with a 3.5-mm noncompliant balloon to 20 atm proximally. The disrupted stent struts visualized by optical coherence tomography were within the vessel lumen (Figures 1A to 1D, blue arrows), and we therefore do not believe that this was a consequence of the post-dilation but rather was caused by abutting of the proximal edge of the BRS by the guiding catheter during the procedure with resultant loss of the structural integrity of the scaffold. In view of this finding, a metallic drug-eluting stent (DES) (Cre8 φ3.5 × 12 mm, Alvimedica/CID, Saluggia, Italy) was implanted at the ostium covering the disrupted BRS struts. The final optical coherence tomography images confirmed an acceptable luminal area with optimal strut apposition.
Although the radial strength of BRS in vivo has been reported to be comparable to cobalt-chromium DES (1), recent bench tests have shown that BRS have less radial strength than do metallic stents (2). However, the longitudinal fragility and integrity of current BRS remain uncertain. On the basis of in vitro testing of DES, those with 2 connectors between hoops have less longitudinal strength than do those with 3 connectors (3). In spite of the fact that Absorb BRS has 3 connectors between hoops, current BRS may be more fragile than metallic DES and is likely a result of the material itself. Furthermore, these BRS deformations cannot be visible by angiography unlike the metallic DES. This case highlights a potential limitation of this device when implanted to treat ostial lesions.
Please note: Dr. Latib has served on the advisory board of Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Onuma Y.,
- Serruys P.W.,
- Gomez J.,
- et al.,
- for the ABSORB Cohort A and B Investigators