Address for correspondence:
Gianluca Caiazzo MD PhD
Cardiology Unit
Ospedale San Giuseppe Moscati
Aversa
Italy
gianluca.caiazzo@gmail.com
Tel and fax: +390815001743
Case history : a 54 years old lady, active smoker with
hypertension and hyperlipidemia, presented at our ED with atypical chest
pain. EKG was unremarkable while echocardiogram showed mild inferior
hypokinesia with normal LVEF (55%). Positive biomarkers for myocardial
damage were found. After obtaining written informed consent, the patient
underwent coronary angiography the same day of admission. A significant
stenosis of the mid-right coronary artery (RCA) was found (Figure 1).
Since the patient was young, the interventional plan was to implant a
sirolimus-eluting bioresorbable magnesium scaffold on the mid-RCA via
right radial artery access with OCT guidance. A 6 French Amplatz Left 1
guiding catheter was positioned at the RCA ostium and two workhorse
coronary wires were passed through the lesion for higher support.
Predilation with a 2.5 x 15 mm semi-compliant balloon at 12 atm was
performed. OCT pullback showed a long significant stenosis with a
balloon-induced dissection in the distal part of the lesion (mean vessel
diameter 2.86 mm), an eccentric calcific plaque in the mid-segment and a
normal vessel in the proximal landing zone (mean vessel diameter 3.38
mm) (Figure 2). Further 1:1 balloon/artery ratio pre-dilation was
performed with a 3.0 x 15 mm non-compliant balloon at 12 atm. After
checking for good expansion of the 3.0 mm balloon in two orthogonal
views, a 3.0 x 25 mm sirolimus-eluting bioresorbable magnesium scaffold
was implanted at 12 atm. Post-dilation with a 3.5 x 12 mm non-compliant
balloon was performed at 18 atm (Figures 3 and 4). OCT evaluation
revealed the extension of significant dissection (>300 μm)
at distal edge (Figure 5). For this reason, the advancement of a second
BRS was attempted, in order to cover the distal edge dissection. After
two attempts, dislocation of the BRS from its delivery system occurred,
with the BRS lying into the proximal segment of the coronary artery,
proximally to the previously implanted scaffold (Figure 6). At this
point, a thin-struts 3.5 x 26 mm drug-eluting stent (DES) was passed
through the lost BRS in the proximal RCA and, after checking for
sufficient overlapping with the first BRS implanted, the DES was
deployed at 14 atm (Figure 7). The decision to deploy a DES (3.5 mm)
within the dislocated BRS, instead of a expanding a balloon, was
dictated by three main reasons: it was highly probable that the lost BRS
might have reported some injury during its dislodgement (the
dislodgement occurred pulling back the scaffold into the guiding
catheter) which was not reassuring in terms of predictable outcomes; the
dislocated BRS was a 3.0 mm scaffold, smaller than the vessel size in
that segment; the dislocated BRS was not in overlap with the previously
implanted scaffold. The distal edge dissection was then covered with a
second 3.0 x 18 mm DES deployed at 14 atm (Figure 7). An OCT pullback
was performed confirming good stents and scaffold apposition, short
overlap between the BRS and the two DES, and presence of the lost BRS
fully expanded and embedded into the vessel wall completely covered by
the proximal DES struts (Figure 8). A final good result was obtained
with a TIMI 3 flow (Figure 7). The patient was discharged after
uneventful hospital stay two days later.
Follow-up : at 9-months angiographic follow-up the coronary
artery looked good with TIMI 3 flow and absence of stent/scaffold
restenosis (Figure 9). OCT analysis showed optimal stent apposition in
the distal segment with no neo-intimal hyperplasia, advanced
reabsorption process of the BRS in the mid-segment with black boxes
still visible and good stent apposition in the proximal part with some
non-significant acquired malapposition probably due to the dislocated
BRS reabsorption between the vessel wall and the DES metallic struts
(Figure 10).
Discussion : The rationale for using BRS during PCI are numerous
since they provide temporary structural support to the vessel while
eluting an anti-proliferative drug, and can be reabsorbed in a
time-predictable fashion (1). The first BRS introduced in the market,
the Absorb BVS, have shown, after initial positive results (2), higher
scaffold thrombosis rates when compared to last-generation drug-eluting
stents (3). Notwithstanding a limited clinical evidence available to
date, magnesium-based BRS represent an interesting novelty in this
field, promising higher radial force than PLLA-based BRS. Our case shows
a good angiographic and OCT mid-term result after magnesium BRS
implantation although a procedural complication occurred. OCT provided
precious information for complication management and interpretation.
Author Contribution:
Gianluca Caiazzo conceived and wrote the manuscript draft.
Mario De Michele have been involved in drafting the manuscript and
revising it critically for important intellectual content.
Luca Golino have been involved in drafting the manuscript and revising
it critically for important intellectual content.
Vincenzo Manganiello have been involved in drafting the manuscript and
revising it critically for important intellectual content.
Luciano Fattore have been involved in drafting the manuscript and
revising it critically for important intellectual content and gave final
approval of the version to be published.