1

Introduction

Stent loss is currently an infrequent complication during percutaneous coronary intervention (PCI) . However, it can have devastating consequences, including stent thrombosis, myocardial infarction and death . Here we describe a case of stent loss during chronic total occlusion (CTO) PCI that was successfully managed by meticulous optical coherence tomography (OCT)-guided stent crushing and trapping. We additionally review the incidence and possible mechanisms of stent loss during PCI, and provide a set of recommendations to manage such complication.

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Case description

A 55-year-old man presented with non-ST-segment elevation myocardial infarction (NSTEMI). Three-vessel disease was diagnosed. Since the patient categorically refused surgical revascularization, percutaneous management of his coronary artery disease (CAD) was pursued. He underwent PCI to the right coronary artery with one drug-eluting stent (DES), as well as on the proximal left anterior descending (LAD) and first diagonal (D1) branch, with two non-overlapping DES ( Fig. 1 A ). Residual CAD after the initial procedure included a mid LAD CTO and a proximal circumflex CTO. Transthoracic echocardiogram and cardiac magnetic resonance imaging showed mildly reduced left ventricular systolic function with viability in all coronary territories. The patient was then scheduled for mid LAD CTO PCI ( Fig. 1 A).

Stent dislodgment and crushing. (A) Pre-procedural coronary angiography: mid left anterior descending (LAD) chronic total occlusion (CTO) with previously deployed stents in the proximal LAD and first diagonal branch. (B) CTO was crossed with antegrade wiring. (C) Result after predilatation. (D) Stent dislodgement indicated by yellow arrowheads. (E) Additional stent implantation from the left main to the mid LAD, crushing the dislodged stent.

Dual femoral access was secured with 7Fr sheaths. The occlusion was long (>20 mm) and calcified, with an ambiguous proximal cap and epicardial interventional collaterals from the D2. According to the hybrid algorithm , a retrograde approach was undertaken. Due to difficulty in navigating the tortuous epicardial collaterals, the procedure was switched to an antegrade approach. The lesion was crossed with an UltimateBROS3 guidewire (Asahi Intecc, Nagoya, Japan) over a Turnpike LP microcatheter (Vascular Solutions, Minneapolis, MN), in a true-to-true fashion ( Fig. 1 B). The lesion was therefore predilated with 2.5 × 20 mm non-compliant (NC) balloon ( Fig. 1 C). However, when a 3.0 × 33 mm Ultimaster DES (Terumo, Tokyo, Japan) was advanced into the proximal-to-mid LAD, resistance was encountered, and the decision was made to perform additional predilatation with a larger balloon. It soon became apparent that the stent got dislodged from the delivery system between the circumflex ostium and the LAD segment just distal to D1, most likely due to angulation and calcification of this segment ( Fig. 1 D).

It was clear that the dislodged stent was partially overhanging over the ostium of the circumflex artery and, additionally, appeared distorted in its proximal portion: for these reasons, we decided not to not to implant it and to attempt retrieval instead. The ‘small balloon technique’ (in which a small balloon is advanced onto the stent wire and inflated, and the two are pulled back into the guiding catheter) was applied to no avail. Therefore, the decision to crush the stent was taken. A second guide catheter was then used to engage the left main. Two Runthrough guidewires (Terumo) were passed to the distal LAD and D1 from the second guide catheter (ping-pong technique) . A 3.0 × 20mm NC balloon was inflated onto the LAD guidewire to crush the dislodged stent and further optimize lesion preparation, while the D1 branch was protected performing kissing balloon inflation (KBI), to prevent ostial D1 compromise (3.0 mm NC balloon to LAD and 2.5 mm NC balloon to D1). A 3.5 × 33mm Ultimaster DES was successfully advanced to cover the crushed stent, and implanted from the left main to the mid LAD ( Fig. 1 E). Further optimization was achieved with a 4.0 mm NC balloon high-pressure postdilatation in the proximal LAD. OCT confirmed acceptable apposition of the crushed stent to the vessel wall, and interestingly also revealed concomitant crushing of the stent deployed across the LAD-D1 bifurcation during the previous procedure (3.5 × 9 mm Ultimaster), most likely due to stent malapposition with subsequent easy crossing of the Runthrough guidewire “behind” the stent struts ( Fig. 2 B–E, a–f). Further optimization, confirmed with OCT assessment, was performed with high-pressure inflation of a 4.5 mm NC balloon in the proximal LAD, T-and-protrusion (TAP) stenting into the ostial-proximal circumflex, and final KBI on both the left main-LAD-circumflex and LAD-D1 bifurcations. Finally, an overlapping Ultimaster was implanted from the mid to distal LAD ( Fig. 2 A, F).

Final result: insights from optical coherence tomography (OCT) imaging. (A and F) Coronary angiography after stent implantation and post-dilatation. (B and D) Location of each stent (light brown-shaded area: stent deployed during previous procedure and crushed during current procedure, red: stent dislodged and crushed during current procedure, blue: stent deployed during current procedure to crush the dislodged stent). (C and E) Plain fluoroscopy after stent implantation and post-dilatation. a–f: OCT images at the levels indicated in panels C and E (b and c: the white arrowhead indicates the stent dislodged and subsequently crushed during current procedure; d–f: the double arrowhead indicates five layers of metal: one layer of the stent used to crush the dislodged stent, two layers of the stent implanted during previous procedure and two layers of the dislodged stent. Note that the dislodged stent was lost within the previously deployed stent, and that the new stent crushed both stents. This is proven by the fact that only one layer of metal can be seen on the opposite vessel wall side. Asterisk in e indicates the ostium of the first diagonal branch.

Optimal angiographic result was confirmed also on OCT grounds ( Fig. 2 A, F, a–f). The patient maintained a normal renal function, was discharged on dual antiplatelet therapy with aspirin and ticagrelor for 12 months, and was asymptomatic on subsequent follow-up.