Effectiveness of Intravascular Lithotripsy on an Underexpanded Stent Due to Severe Calcification

A 75-year-old man who underwent initial percutaneous coronary intervention (PCI) for a calcified lesion 5 years earlier (Figure A1,A2) was hospitalized at another hospital due to angina pectoris. Coronary angiography identified significant in-stent restenosis with severe calcification in the proximal segment of the left anterior descending coronary artery (Figure B1, arrow). High-pressure dilation with non-compliant (3.0×12 mm; 22 atm) and cutting (3.0×10 mm; 12 atm) balloons was performed. However, a sufficient lumen could not be obtained because of stent underexpansion (Figure B2, arrowhead; Figure B3) caused by severe calcification.

Figure.

(A1,A2) Initial coronary angiography (CAG) and calcification before stent implantation. (B1) CAG showing in-stent restenosis in the proximal left anterior descending artery (arrow). (B2) Residual balloon indentation despite high-pressure dilation. Insufficient stent expansion (arrowhead). (B3) Partial lesion dilation. (C1) CAG before intravascular lithotripsy (IVL). (C2) Adequate balloon expansion after IVL. (C3) Final CAG. (D1,D2) Intravascular ultrasound images before and after IVL. PCI, percutaneous coronary intervention.

The patient was referred to Miyazaki Medical Association Hospital for repeat PCI. Coronary angiography showed residual stenosis (Figure C1, arrow; Supplementary Movie 1). Pre-procedure intravascular ultrasound (IVUS) showed inadequate stent expansion and severe calcification around the entire circumference underneath the stent (Figure D1). An intravascular lithotripsy (IVL) balloon (Shockwave, 3.0×12 mm) was inflated to 4 atm and 6 atm with 50 pulses of ultrasound energy. After IVL, IVUS demonstrated adequate stent dilation and multiple cracks in the calcified lesion (Figure D2). Following additional dilation with a scoring balloon (3.0×10 mm; 22 atm; Figure C2), we succeeded in dilating the lesion sufficiently (Figure C3; Supplementary Movie 2).

Treatment for stent underexpansion and restenosis caused by calcification remains challenging. It is an important unmet need. IVL might be feasible and effective for treating in-stent restenosis and inadequate stent expansion with circumferential calcification. Further studies using optical coherence tomography are needed to confirm our findings and to clarify which types of calcified lesions with in-stent restenosis might benefit from IVL.

Disclosures

None.

Supplementary Files

Supplementary Movie 1. Coronary angiography before intravascular lithotripsy.

Supplementary Movie 2. Final coronary angiography.

Please find supplementary file(s);

https://doi.org/10.1253/circrep.CR-24-0096