Adjunctive intravascular lithotripsy for heavily calcified carotid stenosis: a dual-center experience and technical case series.

Background: Heavily calcified carotid stenosis (HCCS) is considered an exclusion for carotid angioplasty and/or stenting (CAS), amenable only to carotid endarterectomy. This study presents preliminary retrospective dual-center experience utilizing the Shockwave S⁴ intravascular lithotripsy (IVL) system (Shockwave Medical) as an adjunct to CAS for HCCS.

Methods: Patients with symptomatic or asymptomatic HCCS (de novo stenosis or in-stent restenosis (ISR)) undergoing IVL+CAS were included. Charts were reviewed for demographic, imaging, procedural, and outcome data. The primary endpoint was composite major adverse event (MAE) rate: death, ipsilateral stroke, or myocardial infarction (MI) within 30 days of IVL+CAS. Secondary endpoints included technical and procedural success, residual stenosis, and ISR postprocedure.

Results: Fifteen patients underwent 17 IVL+CAS procedures: de novo HCCS=13, heavily calcified ISR=4; symptomatic disease was addressed in seven cases. Procedures were performed transfemorally under conscious sedation with dual protection; flow reversal through a balloon guide catheter, and distal embolic protection system (EPS) use. Median pre-IVL+CAS stenosis was 73% (IQR 60-80%). Technical success (IVL+CAS+ EPS use) was achieved in all cases. Median post-IVL+CAS residual stenosis was 27% (IQR 12-33%), achieving <50% residual stenosis and procedural success in all. Five patients required dopamine infusion for postprocedural hypotension. No periprocedural ipsilateral strokes occurred. MAE rate was 6.7% (95% CI 0.2% to 32%), including one MI resulting in death. Additionally, one ISR (6.3%; 95% CI 0.2% to 30.2%) identified 160 days after IVL+CAS was retreated with angioplasty.

Conclusions: IVL+CAS was safe and effective for treating symptomatic and asymptomatic HCCS, achieving high rates of freedom from MAE. IVL has potential to expand the role of CAS in difficult to treat HCCS.