Multi-center experience with intravascular lithotripsy for treatment of severe calcification during transcarotid artery revascularization for high-risk patients

Abstract

Objective: Transcarotid artery revascularization (TCAR) offers a safe alternative to carotid endarterectomy (CEA), but severe calcification is currently considered a contraindication in carotid artery stenting. This study aims to describe the safety and effectiveness of TCAR with intravascular lithotripsy (IVL) in patients with traditionally prohibitive calcific disease.

Methods: All consecutive patients who underwent TCAR+IVL from 2018-2022 at nine institutions were identified. IVL was combined with pre-dilatation angioplasty to treat calcified vessels before stent deployment. The primary outcome was a new ipsilateral stroke within 30 days. Secondary outcomes included any new ipsilateral neurologic event (stroke/transient ischemic attack [TIA]) at 30 days, technical success, and <30% residual stenosis.

Results: Fifty-eight patients (62% male; mean age, 78 ± 6.6 years) underwent TCAR+IVL, with 22 (38%) for symptomatic disease. Fifty-seven patients (98%) met high-risk anatomical or physiologic criteria for CEA. Forty-seven patients had severely calcific lesions. Fourteen patients (30%) had isolated eccentric plaque, 20 patients (43%) had isolated circumferential plaque, and 13 (27%) had eccentric and circumferential calcification. Mean procedure and flow reversal times were 87 ± 27 minutes and 25 ± 14 minutes. The median number of lithotripsy pulses per case was 90 (range, 30-330), and mean contrast usage was 29 mL. No patients had electroencephalogram changes or new deficits observed intraoperatively. Technical success was achieved in 100% of cases, with 98% having <30% residual stenosis on completion angiography. One patient had an in-hospital post-procedural stroke (1.72%). Four patients total had any new ipsilateral neurologic event (stroke/TIA) within 30 days for an overall rate of 6.8%. One TIA and one stroke occurred during the index hospitalization, and two TIAs occurred after discharge. Preoperative mean stenosis in patients with any postoperative neurologic event was 93% (vs 86% in non-stroke/TIA patients; P = .32), and chronic renal insufficiency was higher in patients who had a new neurologic event (75% vs 17%; P = .005). No differences were observed in calcium, procedural, or patient characteristics between the two groups. The mean follow-up was 132 days (range, 19-520 days). Three stents developed recurrent stenosis (5%) on follow-up duplex; the remainder were patent without issue. There were no reported interventions for recurrent stenosis during the study period.

Conclusions: IVL sufficiently remodels calcified carotid arteries to facilitate TCAR effectively in patients with traditionally prohibitive calcific disease. One patient (1.7%) suffered a stroke within 30 days, although four patients (6.8%) sustained any new neurological event (stroke/TIA). These results raise concerns about the risks of TCAR+IVL and whether it is an appropriate strategy for patients who could potentially undergo CEA.

Keywords: Carotid disease; Cerebrovascular; Lithotripsy.