Intravascular laser lithotripsy for calcium fracture in human coronary arteries.
EUROINTERVENTION 2023;
19:e913-e922. [PMID:
38060282 PMCID:
PMC10722992 DOI:
10.4244/eij-d-23-00487]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/11/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND
Electrical intravascular lithotripsy (E-IVL) uses shock waves to fracture calcified plaque.
AIMS
We aimed to demonstrate the ability of laser IVL (L-IVL) to fracture calcified plaques in ex vivo human coronary arteries and to identify and evaluate the mechanisms for increased vessel compliance.
METHODS
Shock waves were generated by a Ho:YAG (Holmium: yttrium-aluminium-garnet) laser (2 J, 5 Hz) and recorded by a high-speed camera and pressure sensor. Tests were conducted on phantoms and 19 fresh human coronary arteries. Before and after L-IVL, arterial compliance and optical coherence tomography (OCT) pullbacks were recorded, followed by histology. Additionally, microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) were performed. Finite element models (FEM) were utilised to examine the mechanism of L-IVL.
RESULTS
Phantom cracks were obtained using 230 μm and 400 μm fibres with shock-wave pressures of 84±5.0 atm and 62±0.4 atm, respectively. Post-lithotripsy, calcium plaque modifications, including fractures and debonding, were identified by OCT in 78% of the ex vivo calcified arteries (n=19). Histological analysis revealed calcium microfractures (38.7±10.4 μm width) in 57% of the arteries which were not visible by OCT. Calcium microfractures were verified by micro-CT and SEM. The lumen area increased from 2.9±0.4 to 4.3±0.8 mm2 (p<0.01). Arterial compliance increased by 2.3±0.6 atm/ml (p<0.05). FEM simulations suggest that debonding and intimal tears are additional mechanisms for increased arterial compliance.
CONCLUSIONS
L-IVL has the capability to increase calcified coronary artery compliance by multiple mechanisms.
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