Long-term changes after carotid stenting assessed by intravascular ultrasound and near-infrared spectroscopy
Abstrakt
BACKGROUND: Long-term effect of carotid stenting (CAS) on the stabilization of the plaque is almost unrecognized. Vascular healing and remodeling might seal the atherosclerotic plaque with neointimal hyperplasia decreasing the vulnerability.
We aimed to assess long-term change in the lipid signal, stent and luminal dimensions and restenosis after CAS with the intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) imaging. METHODS: We performed follow-up angiography and NIRS-IVUS imaging of 58 carotid stents in 52 patients.
Median time from CAS to the follow-up examination was 31 months (range, 5-56). The lipid signal of the stented segment was calculated from a NIRS-derived chemogram (a spectroscopic map) as the lipid core burden index (LCBI, a dimensionless number from 0 to 1,000).
Planimetric and volumetric measurements from IVUS were performed to assess change in minimal stent area (MSA), minimal luminal area (MLA), stent and luminal volume, late stent expansion and percentage in-stent restenosis (ISR) volume. RESULTS: During the follow-up period, the mean (+-SD) LCBI significantly decreased from 32+-56 to 17+-27 (P=0.002).
The mean stent volume significantly increased from 717+-302 to 1,019+-429 mm(3) (P<0.001) with mean stent expansion 43%+-24%. The mean luminal volume increased from 717+-302 to 760+-359 mm(3) (P=0.025) due to ISR encroaching 26%+-15% of the stent volume.
CONCLUSIONS: Lipid signal decreased during the follow-up period suggesting stabilization of the plaque. Late stent expansion was balanced with neointimal hyperplasia.
TRIAL REGISTRATION: The trial is registered under clinicaltrials.gov NCT03141580.