Radial artery thrombus remodeling after transradial access: from fresh components to recanalized channels on OCT

Radial artery thrombus (RAT) is a key substrate of radial artery occlusion after transradial access (TRA), but in vivo phenotyping remains limited.

This study aims to characterize RAT using optical coherence tomography (OCT), propose an OCT-based phenotyping scheme, and describe interval-stratified patterns after TRA.

We retrospectively analyzed a prospectively maintained, single-center registry of consecutive radial artery OCT (RA-OCT) performed after OCT-guided coronary intervention (April 2019-September 2025). RAT was adjudicated by blinded readers using prespecified criteria: Type 1 (fresh), Type 2a/2b (non-recanalized without/with intrathrombus cavities), and Type 3 (recanalized with communicating channels). Phenotypes were compared across proximal, mid, and distal segments as well as across strata defined by time since the most recent ipsilateral TRA.

Eighteen patients underwent RA-OCT. The prevalence of Type 2b increased from proximal to distal segments (11.1% vs. 22.2% vs. 38.9%; P = 0.022), whereas Types 1 and 3 did not vary significantly across segments. Quantitative thrombus burden (thrombus length, minimal lumen area, and area stenosis) was similar across segments. With longer intervals since the most recent ipsilateral TRA, Type 1 decreased (P for trend=0.009) and Type 3 increased (P for trend = 0.014), with Type 3 predominating at ≥181 days.

RA-OCT enables in vivo RAT phenotyping and supports a pragmatic OCT-based classification, demonstrating interval-dependent evolution toward a recanalized architecture after TRA.