Our pilot study had already evaluated the feasibility and safety of transradial and transbrachial carotid artery stenting using Catheter Looping And Retrograde Engagement Technique (CLARET) (Fig. 1). The major limitation of TRA CAS is the inability to use large guiding catheters (7Fr.) when radial artery size is too small. Before the sheathless technique, we used TBA instead of TRA. Now, the sheathless TRA approach for CAS was then introduced (Fig. 2).

33 patients with documented carotid artery stenosis and small radial artery size were selected for CAS via sheathless TRA comparing with 61 patients underwent CAS using TBA. Usual radial artery puncture accommodating a 5Fr. arterial sheath and 7Fr. guiding catheter was used for diagnostic cerebral angiography and subsequent CAS. Routine assessments of radial artery pulsation via color doppler ultrasound or clinical follow up were done at 1 month and 6 month after the procedure.

This sheathless TRA CAS technique offered 100% diagnostic and procedure success. There were no baseline characteristics differences between TRA and TBA (Table 1). Only one patient (3.1%) experienced transient ischemia attack (TIA) during the procedure and immediately recovery during hospitalization. There were no major complications 0% (major stroke or 30 day in-hospital death), nor radial access site complications (compartment syndrome, or acute blood loss need blood transfusion), as compared with TBA CAS, stroke occurred in 3/61 (one major & 2 minor strokes, 4.9%), and 2 brachial pseudo-aneurysm demanding surgical repair (Table 2). Significant longer hospital stay in TBA than sheathless TRA in this study (10.9 ± 8.4 v.s. 8.3 ± 5.5, p=0.042). All radial arteries were patent during 1 month and 6 month clinical follow up. 

The results showed that sheathless TRA CAS in patients with severe carotid artery stenosis and small radial artery size is safe and technically feasible with lower major complications, significant shorter hospital stay and good clinical radial artery patency.