ASAHI SION® black Guidewire: When to Step Up from the Standard SION

The ASAHI SION® black is the highest tip-load wire in the SION family, designed for lesions where the standard SION (0.7 gf) tracks through the vessel correctly but cannot engage the plaque cap with sufficient force for wire advancement. Like all SION variants, it uses the ACT ONE core construction with a composite stainless-steel-to-nitinol transition, but it adds a polymer jacket over the distal 40 cm that increases shaft pushability and reduces frictional resistance during device delivery.

The tip load of approximately 0.8 gf — marginally above the standard SION — may appear a modest increment, but the polymer jacket is the more clinically significant difference. It provides a smoother outer surface that allows microcatheters and balloons to advance more easily over the wire, particularly in heavily angulated or calcified vessels where standard wire coils create drag. The 12 cm coil segment (shorter than the SION’s 28 cm) contributes to the firmer feel at the tip.

A unique feature of SION black within the SION family is the availability of a pre-shape tip option, in addition to straight and J configurations. Pre-shaped tips eliminate the need for manual tip shaping and offer a reproducible curve angle that does not deform under procedural forces — an advantage in operators who prefer standardised tip geometry across cases.

Outer diameter: 0.014 inch throughout. Tip load: approximately 0.8 gf. Coil length: 12 cm (shorter than standard SION’s 28 cm, contributing to greater distal stiffness). Polymer + hydrophilic coating zone: 40 cm from the tip — significantly longer than the SION’s 28 cm hydrophilic zone, providing extended friction reduction along the distal shaft. Core construction: ACT ONE composite.

Available lengths: 180 cm (standard) and 300 cm (exchange length). Available tip shapes: straight (S), pre-shape (P), and J. Catalog numbers: APW14R010S (straight, 180 cm), APW14R310S (straight, 300 cm), APW14R010P (pre-shape, 180 cm), APW14R310P (pre-shape, 300 cm), APW14R010J (J-tip, 180 cm), APW14R310J (J-tip, 300 cm). The pre-shape variant (P) is unique to SION black among the SION family and is supplied with a fixed curvature optimised for most coronary take-off angles.

Within the SION family, SION black sits above the standard SION (0.7 gf, 28 cm hydrophilic) and well above SION Blue (0.5 gf, silicone+hydrophilic hybrid). The longer polymer+hydrophilic coating (40 cm vs. 28 cm) is the clearest differentiator from standard SION: it enables smoother balloon tracking in cases where the shorter coated zone of standard SION still creates friction proximal to the lesion.

Against non-SION alternatives in the same tip-load range, SION black competes with wires like the Abbott Whisper LS and Terumo Runthrough Floppy. The ACT ONE shaft is generally considered to offer superior torque fidelity compared to standard stainless-steel cores in this tip-load class. SION black remains below the CTO wire threshold — operators encountering true fibrous cap resistance should escalate to Fielder XT or the Gaia series rather than continuing with SION black.

The pre-shape tip option distinguishes SION black from all comparable frontline wires in the Asahi catalogue. For laboratories that standardise on pre-shaped tips to reduce case-to-case variability, this is a meaningful practical advantage.

SION black is most commonly chosen as the second wire after the standard SION has navigated to the lesion but failed to cross due to mild plaque resistance — typically in lesions classified as moderately calcified or with a fibrous plaque cap. The operator switches to SION black rather than immediately escalating to a dedicated CTO wire, accepting a modest increase in tip force while retaining the familiar SION handling characteristics.

The extended polymer+hydrophilic coat makes SION black particularly useful in procedures requiring multiple device exchanges over the wire — for example, in calcified lesions requiring predilatation with multiple balloon sizes before stenting. The longer low-friction zone reduces device-related tip movement during exchanges, preserving wire position relative to the lesion.

Ostial lesions in the RCA and circumflex territory, where precise wire tip positioning is essential before crossing and the plaque cap is often mildly calcified, represent another strong indication for SION black. The pre-shape tip option is especially valued here, as it provides a reproducible angle for engaging the ostium without manual reshaping between cases.

When using the pre-shape variant, ensure guide catheter engagement is stable before advancing the wire, as the fixed curvature of the tip engages vessel walls differently from a manually shaped wire. Small guide catheter movements can redirect the pre-shaped tip into side branches; confirm tip position under fluoroscopy at each rotation increment before advancing.

The shorter 12 cm coil segment means the transition from flexible coil to firmer polymer-jacketed shaft occurs closer to the tip than with standard SION. Operators should be aware that the shaft feels notably stiffer within the coil’s proximal reach, which is beneficial for pushability but requires more controlled tip steering in vessels with sharp proximal bends within the first 15 cm of the wire’s distal segment.

If SION black also fails to cross after careful technique optimisation, escalation to Fielder XT (tapered 0.009/0.014 in, polymer-coated) is the standard next step before committing to a dedicated CTO algorithm. Do not persist with SION black beyond 3–5 rotation-and-advance attempts at the plaque cap, as prolonged engagement risks tip deformation.

Modern Medical Solutions supplies ASAHI SION® black across all six catalog configurations (APW14R010S, APW14R310S, APW14R010P, APW14R310P, APW14R010J, APW14R310J) to catheterisation laboratories in Tajikistan and Afghanistan as the authorised Asahi Intecc regional distributor. The pre-shape variant can be stocked on consignment for centres that standardise on pre-shaped tips.

Enquiries regarding stock levels, product demonstrations, and clinical support for SION family selection can be submitted via the contact form on the Modern Medical Solutions website. Asahi Intecc device specifications are maintained at medical.asahi-intecc.com.