ASAHI SASUKE®: Ultra-Low-Profile Microcatheter for Extreme CTO Proximal Cap Penetration

ASAHI SASUKE® is a specialised ultra-low-profile coronary microcatheter from Asahi Intecc, designed specifically for the most difficult CTO proximal cap penetration scenarios — cases where all preceding microcatheter options (Corsair Pro, Corsair Pro XS) have failed to advance through or immediately proximal to the cap despite correct technique. Its 1.5F tip and 2.5/3.3F shaft graded profile (wider proximally, narrower distally) deliver wire support precisely at the cap face, where it is most needed, while minimising the crossing profile at the tip.

The SASUKE is companion to the highest tip-load CTO wires — Confianza Pro and Gaia Next 3 — and is used when the limiting factor to CTO crossing is not just wire tip load but also the inability to advance a microcatheter sufficiently close to the cap to provide adequate back-support. Without a microcatheter at the cap, high tip-load wires dissipate their penetrating force through shaft deflection rather than cap contact. SASUKE solves this by providing the lowest-possible-profile microcatheter presence at the exact cap position.

Catalog: SA145-33N (145 cm working length). The single configuration reflects SASUKE’s position as a niche high-complexity tool rather than a general-inventory item.

Tip diameter: 1.5F (approximately 0.50 mm). Distal shaft diameter: 2.5F (approximately 0.83 mm). Proximal shaft diameter: 3.3F (approximately 1.10 mm). Tip inner diameter: 0.016 inch. Working length: 145 cm (SA145-33N). Compatible guidewire: 0.014 inch.

The graded shaft profile — 1.5F tip to 2.5F to 3.3F — provides structural support and pushability from the proximal large-shaft section while minimising the crossing profile at the tip. This graduated design means push force applied at the hub is transmitted efficiently to the 1.5F tip without requiring the entire shaft to be uniformly thin, which would reduce the microcatheter’s column strength and ability to transmit push force through tortuous anatomy.

SASUKE vs. Corsair Pro XS (2.1F): XS is the standard lower-profile escalation from Corsair Pro. SASUKE is reserved for XS failure specifically at the proximal cap — not for general small-vessel use. If XS reaches the cap face but cannot advance through the fibrous tissue at the cap, SASUKE is the next step. If XS cannot advance due to tortuosity in the proximal vessel rather than cap resistance, guide catheter extension (GuideLiner) should be considered before SASUKE.

SASUKE vs. Caravel (1.9F): Caravel is a passive microcatheter without the column strength of SASUKE’s graded shaft. For extreme proximal cap penetration requiring maximum push force transmission to the 1.5F tip, SASUKE’s stiffer proximal 3.3F shaft provides superior pushability compared to Caravel’s uniform slender shaft. SASUKE is the pushing tool; Caravel is the tracking tool.

SASUKE in the algorithm: The standard proximal cap microcatheter escalation sequence is Corsair Pro → Corsair Pro XS → SASUKE. If SASUKE also cannot be advanced to the cap face, the operator should reconsider the overall CTO strategy — specifically whether the antegrade approach is feasible or whether retrograde should be attempted.

SASUKE is strictly indicated for extreme proximal cap penetration scenarios where Corsair Pro XS has failed to advance to or through the proximal cap despite correct rotation technique with appropriate CTO wires. The operator must be confident that the failure is due to cap fibrosis/calcification proximity profile rather than proximal vessel tortuosity, as the two problems require different solutions.

In cases with a blunt, flush proximal cap (no vessel stump visible at the CTO entry point), SASUKE’s low-profile tip can engage the ostial entry of the occlusion more directly than larger microcatheters, allowing Confianza Pro to penetrate at the exact correct entry angle without the microcatheter tip distorting the approach angle through its larger profile.

SASUKE is also used in reverse CART retrograde technique when the retrograde microcatheter needs to be positioned at the proximal cap from the retrograde direction and the septal channel is very tight — SASUKE’s low profile facilitates retrograde microcatheter advancement through tight retrograde channels while maintaining the pushability needed for the subsequent wire manipulation steps.

SASUKE does not rotate like Corsair Pro — it is a push-only microcatheter. Advancement relies on axial push force transmitted through the graded shaft. Apply slow, steady forward pressure at the hub while confirming advancement fluoroscopically. Limit total hub force to manual comfortable pressure; do not use mechanical advancement aids with SASUKE as the thin tip can perforate tissue under excessive force.

Position the guidewire (Confianza Pro or Gaia Next 3) 2–3 mm beyond the cap face before attempting SASUKE advancement — the wire must provide a clear track for the microcatheter to follow. If the wire is not stable at the cap entry point, SASUKE cannot advance regardless of hub force.

After SASUKE has reached the cap face and the CTO wire has crossed, exchange the crossing wire for a workhorse wire (SION) through SASUKE before balloon advancement. Then withdraw SASUKE and advance a larger microcatheter (Corsair Pro) over the workhorse wire for subsequent wire exchanges. Do not attempt to advance balloons or stents over the crossing wire while SASUKE is still in position.

Modern Medical Solutions supplies ASAHI SASUKE® (SA145-33N) to complex CTO programmes in Tajikistan and Afghanistan as the authorised Asahi Intecc distributor. SASUKE is a low-volume, high-complexity item recommended for centres performing 30 or more CTO procedures annually with established CTO algorithm expertise.

For centres considering adding SASUKE to their CTO toolkit, Modern Medical Solutions can provide algorithm integration guidance and case consultation support. Contact the team via the Modern Medical Solutions website for ordering and clinical advisory services.