ASAHI Corsair® ARMET: Retrograde Microcatheter for CTO PCI Septal and Epicardial Collateral Navigation

The ASAHI Corsair® ARMET is a specialised microcatheter from Asahi Intecc engineered specifically for the retrograde approach to chronic total occlusion percutaneous coronary intervention. In retrograde CTO PCI, a second guidewire is advanced retrogradely through coronary collateral channels — septal perforators or epicardial collaterals — from a non-occluded donor vessel, across the CTO body from the distal cap, to reach the proximal cap. The ARMET is the microcatheter that navigates these collateral channels over the retrograde wire.

Coronary collateral channels — both septal and epicardial — are notoriously tortuous, narrow, and fragile. Standard microcatheters, including the Corsair Pro, are sometimes too stiff or too large in profile to navigate the most challenging collateral channels, creating risk of collateral perforation. The ARMET addresses this by offering a softer shaft and lower profile than the standard Corsair Pro while retaining the rotatable braided shaft design that makes Corsair microcatheters effective at drilling through tortuous occlusion segments.

The ARMET features the characteristic braided shaft of the Corsair family, allowing clockwise rotation at the hub to advance and counterclockwise to retract through tight anatomy. The distal profile is lower than the standard Corsair Pro 2.6F, reducing friction during collateral channel navigation. The microcatheter accepts standard 0.014 in coronary guidewires including the SION family, Fielder family, and Gaia series.

The ARMET is available in a single working length appropriate for standard retrograde CTO PCI setups. The hydrophilic outer coating along the distal segment reduces friction during collateral channel navigation, and the tip is soft to minimise vessel wall contact force.

Septal collateral channel navigation is the primary application for the ARMET. After identifying a suitable septal channel on angiography and selecting the retrograde wire (typically ASAHI SION Blue for initial entry, escalating to SION or SION Black for more resistant channels), the ARMET is advanced over the wire through the septal perforator to the CTO distal cap. The ARMET’s low profile and soft shaft allow it to negotiate the hair-pin turns that characterise septal anatomy.

Epicardial collateral navigation with the ARMET requires even more care, as epicardial channels are often larger calibre but more tortuous and more prone to perforation if the microcatheter tip contacts the channel wall under force. The ARMET’s softer shaft reduces the risk of tip force transmission in these fragile channels. After retrograde wire crossing via the ARMET, standard wire externalisation and retrograde CTO completion techniques apply.

Rotate the ARMET clockwise (2–3 full rotations) as you advance through the septal channel to help drill through any resistance rather than pushing axially. Counterclockwise rotation retracts if the tip is stuck. Never push the ARMET against hard resistance without rotation — axial force in a septal perforator can cause perforation.

Monitor the retrograde wire tip fluoroscopically throughout ARMET advancement. If the retrograde wire buckles ahead of the ARMET, stop and reassess — the wire has met resistance that may indicate a channel exit point or a tight section requiring more careful wire navigation before advancing the ARMET.

Modern Medical Solutions is the authorised Asahi Intecc distributor for Tajikistan and Afghanistan. The Corsair ARMET is available for CTO PCI programmes in Tajikistan and Afghanistan performing retrograde approaches.

Contact Modern Medical Solutions to discuss the ARMET alongside the Corsair Pro and Corsair Pro XS as a complete Corsair microcatheter portfolio covering both antegrade and retrograde CTO PCI roles.