Case 178: Manual of CTO PCI - Microcatheter uncrossable troubleshooting

A patient presented with NSTEMI due to thrombosis of a SVG to the first obtuse marginal branch. The SVG-OM was recanalized using thrombectomy and balloon angioplasty but the patient continued to have severe lifestyle-limiting angina and was referred for PCI of the native OM1 CTO. Repeat angiography showed 90% stenosis in the mid segment of the SVG-OM1. The proximal cap was ambiguous: the circumflex had a prior stent and there was no stump. We did primary retrograde crossing attempts using a Corsair XS and Sion black. We could not advance the microcatheter close to the distal cap, but could advance further after ballooning with a retrograde Sapphire 1.0x15 mm balloon. We were unable to cross retrogradely with Pilot 200 and a Gaia 2nd, as the wire remained “extraplaque”. We did an antegrade crossing attempts with a Venture and a Gaia 2nd and Hornet 14 guidewire using the retrograde guidewire as marker without success. We were eventually able to advance a retrograde Gaia 2nd into the proximal true lumen and the antegrade guide catheter, but could not advance the retrograde microcatheter through the CTO. After ballooning with a retrograde 1.0 mm balloon and using an antegrade guide extension and a new microcatheter we delivered a new microcatheter into the antegrade guide catheter and externalized an R350 wire. We could not advance an antegrade balloon or microcatheter through the proximal cap and failed to perform rotational atherectomy. We rewired retrogradely the CTO and were then able to advance an antegrade Sapphire 1.0 mm balloon followed by other balloons. We used the reversed guidewire technique to advance an antegrade Fielder FC to the distal segment of OM1. We then delivered a stent across the SVG anastomosis. We proceeded with stenting the circumflex/OM1 bifurcation using the DK crush technique, but were unable to advance a guidewire for the 2nd rewiring despite using a Sasuke and a Sion black. We wired retrogradely through the bifurcation into the antegrade guide catheter but could not advance a retrograde microcatheter through. We did “tip in” with an antegrade Corsair and were then able to advance it through the bifurcation and exchange for an antegrade Sion blue wire, followed by successful 2nd kissing balloon inflation. The SVG was coiled with 3 Penumbra coils with an excellent final result.