LAUSR

A 75-year-old man with a history of percutaneous coronary intervention (PCI) of the left circumflex artery (LCX) with a drug-eluting stent was transferred to our institution. The first angiography with 4Fr catheter showed that the LCX was occluded after the origin of the atrial circumflex branch (AC) (Fig. 1a). We inserted an 8 Fr guiding catheter into the left coronary artery and subsequently inserted a floppy wire into the AC branch. Tip-injection imaging and sidebranch anchoring technique using a dual-lumen microcatheter (DLC) with XT-A and Gaia NEXT2 (ASAHI INTECC, Aichi, Japan) were performed; however, the tip of the guidewires could not penetrate into the chronic total occlusion (CTO) proximal cap (Fig. 1b). To obtain more force, we inserted a balloon catheter on a 2nd floppy wire into the AC and anchored the 1st one (Fig. 1c). After fixing the DLC position, Gaia NEXT2 passed the CTO entry and progressed to approximately 2 cm (Fig. 1d). After changing the DLC to a single-lumen microcatheter (Fig. 1e), we succeeded in antegrade-wiring to the distal true lumen and subsequent revascularization (Fig. 1f). A side branch originating at the level of the proximal cap is an unfavorable anatomic feature of antegrade CTO-PCI [1]. Compared to a single-lumen catheter (Fig. 1g, h), the side-branch anchoring technique with DLC (Fig. 1i, j) has more push-load and allows precise guidewire manipulation [2]. However, the CTO entry is often stiff and prevents the microcatheter from following the precedence wire; therefore, bare wire control is required for a certain distance from the CTO entry. Creating more back-up force with the “locked” DLC technique (Fig. 1k, l) might solve this problem in certain situations.