We approached from bilateral femoral artery with 8Fr AL1 for RCA and 7Fr EBU for LCA. We started from antegrade approach with IVUS guidance. XTA was used for entry puncture initially. However, due to hevay calcification at the entry, we shifted to Gaia 1-->Gaia 2-->Gaia 3. Wire de-escalated to UB3 after Gaia 3 advanced into the CTO body. We manipulated the UB3 in accordance to the shadow of calcification and we finished the antegrade preparation after UB3 went into subintimal space.
We then shifted to retrograde approach from LAD septal channel. Under the support of Caravel, SUHO 03 crossed the bend part of septal and went into the PDA. The tip injection showed the blunt morphology of PDA CTO exit. We attacked the exit with XTA first. The wire easily deviated from the direction of correct route. Wire was escalated to Gaia 3. After some efforts, we made antegrade and retrograde wire overlapped each other. Guide-extention rCART was performed and Gaia 3 went into AGC. Under the balloon trapping in the AGC, we tried to pushed the RMC into AGC but failed. The MC stuck inside the CTO body with heavy calcification. We tried rendezvous technique in AGC but the AMC failed to cross the calcified point in the CTO, too. Then, we tried to place both AMC and RMC as close to each other as possible, and changed the RGW to RG3 and successfully controlled the RG3 into AMC. After extenalization, balloon angioplasty-->1.25mm RA-->balloon angioplasty-->DES stenting were done well.
Intra-coronary RG3 rendezvous is a special technique for retrograde micro-catheter failure to advance into the antegrade guiding catheter. The space created by retrograde wire is always large enough for RG3 to cross. Before withdrawing the retrograde wire, we have to 1. make both side micro-catheter as close to each other as possible 2. make a relatively small bend at the tip of RG3 3. try to rendezvous at a horizontal plane. This technique should be the last resort when you try other methods to pass your retrograde micro-catheter because you always take some risks to lose your wire in CTO if you fail.