Case 242: Manual of CTO PCI - Sequential guide technique

A patient was referred for PCI of a right coronary artery CTO due to medically refractory dyspnea on exertion. The RCA had a blunt proximal cap, long occlusion length, and retrograde filling via epicardial collaterals, both from the circumflex and from the distal LAD. The epicardial collateral from the distal LAD to the PDA was large without severe tortuosity and was mainly filling via a LIMA (the LAD was patent but had disease in the mid segment).
We used the “sequential guide catheter technique”: we obtained bilateral femoral arterial access and initially engaged the LIMA-LAD and the left main. We crossed the apical LAD epicardial collateral with a Caravel microcatheter delivered through the left main while visualizing via injections from the LIMA (dissociation of visualization and equipment delivery – see prior publication on this: https://pubmed.ncbi.nlm.nih.gov/20440.... We then exchanged the LIMA guide for an AL1 guide that engaged the RCA.
The retrograde microcatheter could not be advanced past the distal RCA due to severe calcification. We advanced an antegrade knuckled guidewire to the mid RCA, delivered an antegrade guide extension using the inchworming technique and successfully performed guide-extension reverse CART. However, the retrograde microcatheter could still not be advanced past the distal RCA, despite using multiple microcatheters and a Sapphire 1.0 mm balloon. Moreover, the tip of a Turnpike LP broke off and remained inside the vessel.
After multiple failed attempts we used the retrograde wire as marker and successfully crossed into the PDA. We had difficulty wiring the right posterolateral but eventually we crossed it using the STAR technique. Following stenting of the RCA into the PDA and kissing balloon inflation into the PDA and right posterolateral a nice final result was achieved.