Abstract Body (Do not enter title and authors here): Background: Heavily calcified coronary bifurcation lesions present significant challenges during percutaneous coronary intervention, particularly during atherectomy due to the risk of side branch occlusion from plaque shift. We describe the "Double Guiding Catheter Technique" to minimize side branch closure and wire damage to non-atherectomy vessels during bifurcation orbital atherectomy (OA).

Case: A 74-year-old male with a recent NSTEMI presented for elective coronary artery revascularization. A coronary angiogram revealed non-obstructive left coronary arteries and a dominant right coronary artery (RCA) with heavily calcified stenosis at the bifurcation of the right posterolateral (RPL) and right posterior descending (RPD) branches. After placing temporary transvenous pacing and inserting sheaths in the right radial and right femoral arteries, both the RPL and RPD were wired with coronary guidewires. Using a coronary microcatheter, the wire in RPL was replaced with a ViperWire guidewire for OA, while the microcatheter in RPD served as guidewire protection. OA of RPL was successfully performed with the Diamondback 360° OA system (Cardiovascular Systems Inc), followed by multiple dilatations with non-compliant balloons and placement of two drug-eluting stents in the distal RCA to RPL and RPD, achieving good angiographic and IVUS results.

Discussion: The Double Guiding Catheter Technique has been described in a few case reports of heavily calcified left main coronary bifurcation atherectomy which is limited to relatively proximal lesions due to the need to pass a second wire to a non-atherectomy vessel outside a guide extension catheter for the main branch. This is the first reported case of OA using this technique in the right coronary artery and a relatively distal part of the coronary artery. The primary advantage of this technique is eliminating the need to withdraw one of the two wires, which can be challenging when recrossing the side branch. The microcatheter can safely protect the other branch wire during atherectomy.

Conclusion: By maintaining both wires with a protective microcatheter, OA of coronary bifurcation stenosis can be successfully achieved, potentially reducing the risk of wire transection.