“Buddy Wire” Technique to Overcome Proximal Coronary Tortuosity During Rotational Atherectomy

Rotational atherectomy remains a valuable tool with specific niche indications in the percutaneous interventional management of obstructive coronary disease.1 Recent studies suggest that plaque modification of severely calcified coronary lesions with rotational atherectomy facilitates stent deployment and increases the procedural success rate.^1–3 Advancement of the Rotablator^® burr ^{(Boston Scientific Corporation, Natick, Massachusettts)} may, in some cases, be hampered by intrinsic vessel characteristics such as proximal tortuosity and diffuse intra-luminal atheromatous plaque.¹ We report a novel application of the previously described “buddy wire” technique that facilitated the advancement of the Rotablator burr through severe proximal tortuosity, affording successful rotational atherectomy and stenting of a calcified obstructive lesion in the middle right coronary artery. Case Report. A 61-year-old man with a history of hypertension, diabetes mellitus and previous myocardial infarction presented with recurrent anginal chest pain. Four months earlier, the patient was evaluated with coronary angiography performed at another institution. The only significant finding was a 10 mm lesion with 95% stenosis affecting the mid-portion of a dominant right coronary artery (RCA). Percutaneous intervention was attempted with high-pressure balloon angioplasty that resulted in balloon rupture. The procedure was then aborted, leaving a residual stenosis of 60%. Subsequently, the patient underwent a 7-week course of enhanced external counterpulsation (EECP) while on a medical regimen maximized to patient tolerance. However, he remained symptomatic, and was evaluated with a thallium stress test that demonstrated an inferolateral infarction with significant residual ischemia affecting the inferior and inferolateral walls. The patient was then referred to our institution for a repeated attempt to revascularize his coronary lesion. The patient was in no acute distress and had normal vital signs. His physical exam was unremarkable, and his 12-lead electrocardiogram revealed sinus bradycardia with an inferior wall myocardial infarction of undetermined age. The patient’s chemistry and vital signs are detailed in Table 1. Procedure. Using a modified Seldinger technique, a 6 French (Fr) sheath was placed into the right femoral artery, and using 6 Fr catheters, diagnostic coronary angiography was performed, demonstrating a 95% heavily calcified eccentric mid-RCA lesion (Figure 1). Given the lesion’s characteristics, we planned to modify the plaque with rotational atherectomy prior to stent deployment. A 6 Fr sheath was then placed in the right femoral vein, allowing the placement of a temporary transvenous pacemaker. The tip was positioned in the apex of the right ventricle and the pacemaker was set to demand mode at a rate of 50 beats/minute. The 6 Fr arterial sheath was upsized to 8 Fr, and an 8 Fr Judkins right 4 curve guiding catheter was used to cannulate the RCA. The mid-RCA lesion was then successfully crossed with a .014 inch x 325 cm Rotawire™ Extra Support guidewire (Boston Scientific), and a 1.75 mm burr was advanced over the wire and into the proximal segment of the RCA. However, despite the use of a small burr size (burr-to-artery ratio (60,000–90,000 rpm, DynaGlyde™, Boston Scientific). Therefore, the burr was withdrawn into the guiding catheter and a .014 inch x 180 cm Graphics Intermediate wire (Boston Scientific) was used to cross the mid-RCA lesion to serve as a “buddy wire”. Subsequently, we were able to advance the 1.7 mm burr across the proximal RCA bend, overcoming the wire bias (Figure 3). Debulking and plaque modification were performed without complications. Subsequently, a 3.5 x 15 mm Multi-Link Zeta™ stent (Guidant Corporation, Santa Clara, California) was deployed with high-pressure inflations. Successful revascularization was achieved, with a reduction of the stenosis of less than 10% (Figure 4). Discussion. The incidence of perforation during rotational atherectomy is approximately 0.6%.⁴ Lesion tortuosity with an angulation greater than 30 degrees and wire bias are risk factors for perforation.^4,8 The Rotablator burr can be difficult to navigate through tortuous and heavily calcified vessels due to wire bias. In rotational atherectomy, the guidewire acts as a rail for advancing the burr; furthermore, it determines the ablation vector of the burr. Performing rotational atherectomy in a vessel segment with wire bias may result in perforation because the burr under these conditions will perform tangential or preferential cutting, rather than differential cutting.^5,6 Changing to a smaller diameter burr (burr-to-artery ratio 1,5 In other situations, activating the drive at a slow-rotation speed to displace friction may allow the burr to pass.¹ However, this may potentially lead to rotational dissection and the “furrowing effect” — an IVUS-documented phenomenon whereby directional plaque ablation creates a unilateral furrow into the intimal-medial layers of the vessel.^6,9 The forward-slide maneuver, during which the Teflon sheath is advanced simultaneously while moving the slide to the most forward position on the advancer, is another technique that may allow the burr to pass.⁷ However, if “off-loading” is not adequately performed with this technique, tension may build up in the burr-wire system. This may lead to a sudden forward jump of the burr, causing dissection or vessel perforation. The buddy wire technique was first described in 1987 for lesion protection during fixed-wire balloon angioplasty.⁸ Subsequently, this technique was applied to facilitate balloon or stent advancement through tortuous complex coronary anatomy. We applied the buddy wire technique, which allowed us to safely overcome wire-bias and proximal tortuosity during the performance of rotational atherectomy. We used the buddy wire to relieve wire bias and direct the burr away from the wall to allow rotational atherectomy without causing perforation or dissection. We propose this old technique as an alternative method to allow advancement of the Rotablator burr through tortuous and calcified vessels.

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