The Buddy Wire Technique Is Useful in Transradial Coronary Stenting of Complex, Calcified Lesions: Report of Three Cases

The transradial approach for percutaneous coronary interventions represents an effective and safe alternative to the traditional transfemoral approach, allowing earlier ambulation and discharge, greater comfort for the patient, and less vascular complications, especially in cases involving concomitant aggressive antithrombotic therapy.^1,2 However, this approach is more demanding for the interventionalist who is faced with a steep learning curve,³ more difficult manipulation of catheters and, often, lower back-up as compared to the femoral route, which is considered safer and more attractive when dealing with complex coronary anatomy. Despite the availability of very low profile balloons, new generation stents, rotational atherectomy, and GP IIb/IIIa receptor blockers, the management of tight, angulated stenosis in calcified vessels can sometimes be a difficult task, even for expert operators. We report three cases showing that transradial coronary stenting of such lesions can be successfully completed using 6 French (Fr) guiding catheters with the aid of a buddy wire, without the need to switch to the femoral approach. Case 1. The first patient was a 72-year-old male who was referred to our institution for recurrent ischemia after an acute anterior myocardial infarction treated with systemic fibrinolysis. Coronary angiography, performed by the right transradial approach, showed left anterior descending artery disease with a tight, proximal calcified stenosis. The left coronary artery was then engaged with a 6 Fr JL 4.0 Zuma guiding catheter (Medtronic AVE, Inc., Santa Rosa, California), and rotational atherectomy was performed with a 1.25 mm burr (Rotablator®, Boston Scientific Corporation, Redmond, Washington). Despite progressive predilatation of the lesion with 2.5, 3.0 and 3.5 mm balloons, we could not advance the Multilink Zeta 3.5 x 18 mm stent (Guidant Corporation, Santa Clara, California); therefore, a second ChoICE® Floppy 0.014 inch buddy wire (Boston Scientific, Maple Grove, Minnesota) was advanced in the vessel and gently retrieved while pushing the stent, which was correctly deployed with optimal angiographic result. Case 2. A 78-year-old patient was referred to our institution for recent onset unstable angina with inferolateral ST-segment depression, raised troponin T-levels, and tirofiban intravenous infusion. Selective injection of the right coronary artery (RCA) showed a dominant vessel with a tight, calcified lesion just before the crux, and two angulated, moderately calcified lesions at the end of the first segment and in the second segment, respectively (Figure 1). Selective injection of the left coronary artery showed ostial occlusion of the left anterior descending artery which was entirely collateralized by the RCA through septal branches. Given the clinical instability of the patient and the coexistence of prostate cancer needing further evaluation, before coronary artery bypass grafting could be proposed, we decided to dilate the RCA, which was engaged with a 6 Fr AL 1.0 Zuma guiding catheter. After advancing a ChoICE Floppy 0.014 inch guidewire in the postero-lateral branch, we predilated the more distal lesion before trying to deploy a Multilink Zeta 3.5 x 13 mm, but the device could not be pushed beyond the first angulated lesion of the artery, so we directly stented it with a Lekton 3.5 x 13 mm (Biotronik, Berlin, Germany). Nevertheless, correct positioning of the Zeta stent more distally was still impossible, thus we placed a second 0.014 inch buddy wire (ChoICE Floppy) and were able to easily advance the stent beyond the lesion by simply pushing it and simultaneously gently pulling back the buddy wire, which was then retrieved before stent deployment (Figure 2). Direct stenting of the angulated lesion on the second segment was then attempted but, again, the buddy wire was needed to push the stent. The fnal angiographic result on the three segments treated was optimal, with TIMI 3 flow, no residual stenosis, and no dissections (Figures 3 and 4). Case 3. Myocardial scintigraphy in a 66-year-old patient with chronic exertional angina revealed inferior ischemia. Coronary angiography by the right transradial approach showed a very tight, calcified stenosis between the first and second segment of the right coronary artery. The patient was then enrolled in the experimental protocol CLASS (clinical evaluation of the Driver stent by Medtronic AVE, Inc., Santa Rosa, California), and received tirofiban intravenously. The RCA was engaged with a 6 Fr AL 1.0 Zuma guiding catheter, the lesion was crossed with a ChoICE floppy 0.014 inch guidewire and, after predilatation with a 3.0 mm balloon, a 3.5 x 12 mm stent Driver was deployed with good angiographic results. Five hours later, the patient developed chest pain, hypotension, and ST-segment elevation in the inferior leads; angiographic control, again by right transradial approach, showed an occlusive dissection of the third segment. Through a 6 Fr AL 1.0 Zuma guiding catheter, we were able to gain access to the posterolateral branch with a 0.014 inch ChoICE Floppy guidewire, and we performed PTCA on the second and third segments of the artery using a 3.0 x 30 mm balloon. Nevertheless, we were able to advance the stents (AVE S7 3 x 15 mm and 3.5 x 15 mm, Medtronic AVE) to cover the dissection only with the aid of a 0.014 inch ChoICE Floppy buddy wire. The final angiographic result was good, with TIMI 3 flow and only moderate residual stenosis at the crux. Discussion. The buddy wire technique was originally described by Selig for lesion protection during fixed-wire balloon angioplasty.⁴ Thereafter, the two-guidewire technique to facilitate stent deployment in tortuous vessels was reported by several authors, generally using stiff guidewires in order to straighten the vessel and give additional guiding catheter support.^5,6 Although most of these reports involve old-generation stents such as the Palmaz-Schatz, the deployment of low-profile, new-generation stents can sometimes prove difficult, not only when direct stenting is attempted, but also after adequate balloon predilatation in extremely tortuous vessels.⁷ These technical difficulties might be expected to increase when using the transradial approach, given the more difficult manipulation and lower back-up as compared to the femoral approach. Nevertheless, transradial PCI is very comfortable for the patient and very attractive because of the low risk of vascular access site complications and the fact that a vascular closure device is not required. In past reports on the buddy wire technique, the authors used stiff guidewires in order to straighten the vessel. Potential pitfalls of this approach include increased risk of distal perforation or dissection, as well as the appearance of so-called pseudostenosis and pseudodissections in normal segments, with potential intimal damage.⁸ We used a 0.014” floppy guidewire as the buddy wire, which did not straighten the vessel, but acted as a “rail” along which the stent could easily slide, probably without sticking on the calcified, irregular surface of the inner vessel wall. Simultaneous gentle traction on the buddy wire while pushing the stent across the lesion was also helpful. In our opinion, the described mechanism, together with the increased support achieved with an extra wire, can facilitate stent delivery. Although technological progress in the field of coronary stenting will probably provide new devices with even lower profiles and better crossability, the indications for coronary stenting will continue to expand, with a growing proportion of patients being treated with both high-risk clinical features (very elderly, renal failure, acute coronary syndromes needing aggressive antithrombotic therapy with increased risk of bleeding) and complex coronary anatomy. In these cases, a buddy wire could be very useful to successfully complete the procedure, not only when a strategy of direct stenting is adopted, but also when debulking and predilatation are not sufficient to allow stenting, or a dissection of a calcified vessel is present. In 2002, we performed more than 1,300 percutaneous coronary interventions, with the transradial approach with 5 Fr guiding catheters being used in 85% of cases. Nevertheless, even in a high-volume center, transradial coronary stenting of technically demanding lesions can be difficult, especially when 6 Fr guiding catheters with good back-up are used. In our opinion, the buddy wire technique could represent a useful approach for transradial PCI when dealing with complex anatomy. stefanorigattieri@tiscali.it

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