Teaching Case

70-year-old patient with asymptomatic stenosis of carotid artery (80% NASCET criteria). A carotid artery stenting was scheduled.
In his medical history chronic renal failure and hypertension were reported. In 2004 multiple sclerosis was diagnosed, asymptomatic in the last 15 years.

Procedure was done under continuous monitoring of vital parameters. After puncturing the left common femoral artery and selective catheterization of the left common carotid artery (CCA), preliminary angiography demonstrated an atheromatous plaque that narrowed the calibre of the vessel (85%) in the proximal tract of ICA (Fig. 1). The stenosis was crossed with angiographic microguidewire (Nitrex, .014, Covidien), a distal filter was positioned (Spider-EV3 5 mm, Covidien) and a selfexpandable stent (Precise-Cordis 8x30 mm) (Fig. 2) was deployed in the stenotic tract. Afterwards, to optimize calibre of the stent, a PTA catheter was advanced in it, unsuccessfully. Therefore a further guidewire was positioned within the stent (Nitrex, Covidien) to increase support through "Buddy Wire Technique": at this point also the balloon (5 mm) was correctly advanced (Fig. 3, 4). Final angiography showed restoration of appropriate vessel calibre (Fig. 5) and absence of distal embolization. After the procedure the patient was set on double antiplatelet therapy as for protocol.

Endovascular procedures are influenced by the anatomy of the vascular sites treated, especially the tortuosity of the arterial vessels may prevent the stability of the catheter. In these cases the positioning of another guidewire increases the stability of the catheter, therefore the success of the procedure. This technique is called "Buddy Wire technique" where the term "Buddy" is used with the meaning of "friend" or "pal". In literature only few cases reporting the introduction of a second guidewire as only option for therapeutical success are described, both in the peripheral endovascular procedures and in the coronary arteries [1-3].
In our case the use of the "Buddy Wire" determined the success of the procedure because the introduction of the balloon within the stent positioned in the carotid artery was impossible for the absence of an appropriate support from the catheter.
O'hare [4], furthermore, introduced a new use of the "Buddy Wire": instead of using a second guidewire to increase the stability of the catheter, the wire was used to avoid the access of the primary guidewire within a non-target vessel. The author reports a case of dissecting aneurysm of the vertebral artery, where the "Buddy Wire" is used to prevent the access of the PICA, therefore reaching the dissecting aneurysm more easily.