Knuckle technique guided by intravascular ultrasound for in-stent restenosis occlusion treatment.
Bottom Line: Limited data suggest that the treatment success rate is dependent on the possibility to cross into the lumen of an occluded stent, and the decision about what technique to use varies by operator preference.The knuckle technique is used to create a deliberate dissection plane in various CTO techniques.A guide wire is pushed until a complex loop is formed and advanced through the lesion.
Affiliation: Clinical Centre Kragujevac, Kragujevac, Serbia.
One of the rarest lesions is in-stent restenosis chronic total occlusion (CTO). Limited data suggest that the treatment success rate is dependent on the possibility to cross into the lumen of an occluded stent, and the decision about what technique to use varies by operator preference. The knuckle technique is used to create a deliberate dissection plane in various CTO techniques. A guide wire is pushed until a complex loop is formed and advanced through the lesion. In this report we present a case where a knuckle wire guided by intravascular ultrasound control is used to penetrate the distal cap in an in-stent restenosis CTO lesion.
No MeSH data available.
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Mentions: A 69-year-old woman presented to the cath lab due to exertion chest pain. A year previously the patient had successful percutaneous coronary intervention (PCI) of a large obtuse marginal (OM) branch of the left circumflex artery (LCx) in the setting of acute myocardial infarction (Figure 1). Echocardiography revealed a hypokinetic lateral wall with slightly reduced ejection fraction. Coronary angiography showed a large occluded OM branch with visible stent struts. The occlusion extended throughout the stent with slow antegrade flow showing distal segment of artery (Figure 2). The treatment procedure was started using a femoral approach with a 6 Fr EBU guiding catheter and a Fielder XT guidewire with the support of a Finecross microcatheter (Terumo interventional systems). Due to flush occlusion of the ostial OM branch, it was extremely difficult to negotiate and penetrate the proximal cap from the LCx main branch 2–3 mm into the occlusion. The Fielder XT guidewire was exchanged for ASAHI MiracleBros 3 and ASAHI Confianza PRO 12 guidewires, but both failed (Figure 3). Using stent struts as markers of the vessel border we managed to push the wire further distally, but we were unable to get it past the very hard distal cap. After verification of the position of the wire tip, a microcatheter was pushed into the stented segment and the Fielder XT wire was reintroduced (Figure 4). Movement of the microcatheter made enough space for us to bend the wire tip and form a triple knuckle, and then to carefully push through the distal cap and into the distal segment. After successfully passing the microcatheter and checking the intraluminal position of the system by aspiration of the blood, we exchanged the wire for a standard Runthrough guidewire and pre-dilated the whole segment (Figure 5). For better understanding of the vessel anatomy and achieved results, an intravascular ultrasound (IVUS) examination was performed (Figure 6), revealing that the guidewire was properly positioned in the stent. Intravascular ultrasound examination also showed the most distal stent strut with large neointima (Figure 7), the mid section of the treated segment with unopposed stent strut as a target for restenosis, stent thrombosis with a kind of flap as a consequence of the knuckle, and the more proximal part showing mixed plaque characteristics (Figure 8). Finally, DES was implanted in the OM branch using the stopper balloon in LCx for ostial positioning, and we also treated distal LCx (Figure 9). The patient was discharged the next day with no electrocardiographic changes or enzyme elevation. We also performed 1- and 3-month follow-up, and the patient remains symptom free.
No MeSH data available.