Case Report Successful Intravascular Ultrasound-Guided Transradial Coronary Intervention with a 4Fr Guiding Catheter Yasuhiro Nakano 1 and Kenji Sadamatsu 2 1 Department of Cardiovascular Medicine, Saga-Ken Medical Centre KOSEIKAN, Saga, Japan 2 Department of Cardiovascular Medicine, St. Mary’s Hospital, Kurume, Japan Correspondence should be addressed to Yasuhiro Nakano; notch14df@gmail.com Received 23 June 2016; Accepted 25 August 2016 Academic Editor: Expedito E. Ribeiro Copyright © 2016 Y. Nakano and K. Sadamatsu. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Minimizing the catheter size can reduce vascular access complications and contrast dye usage in coronary angiography. Te small diameter of the 4Fr guiding catheter has limited the use of several angioplasty devices such as intravascular ultrasound (IVUS) in the past. However, the combination of a novel IVUS catheter and a 0.010 guidewire makes it possible to perform IVUS-guided percutaneous coronary intervention (PCI) with a 4Fr guiding catheter. We herein report the case of a 51-year-old man with silent myocardial ischemia who underwent IVUS-guided transradial PCI with a 4Fr guiding catheter. 1. Introduction Minimizing the catheter size can reduce vascular access complications and contrast dye usage in coronary angiog- raphy (CAG) [1]. Intravascular ultrasound- (IVUS-) guided percutaneous coronary intervention (PCI) is associated with signifcantly lower rates of adverse clinical events compared with angiography-guided PCI [2]. Although the small diame- ter of a 4Fr guiding catheter has several critical limitations in the use of angioplasty devices such as IVUS, the combination of a novel IVUS catheter and a 0.010 guidewire may make it possible to perform IVUS-guided PCI with a 4Fr guiding catheter. 2. Case Presentation A 51-year-old man was admitted to our hospital for acute inferior ST-elevation myocardial infarction 1 month previ- ously, and emergent coronary angiography revealed in-stent restenosis in the distal right coronary artery and severe steno- sis of the proximal portion of the second diagonal branch (D2). In-stent restenosis was the culprit lesion and was treated with a drug-coated balloon. One month later, the patient was readmitted to our hospital for elective PCI to the D2 lesion (Figure 1). A 4Fr BL3.5 guiding catheter (KIWAMI Heartrail, Terumo, Tokyo, Japan) was used to engage the lef coronary artery and a 0.010 inch guidewire (Decillion HS, Asahi Intecc, Aichi, Japan) was advanced across stenosis into the distal D2. An IVUS catheter (OptiCross5, Boston Scientifc, Natick, MA) was passed smoothly in the 4Fr guiding catheter and the D2 lesion. IVUS images demonstrated that the stenotic lesion was an eccentric fbrous plaque with superfcial calcium. Afer predilation of the lesion with a 2.5 × 15 mm scoring balloon (Scorefex, OrbusNeich, Hong Kong, China), a 3.0 × 16 mm everolimus-eluting stent (Promus Premier, Boston Scientifc, Natick, MA) was deployed successfully in the D2 lesion. IVUS images revealed incomplete apposition of the stent struts in the proximal edge (Figure 2); therefore, post- dilation of the stent proximal edge was performed using a 3.5 × 8 mm noncompliant balloon (Powered Lacrosse 2, Goodman, Aichi, Japan) at a maximum of 16 atm. Te fnal IVUS fndings revealed that the apposition of the stent strut was improved (Figure 3), and fnal angiography showed good results (Figure 4). 3. Discussion TRI can reduce vascular access complications and contrast dye usage in coronary angiography [3]. However, radial artery Hindawi Publishing Corporation Case Reports in Cardiology Volume 2016, Article ID 6369812, 3 pages http://dx.doi.org/10.1155/2016/6369812