Rare complications of Guideplus guide-extension catheter during complex percutaneous coronary intervention

Guide-extension catheters (GECs) are effective in providing reinforced backup support and coaxial alignment, leading to successful complex percutaneous coronary intervention (PCI). However, several GEC-associated complications have been reported, including coronary injuries, thrombotic events, and GEC fractures. The Guideplus GEC (Guideplus II ST; Nipro, Osaka, Japan) has a higher crossability due to its unique hydrophilic-coated soft cylinder, which is frequently used in complex PCI for diffuse, tortuous, and heavily calcified lesions. We describe two cases of Guideplus GEC-associated complications during complex PCI: Case 1 with a radiopaque marker dislodgement and Case 2 with a stent dislodgment. In both cases, the Guideplus GEC was used within 7-Fr guiding catheters, employing the mother-and-child technique. A large inner-catheter gap between these catheters caused by a positioning bias due to arterial bends (the aortic arch in Case 1 and brachiocephalic arterial bends in Case 2) may have caused these complications due to its interference with coronary devices (the trapping balloon in Case 1, and the scoring balloon in Case 2). Early cognition and management of these potential Guideplus GEC-associated complications are important to prevent further deterioration. LEARNING OBJECTIVES: The Guideplus guide-extension catheter (GEC) with a hydrophilic-coated soft cylinder can deliver coronary devices to complex lesions owing to its high crossability. However, delivering coronary devices with the Guideplus GEC should be carefully performed because a large inner-catheter gap between Guideplus GEC and a guiding catheter may occur if a proximal port of the Guideplus GEC is located at an arterial bend. In such settings, Guideplus GEC-associated complications must be carefully observed, including radiopaque marker dislodgement and stent dislodgement.