A simple practical balloon anchoring technique within the guide catheter for chronic total occlusion (CTO) of the coronary artery

Dear Editor: Chronic total occlusions (CTOs) of the coronary artery are commonly encountered complex lesions [1] . Percutaneous coronary intervention (PCI) for CTO is technically challenging due to low procedural success rates [2] . Microcatheter is one of the important devices for treatment of CTO [3] . It has been widely used attributed to the excellent crossability whenever angulation and tortuousity of the coronary artery is encountered [4] . In the process, the microcatheter has to be withdrawn from the guide wire after the wire is proved to locate in the true lumen. For microcatheter removal, the guidewire should be fixed to avoid shifting by either adding prolonged wire to the guidewire or using prolonged wire (such as RG3) at the beginning of the operation, and then pressing the proximal part of the guidewire to fix it. However, in actual operation, the distal part of the guidewire may shift. Besides, the time for removing the microcatheter is much longer with prolonged guidewire. To overcome the previous problem, we designed a new technique for withdrawing the microcatheter: the balloon anchoring technique within the guide catheter. Detailed steps are as follows: (1) Insert the guidewire into the occluded segment in support of the microcatheter and insert the microcatheter into the occluded segment alongside the wire. Remove the wire when it has arrived at distal vascular lesions through the occluded segment the wire. After the wire is proved to locate in the ture lumen of blood vessel by the contrast agent injected from the microcatheter, the wire is advanced into the occluded segment. (2) Withdraw the microcatheter several centimeters in the guide catheter (probably at the end of ascending aorta). (3) Insert a predilation balloon with diameter ranged from 2.02.5mm (the balloon can be used in percutaneous transluminal coronary angioplasty (PTCA) afterwards)into the distal end of the catheter via the guide catheter on the outside of the microcatheter (Fig. 1A). (4) Release the balloon with pressure ranged from 8 to 10atm and press the guidewire on the wall of the guide catheter, then withdraw the microcatheter with slow and uniform speed under X-ray fluoroscopy (Fig. 1B). (5) Withdraw the predilation balloon gradually when the microcatheter is completely removed. Here we present a case which was performed with the new tchnique. A 84-year-old male patient was admitted to our hospital because of chest tightness for 8years. Conventional coronary angiography demonstrated approximately 60-70% stenosis in proximal-segment of left anterior descending artery (LAD), around 50% stenosis in proximal-segment of diagonal branch and around 90% stenosis in proximal-segment of OM2. Left circumflex artery (LCx):30% stenosis in proximal-segment and 60% stenosis in distal-segment. Coronary angiography showed a CTO of the proximal right coronary artery (RCA). No stenosis was found in LM. After seeking the