In Vitro and Human Studies of a 4F Double-Coaxial Technique (“Mother-Child” Configuration) to Facilitate Stent Implantation in Resistant Coronary Vessels

Background—We recently developed a 4F child catheter that can be inserted into 6F or larger conventional guiding catheters. The use of 4F mother-child technique may improve the delivery of coronary stents to complex lesions. Accordingly, we sought to determine the potential of using a 4F mother-child technique to treat complex coronary lesions. Methods and Results—The support power and the trackability of the mother-child technique of 4-in-6 were evaluated using a coronary artery tree model. In addition, the results of 51 lesions treated by using a 4F child catheter were retrospectively analyzed. The in vitro experiment demonstrated that backup support of the 4-in-6 system was increased when the child catheter was advanced into the coronary tree ≥5 cm (P≤0.01); further, the 4F child catheter was associated with superior trackability as compared with a 5F child catheter (15.0 cm [15.0 to 15.0] versus 13.0 cm [12.8 to 13.0], P<0.005). A total of 51 lesions, in which conventional techniques had been unsucces...