title: In vitro and human studies of a 4F double-coaxial technique ("mother-child" configuration) to facilitate stent implantation in resistant coronary vessels.
abstract: 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.
  
  
  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 unsuccessful, were treated using the 4F mother-child technique. Lesion success was achieved in 48 (94%) lesions. Stent deployment was attempted in 44 (86%) and was successful in 40 of 44 (91%). There were 2 instances of stent dislodgment.
  
  
  CONCLUSIONS
  With the superior trackability of the 4F child catheter and with increased backup support of the mother-child system, the 4F mother-child system provided >90% success rate for lesions in which conventional techniques had failed. The 4F mother-child system may become a viable alternative to conventional techniques in treating complex coronary lesions.
authors.affiliation: Department of Cardiology and Catheterization Laboratory and Cardiovascular R&D Center, Shonan Kamakura General Hospital, Kamakura, Japan. stake@muse.ocn.ne.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takeshita
authors.forename: Koki
authors.initials: K
authors.lastname: Shishido
authors.forename: Kazuya
authors.initials: K
authors.lastname: Sugitatsu
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Okamura
authors.forename: Shingo
authors.initials: S
authors.lastname: Mizuno
authors.forename: Kenji
authors.initials: K
authors.lastname: Yaginuma
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Suenaga
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Junya
authors.initials: J
authors.lastname: Matsumi
authors.forename: Saeko
authors.initials: S
authors.lastname: Takahashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation* / Q000379:methods; D057785:Catheters; D023921:Coronary Stenosis / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents