Guide catheter extension lock enables the strongest backup force during the antegrade approach in percutaneous coronary intervention.

Sufficient guide catheter backup is crucial for successful percutaneous coronary intervention (PCI). We have developed a new technique for locking a small child catheter to the vessel wall by balloon dilatation outside the child catheter at the proximal site of the main branch. We call this the "guide catheter extension lock" ("Kiwami® lock", Kiwami® child catheter, Terumo Corp. Tokyo, Japan). The guide catheter extension lock backup force was evaluated in an experimental model, and we report a case of chronic total occlusion treated with PCI using this technique. The guide catheter backup force was measured using an artificial cardiac vessel model with a right coronary artery and side branch. We evaluated the backup forces of the guide catheter extension lock and other techniques using an 8Fr Judkins right guide catheter (child catheter: 45.0 ± 4.6 g force [gf]; a 7Fr delivery catheter (Guide-Liner®, Vascular Solutions, Minneapolis MN, USA): 67.4 ± 14.4 gf; an anchoring balloon technique at the side branch: 98.3 ± 11.9 gf; and the guide catheter extension lock: 112.1 ± 13.0 gf). The guide catheter extension lock technique provided the strongest backup force. Our clinical experience shows that this technique is effective during PCI.