Reverse Tip Detection: An IVUS-Guided Strategy for Retrograde Wire Crossing in CTO PCI

Reverse controlled antegrade and retrograde subintimal tracking (R-CART) is a widely used retrograde strategy for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). However, conventional R-CART may fail when the antegrade wire is located within the subintimal space while the retrograde wire remains within the intraplaque space or true lumen because of anatomical layer mismatch. We describe a novel bailout technique, reverse tip detection (R-TD), which applies the concept of the tip detection method to the retrograde approach under intravascular ultrasound (IVUS) guidance.

Two CTO PCI cases in which conventional R-CART failed because of anatomical layer mismatch were successfully treated using R-TD. In both cases, antegrade IVUS-guided visualization of the retrograde guidewire tip enabled intentional redirection of the retrograde wire into the antegrade-created subintimal space, creating a subintimal-subintimal connection. This facilitated successful guidewire connection, advancement of the retrograde microcatheter, subsequent wire de-escalation, and completion of CTO crossing without the need for additional dedicated re-entry devices.

R-TD is a feasible IVUS-guided bailout strategy for R-CART failure caused by anatomical layer mismatch. By enabling controlled retrograde wire redirection into the antegrade-created subintimal space, R-TD may simplify retrograde CTO crossing while avoiding unnecessary balloon escalation and additional dedicated devices, potentially improving procedural success and safety.