Titrated Contrast Recanalization: A Novel Controlled-Contrast Technique for Anterograde Crossing of Chronic Total...

Anterograde wiring is fundamental to Chronic total occlusions percutaneous coronary intervention (CTO) percutaneous coronary intervention but often limited by guidewire crossing difficulty. We introduce a novel Titrated Contrast Recanalization (TCR) technique to facilitate anterograde crossing. Consecutive patients undergoing CTO percutaneous coronary intervention using TCR as the primary strategy between August and December 2025 were enrolled. TCR used an automated microinjector to deliver 0.1 to 0.5 ml contrast into CTOs with real-time pressure monitoring, enhancing CTO architecture visualization for wire guidance. Lesions were classified by contrast penetration patterns: type 1, localized patchy confined within the occlusion; type 2, linear microchannels through the occlusion; or type 3, patchy staining extending beyond the vessel contour or tracking longitudinally along the vessel wall. Polymer-jacketed wires were used for linear microchannels; anterograde wire escalation or the parallel-wire techniques were applied to types 1 and 3, while retrograde or anterograde dissection re-entry serving as a last resort. The primary endpoint was successful anterograde crossing; secondary endpoints were TCR-related complications. Among 71 CTOs (mean lesion length >20 mm in 76.1%; moderate/heavy calcification in 64.8%), successful anterograde crossing was achieved in 70 cases (98.6%) with no TCR-related complications. Anterograde crossing with polymer-jacketed wires succeeded in 40 lesions; anterograde wire escalation and parallel-wire techniques were successful in 8 and 15, respectively; the remaining 7 were recanalized by intravascular ultrasound guidance, retrograde, or anterograde dissection re-entry. Median crossing time was 8 minutes (IQR, 6 to 13) and median microinjected contrast per TCR was 0.37 ml (IQR, 0.29 to 0.40). In conclusion, TCR is a feasible anterograde-first technique with promising efficacy and safety outcomes.