The Direct Antegrade Recanalization Technique Using the Crosser iQ for Below-the-Knee Chronic Total Occlusions A Retrospective Single-Center Study

Background This study aimed to assess the feasibility and procedural safety of the direct antegrade recanalization technique using the newly developed Crosser iQ catheter for below-the-knee (BTK) chronic total occlusions (CTOs). Methods This retrospective, single-center study included 50 consecutive patients with chronic limb-threatening ischemia who underwent endovascular therapy for BTK CTOs between September 2024 and December 2025. The Crosser iQ catheter was used as the primary crossing device, employing either a wire-first or crosser-first strategy within a structured direct antegrade approach. The primary endpoint was technical success, defined as successful distal true-lumen crossing achieved with the Crosser iQ catheter. Secondary endpoints included residual stenosis ≤ 30% and procedure-related complications, including slow flow, metallic tip detachment, and vessel perforation. Exploratory univariate analyses were performed to assess lesion- and procedure-related factors associated with slow flow. Results Technical success was achieved in 47 of 50 lesions (94%). The mean Crosser activation length and activation time were 121 ± 35 mm and 1.4 ± 0.49 minutes, respectively. Slow flow occurred in four cases (8%), and metallic tip detachment occurred in two cases (4%); no vessel perforation was observed. Exploratory analyses demonstrated no significant associations between slow flow and lesion characteristics, including total lesion length, CTO length, and calcium severity assessed by the Peripheral Arterial Calcium Scoring System. Similarly, procedural variables, including crosser activation length and activation time, were not significantly associated with slow flow. An antegrade-only crossing strategy showed a nonsignificant trend toward a higher incidence of slow flow ( P  = 0.087). Conclusions This retrospective single-center experience suggests that the direct antegrade recanalization technique using the Crosser iQ is feasible and appears safe for the treatment of complex BTK CTOs. The controlled subintimal crossing strategy achieved a high technical success rate with a low incidence of slow flow, supporting its potential role as a safety-oriented approach in BTK endovascular therapy.