Electrical Bioimpedance Sensing-Based Microcatheter Alignment in CTO-PCI

Percutaneous coronary intervention (PCI) is increasingly utilized for treating chronic total occlusion (CTO) coronary arteries. When direct passage through the occlusion is not feasible, the retrograde “kissing wire technique” (KWT) provides a valuable cannulation alternative. The KWT technique employs two microcatheters: one in the subintimal layer and the other in the true lumen on the opposite side of the occlusion. The latter microcatheter acts as a visual marker to guide the reentry of the microcatheter located in the subintimal layer toward the true lumen. However, accurately determining the microcatheter’s orientation, which is crucial for ensuring the correct reentry direction and avoiding the pericardial space, remains a significant challenge. This work presents a new method based on multi-electrical bioimpedance (EBI) sensing and cubic spline interpolation (CSI). The angular range for the correct reentry orientation was calculated based on the dimensions of the blood vessel and the microcatheters. By measuring the EBI from each electrode around the microcatheter tip, the catheter position is estimated through the minimum EBI, indicating the optimal reentry point. Experiments conducted in pure saline and in vitro conditions demonstrate that the approach reduces errors by over 30% at three distinct roll angles compared to the angular range. Furthermore, experiments across all angles revealed a maximum estimation error approximately 60% lower than the clinical standard. These results indicate significant potential for enhancing the efficacy and reducing the risks of the KWT technique through the EBI-guided approach.