The use of video motion analysis to determine the impact of anatomic complexity on endovascular performance in carotid artery stenting.

OBJECTIVE: Video motion analysis (VMA) uses fluoroscopic sequences to derive information on catheter and guidewire movement and is able to calculate two-dimensional catheter tip path length (PL) on the basis of frame-by-frame pixel coordinates. The objective of this study was to evaluate the effect of anatomic complexity on the efficiency of completion of defined stages of simulated carotid artery stenting as measured by VMA.

METHODS: Twenty interventionists each performed a standardized easy, medium, and difficult carotid artery stenting case in random order on an ANGIO Mentor (Simbionix, Airport City, Israel) simulator. Videos of all procedures were analyzed using VMA software, and performance was expressed in terms of two-dimensional guidewire tip trajectory distance (PL). Comparisons of PL were used to identify differences in cannulation performance of the participants between the three cases of varying difficulty. The procedure was subdivided into four procedural phases: arch navigation, common carotid artery (CCA) cannulation, external carotid manipulation, and carotid lesion crossing. Comparisons of PL were used to identify differences in performance between the three cases of varying difficulty for each of the procedural phases.

RESULTS: There were significant differences in PL in relation to anatomic complexity, with a stepwise increase in PL from easy to difficult cases: easy, median of 5000 pixels (interquartile range, 4075-5403 pixels); intermediate, 9059 (5974-14,553) pixels; difficult, 17,373 (11,495-26,594) pixels (P < .001). Similarly, during CCA cannulation, there was a stepwise increase in PL from easy to difficult cases: easy, 749 (603-1403) pixels; intermediate, 3274 (1544-8142) pixels; difficult, 8845 (5954-15,768) pixels (P < .001). There were no observed differences across the groups of anatomic difficulty for the phases of arch navigation, external carotid manipulation, and carotid lesion crossing.

CONCLUSIONS: Increasing anatomic complexity leads to significant increases in PL of endovascular tools, in particular during CCA cannulation. This increase in tool movement may have a bearing on clinical outcome.