Femoral Bifurcation Morphological Analysis: Optimal Diameter of the Common Femoral Artery Stent

Abstract

Introduction: Common femoral artery (CFA) stenting appears as a promising treatment for de novo CFA stenosis. Nevertheless, stenting of CFA bifurcation lesions is complex because of harmonious asymmetric geometry between the CFA and deep or superficial femoral artery. In order to ensure an optimal flow and to reduce the risk of restenosis, the stents must be implanted according to the diameter of the CFA and the diameter of the daughter vessels. In daily practice, to optimize the implantation of stents in this bifurcation, a fast and efficient method is needed to guide the physician during the procedure. The aim of our study was to validate a mathematical formula for the CFA bifurcation and to compare it to 4 existing models. Methods: We retrospectively included all patients who underwent transcatheter aortic valve implantation and who had a healthy CFA bifurcation on the CT-scan. Diameters of the mother vessel (Dm) and of each daughter vessel (Dl: larger daughter vessel; Ds: smaller daughter vessel) were measured. The ratio between the CFA and the two daughter vessels [Dm / (Dl + Ds)] was calculated, which made it possible to propose our mathematical model [Dm= (Dm / Dl + Ds) x (Dl+Ds)]. The diameter of the mother vessel was calculated according to the four existing validated physical models (Murray, HK, Flow, Finet). Finally, we calculated the relative error between the prediction of the four models and the measurements. Results: 110 CFA bifurcations from 60 patients were included. Mean mother-vessel (CFA) diameter was 7.75 ± 1.67 mm. Mean larger daughter-vessel diameter was 5.79 ± 1.21 mm and mean smaller daughter-vessel diameter was 5.23 ± 1.09 mm. A reduction of 25 % was seen between the mother-vessel and the larger daughter-vessel. The mean ratio between the CFA and the daughter vessels was 0.71. Mean angle between the superficial femoral artery (SFA) and the deep femoral artery (DFA) was 28.47° ± 5.51°. Murray's law was the only law to have a statistically significant deviation from the reel mother-vessel diameter (p< 0.001). Our model and the flow law were the most accurate with a relative difference of 1.59 ± 11.97% and 1.01 ± 11.94%, respectively. The HK and the Finet law are acute when the daughter diameters ratio are greater than 0.8. Conclusion: We developed a simple fractal ratio between the CFA and the daughter vessels [Dm=0.71 x (Dl+Ds)]. This ratio could be easily used in daily practice during CFA percutaneous reconstruction to identify the optimal diameters of the diseased vessels. Disclosure: Nothing to disclose