Impact of In Vivo Ranges of the Variances in the Flow Velocity Waveforms and Flow Split Ratio on the Hemodynamic Effects of the Anastomotic Cuff at Distal End-to-Side Anastomosis

Purpose The blood flow inside distal end-to-side anastomoses may be affected by inlet flow velocity profiles and outlet blood distribution ratios. This study investigated the in vivo range of these variables and their impact on the hemodynamic effects of an anastomotic cuff using a computational fluid dynamics approach. Materials and Methods Predesigned expanded polytetrafluoroethylene cuffed grafts were used in 22 femoropopliteal bypasses and straight grafts were used for 10 cases. The flow distribution was examined by angiographic techniques and the inlet flow velocity was determined by a spectral Doppler method. Results The caudal outflow distribution ratio was 95.6% ± 7.2% (75%–100%). The positive peak flow velocity was 1.66 ± 0.25 m/s. The ratio of the absolute value of the negative to positive peak velocity was 0.32 ± 0.12. The cuff increased wall shear stress along the artery floor regardless of the flow velocity profiles at 100% of the caudal distribution ratio but not at 75%. Conclusion The hemodynamics inside the anastomosis were thus found to be affected by these flow variables. The proper indications for the cuff should therefore not be decided based simply on the location of the anastomosis without taking the fluid dynamic factors in the vicinity of the anastomosis into full consideration.