The new technique was based on a bi-triangulated preparation of the branching-vessel end, HTS assay resulting in a “fish-mouthed” opening. We performed two different types of end-to-side anastomoses in forty pig coronary arteries and produced one elastic,

true-to-scale silicone rubber model of each anastomosis. Then we installed the transparent models in a circulatory experimental setup that simulated the physiological human blood flow. Flow velocity was measured with the one-component Laser-Doppler-Anemometer system, recording flow axial and perpendicular to the model at four defined cross-sections for seven heart cycles in each model. Maximal and minimal axial velocities ranged in the conventional model between 0.269 and −0.122 m/s and in the experimental model between 0.313 and −0.153 m/s. A less disturbed flow velocity distribution was seen in the experimental model distal to the anastomosis. The OES-technique showed superior flow profiles distal to the anastomosis with

minor tendencies of flow separation and represents a new alternative for end-to-side anastomosis. © 2013 Wiley Periodicals, Inc. Microsurgery 34:28–36, 2014. Free flap transfers have reached a high rate of success and represent the gold standard procedure for defect reconstruction at the head and neck.[1] The essential vascular support can be maintained either by end-to-end or end-to-side anastomosis. AZD1208 mouse The superiority of one technique has been an item of debate for decades.[2-4] Both techniques have their special advantages and disadvantages and the usage of either of them should be based upon clinical circumstances and microsurgeon’s experience.[5-7] In the 1970s and early 1980s, the end-to-side anastomosis was proclaimed as the technique of choice, as it was told Teicoplanin to be associated with some advantages in blood

flow.[2, 8-10] The possibility to vary the fashion of creating a “side window” (vesselotomy) of the main vessel, the preparation of the branching vessels’ end and the angle of the branching vessel fed the search for the perfect technique. Following, numerousness variations of the end-to-side technique have been published.[5, 11-13] But rheological changes in the range of the transitional flow, have not been investigated.[14, 15] Flow patterns and hemodynamic forces, especially in branches and curvatures, are able to sustain molecular signalling of pro-inflammatory and proliferative pathways.[16] Since flow separation distal to bifurcations is inter alia strongly dependent on the geometry (physiologically or surgically induced), branch-to-trunk flow rate ratio, pulsatility, elasticity of the vessel wall, and special flow pattern of blood,[17-19] every surgeon dealing with vessels should have basic knowledge of blood flow. Nowadays, microsurgical researcher have access to different simulative models, whether in vivo or in vitro models.