Currently, end-to-end anastomosis of blood vessels is performed using suturing, which is time consuming, expensive, and subject to large degrees of human error. One promising alternative is a ring–pin coupling device. This device has been shown to be useful for venous anastomosis, but lacks the versatility necessary for arterial applications. The purpose of this study was to optimize a vascular coupling design that could be used for arteries and veins of various sizes. To achieve this, finite-element (FE) analysis was used to simulate the vessel–device interaction during anastomosis. Parametric simulations were performed to optimize the number of pins, the wing pivot point, and the pin offset of the design. The interaction of the coupler with various blood vessel sizes was also evaluated. Maximum strain in the vessel wall increased with the number of pins. The positions of the wings and pins were also important in dictating maximum strain, and improper dimensions lead to failure of the installation process. Extra force applied to the distal end of the vessel, or a supplementary tool, will be required during the coupler installation process to prevent vessels less than 3 mm inner diameter (0.5 mm wall thickness) from slipping off the coupler.