End-to-side arterial anastomoses require a high level of technical competency. The main challenge to a successfully patent anastomosis is intimal interposition during the standardized microvascular suturing. Technical errors during arteriotomy pose a significant challenge for the microsurgical technique, making the end-to-side anastomosis prone to failure. We describe a basic yet fundamental method of performing an arteriotomy, the "crater" technique, which facilitates good visualization of all vessel layers before placement of microsurgical sutures. Using curved microsurgical scissors, the adventitia layer is dissected off the outer surface of the side vessel, a V-shaped cut is then made obliquely at a 30-45 degrees angle to the longitudinal axis of the vessel, and a full thickness oblique cut is made along an elliptical circumference, as the curved scissors enable the creation of a slope-like crater. This concept ensures the intimal layer is adequately exposed through the complete circumference of the arteriotomy rim, while enabling a variable increase in the arterial wall hypotenuse-width circumference. When performed in a standardized manner, the crater arteriotomy can minimize the risk of endothelial misalignment and further technical errors during suturing, thus minimizing the risk of anastomotic failure.