Interpositional vein grafting is the gold standard for the replacement of vascular defects. Although many microsurgeons have used classical Suture anastomosis successfully, it is still technically challenging, especially for the inexperienced Surgeon. We present a new technique that facilitates autogenous vein grafting by using a commercially available silastic tube employed temporarily during the suture anastomosis and removed at the end of the procedure. Effects of this technique on operative time and patency were tested by an experienced and an inexperienced microsurgeon. Each surgeon operated on a total of 20 rats divided in experimental and control groups of 10 animals each. The experimental group was operated on with silastic-tube-assisted suture anastomosis, and the control group was operated on using the classical suture anastomosis without using the device. For the experienced microsurgeon, proposed modification resulted in a statistically significant reduction in operative time without an effect on patency. For the inexperienced microsurgeon, the proposed modification resulted in a statistically significant reduction in operative time and also enhanced patency rates significantly. Interpositional vein grafting over a temporary silastic tube is a practical modification of the classical microvascular anastomosis that adds speed and ease to the microvascular vein grafting procedure and prevents back-wall biting, particularly for inexperienced microsurgeons.