**1. Introduction**

Flaps have been increasingly used in plastic and reconstructive surgery for tissue defects. Although the success rate of flap surgery reaches up to 99%, complications can occur even in the most experienced hands [1]. Vascular blood flow insufficiency is the leading cause of partial or total flap losses [2]. Ischemia-reperfusion (I/R) injury is the most important reason of vascular insufficiency to considerate. It is also the remarkable cause of flap compromise and organ dysfunction during organ transplantation and free flap surgery [3, 4].

The ischemic area of flaps is generally more distal to the region of vascular supply. Even the ischemia occurs for a short time period, it can generate reactive oxygen species (ROS). The reperfusion period, which occurs after ischemia, causes the restoration of blood flow and oxygen influx in the ischemic tissue and can finalize in cellular, inflammatory, and metabolic changes in the living cell. These changes caused by free radicals execute structural and functional alterations in the cell and may contribute to tissue necrosis [5]. This process can be prevented or decelerated with the use of antioxidant drugs that decrease the toxic metabolites responsible for tissue damage. Because postsurgical I/R injury is one of the most important causes of flap failure, in this review, we aim to show the pathophysiology of I/R injury and how the antioxidants show their beneficial effects on flap salvage.
