Caffeine Does Not Reduce Blood Flow Following Arterial Anastomosis in the Rat.

 Patients are usually advised not to consume caffeine following digital replantation. This study examined the effect of caffeine on blood flow distal to the site of anastomosis in the femoral arteries of rats.  A total of 28 Sprague-Dawley rats were used for this study. The femoral arteries were exposed bilaterally and baseline blood volume flow measurements were taken on intact arteries using a transit time flow-meter probe. All rats underwent transection and microvascular anastomosis of the femoral artery on the right side while the left side remained intact to serve as a control. The rats were then divided into two groups. In group 1, caffeine was administered (intraperitoneal injection of 40 mg caffeine/kg of body weight dissolved in saline) and in group 2 no caffeine was given. In both the groups, bilateral flow measurements were then taken at 30 and 60 minutes, respectively, following completion of the anastomosis.  All anastomoses remained patent during the study time period. Caffeine had no statistical effect on blood flow distal to the anastomosis. Both anastomosed and control arteries demonstrated a statistically significant increase in blood flow at 30 and 60 minutes, respectively, postanastomosis that was independent of caffeine administration.  Caffeine does not have a statistically significant effect on blood flow distal to the anastomosis following microsurgical repair of the rat femoral artery.