Hemodynamics of the rodent abdominal skin flap following primary ischemia

The effect of varying periods of ischemia and reperfusion times on subsequent blood flow was studied in the rodent abdominal skin flap. Using perfusion fluorometry, measurements of blood flow were quantified in 60 Sprague-Dawley rats undergoing clamp-induced ischemic periods ranging from 0 to 6 hours and reperfusion times ranging from 2 to 8 hours. Flaps subjected to ischemia times of 0, 2, 4, or 6 hours require 8 hours of reperfusion time before reaching baseline levels of blood flow. Blood flow in flaps subjected to 6 hours of ischemia was statistically less than the flow in flaps ischemic for 0, 2, and 4 hours and was directly related to length of reperfusion. These results demonstrate that flap perfusion does not fully take place immediately after clamp release. The factors thought to be responsible for these findings and the implications for the design and interpretation of flap ischemia experiments are discussed.