Primary critical ischemia time in the hairless mouse ear

The primary critical ischemia time of the hairless mouse ear was determined using a probit analysis. An atraumatic clamp was used across the pedicle base of the ear to induce total ischemia at 0, 2, 4, 6, 7, 7.5, 8.0, 8.5, 9.0, 9.5, and 12 hours of normothermic ischemia. Seventy-seven ears were examined 7 days after the ischemic interval for evidence of necrosis. The median critical ischemia time was determined to be 8.2 hours with 95 percent fiducial limits of 7.74 hours and 8.69 hours.