The preoperative preservation of amputated digits: an assessment of proposed methods

Cooling of recently amputated digits is recommended to preserve tissue pending reimplantation. Although many methods are describe for cooling digits, it is unknown which method is optimal.

Six methods were compared in which fresh chicken feet were wrapped in saline-soaked gauze, placed in a plastic bag or a specimen jar, and then placed in a fixed quantity of ice and water in one of a plastic bag, kidney dish, or sealed plastic container. Serial measurements were made of the (1) tissue temperature and (2) point at which ice in the solution was no longer visible. Each method was repeated 12 times, resulting in 72 sets of measurements.

There was a significant variation in the time each method took to reach the target tissue temperature (p < 0.001) and the duration that the tissue was kept within the target temperature range (p < 0.001). Of the six methods tested, placing the chicken foot into a specimen jar and subsequently placing this into a specimen bag containing ice and water kept the tissue within the target temperature range (4 degrees C +/- 2 degrees C) for the longest duration [225.8 minutes, 95% confidence intervals (CI), 201.5-250.1]. The Bag-in-kidney dish method performed worst, with the slowest time to reach target temperature (58.0 minutes, 95%CI, 46.0-70.0) and the shortest duration at this temperature (62.0 minutes, 95%CI, 46.3-77.7).

Of the six methods examined, the best method for achieving a target temperature of 4 degrees C +/- 2 degrees C is by wrapping the tissue in saline-soaked gauze, placing it in a specimen jar and placing this into a specimen bag that contains ice and water.