Tetrazolium reductase as an index of viability of stored skin

Abstract

The take or failure of 264 split-skin grafts on burned patients has been investigated; the single most important reason for failure was non-viability of the graft at its time of application, as measured by the relative tetrazolium reductase (TR) activity. There was a high correlation between relative TR activity of less than 50 per cent and graft failure, and between TR activity of greater than 50 per cent graft take. The longest period for which a graft could be stored at −10°C and remain viable was 12 days; a few were non-viable before 10 days. Repeated freezing and thawing of stored skin grafts reduced the length of viability by 40 per cent compared with grafts which had been frozen and thawed only once. The tetrazolium reductase activity provides a quick reliable prognostic indication of whether or not a graft should be applied with the anticipation of a take.