Comparison of six methods for the assessment of ischemia-reperfusion injury in skeletal muscle following composite tissue allotransplantation.

Ischemia/reperfusion (I/R) injury is one of the factors determining tissue survival in replantation and transplantation surgery. However, more than 20 methods have been used to evaluate I/R injury in muscle. The aim of this study was to examine I/R injury in muscle tissue in a model of composite tissue allotransplantation (rat hindlimb transplantation), based on the analyses of six parameters: nitroblue tetrazolium staining (NBT); histology of the anterior tibial and extensor digitorum muscle; wet-to-dry weight ratio; serum potassium; and serum creatine kinase (CK)), in order to identify the most practicable and reliable outcome parameter. Results demonstrated that NBT staining and the wet/dry weight ratio are reliable tools for outcome measurement. The wet/dry weight ratio is the easiest to perform and the authors consider it to be useful for screening purposes. Histologic assessment shows areas of necrosis, but is not a reliable method for semi-quantitative evaluation. Serum potassium and CK levels were higher following transplantation, but they cannot be recommended for assessment purposes, as no significant correlation with other parameters was seen. These findings help further researchers in their selection of reliable outcome parameters to measure I/R injury in skeletal muscle.