Comparing the use of glycerol preserved and cryopreserved allogenic skin for the treatment of severe burns: differences in clinical outcomes and in vitro tissue viability.

Cryopreserved (CryoPA) and Glycerol-preserved (GPA) skin allografts are commonly used in the treatment of severe burn injuries. However, comparable data on their differences in clinical outcome is scarce. This retrospective review aims to study the effect of allograft viability on clinical outcomes. The records of 48 severe burn patients who either received CryoPA or GPA were reviewed. Key burn mortality determinants were used to match the 2 groups. Clinical outcomes such as mortality rate (MR) and the length of hospital stay (LOS) were obtained. A separate in vitro comparison included histological assessments and the use of tetrazolium reductase activity to compare tissue viability. Both groups showed a comparable profile in burn mortality determinants. Patients who received CryoPA had a lower MR of 25% compared to 34.8% (P=0.250) in the GPA group and a lower LOS of 39.2-45.9 days (P=0.730), respectively. The histological structural integrity was found to be well preserved with both methods although CryoPA was confirmed to be the more viable product (P<0.05). The lower MR associated with CryoPA cannot be totally ignored. However, the mechanism through which viable skin allografts improves MR of severe burns patients remains to be elucidated.