OBJECTIVETo evaluate the effect of exteral use of papaverine cream on enhancement of skin graft.

METHODSFive mini-pigs were used for the study. 20 full-thickness wounds were created on the back of each animal. Along the midline of the abdomen, a 40 cm x 2 cm full-thickness skin graft was harvested and the wound sutured.The full-thickness graft was prepared and trimmed to 2 cm x 2 cm of 0.6 mm thickness split-skin grafts, which were transplanted to each wound with tie-over bolsters. The sutures were removed 2 weeks after the operation. Twelve pairs of 100%-survived skin grafts were selected and divided into group A (the left side) and group B (the right side), with each pair locating on the same and opposite position. From the day of suture removal, 2% papaverine cream was used to group A while plain cream was used to group B. The grafts were measured and observed for healing condition at the time of suture removal and the first, second, third, fourth, fifth, and sixth month. The surface area of the graft was measured and the shrinking ratio was calculated. After the animals were killed at the sixth month, samples of the skin grafts were taken and processed with 10% formalin, routine paraffin wax and Hematoxylin-eosin staining. The tissue structure was observed and the results were analyzed statistically.

RESULTSThe grafts in two groups did not have significant differences at the time of suture removal. Observations from the first to the sixth month showed that the two groups had significant differences in skin graft contracture and histological changes. HE stains demonstrated that the skin grafts in group A had less fibroblasts, more microvessels and orderly-arranged collagenous fibers.

CONCLUSIONSExternal use of papaverine cream can inhabit the contraction of skin grafts. It is a safe, effective, simple, and reliable method,which has the advantages of easy delivery,cheapness, less injury and infection,and no side effects.