Development of a porcine excisional wound model.

OBJECTIVES

To develop a porcine model for cutaneous tangential excisional wounds.

METHODS

This was a prospective, longitudinal, blinded experiment on four isoflurane-anesthetized swine. Forty standardized excisional wounds (1 square inch each) were created with an electric dermatome set at a depth of 300, 600, 750, or 900 microm. Full-thickness wounds were created with a surgical blade (n = 8 for each depth). Wounds were treated with polyurethane film. Full-thickness punch biopsies were taken after one, two, three, four, five, and 14 days for blinded histopathological evaluation. The main outcome was the percent wound reepithelialization (REP) calculated by dividing the length of neoepidermis in cross-section by the specimen's diameter (interobserver correlation = 0.99). Analysis of variance was used to compare percent REP among wound depths. This study had 80% power to detect a 33% difference in REP across groups (two-tailed alpha = 0.05).

RESULTS

There were significant differences in percent REP across wound depths for days 2-5 (p < 0.001 for all days). The more superficial wounds (300 to 600 microm) were mostly reepithelialized by day 4, whereas wounds ranging in depth from 750 to 900 micro m were mostly healed by day 5. Full-thickness wounds had no evidence of REP even after 14 days.

CONCLUSIONS

The authors describe an excisional wound model in swine. Rapid reepithelialization occurs within three to five days in wounds <900 microm deep.