Wound tension and blood flow in skin flaps.

The relationship between wound-closing tension, blood flow, and flap viability is examined using piglets as an experimental model. Twenty-seven rectangular skin flaps with random-pattern blood flow were created and closed under varying tensions. Closing tensions were accurately measured using a stabilized mechanical force gauge. In flaps with an impaired blood supply, there was a statistically significant increase in flap necrosis for those flaps closed with greater than 250 g of tension. The laser Doppler demonstrated a clear-cut inverse relationship between flap tension and blood flow in these flaps which correlated well with the experimental flap necrosis seen.