Effects of local pressure on cutaneous blood flow in pigs.

Objective: to evaluate the effects of increasing pressures on the cutaneous blood flow in the skin of pigs.
Methods: we conducted an experimental study in pigs submitted to subcutaneous magnetic implants (n=30). After healing, were applied external magnets with varying magnetic forces to the skin, generating compression. We evaluated the cutaneous circulation of the skin under compression by the Laser Speckle Contrast Imaging (LSCI) technique. We measured the depth of the implants by ultrasonography, and applied computational simulations to the calculation of the different pressure values, considering the different distances between implants and external magnets.
Results: nineteen implants presented complications. The remaining 11 were submitted to different magnetic compression forces and perfusion analysis. Two linear regression models showed an inverse correlation between exerted pressure and cutaneous perfusion, with significant variation, mainly in the initial pressure increases, of up to 20mmHg.
Conclusion: The main reduction in cutaneous blood flow resulted from initial increases of up to 20 mmHg. The results suggest that tissue ischemia can occur even in low-pressure regimes, which could contribute to the appearance of skin lesions, particularly ulcers related to medical devices.