[Analysis of Critically Perfused Tissues by Laser Speckle Contrast Analysis (LASCA) Perfusion Imaging]

Background: The success of tissue transplantation and long-term tissue stability after wound healing depends on sufficient tissue perfusion. Laser Doppler-supported procedures allow for an objective measurement of relative tissue perfusion. The development of Speckle-based Laser Doppler imaging now enables a real-time representation of tissue perfusion. The perfusion of tissues relevant in plastic surgery such as scars, phalangeal replantations and burn wounds were systematically analysed by Laser Speckle Contrast Analysis (LASCA) imaging. Method: Perfusion of skin, scars, replanted fingers and different burn wound degrees (IIa, IIb and III) were systematically examined by LASCA imaging. Baseline perfusion of control tissue and perfusion values of compromised tissues were quantified and compared. Results: LASCA imaging shows significant differences in baseline perfusion of skin compared to atrophic scars, hypertrophic scars and keloids. Finger replantations with subsequent replantation failure show a characteristic and significant hypoperfusion in line with the expected clinical feature. A significant difference in tissue perfusion is seen in superficial (IIa) and superficial deep (IIb) burns, which are hard to distinguish on clinical examination. Deep burns (III) are characterised by hypoperfusion, which differs significantly from grade IIa and IIb burn wound perfusion, but not from baseline skin perfusion. Furthermore, the characteristic perfusion values of different burn degrees correspond to the varying treatment strategies. Conclusion: LASCA imaging is a robust method of perfusion imaging, which combines high resolution and speed. Hypoperfusion of tissues relevant to plastic surgery such as scars, phalangeal replantations and the different burn degrees (IIa, IIb and III) can be detected by LASCA imaging with high precision. Ease of use and immediate real-time imaging make LASCA imaging a reliable tool for the evaluation of tissue perfusion after plastic surgery procedures, which may influence further treatment decisions.