Raman and fluorescence spectroscopic evaluation of NIR laser welded human and porcine aorta tissues

摘要

Laser tissue welding involves the partial denaturing and renaturing of the collagen triple helical structure. Although the mechanisms of laser tissue welding are not well understood, water hi tissues plays an important role in the process. High quality welding of human and porcine aorta tissue have been achieved using NIR lasers tuned to the water absorption band around 1450 nm. Fluorescence and Raman spectra from welded and non-welded regions are compared for ex vivo human and porcine aorta tissues. The fluorescence from the outer surface of welded aorta was substantially weaker than the fluorescence from the non-welded region. The Raman spectra from the welded and non-welded tissue regions appeared similar in the energies of the observed vibrational levels but the intensity of the fluorescence wing was considerably greater from the outer surface of the welded region as compared to the non-welded region. For the outer surface of the aorta, the emission intensity from the welded region was larger than for the non-welded region.