Laser welding and collagen crosslinks

Abstract

The strength and stabilityof laser-weldedtissue maybe influencedin pa@ by the effectsof laser exposure on collagen crosslinking.We thcmfm studiedthe effixts of diode laserexposure(805 nrn , 1-8 watts, 30 seconds) + indocyanine green dye (ICG) on calf tail tendon collagen crosslinks. 'Ihe efllsct of KG dye alone on crosslink content prior to laser exposure was investigated; unexpectedly, we found that KG-treated tissue had significantly increased DHLNL and OHP, but not HLNL. Laser exposure after 1(% application reduced elevated DHLNL and OHP crosslink content down to their native levels. The monobydrqdated crosslink HLNL was inversely cordated with laser output (pcO.O1 by linear regression analysis). DHLNL content was highly correlated with content of its maturational produce OHP, suggesting that precumr-pmduct relationships are maintained.We conclude that (1) ICG alone induces DHLNL and OHP crosslhk fonnatiom (2) subsequent laser exposure reduces the' ICG-induced crosslinks down to mtive levels (3) destroys normally occurring HLNL crosslii.