Delayed tissue death probed with sunlight surgery

摘要

We report pronounced delayed tissue death in photothermal surgery performed with highly concentrated sunlight on thelivers of healthy live rats. Pathology reveals that lesion volumes increase by up to a factor of 5 within approximately 24h after surgery, and then stabilize. Islands of viable cells can persist within damaged tissue, in the immediate vicinity ofblood vessels, but also necrose within about 48 h. Delayed cell death is an unambiguously non-thermal process,apparently linked solely to biochemical messengers. The dramatic enlargement of the affected region appears to havebeen essentially overlooked in laser surgery studies. The ramifications include (a) proper gauging of the required scaleof tissue damage during surgery, toward averting excessive destruction of untargeted surrounding tissue; and (b)avoiding false positives from the substantial amount of tissue that appears viable immediately after surgery but willnecrose within 24 h. The comparable performance of high-flux solar and concentrated laser light for hyperthermictreatments permits effective surgery and the probing of tissue death dynamics with a solar energy system that is simplerand markedly less expensive than surgical lasers.