Experimental Study On The Denudation Of Bladder Mucosa By Carbon Dioxide Laser

Objective: Denudations of canine bladder mucosa by carbon dioxide laser transmitted through indigenous metal hollow wave guide were performed in order to evaluate the feasibility, validity and safety of the operation.Methods: Under open surgical procedures, 18 Beagle canines' bladder mucosa were denuded by carbon dioxide laser which was transmitted through indigenous metal hollow wave guide. Post operative complications, regeneration of bladder mucosa and functions of the urological system were evaluated by ordinary optical microscope, intravenous pyelography and urodynamic tests. The molecular boundary between the lased and the normal bladder tissue was investigated by Fourier Transformed Infrared micro-spectroscopy. Meanwhile, the underlying possibility of carbon dioxide laser to in induce the post operative bladder fibrosis was also investigated through a parallel test in the cultured fibroblasts. Finally, simulated denudations of bladder mucosa under water were performed to test the feasibility of carbon dioxide laser to be used with the combination of intravesical urologic procedures.Results: Indigenous metal hollow wave guide has certain flexibility and maneuverability adapting to the surgical procedures. Leaving with the untouched bladder muscle (identified by the naked eyes and optical microscope), the bladder mucosa could be thoroughly denuded in less than 15 minutes and costs no more than 20000 Joules in each procedures. After surgery, regenerative bladder mucosa could be found since the 30th day, and last to the 120th day with a complete coverage of the bladder inner cavity surface. Post operative functional indexes, such as maximum bladder capacity and bladder compliance, and serum creatinine level, were found to have no obvious differences with that of before. FT-IR study revealed that optical energy could reach the bladder muscular layer and induced alteration of the secondary structure of proteins within no more than 90 millimeters. In vitra, carbon dioxide laser could down-regulate the growth of cultured human skin derived fibroblasts in a manner of amount-to-efficacy dependence, which indicates that carbon dioxide laser might has no potential stimulating effects on the formation of post operative bladder fibrosis. Carbon dioxide laser could effectively denuded bladder mucosa under water with more less injuries to the bladder muscle.Conclusion: Carbon dioxide laser could effectively denude the canine bladder mucosa without any severe surgical complications and functional deteriorations in the canine urological systems. Carbon dioxide laser, which act more likely a kind of kinetic energy carrying optical particles, could induce modifications of secondary structure of proteins in the bladder muscles instead of significant histological changes. Carbon dioxide laser has no definite relationship with the post operative canine bladder fibrosis. There is obviously the possibility that transurethral denudation of bladder mucosa could be performed with the organically integration of carbon dioxide laser and the metal hollow wave guide.