The Application And Basic Research Of 532nm Green Laser Partial Nephrectomy

As the highest death rate of urologic cancer,the morbidity and detection rates of the renal carcinoma are more and more.And the small tumor of the kidney which volume less than 4cm is often be found.To get the smallest injury of partial nephrectomy(PN),various ways of the surgery were applicatted.As the laser surgery possesses better hemostasis and outstanding after-surgery efficacy,studies of laser partial nephrectomy(LPN)becomes increasingly pronounced and attracts extensive attention.As a laser surgery system,532 nm Blue Laser has been used so many years and its technology is maturity,while lack of the special research of the different circumstance such as in the air and saline.Objective: 1.To compare the effects of 30 W 532nm lithium triborate(LBO)green light laser partial nephrectomy in different mediums of normal saline and air,and explore the feasibility of the green light laser supported partial nephrectomy in the laparoscopic of the air.2.To assess the ex vivo renal effects of the low power of LBO 532 nm laser transmitted by 600?m –fiber at long distance and short time irradiation and to explore the suitable distance and time of the laser emission for hemostasis for partial nephrectomy.3.Via open partial nephrectomy(OPN)for Beagles in the air environment,observing the different speed of laser vaporization of the kidney,measuring the thickness of the carbonization,solidification and the thermal damage after the acute and chronic OPN,and exploring the effectiveness,security and feasibility of 532 nm green laser OPN in the surroundings of gas.Materials and Methods: 1.Specimens of fresh renal tissue in normal saline and air were vaporized utilizing the core diameter of 600 ? m straight fiber emitting a 532 nm wavelength at 30 W using the LBO green laser,and at a working distance of 0.5mm to 3mm and a treatment speed of 0.5mm/s to 2.0mm/s.The depth,width and coagulation of the vaporization were measured by vernier caliper and the efficiency of vaporization was calculated.The histological HE of the tissue was assessed and the results of data were analyzed using independent sample T-test.2.The fresh porcine kidney was used to be irradiated by the 600?m-fiber emitting a 532 nm wavelength,at 10 W,20W,30 W respectively,using the LBO laser at a working distance of 1cm to 5cm and with irradiating time 5s,10 s,15s.Dimensions of the irradiated tissue,including coagulation and vaporization depth and width,and the tissue pathological slices were assessed under the microscope.3.Beagle dogswere accepted intravenous pentobarbital anesthesia,taken the upper abdomen incision,layer by layer until the renal peritoneal fascia,and exposed kidneys.Utilizing 30 W green laser,four dogs were under OPN.The time of operation,partial resection of the kidney and the estimated amount of blood loss were assessed,and the weight of the excised kidney were weighed.Kidneys of the Beagles were taken 3 hours after the operation and 2 weeks after the operation.The kidney tissues were fixed with 4% paraformal for more than 12 hours and examined by pathology.Thethickness of the carbonation,the solidified layer,thermal damage area,and the thickness of the inflammatory reaction were assessed by the microscope.Results: 1.30 W LBO green laser possessed more efficiency of vaporization in the medium of air than in the normal saline,and the thickness of coagulation is not increase.The efficiency of vaporization in the air was 2.5 times then in the normal saline,and the results,whose value of P less then 0.05,were considered significant;the average thickness of the coagulation was thinner in the air,and the result,whose value of P was 0.009,was also considered significant.2.With the working distance more and more far,the power of the laser increasing and the irradiated time becoming longer,the light spot is larger,the coagulation width are broadening and depth are thickening,but the carbonization and vaporization of the renal appear.But ultimately although the laser power was 30 w and the irradiating time was 10 s,when the working distance is 4cm,the carbonization and vaporization of the tissue is disappeared.And the thickness of the coagulation was 6mm? 3.Green laser OPN in the Beagle dogs has perfect function of hemostasis.When the vaporization was in the normal saline,the efficiency was lower then in the air surroundings,but the results of the hemostasis had no difference.After 3 hours of the surgery,the carbonization and the thermal damage were not obvious through the HE of the tissue.After 2 weeks of the surgery,the dogs were anatomied,and the renal,where hematoncus was not been observed,was well sutured.The rest of the renal tissue had no inflammatory response.Conclusions: 1.In the medium of air,LBO green laser possesses more efficiency of vaporization and not increase the thickness of coagulation and via this ex vivo study,we testified the efficiency and security when operating the green laser supported partial nephrectomy in the environment of air.2.In our experiment,utilizing the 600?m-fiber delivered the low power of the 532 nm green laser,with the working distance ranging from 1cm to 4cm,and the irradiated renal tissue varied different consequences which could offer the guidance of the laser application in the clinical.The insufficient of this experiment was used the only laser and fiber,so we will try different kinds of lasers and fibers in the future test.3.When the occlusion of the renal vessels were done,the 532 nm green laser OPN could be more efficiency.We can lower the power and increasing the distance of laser to obtain perfect hemastasis.This study demonstrated that 532 nm green laser OPN was effectiveness,security and feasibility in the surroundings of gas.