ABSTRACT
Objective To observe the sequential ultrastroctural and electrophysiological changes in the sciatic nerve coagulated by a newly-designed microwave antenna. Methods A total of 75 Sprague-Dawley rats were randomly divided into groups A,B and C and irradiated with microwaves at 10,20 or 30 Watts,for 6 seconds to coagulate the left sciatic nerve.Electrophysiological effects and sequential uhrastructural changes were observed on the 0th,2nd,7th,30th and 60th days after coagulation.A static sciatic index was calculated based on measurements of the footprint on the 7th,30thand 60th days after coagulation.Results On the Oth,2nd,7th and 30th days after cpagulation,the static sciatic index,the nerve conduction velocity and the amplitude of the action potentials in groups B and C had decreased significantly compared with those before coagulation.On the 60th day after coagulation.significant recovery was observed in groups A and B,but not in group C.Only mild alteration in uhrastructure was found,and only in group A.The prominent changes in uhrastructure in group B included broken Schwann cell membranes and myelin disintegration.There were severe injuries in group C,including myelin disintegration,cell deformity,coagulative necrosis,axon necrosis,basement membrane necrosis and demyelination.The structure of the sciatic nerve in group B had partially recovered after 60 days,but group C showed no recovery at all. Conclusion Microwave coagulation of a nerve can block its conduction.and even destroy the nerve.Percutaneous microwave coagulation is clinically feasible and call be an alternative treatment for pain.
ABSTRACT
AIM: To evaluate the feasibility and safety of microwave coagulation with novel microwave antenna through observing physiological and pathological changes after the coagulation on rat skeletal muscle. METHODS: The experiment was performed at the Central Laboratory of Zhujiang Hospital of Southern Medical University from December 2006 and September 2007. ①Using MTC-3C microwave tissue coagulation device, monopole microwave antenna after anti-adhesion was vertically inserted into SD rat skeletal muscle for heat coagulation at 20 W?8 s. ②The instant enzyme activity changes after microwave coagulation therapy (MCT) was detected by 2, 3, 5-Triphenyl Tetrazolium Chloride (TTC) staining. The cell apoptosis rate in outer fields of coagulation was evaluated by flow cytometry 0, 12 and 24 hours after coagulation, and the treated muscle was examined pathologically on days 0, 2, 7, 30, and 60. RESULTS: ①The coagulation areas were stained in white immediately after MCT by TTC staining, while the outer normal areas were in red. There were apoptotic cells around coagulation areas, and the highest percentage appeared 12 hours later, reduced thereafter. ②In 24 hours after coagulation, only mild alteration of cellular morphology was found. Two days after MCT, necrosis cells were prominent in transition zone, and the inflammation cells were predominantly composed of macrophage and lymphocytes in the zone, while the cells in the coagulation zone remained structure; 7 days after MCT, the fibroblast and granulation tissue occurred in the transition zone, and the myocyte in the coagulation zone were of necrosis; 30 days after MCT, there were still many inflammation cells in the coagulation zone with some collagenous fibrils in the transition zone; 60 days after MCT, the necrosis cells reduced and the outer margin of the transition zone was encapsulated by marked collagenous fibrils. Tissue repair started from the outer margin of the transition zone to the central coagulation zone. CONCLUSION: Novel microwave tissue coagulation is safe and feasible to be used in the treatment of some minor-carcinoma and some tumors on body face.