The Effect of Monopolar and Bipolar Electrocoagulation in Spinal Cord

ABSTRACT

The monopolar and bipolar coagulation lesions were generated in the spinal cord of rabbits. Microscopic study, and the distance from surface lesion center to its margin, the lesion depth, the extent of lesion in cross section, and the area of cross section through the lesion center of monopolar and bipolar electrocoagulation in generation of spinal cord lesion were studied by Evans blue and hematoxylin-eosin stain. The results were as follows 1) Microscopically, the lesions were characterized by ground substance depigmentation, vacuolization and neuronal damage with pyknotic and angulated nuclei and loss of detail. In section stained with Evans blue, the lesion was demarcated with blue-green discoloration of the parenchyma and superficial necrosis was at coagulation sites. 2) The distance from surface lesion center to its margin was proportionally increased as the increase of magnitude of electric current for monopolar and bipolar coagulation, while the distance was independent of the mode coagulation and stain. 3) The depth of lesion was proportionally increased as the increase of magnitude of electric current for monopolar and bipolar coagulation, while the depth was also independent of the mode coagulation, but the depth of Evans blue stain was 2 times than H-E stain. 4) The extent of lesion in cross section was increased as the increase of magnitude of electric current for both coagulation modes, while the extent was independent of the mode of coagulation and stain, too. 5) The area of cross section through the lesion center was gradually increased as the increase of magnitude of electric current for both coagulation modes, while the area was independent of the mode of coagulation and stain.