Helium (argon) plasma coagulation in neurosurgery. morphology of tissue damage and reparation

Plasma coagulation, used in some neurosurgical operative settings, is currently under experimental investigation for the precise assessment of the kind and extent of tissue damage. We established a standardised trial to investigate the effects of helium (argon) plasma coagulation - H(A)PC - on rat brain tissue. The tissue reactions were observed with common methods of morphology including immunohistology and electron microscopy. A time dependent profile of the tissue reactions was performed from day 1 after operation up to 6 weeks. The tissue reaction consisted of clearly demarcated concentric zones. The depth of the lesion was about 1 mm maximally, at the beginning. Reparative forces acted at variance both in the different layers and at the edges versus the center of the damage. A manifold but reproducible picture emerges in the various compartments allowing the study of different aspects of organisation and/or elimination of tissue components. This study has demonstrated that a defined circumscribed and reproducible small lesion can be performed with H(A)PC. As in other areas of surgery, this technique has proven to be minimally traumatic. Clinical application of this technique in neurosurgery is therefore promising. In addition, H(A)PC lesions are obviously best suited for morphological studies of early and late reparative reactions in cells and tissues.