Bioelectrochemical Aspects of the Treatment of Tissue with Direct Current

Abstract

In the electrochemical treatment of tissue the main reactions at the anode are the formation of oxygen in addition to acidification due to liberated hydrogen ions, and formation of chlorine. At the cathode, hydrogen is formed and hydroxide ions are liberated. Mass balance calculations indicate that the formation of oxygen is the dominant anode reaction under the conditions prevailing in tissue. Calculations on the spreading of hydrogen ions and chlorine have been made by means of two different methods, respectively. One of the methods is based on mass balance, the so-called stoichiometric method, and the other one is based on the diffusion rates of species formed at the anode during electrolysis. It appears from this analysis that the liberated hydrogen ions determine the spreading of the zone of destruction. 1

Liver electrolysis: pH can reliably monitor the extent of hepatic ablation in pigs

“…It is probably due to a combination of cytotoxic chemical production, pH changes and membrane disruption, although ischaemia and other host factors may also play a role [13][14][15][16][17][18][19][20][21][22]24,[28][29][30][31].…”

“…Numerous chemical reactions occur as a result, and differential hydrogen ion concentrations form at the electrodes according to the following equations [15,21,22] :…”

Changes of the solution pH due to exposure by high-voltage electric pulses

“…Pillai et al [27] observed the shift of the pH of a donor solution of up to 4-5 pH units during ionthophoresis. Large changes in pH in the vicinity of electrodes (the acidification around the anode and alkanization at the cathode) were also supposed to be the determining factors in the destruction of tissues in electrochemical treatment of tumors [28,29]. Although there was evidence that cell electromanipulation procedures in vitro can change the pH of a medium [17,18,30], no detailed analysis of this effect has been made at this point.…”

Liver ablation techniques: a review

“…This produces a strongly acidic Overall recurrence at 5 years environment around the anode and conversely the area around the cathode becomes alkaline. The rate of passage of the current means that the gassing limits of the electrodes are exceeded and chlorine and molecular hydrogen in gaseous form are released as bubbles, which results in tissue destruction around the anode and cathode [100,101].…”