Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

Abstract

BackgroundCryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution.MethodTo examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining.ResultsUsing optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways.DiscussionThe results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface.ConclusionElectrolysis can occur in a frozen domain at high subfreezing temperature, probably above the eutectic. It appears that the most effective period for delivering electrolytic currents in cryoelectrolysis is during the high subzero temperatures stage while freezing and immediately after cooling has stopped, throughout the thawing stage.

Advances in the Electrochemical Treatment of Cancers and Tumors: Exploring the Current Trends, Advancements, and Mechanisms of Electrolytic Tumor Ablation

“…Unfortunately, a problem exists when using cryosurgery; there is a range of temperatures and cooling rates of affected tissue and thus it is not uncommon for some of the target cells to survive treatment, thus a combination of electrolytic and freezing techniques was combined for this study. [26] This combination of electrolysis and cryosurgery has been dubbed cryoelectrolysis. An in vitro study of cryoelectrolysis on pig liver was the subject of testing where 3 tests were employed: a 10-minute cryosurgery only, a 10 minute EChT only, and a 10-minute freezing period was followed by electrolytic treatment of the pig liver.…”

“…Cryosurgery utilizes a needle‐like probe into a targeted tissue as a freezing interface propagates through surrounding tissue. Unfortunately, a problem exists when using cryosurgery; there is a range of temperatures and cooling rates of affected tissue and thus it is not uncommon for some of the target cells to survive treatment, thus a combination of electrolytic and freezing techniques was combined for this study . This combination of electrolysis and cryosurgery has been dubbed cryoelectrolysis.…”

Exploratory study on tissue ablation with cryoelectrolysis

“…Experiments with pH dyes in frozen gels, have shown that products of electrolysis can diffuse from the electrolysis electrode through the frozen media, at high subfreezing temperatures [ 29 ]. A subsequent study [ 30 ], simulated a cryoelectrolysis procedure in a gel. It was found that the products of electrolysis diffuse from the cryoelectrolysis probe (a conventional cryosurgery probe in which the metal body served also as the electrolysis electrode) outward during the early stages of freezing and throughout the thawing period.…”

“…Several studies were published on the concept of cryoelectrolysis [28][29][30][31][32]. First, a study was performed to determine if products of electrolysis can diffuse through a frozen media.…”