Dual mode single agent thermochemical ablation by simultaneous release of heat energy and acid: Hydrolysis of electrophiles

Purpose: This study aimed to investigate two readily available electrophilic reagents, acetyl chloride (AcCl), and acetic anhydride (Ac2O), for their potential in tissue ablation. Materials and methods: Reagents were diluted in diglyme as solutions up to 8mol/L and tested in a gel phantom with NaOH solutions and ex vivo in porcine liver. Temperature, pH, and volume measurements were obtained. Infrared and gross pathological images were obtained in bisected specimens immediately after injection. Results: AcCl was much more reactive than Ac2O and AcCl was therefore used in the tissue studies. Temperature increases of up to 37°C were noted in vitro and 30°C in ex vivo tissues using 4mol/L AcCl solutions. Experiments at 8mol/L were abandoned due to the extreme reactivity at this higher concentration. A change in pH of up to 4 log units was noted with 4mol/L solutions of AcCl with slight recovery over time. Ablated volumes were consistently higher than injected volumes. Conclusions: Reaction of electrophiles in tissues shows promise as a new thermochemical ablation technique by means of only a single reagent. Further studies in this area are warranted.