Experimental study on ablation of leiomyoma by combination high-intensity focused ultrasound and iodized oil in vitro

Aim: The aim of the current study was to investigate whether iodized oil (IO) enhances high-intensity focused ultrasound (HIFU) ablation of uterine leiomyoma and to determine the features of hyperechoic changes in the target region. Methods: Forty samples of uterine leiomyoma were randomly divided into an experimental group and a control group. In the experimental group, the leiomyoma was ablated by HIFU 30min after 1mL of iodized oil had been injected into the center of the myoma. The hyperechoic values and areas in the target region were observed by B-modal ultrasound after HIFU ablation. The samples were cut successively into slices and stained by triphenyltetrazolium chloride (TTC) solution within 1h after HIFU ablation. The diameters of TTC-non-stained areas were measured and tissues in the borderline of the TTC-stained and -non-stained areas were observed pathologically. All procedures in the control group were the same as those in the experimental group except IO was replaced by physiological saline. Results: The hyperechoic value in the target region in the experimental group was higher than that in the control group 4min after HIFU ablation (P<0.05). Hyperechoic areas in the target region as well as TTC-non-stained volumes in the experimental group were greater than those in the control group (P<0.05). Routine pathologic observation showed that coagulation necrosis of leiomyoma occurred in the target region in both groups. Conclusion: IO causes coagulation necrosis, enlarges tissue damage, and postpones the attenuation of hyperechoic changes in the target region when HIFU ablation is carried out for leiomyoma in vitro.