Ultrasonogram Research Of Ex Vivo Human Hysteromyoma Reperfusion Under HIFU Radiance With Microbubble

BackgroundsHysteromyoma is the most common benign tumor of female reproductive system, predilection in women of 30-50 years old, which is the main cause of menometrorrhagia and abnormal uterine bleeding(AUB), although most of patients suffered of it are absence of symptoms while a few appear vaginal bleeding, lump touched from abdomen, bladder oppression, torsion of pedicle et al. At present, the main therapies of hysteromyoma with symptoms include operation, drug treatment, small trauma treatment, High intensity focused ultrasound (HIFU) treatment, et al. HIFU has great potential for treatment of hysteromyoma for its advantages of no ionization radiation, noninvasive and retreatmentable.In the process of HIFU radiance target area, Acoustic environment in tissue (AET) is an important factor that influence the accumulation of HIFU energy. In recent years, many researches suggested that ultrasonic contrast agent was an potentiator of improving HIFU therapeutic effect in a dose-dependent manner.There is no good animal model of hysteromyoma, therefore, ex vivo circulation model of human hysteromyoma were constructed to investigate dynamic variances of gray scales in target area after perfused with SonVue in different dose and radiance by HIFU and observe the correlation between hyperechogenicity area and actual necrosis area at different time points after radiance and provide evidences for ultrasound real time monitoring the process of treating hysteromyoma by HIFU with SonVue.ObjectiveDynamic variances of gray scales in target area after human ex vivo hysteromyoma reperfused with SonVue in different dose and radiance by HIFU and the correlation between hyperechogenicity area and necrosis area at different time points after radiance were investigated to obtain the accurate radiance dose, exposure time and how to judge necrosis area by ultrasound.Materials and methodsSubjects18 complete fresh ex vivo uterus from patients suffered from hystero- myoma by total hysterectomy was obtained with the permission of patients and school Ethics Committee.Equipments and drugsBT-50E peristaltic pump (Chongqing Jieheng peristaltic pump limited company), rotation speed:0.1-50rpm, stream speed:0.001-18ml/min.Philips IU22 color doppler ultrasonograph, frequency of probe: 3.5MHz.JC200 HIFU device and gray measure software (Chongqing HAIFU (HIFU) Technology Co, Ltd).SonoVue (Bracoo, Milan, Iatly ) was used as contrast agent in the study.Heparin, Ringer lactate solution, Triphenyl tetrazolium chloride (TTC) staining solutionMethodsEx vivo uteruses were pumped into heparinizated Ringer-Locke liquor from both uterine arteries by peristaltic pump immediately after obtained. Then the reperfusion information of uterus was detected by Color doppler flowing image (CDFI) and Pulse wave(PW) imaging. Grouping:Single HIFU radiance group, HIFU with SonoVue groupIn single HIFU radiance group, ex vivo uterus connected with vitro perfusion device was put into container with de-aerated water. Then the peristaltic pump was opened and Ringer-Locke liquor was pumped into uterus from the peristaltic pump. Hysteromyoma planes without cystis degeneration were selected to radiate by HIFU in fixed points. Parameter: acoustic power:200w;depth:20mm;radiance mode:fixed-point radiance; exposure time:5s, 10s. Sonograms of target area were captured every time before HIFU radiance and after radiance for 0, 1, 2, 5min and gray scale and hyperechogenicity areas of target area sonograms were measured. Hysteromyoma was split and stained by TTC after HIFU radiance to search lesion area and measure necrosis area before paraffin section and HE staining were progressed. Influences of different dosage of HIFU on gray scale of target area and differences between gray scales of different time were analyzed by SAS8.1 statistical package and coefficient correlation between hyperechogenicity areas of target sonograms and necrosis areas was calculated.In HIFU with SonoVue group, SonoVue of different concentrations was pumped into hysteromyoma from the 3-way stop cock of peristaltic pump after the pump was turned on. Hysteromyoma planes filled with SonoVue were selected by ultrasound and radiated by HIFU. Radiance parameters, observing indexes, statistical method, postdose treatment were similar to single HIFU group.Results 1.After heparin anticoagulant ex vivo human hysteromyomaspecimens were reperfused, CDFI showed chroma signal filled the periphery of hysteromyoma and occasionally punctiform chroma signals were seen in the hysteromyoma and barred constant speed PW frequency spectrum signals like portal veins were seen. It indicated that reperfusion of hysteromyoma specimens was successful and Ringer lactate solution has been pumped into the inner of hysteromyoma.2.Target gray scales were different at different time points after single radiance by HIFU in fixed. The gray scale values were highest 0min after radiance and trended to stable 1min after radiance. The target gray scale values was 29.40±3.44 1min after radiance by HIFU with an acoustic power of 200w, radiance depth of 20 mm and exposure time of 10s. Hyperechogenicity areas of target depressed in a time-dependent manner. The coefficient correlation between hyperechogenicity areas of target sonograms and necrosis areas was high and got highest 2min after radiance, the highest correlation coefficient was 0.99957.3.In HIFU associated with SonoVue group, the gray scale values trended stable 2min after radiance. The coefficient correlation between hyperechogenicity areas of target sonograms and necrosis areas got highest at the time point 5min after radiance.Conclusion1.Reperfusion model of ex vivo hysteromyoma specimens was constructed to imitate the blood circulation of in vivo uterus and provide in vivo environments of basic and clinic research on hysteromyoma.2.1min after single radiance by HIFU, the target gray scale values trended stable. The coefficient correlation between hyperechogenicity areas of target sonograms and necrosis areas was highest 2min after radiance.3.After radiance by HIFU associated with SonoVue, the target gray scale values needs more time to trended stable and the coefficient correlation between hyperechogenicity areas of target sonograms and necrosis areas was lower.4.The target gray scale values increases with the concentration of microbubble.5.It needs enough concentration of microbubble to increase the curativeeffect of HIFU.