Objective To study the dynamic imaging changes of the uterine leiomyomas before and after uterine arterial embolization (UAE) treatment and to discuss its therapeutic mechanism. Methods Color Doppler senography and both plain and enhanced MR[scanning were performed in 45 patients with uterine leiomyomas before and after UAE. Plain CT scan was performed in all patients after UAE. All the patients were followed up for 3-16 months (average 10±3.5 months). Results In 41 of the total 45 cases, the color Doppler senography showed rich blood flow signals in leiomyomas and myometrium before UAE and no or less blood flow signals in both leiomyomas and myometrium on the first day after UAE. On the seventh day, the blood flow signal was still absent in leiomyomas while it was restored in myometrium, and the same phenomena remained in the first, the third and the twelfth month after UAE. In the other four eases, color Doppler sonography demonstrated blood flow signals inside leiomyomas on the seventh day after UAE and it remained till twelve months after embolization. The embolic agent (Lipiodol) was found in both leiomyomas and myometrium on CT scan for 45 cases on the first day of UAE. CT scan also showed the deposit of the Lipiodol in myometrium, but Lipiodol gradually vanished in leiomyomas at one, three and the twelve months after UAE. The enhancement was apparent in leiomyomas and myometrium on MRI scan in all 45 cases before UAE. The enhancement was found in the myometrium, but not in leiomyomas, on MRI scan in 39 cases 3 months after UAE. The other six cases demonstrated different degrees of enhancement in leinmyomas after embolization. In two cases the detachment of the leiomyomas were observed after embolization and the desquamating materials were pathologicallyproved to be necrotic tissue. The difference in the measuring data about leiomyoma volume between MPI and color Doppler sonography was of no statistical significance (P > 0.05). Conclusion The therapeutic mechanism of UAE for uterine leiomyomas is selectively embolizing the vascular bed of uterus, leading to subsequent necrosis of leiomyomas. The color Doppler sonography should be the fast choice for the dynamic imaging follow-up after UAE.

BACKGROUND: The uterine arterial embolization which is a major method to treat hysteromyoma has bean widely used in clinic and achieved a satisfactory therapeutic efficacy. The study addressing the effect of trisacryl gelatin microspheres on uterine arterial embolization in a hysteromyoma guinea pig model has less bean reported yet. OBJECTIVE: To vedfy the feesibility of trisacryl gelatin microspheres to uterine arterial embolization in hysteromyoma guinea pig models. METHODS: A total of 30 adult female guinea pigs were randomly divided into two groups: pelvic cavity artery moulding group (n=10) was performed pelvic vascular casting mould to demonstrate the anatomical characteristics, such as source, running shape, length, diameter and branches; arterial embolization group (n=20) was induced hysteromyoma model using astrogen-progestogen replacement therapy and performed technical research and pathological analysis by bilateral uterine arterial embolization. RESULTS AND CONCLUSION: The trunks of uterine arteries were erupted from internal iliac arteries. The diameter of the trunks and its arcuate branches were (0.350±0.022) mm and (0.160±0.012) mm, respectively. The 20 guinea pigs of the arterial embolization group were succeeded in operating bilateral arterial embolization. The dosage of 40-120 pm and 100-300 μm trisacryl gelatin microspheras were (0.040t±0.005) mL and (0.017±0.002) mL respectively during the operation. The achievement ratio of establishing model was 75% in the arterial embolization group. On the pathological section, the microspheres could be found in the uterine arterial arcuate branches and second branches within the subsercsa and third branches. The myometrium Was thickening. The cells of the leiomyoma nodules arranged in palisade or weaving shapes. Ischemia and necrosis were evidently present in leiomyomas of guinea pigs after embolization, but the myometria and endometria had no pathological change of ischemia and necrosis. It is feasible to use trisacryl gelatin microspheres to operate uterine arterial embolization for hysteromyoma of guinea pigs and the embolization effects are satisfactory.

BACKGROUND: Currently, the widely used intervertebral disc degeneration models are induced by altering intervertebral disc biomechanics, damaging intervertebral disc structure or changing hereditary features with genetic technique. All these methods are vades from natural duration of intervertebral disc degeneration. OBJECTIVE: To evaluate the feasibility of the establishment of rabbit model of ischemic lumbar vertebrae adjacent to endplate by percutaneous puncture followed by pingyangmycin injection. METHODS: A total of 46 New Zealand white rabbits were selected and two vertebraes were divided as experimental group (L_5) and control group (L_4) in every rabbit. Vertebrae adjacent to endplate was punctured. Pingyangmycin (2 g/L) 1 mL was injected into rabbits in the experimental group. And 1 mL normal sodium was injected into the control group. Lumbar artery angiography was performed in 4 rabbits before operation. Six rabbits were randomly performed MRI and then were executed for vertebral histology at weeks 1,2, 3, 4, 5 and months 2, 3 after operation. Ischemic areas of L_5 were measured by the MRI and histological section at week 4 after operation. RESULTS AND CONCLUSION: MRI and histology of control group had not specific changes. MRI had not significant signal intensity changes in the first 2 weeks in the experimental group. At week 3 after operation, it demonstrated slightly hyperintense signal on T_2-weighted image (T_2WI) and fat-suppression T_2-weighted image (FS T_2WI), while fat-suppression T_1-weighted image (FS T_1WI) was hypointense signal. The signal changed more obviously at week 4. Histology of experimental group had not specific changes in the first 2 weeks. From weeks 3-4, bone trabecula arranged confusedly and disorderly, with gradually decreased osteocyte and marrow haemocytes, while adipocytes increased and coalesced. Cartilage corpuscle of endplate decreased and architecture became disorder. But the anulus fibrosus and nucleus pulposus had no obviously changes. The intervertebral disk of the experimental group degenerated at week 5, and the ischemia of lumbar vertebrae still existed and intervertebral disk degenerated more obviously at months 2-3 after operation. There was significant positive correlation of ischemic areas of experimental group between MRI and histology at week 4 (t-=0.965, P < 0.001). The rabbit model of ischemic lumbar vertebrae adjacent to endplate can be established successfully by peroutaneous puncture vertebrae adjacent to endplate followed by pingyangmycin injection. The operation is minimally invasive, simple and reproducible, with high success rate. This is a fairly ideal animal model to study the degeneration of the lumbar spine and intervertebral disc.

[Objective]This study was designed to evaluate the effects of percutaneously puncturing vertebrate adjacent to cartilage endplate and injecting pingyangmycin on lumbar intervertebral disc and cartilage endplate in New Zealand Rabbits.[Methods]Thirty-six New Zealand white rabbits were enrolled in this study.The fifth lumbar vertebmte(L_5)was injected with pingyangrnycin as experimental group,and the fourth lumbar vertebmte(L_4)injected normal sodium as control group.Six rabbits were selected randomly,then MRI and histological observation was performed in the first,second,third,fourth,Fifth week and third month after operation respectively.Moreover,the correlation analysis was performed between MRI and histological measurements for areas of the lesion in L_5.[Results]There was no obvious changes on MRI and histological examination in control group.For experimental group,there were also no obvious changes in the first two weeks after bperation.However,in the third week,it demonstrated slightly hyperintense signal on T_2WI and fat-suppression T_2WI(FS T_2WI),while FS T_1WI was hypointense signal.The signal changed more obviously in the fourth week.Histologically,the structure of vertibrates arranged disordedy,chondrocyte of endplate decreased and architecture became disorder.Anulus fibrosus and nucleus pulposus did not change.The cartilage endplate and intervertebral disc degenerated in the fifth week.Both of them degenerated more obviously in third month.There was a strong correlation between MRI and histological measurements for areas of the lesion in the fourth week(r=0.965,P＜ 0.001).[Conclusion]Degeneration of lumbar intervertebral disc and cartilage endplate in New Zealand Rabbits can be induced by percutaneously puncturing vertebrate adjacent to cartilage endplate and injecting pingyangmycin.