Gadolinium-enhanced MR imaging in the evaluation of uterine fibroids treated with uterine artery embolization

Uterine and Fibroid Imaging Analysis from the FIRSTT Study

Background: Women with uterine fibroids often seek uterine-preserving treatments, rather than hysterectomy. Imaging-defined endpoints following nonsurgical treatments for fibroids are limited. Materials and Methods: Fibroid Interventions: Reducing Symptoms Today and Tomorrow (FIRSTT), a randomized controlled trial of uterine artery embolization (UAE) versus magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS), enrolled premenopausal women with symptomatic uterine fibroids. In this subanalysis, we report imaging results up to 36 months after UAE or MRgFUS. Magnetic resonance imaging (MRI) was performed at baseline for all women and during the 36 months after treatment if they did not meet other study endpoints. The main outcome of this subanalysis was fibroid volume reduction (defined both in terms of total fibroid load and volume of the largest fibroid), uterine volume reduction, and nonperfused volume. Results: During 2010-2014, 25 of the 37 women who were randomized and treated at Mayo Clinic had a 24-month follow-up MRI (11 UAE; 14 MRgFUS); among these women, 15 (7 UAE and 8 MRgFUS) had a 36-month follow-up MRI. Average age for the cohort was 44.1 (standard deviation, SD = 4.4) years. Nine patients had a second fibroid procedure by 36 months (seven in the MRgFUS arm and two in UAE arm). Median total fibroid load reduction was ∼50% in both treatment arms at both 24- and 36-month follow-up. Volume of the largest fibroid decreased more in the MRgFUS arm, whereas uterine volume decreased more in the UAE arm (neither reached statistical significance). At 24 months, median nonperfused volume was higher in the UAE arm (92%) than the MRgFUS arm (10%). Conclusions: Similar fibroid volume reduction was seen for the MRgFUS and UAE treatments in this comparative effectiveness study. Nonperfused volume 24 months after the procedure was higher in the UAE arm than in the MRgFUS arm. Clinical Trial Registration Number: NCT00995878, clinicaltrials.gov.

Uterine Artery Embolization of Uterine Leiomyomas: Predictive MRI Features of Volumetric Response

OBJECTIVE. The purpose of this article was to evaluate MRI features of uterine leiomyomas that predict volumetric response after uterine artery embolization (UAE). MATERIALS AND METHODS. This retrospective study included 75 patients with 212 uterine leiomyomas who were successfully treated between August 2013 and December 2018. To predict uterine volumetric response, age, number of lesions, and baseline uterine volume were assessed. To predict leiomyoma volumetric response, a multivariate regression analysis was performed to evaluate six predictive factors: location, baseline leiomyoma volume, signal intensity on T1-weighted and T2-weighted MRI, heterogeneity of signal intensity on T2-weighted MRI, and vascularity on subtraction imaging (SI). A five-variable predictive ROC model was developed to evaluate the diagnostic accuracy of the signal intensity ratio on T2-weighted MRI, enhancement ratio, heterogeneity ratio on T2-weighted MRI, location, and baseline leiomyoma volume in predicting at least 40% leiomyoma volumetric response. RESULTS. Age, number of leiomyomas, and baseline uterine volume were not predictive of uterine volumetric response. A submucosal location was the best predictive factor of leiomyoma volumetric response, and it showed 32.2% more leiomyoma volumetric response compared with a nonsubmucosal location (p < .001). Hyperintensity on T2-weighted MRI was the second best predictive factor of leiomyoma volumetric response, and it showed 16.9% more volumetric response compared with hypointense leiomyomas (p = .013). A small baseline leiomyoma volume (< 58 cm³) was associated with 10.2% more leiomyoma volumetric response compared with larger leiomyomas (p = .01). Leiomyomas that were hyperintense on SI showed 7.9% more leiomyoma volumetric response compared with those that were hypointense (p = .014). The five-variable ROC model showed high diagnostic accuracy with an AUC of 0.85, sensitivity of 82%, and specificity of 71%. CONCLUSION. A submucosal location, hyperintensity on T2-weighted MRI, small baseline leiomyoma volume (< 58 cm³), and hyperintense leiomyoma on subtraction imaging are the main independent favorable predictors of leiomyoma volumetric response after UAE. An accurate predictive ROC model was developed that may help in selecting patients suitable for UAE. Quantitative assessment of heterogeneity on T2-weighted MRI showed promising results as a predictor of volumetric response, and further research in this area using texture analysis and radiomics is suggested.

Extracellular matrix metalloproteinase expression in endometrial tissue after arterial embolization of myomas

OBJECTIVES

Arterial embolization of myomas (AEM) is controversial because of the changes that occur in the extracellular matrix (ECM) of the endometrium and its effect on gestational success in infertile patients desiring reproductive capability. Therefore, we performed this study on the expression of genes in the ECM of the endometrium, such as those coding metalloproteinases (MMP), before and 6 months after embolization of the uterine arteries.

METHODS

Seven women with leiomyomas were evaluated, and MMP3 and MMP10 levels were measured. The women underwent pelvic nuclear magnetic resonance (NMR), examination, and endometrial biopsy between the 20th and 24th day of the menstrual cycle, and pre- and post-AEM (after 6 months). For data analysis, the Cq comparative method, also known as the 2-ΔΔCT method, was used to calculate the relative quantities of MMP gene expression among the samples collected.

RESULTS

There was a significant decrease by 9.52 times in the expression of MMP3 (p=0.007), and a non-significant change in the expression of MMP10 (p=0.22) in post-AEM-treated women than pre-AEM-treated women.

CONCLUSIONS

The results suggest that ECM continues to undergo tissue remodeling 6 months after AEM, at least with regard to MMP3 expression, suggesting that AEM affects the ECM for at least 6 months after the procedure.

Endovascular treatment of uterine myomatosis: a systematic review

Uterine Artery Embolization (UAE) is a noninvasive alternative to open surgery for treatment of uterine myomatosis. This study aims to analyze the efficacy and safety of UAE in these cases. A systematic review was carried out of studies available on the Medline (via PubMed) and the LILACS and PEDro (via the Biblioteca Virtual em Saúde) databases. The searches found 817 studies, 7 of which were selected according to the eligibility criteria (analytical, longitudinal, retrospective, or prospective studies), with a total of 367 patients studied. The variables analyzed and the characteristics of the studies included were collated and input to a database. Rates of volume reduction of the uterus and the dominant myoma were 44.1% and 56.3%, respectively. Mean rate of complete infarction of the dominant myoma was 88.6% (82-100%). The mean number of complications observed was 15±8.6 cases, most of which were classified as minor, and no deaths were recorded. The mean number of re-interventions in absolute values was 12.2±15.5 cases. Therefore, in the literature analyzed, uterine artery embolization is an effective procedure with a low rate of complications for treatment of uterine leiomyomatosis.

Susceptibility weighted MRI after uterine artery embolization for leiomyoma

PURPOSE

To evaluate whether susceptibility-weighted MR imaging (SWI) findings are associated with tumor infarction on contrast-enhanced MRI (CE-MRI) after uterine artery embolization (UAE) for leiomyoma.

METHODS

This was a single institution, retrospective study. Between February 2016 and April 2017, 27 consecutive patients underwent UAE and completed SWI and CE-MRI before and 1 week after UAE. Two blinded readers independently reviewed the MRI of 261 tumors ≥1 cm in all patients. We evaluated the relationship between the hypointense peripheral rim observed on the tumor surface on post-procedural SWI and the infarction rates (≥90%, <90%) of each tumor based on post-procedural CE-MRI. Inter-reader correlation coefficients (ICC) and the sensitivity and specificity of the rim were measured.

RESULTS

Substantial inter-reader agreement was noted in post-procedural SWI interpretations (ICC = 0.681, 95% CI; 0.547, 0.771). The rim was observed in 66.7% (174/261) of tumors by reader 1 and 55.9% (146/261) of tumors by reader 2 on post-procedural SWI. Correlations were observed between the rim and ≥90% tumor infarction by readers 1 and 2 (Spearman's coefficient = 0.474 and 0.438, p < 0.001 and p < 0.001, respectively). The sensitivity and specificity of the rim to tumor infarction were 77.2 and 82.6% (reader 1), and 65.8 and 100% (reader 2), respectively.

CONCLUSIONS

The present study demonstrated that the hypointense peripheral rim was observed on some leiomyomas on SWI immediately after UAE. The rim correlated with tumor infarction on post-procedural CE-MRI. This SWI finding was helpful for evaluating embolic effects on leiomyomas in the acute phase after UAE.

Efficacies of uterine artery embolization for symptomatic uterine fibroids using gelatin sponge: a single-center experience and literature review

AIM

The aim of this study was to retrospectively analyze the efficacies of uterine artery embolization (UAE) using gelatin sponge for symptomatic uterine fibroids.

METHODS

A series of 60 consecutive premenopausal women underwent UAE using gelatin sponge particles or porous gelatin particles. Patients were routinely followed up at 1, 3, 6, and 12 months after the procedure and asked to report any procedure-related complications. At each follow-up, an original clinical questionnaire was completed by the patients to evaluate changes in fibroid-related symptoms. Pelvic magnetic resonance imaging was performed before and at 3 and 12 months after the procedure, and the changes in volume of the dominant fibroid were calculated.

RESULTS

Bilateral UAE was successfully performed in all the patients. Median age was 45 years (range 34-53 years), and median follow-up period was 25.2 months (range 1-116 months). At the 3- and 12-month follow-up, the dominant fibroid volumes were found to be significantly decreased by 33.4% (95% confidence interval [CI]: 24.9-41.1) and 48.4% (95% CI: 40.7-56.1) compared to baseline volumes, respectively. Excluding patients not having menorrhagia or bulk-related symptoms, at 12 months 49 of 50 (98%) women showed improvement in menorrhagia, and 45 of 47 (95.7%) women showed improvement in bulk-related symptoms. During the follow-up period, ten patients (16.7%) required further interventions including two patients who had undergone hysterectomy. No sequelae were experienced by any of the patients.

CONCLUSION

UAE using gelatin sponge was associated with a high clinical success rate and good fibroid volume reduction compared to UAE using other embolic agents.

Uterine artery embolization for leiomyomas: percentage of infarction predicts clinical outcome

PURPOSE

To determine the effect of partial versus complete leiomyoma infarction on relief of leiomyoma-related symptoms and freedom from invasive reinterventions and to assess if patient age, location of the dominant leiomyoma, number of leiomyomas, or baseline uterine and dominant leiomyoma volume were associated with clinical failure.

MATERIALS AND METHODS

Study protocol was approved by the institutional review board, and informed consent was obtained. One hundred fifteen consecutive women (median age, 42 years; range, 34-61 years) with symptomatic uterine leiomyomas underwent contrast material-enhanced magnetic resonance (MR) imaging at baseline and 24-72 hours after uterine artery embolization (UAE) to determine the percentage of infarction of leiomyoma tissue (complete = 100%, almost complete = 90%-99%, and partial = 0%-89%). Clinical outcome and frequency of reinterventions were compared for up to 36 months.

RESULTS

One hundred thirteen patients completed at least one clinical follow-up. Twenty-four months after UAE, 50% +/- 15.2 (standard error) of the patients with partial infarction and 80% +/- 13.4 (standard error) of patients with almost complete infarction had undergone no reintervention. No patient with complete infarction needed a second treatment (P < .001). The hazard ratios for reintervention between the complete infarction group and the almost complete and partial infarction groups were 15.88 (95% confidence interval [CI]: 1.22, 2225.54; P = .034) and 73.08 (95% CI: 8.33, 9636.35; P < .001), respectively. There were significant differences in hazard ratios between patients with partial and those with complete infarction for persistence or recurrence of menorrhagia (hazard ratio, 7.45; 95% CI: 2.08, 28.31; P = .002) and bulk-related symptoms (hazard ratio, 5.90; 95% CI: 1.66, 21.92; P = .007). There was no significant correlation between patient age, number of leiomyomas, location of the dominant leiomyoma, or baseline uterine and dominant leiomyoma volume and clinical failure.

CONCLUSION

Women with leiomyoma infarction above 90% on contrast-enhanced MR images after UAE show significantly better symptom control and fewer reinterventions than do patients with a lower infarction rate.

Comparison of four embolic materials at uterine artery embolization by using postprocedural MR imaging enhancement

PURPOSE

To test the hypothesis that not all embolic materials are equivalent by using postprocedural magnetic resonance (MR) imaging enhancement of uterine fibroids in patients treated with uterine artery embolization (UAE).

MATERIALS AND METHODS

Approval and a waiver of consent from the institutional human investigations committee was received for this study. The study was HIPAA compliant. A total of 84 women who underwent 6-month MR imaging follow-up constituted this retrospective study. Within this group, 25 women were treated with Contour polyvinyl alcohol (PVA) particles, 23 were treated with Contour SE particles, 19 were treated with Embosphere microspheres, and 17 were treated with Bead Block microspheres. Pre- and postprocedural MR imaging results were analyzed for the total number of fibroids present in the uterus of each patient and for the percentage of individual fibroid enhancement. Enhancement of individual fibroids was measured with quartile intervals. Greater than 25% residual enhancement of a fibroid after embolization was considered an incomplete infarction. The overall percentage change in enhancement was calculated for each patient. Bivariate analysis by using generalized linear modeling and one-way analysis of variance was used to assess differences in infarction with different embolic materials.

RESULTS

Among patients treated with Contour and Embosphere, there was a mean reduction in enhancement by 76.60% and 83.07%, respectively, compared with a mean reduction of 52.53% and 49.78% in patients treated with Bead Block and Contour SE, respectively. There was a significant difference in postembolization enhancement between Bead Block and Embosphere, Bead Block and Contour, Contour SE and Embosphere, and Contour SE and Contour.

CONCLUSION

Patients treated with Bead Block or Contour SE demonstrated a reduced degree of infarction at follow-up MR imaging compared with patients treated with Contour or Embosphere.

Repeat uterine artery embolization following poor results

It was the objective of this study to assess the efficacy of repeat uterine artery embolization following lack of symptom relief from initial procedure. We performed a retrospective chart review of patients undergoing embolization for symptomatic uterine myomata between 1994 and 2007. Success was defined based upon responses to symptom-relief questionnaires. Patients who reported no relief or worsening of symptoms were offered repeat embolization as well as surgical intervention. Patients who elected to undergo repeat embolization were evaluated for success following the procedure. During the study period, 1058 patients underwent initial bilateral uterine artery embolization. Forty-two (3.97%) patients reported unsuccessful symptom relief. Thirty-nine patients who reported poor results underwent a second bilateral embolization. Thirty-four of these patients completed symptom-assessment questionnaires; thirty-two patients (94.1%) reported symptom relief lasting at least six months post-procedure. The vast majority of our patients who underwent a second embolization after initial poor results had successful symptom relief. Patients should be offered a second uterine artery embolization after a poor outcome.

Rabbit VX2 tumors as an animal model of uterine fibroids and for uterine artery embolization

PURPOSE

To determine the suitability of the rabbit VX2 tumor animal model for uterine fibroids and uterine artery embolization (UAE).

MATERIALS AND METHODS

The authors implanted and grew one uterine VX2 tumor per rabbit in six rabbits. UAE was performed by using 100-300 microm embolic particles and confirmed with x-ray digital subtraction angiography, magnetic resonance (MR) imaging, and necropsy. Unenhanced and contrast medium-enhanced MR images of VX2 tumors were obtained before and after UAE. Relative MR signal-to noise-ratio (SNR) was measured in the uterine VX2 tumor and in normal uterine tissue before and after UAE and compared by using a paired t-test (P = .05).

RESULTS

VX2 uterine tumors were successfully grown, and both VX2 tumor presence in the uterus and UAE were seen angiographically and confirmed with necropsy in all six rabbits. Statistically significant reductions in relative SNRs were measured in tumors (SNR before UAE, 15.3 +/- 5.15; SNR after UAE, 3.84 +/- 3.94; P < .0001). No statistically significant decrease in SNR was measured in normal uterine tissue before and after UAE (P = .63 for the right uterine horn and P = .93 for the left uterine horn).

CONCLUSION

Rabbit VX2 uterine tumors may be a suitable animal model of uterine fibroids and UAE.

Myoma necrosis following Gelfoam embolization of uterine myomata

The aim of this study was to assess the risk and clinical significance of purulent necrosis following Gelfoam uterine artery embolization in the minimally invasive management of uterine leiomyomata. This study compares the incidence of purulent necrosis in leiomyomata affecting women who underwent Gelfoam embolization with those who had embolization with traditional particles. From January 20 to May 26, 2005, 54 patients were embolized for symptomatic fibroids. Forty-three were embolized with traditional particles, 11 with Gelfoam alone. Of the Gelfoam group, four women suffered purulent necrosis of leiomyomata, whereas in the traditional particle group, only one patient experienced this complication (p = 0.005). The women in the Gelfoam group were generally younger than those in the particle group (p = 0.00014). The average gravida and parity of the Gelfoam group were less than for the particle group--(p = 0.221) and (p = 0.041), respectively. The total uterine volume was similar for both groups. Within the Gelfoam 50% shaded block group there was no significant difference in fertility, age, total uterine volume, largest fibroid size, or number of pledglets used (P > 0.05) when comparing women with and without purulent necrosis. The average time from embolization to onset of symptomatic purulent necrosis was 11 days. All four patients with purulent necrosis of leiomyomata were successfully treated with myomectomy (three abdominal, one vaginal). Notwithstanding the small numbers in the series, patients embolized with Gelfoam appear to be at higher risk for development of post-embolization purulent necrosis of leiomyomata than patients who are embolized with traditional particles.

Use of a combined MR imaging and interventional radiology suite for intraprocedural monitoring of uterine artery embolization

PURPOSE

The optimal embolic endpoint for uterine artery embolization (UAE) is unknown. It is difficult to quantify substasis endpoints with the use of conventional x-ray interventional radiology (IR) guidance. Although magnetic resonance (MR) imaging can detect perfusion changes, intraprocedural perfusion changes within targeted uterine leiomyomas and the remaining uterine wall remain unknown. A hybrid MR/IR unit was used to test the hypothesis that MR imaging can detect changes in uterine perfusion-dependent signal enhancement immediately after UAE.

MATERIALS AND METHODS

In this prospective study, UAE was performed in a hybrid MR/IR unit in women with symptomatic uterine leiomyomas. This MR/IR unit contains a wide-bore 1.5-T MR scanner connected by a sliding table to an adjacent x-ray digital subtraction angiography unit. Gadolinium-enhanced MR imaging was performed before and after UAE. Relative signal-to-noise ratio (SNR) was measured within each tumor and the adjacent uterine wall, and mean relative SNR changes were compared before and after UAE with the paired t test (alpha=0.05).

RESULTS

UAE was technically successful in all six women, in whom 10 tumors were assessed (seven intramural, two submucosal, one subserosal). Mean relative SNR of the tumors before UAE was 62.2+/-25.0 and was reduced to 41.1+/-17.7 after UAE (P<.01). Mean relative SNR of the adjacent uterine wall was 64.2+/-14.3 before UAE and decreased to 28.8+/-14.9 after UAE (P<.01).

CONCLUSIONS

Immediate reductions in perfusion-dependent enhancement in targeted uterine leiomyomas and the adjacent uterine wall can be detected during UAE with the use of a hybrid MR/IR unit. Further studies are now warranted to compare long-term clinical outcomes versus immediate changes in perfusion at the time of UAE.

MR volumetric measurements of the myomatous uterus: improved reliability of stereology over linear measurements

RATIONALE AND OBJECTIVES

Stereology is a simple, fast method for object segmentation that involves counting the number of intersections of a randomly positioned grid over an object. The objectives of this study were to determine observer reliability in making stereologic- and ellipsoid-based measurements of uterine and leiomyoma volumes and to test the agreement between these two methods of measurement.

MATERIALS AND METHODS

Two observers made uterine and dominant leiomyoma volume measurements on MR images in 30 patients using stereology and the popular ellipsoid-based technique. Stereologic volume measurements were made from high-resolution T2 images in two perpendicular planes (axial and sagittal). Ellipsoid volume was calculated by multiplying the maximal sagittal, anteroposterior, and transverse dimensions by pi/6. For these measurements, interobserver reliability was tested with paired t-tests and percent differences were determined. A mean stereologic volume and a mean ellipsoid volume were determined and tested for agreement with a paired t-test. Percent differences were also calculated.

RESULTS

Stereologic measurements demonstrated excellent interobserver reliability with 0.3% difference in mean uterine volumes (P = .69) and 0.3% difference (P = .81) in mean leiomyoma volumes. The ellipsoid method resulted in poorer interobserver reliability with 7% difference (P = .01) in mean uterine volumes and 4% difference (p = .24) in mean leiomyoma volumes. The ellipsoid method also significantly overestimated uterine volumes by 14% (P < .01) compared with stereology.

CONCLUSION

Stereology provided high interobserver reliability for leiomyoma and overall uterine volume measurements and was more reliable than the ellipsoid method, which uses linear measurements. Stereology appears well suited when precise volume measurements are desired for assessing response to uterine arterial embolization treatments.

Magnetic Resonance Angiography of Uterine Artery: Changes with Embolization Using Gelatin Sponge Particles Alone for Fibroids

PURPOSE

To assess uterine artery recanalization, together with tumor devascularization, after embolization using gelatin sponge particles alone for fibroids.

METHODS

Twenty-seven patients underwent uterine artery embolization (UAE) for fibroids using only gelatin sponge particles. The angiographic endpoint of embolization was defined as near stasis of contrast medium in the ascending segment of the uterine artery. All patients underwent contrast-enhanced magnetic resonance angiography (MRA) before and 4 months after UAE, and contrast-enhanced magnetic resonance imaging (CE-MRI) before, 1 week after, and 4 months after UAE. The visualization of the uterine arteries before and 4 months after UAE was assessed using MRA. The infarction rates of the largest tumor were assessed using CE-MRI 1 week after UAE.

RESULTS

MRA 4 months after UAE showed 100% (53/53) of the descending and transverse segments, and 88% (43/49) of the ascending segments that had been noted on baseline MRA. The visualization of the ascending segments on MRA 4 months after UAE was identical to that on baseline MRA in 20 of 27 patients (74%). CE-MRI showed complete infarction of the largest tumor in 22 of 27 patients (81%), and 90-99% infarction of the largest tumor in the remaining 5 of 27 patients (19%).

CONCLUSION

Based on the MR study, in most cases uterine artery recanalization occurred, together with sufficient devascularization of fibroids, after UAE using gelatin sponge particles alone.

Solving the Problem Pelvic Ultrasound With Magnetic Resonance Imaging

Ultrasound is the screening method of choice for evaluation of pelvic anatomy and abnormalities of the female pelvis. It allows for detailed assessment of the uterus, endometrium, and ovaries. However, there are times when the sonographic diagnosis is nonspecific. This review article details the use of magnetic resonance imaging for assessment of uterine duplication anomalies, adnexal and uterine masses, and for aiding in the assessment of pregnant patients with nonspecific sonographic findings in the pelvis.

Predictive value of magnetic resonance imaging signal and contrast-enhancement characteristics on post-embolization volume reduction of uterine fibroids

PURPOSE

To assess the magnetic resonance imaging (MRI) signal and contrast-enhancement features of uterine fibroids before and after embolization, and to determine whether or not there are pre-embolization MRI characteristics that predict the volume reduction of fibroids.

MATERIAL AND METHODS

Uterine fibroid embolization (UFE) was carried out in 28 fibroids of 20 patients, all of whom were symptomatic. The patients were prospectively evaluated with T1-weighted, T2-weighted, and gadolinium-enhanced T1 MRI sequences before and 6 months after embolization. The relationship between the characteristics of MRI signal and contrast-enhancement features of fibroids before the procedure and the change in size of the lesions after treatment was investigated.

RESULTS

Before embolization, the mean volume of fibroids was 123 cm3 (8-560 cm3). The decrease rate in fibroid volumes was 44.6% (range 7-70%) 6 months after embolization. Volume reduction was more prominent in fibroids that had a high signal intensity on T2-weighted images and a marked contrast enhancement on T1-weighted images (P < 0.001). However, the volume reduction was insufficient in fibroids with high signal characteristics on pre-contrast T1-weighted images (P < 0.001).

CONCLUSION

MRI is an effective method for revealing size and signal changes of fibroids after embolization. MRI signal characteristics and the contrast-enhancement pattern of fibroids before embolization can predict tumor volume reduction after embolization.

Long-Term Outcomes of Uterine Artery Embolization Using Gelatin Sponge Particles Alone for Symptomatic Fibroids

OBJECTIVE

The purpose of this study was to evaluate the long-term outcomes of uterine artery embolization using only gelatin sponge particles for symptomatic fibroids.

MATERIALS AND METHODS

As part of an ongoing study of the procedure for fibroids, prospective data of the initial 96 consecutive women treated between December 1997 and December 2001, were collected in January 2005. It had been more than 3 years since embolization in all cases. The follow-up period ranged from 4 to 60 months (mean, 37.4 months). On the basis of serial questionnaires, we investigated the cumulative rates of symptom control, gynecologic interventions, and overall failure, using the Kaplan-Meier product limit estimator. Symptom control was defined as meaning patients whose symptoms had improved as indicated on the last questionnaire and who had not undergone any further gynecologic intervention because of symptoms. Overall failure was defined as meaning the patients who indicated that there had been no symptom improvement or recurrence or that they had undergone further gynecologic interventions.

RESULTS

Of all 96 women, 16 (17%) were lost to follow-up during the period. Cumulative rates of symptom control were 96.9% at 1 year, 89.5% at 3 years, and 89.5% at 5 years. Cumulative rates of complications related to the gynecologic intervention and overall gynecologic interventions were 2.1% and 4.2%, respectively, at 1 year, 2.1% and 5.4% at 3 years, and 2.1% and 10.5% at 5 years. Cumulative rates of overall failure were 4.2% at 1 year, 12.7% at 3 years, and 12.7% at 5 years. Major complications were noted in 3.1% (3/96). Of these three women, two required hospitalization for transvaginal resection of sloughing fibroids and one developed sexual dysfunction. Two women became pregnant, but both pregnancies resulted in miscarriage.

CONCLUSION

Uterine artery embolization using gelatin sponge particles alone can achieve long-term symptom control for fibroids in most cases.

Incidence of Nonviable Leiomyomas on Contrast Material–Enhanced Pelvic MR Imaging in Patients Referred for Uterine Artery Embolization

PURPOSE

To assess the incidence of nonviable leiomyomas in patients referred for uterine artery embolization (UAE) with use of contrast material-enhanced pelvic magnetic resonance (MR) imaging and to determine the effect of this information on interventional radiologists' decision to perform UAE or consider other treatment options.

MATERIALS AND METHODS

One hundred consecutive women referred for UAE for treatment of symptomatic leiomyomas were studied. Of these, 94 patients underwent MR imaging examinations, which were retrospectively reviewed. Leiomyoma locations (ie, submucosal, intramural, subserosal), volume (length, width, height), and percent nonenhancement were recorded and the measurements were divided into four categories (0-25%, 25%-50%, 50%-75%, 75%-100%).

RESULTS

In 94 patients, 381 leiomyomas exceeding 3 cm in each dimension were recorded. Twenty-one patients (22%) did not receive embolization based on the findings of preprocedural MR imaging. In six patients (6%), there were nine nonviable dominant tumors with an average size of 7.8 cm3. These cases were not treated with UAE. Another 15 patients (16%) did not undergo UAE based on other MR imaging findings (including uterine size, presence of isolated adenomyosis, and endometrial lesions).

CONCLUSIONS

Contrast material-enhanced MR imaging before UAE is highly useful in the evaluation of patients referred for UAE. MR imaging can be used to determine the viability of tumors and detect other findings that preclude UAE.

Uterine Artery Embolization for Leiomyomas: Pre- and Postprocedural Evaluation with US

Transabdominal and transvaginal ultrasonography (US) are commonly used to assess the uterus and pelvis prior to and following uterine artery embolization (UAE) for symptomatic leiomyomas (fibroids). Preprocedural US may help identify relative contraindications for UAE, whereas postprocedural US can help determine the quality and quantity of fibroid involution and help identify any complications associated with the procedure. The consulting radiologist should be familiar with certain typical postprocedural US findings, which might otherwise be improperly interpreted, leading to unnecessary intervention. Magnetic resonance (MR) imaging or computed tomography will frequently provide the most accurate information in UAE patients with certain pathologic conditions, and early study results suggest that MR imaging may be helpful in predicting treatment response. Nevertheless, US is a readily available first-line imaging modality and a well-accepted method for both pre- and postprocedural evaluation of patients who undergo UAE. A proper understanding of the US findings in this patient population allows objective determination of treatment response and detection of most of the commonly recognized complications that are associated with UAE.

Uterine fibroid embolization can still be improved: observations on post-procedure magnetic resonance imaging

PURPOSE

To evaluate the efficacy and completeness of uterine fibroid embolization (UFE) measured by changes in volume and signal intensity at magnetic resonance imaging (MRI), and to compare with clinical outcome.

MATERIAL AND METHODS

40 women with symptomatic uterine fibroids underwent bilateral uterine artery embolization. At MRI studies, including post-contrast sequences before and repeatedly after treatment, the uterus and dominant fibroids were evaluated for volume, location, and contrast enhancement. Prior to treatment, all myomas showed significant contrast enhancement. The mean uterine volume was 929 ml. Clinical examinations with emphasis on menorrhagia, pelvic pain, and urinary dysfunction were performed before and 6 and 12 months after treatment.

RESULTS

UFE was bilaterally successful in 38 patients. After UFE, MRI showed no enhancement of myomas in 30 patients. In 8 patients, post-procedural MRI revealed partially remaining vascularization of fibroids despite angiographically complete embolization of the uterine arteries. On average, uterine volume decreased by 46.2% at 12 months. There was significant improvement of symptoms in the majority of patients, but slightly less improvement in patients with partially remaining vascularization of myomas.

CONCLUSION

UFE causes significant volume reduction of myomas and clinical improvement. MRI can reveal remaining vascularization in myomas despite angiographically complete embolization of uterine arteries.

Percutaneous uterine artery embolization for the treatment of symptomatic fibroids: current status

Uterine artery embolization (UAE) is increasingly being used as an alternative treatment to hysterectomy for symptomatic fibroids. Symptoms of pelvic pressure, urinary frequency and menorrhagia are controlled in 73-98% of patients who undergo UAE. At the 1-year follow-up, the uterus may shrink by up to 55% but re-growth of fibroid may however occur. The rate of major complications and amenorrhoea following this procedure is low, ranging in most series from 1 to 3.5% and 1 to 7%, respectively. Nevertheless, the rate of amenorrhoea in women over 45 seems to be higher. In order to completely block the arterial supply to the fibroid, UAE is typically performed in both uterine arteries. Different embolic agents are used such as polyvinyl alcohol, gelfoam and more recently gelatine tris-acryl microspheres. After UAE, perfusion of the uterus is maintained. Uterine function is therefore conserved and although women who become pregnant after UAE seem to be at risk for malpresentation, pre-term birth, cesarean delivery and postpartum hemorrhage, successful pregnancies after UAE have been reported in some series. A major technical problem with UAE remains the possible presence of fibroid blood supply from other sources, such as the ovarian arteries or other pelvic branches, which can lead to failure of the procedure. In conclusion, although randomized trials are still underway, UAE appears a good option for those patients who whish to conserve their fertility or when surgery is contra-indicated. However, to evaluate the long-term effects of UAE longer follow up is required.

Uterine Artery Embolization for Pedunculated Subserosal Fibroids

OBJECTIVE

The objective of our study was to assess the outcomes of uterine artery embolization as a treatment for pedunculated subserosal fibroids, which we defined as those in which the diameter of the stalk was 50% narrower than the diameter of the fibroid.

MATERIALS AND METHODS

During a 72-month period, 196 consecutive women underwent embolization for treatment of symptomatic uterine fibroids that were confirmed on baseline sagittal and axial MR images. We identified those women with pedunculated subserosal fibroids treated with embolization and retrospectively assessed complications and out-comes of embolization using a serial questionnaire and MRI.

RESULTS

Of the 196 women, 12 (age range, 34-48 years; mean age, 42.3 years) had one or more pedunculated subserosal fibroids. Fifteen pedunculated subserosal fibroids were identified on baseline MR images in the 12 patients. The mean tumor diameter was 8.3 cm (range, 4.0-15.5 cm; 95% confidence interval [CI], 6.7-9.9 cm). The mean stalk diameter was 3.1 cm (range, 2.0-5.5 cm; 95% CI, 2.5-3.7 cm). The follow-up period ranged from 5 to 51 months (mean, 18.1 months). No serious complications such as separation of the tumors from the uterus, torsion of the tumors, or infection occurred after embolization. Enhanced MR images obtained 1 week after embolization showed that complete devascularization of the tumors had been achieved in 73% (11/15) of the tumors. The rates of mean tumor volume reduction were 41% (range, 12-73%) 4 months and 53% (range, 31-85%) 1 year after embolization. The mean stalk diameter was 3.2 cm (range, 1.7-5.4 cm; 95% CI, 2.5-3.9 cm) 4 months and 2.9 cm (range, 1.1-4.2 cm; 95% CI, 1.8-3.9 cm) 1 year after embolization. No significant difference in stalk diameters was noted 4 months (p=0.617) or 1 year (p=0.963) after embolization compared with the diameters before the treatment. The rates of mean uterus volume reduction were 35% (range, 15-47%) 4 months and 47% (range, 35-60%) 1 year after embolization. Marked or moderate improvement in bulk-related symptoms was achieved in 100% (10/10) of the women at 4-month follow-up, 100% (5/5) at 1-year follow-up, and 100% (2/2) at 2-year follow-up.

CONCLUSION

We found no serious complications after embolization for pedunculated subserosal fibroids with stalk diameters of 2 cm or larger. Successful outcomes can be obtained in such tumors.

Risk of Intrauterine Infectious Complications after Uterine Artery Embolization

PURPOSE

To identify risk factors for the development of intrauterine infection following uterine artery embolization.

MATERIALS AND METHODS

A retrospective review of uterine artery embolizations (UAE) performed for the treatment of symptomatic fibroids from January 2000 to July 2003 was conducted. With logistic regression and the Fisher exact test, multiple variables were analyzed as predictors for intrauterine infectious complications requiring medical and/or surgical therapy, including the use of preprocedural antibiotics, embolic agent used, quantity of embolic material, location of fibroids (submucosal, nonsubmucosal), and size and location of the dominant fibroid.

RESULTS

A total of 414 UAE procedures were performed in 410 patients with a technical success rate of 99%. Average age of the patient cohort was 42.8 years (SD, 5.8 years). One hundred forty-eight patients (36.1%) had submucosal fibroids or fibroids projecting submucosally, 262 patients (63.9%) had nonsubmucosal fibroids. Intrauterine infectious complications requiring intravenous antibiotic therapy and/or surgery occurred in five patients (1.2%). A total of five infectious complications requiring therapy occurred in the submucosal group (3.4%) and none in the nonsubmucosal group. Patients within the submucosal group were more likely to develop intrauterine infectious complications than patients with nonsubmucosal fibroids based on univariate analysis (P = .006) but with logistic regression, the association was not significant (P = .079). No significant difference with embolic agent, quantity of embolic particles, use of preprocedure antibiotics, or size of or location of the dominant fibroid was found.

CONCLUSION

No specific risk factor for intrauterine infection following UAE was identified in this study. Infection after UAE is rare and appears to be a sporadic occurrence. Nevertheless, close surveillance is warranted in all women following UAE given the potential morbidity of this complication.

Childbirth and Myoma Treatment by Uterine Artery Occlusion: Do They Share a Common Biology?

When the uterine arteries are bilaterally occluded, either by uterine artery embolization or by laparoscopic obstruction, women with myomas experience symptomatic relief. After the uterine arteries are occluded, most blood stops flowing in myometrial arteries and veins, and the uterus becomes ischemic. It is postulated that myomas are killed by the same process that kills trophoblasts: transient uterine ischemia. When the uterine arteries are bilaterally occluded, either by uterine artery embolization (UAE) or by laparoscopic obstruction, women with myomas experience symptomatic relief. After the uterine arteries are occluded, most blood stops flowing in myometrial arteries and veins, and the uterus becomes ischemic. Over time, stagnant blood in these arteries and veins clots. Then, tiny collateral arteries in the broad ligament (including communicating arteries from the ovarian arteries) open, causing clot within myometrium to lyse and the uterus to reperfuse. Myomas, however, do not survive this period of ischemia. This is unique organ response to clot formation and ischemia. What allows the uterus to survive a relatively long period of ischemia while myomas perish? Childbirth appears to be the predicate biology. Following placental separation, the uteroplacental arteries and the draining veins of the placenta are torn apart at their bases in the junctional zone of the myometrium and bleed directly into the uterine cavity. Left unchecked, every woman would bleed to death in less than 10 minutes after placental delivery. Most women do not bleed to death because vessels in the uterus clot after placental delivery. During pregnancy, clotting and lytic factors in blood increase many fold. Following delivery, uterine contractions continue, intermittently, periodically slowing the velocity of flowing blood through myometrium. The combination of slowed blood flow, elevated clotting proteins, and torn placental vessels (known as Virchow's triad) causes blood in myometrial arteries and veins to clot. Fibrinolytic enzymes later lyse clot in arteries and veins not associated with placenta perfusion, and the uterus is reperfused. Remnant placental tissue - primarily uteroplacental arteries and veins - does not survive this period of ischemia. Placental tissue dies and over weeks is sloughed into the uterine cavity. At the same time, residual endometrial tissue grows under the sloughing placental tissue thus re-establishing the endometrial lining. It is postulated that myomas are killed by the same process that kills trophoblasts - transient uterine ischemia.

Triple-Phase Dynamic MRI of Intratumoral Vessel Density and Hyalinization Grade in Uterine Leiomyomas

OBJECTIVE

Our purpose was to clarify the relationship between the tissue vascularity shown on triple-phase dynamic MRI and the number of intratumoral vessels and degree of hyalinization, which are two histopathologic changes in leiomyoma. SUBJECTS AND METHODS. The subjects were 10 premenopausal patients with 20 leiomyomas who had undergone surgery without preoperative gonadotropin-releasing hormone analogue treatment. Intratumoral vessel density was determined by the mean number of intratumoral vessels with at least one smooth-muscle layer in the optic fields magnified 100 times. Hyalinization grade was determined by the severity of hyalinization, histopathologically classified in three grades. The enhancement index (EI) of the leiomyoma was calculated using the formula EI(t) = [S(t) - S(0)] / S(0), where S(0) is the signal intensity on pre-enhanced T1-weighted images and S(t) is the signal intensity on each dynamic phase image (t = 20, 60, and 180 sec) [corrected]. The histopathologic parameters of intratumoral vessel density and hyalinization grade were compared with the enhancement indexes obtained from the triple-phase dynamic MRI.

RESULTS

We found positive correlations between intratumoral vessel density and EI(60) and between intratumoral vessel density and EI(180) (in both cases, p = 0.0028 and r = 0.69). We found significant differences among the mean enhancement indexes for each hyalinization grade at all dynamic phases (p < 0.01). The leiomyomas with lower intratumoral vessel densities tended to show greater hyalinization.

CONCLUSION

Our results showed that leiomyomas with only slight hyalinization or with abundant vessels were well enhanced, but the leiomyomas with severe hyalinization enhanced poorly.

Is a Large Fibroid a High-Risk Factor for Uterine Artery Embolization?

OBJECTIVE

The objective of our study was to determine whether tumor size, specifically uterine fibroids of 10 cm or larger, predisposes a patient to an unacceptably high risk at uterine artery embolization.

MATERIALS AND METHODS

One hundred fifty-two consecutive women underwent embolization for uterine fibroids. Complications and outcomes were analyzed using questionnaires and serial MRI between women with one or more uterine fibroids of 10 cm or larger diameter (mean, 12.4 cm; range, 10-19 cm) (n = 47, group 1) and women with each uterine fibroid of less than 10 cm diameter (mean, 6.8 cm; range, 2-9.5 cm) (n = 105, group 2).

RESULTS

Thirty complications (19.7%, 30/152), which occurred in 27 women (17.8%, 27/152), were noted. However, 25 of 30 complications were minor, requiring no or nominal therapy. They occurred in 19.1% (9/47) of group 1 and in 15.2% (16/105) of group 2 women (p = 0.637). Major complications requiring major therapy, unplanned increased level of care, or unanticipated prolonged hospitalization (> 48 hr) or including permanent adverse sequelae were noted in 6.4% (3/47) of group 1 and in 1.9% (2/105) of group 2 women (p = 0.172). Of these five women, four underwent surgery because of sloughing fibroids. Permanent adverse sequelae were observed in one woman of group 1, who has had sexual dysfunction after embolization. No deaths occurred in either group. There was no significant difference in most outcomes or in intervals until the complete disappearance of postprocedural pain and full recovery between the two groups.

CONCLUSION

We found no increased risk to patients undergoing uterine artery embolization for fibroids on the basis of tumor size. Successful outcomes can be obtained for such lesions.

MR Imaging of Disorders Associated with Female Infertility: Use in Diagnosis, Treatment, and Management

Magnetic resonance (MR) imaging has extended the usefulness of imaging in evaluation of pelvic disorders associated with female infertility. The causes of female infertility include ovulatory disorders (ie, pituitary adenoma and polycystic ovarian syndrome), disorders of the fallopian tubes (ie, hydrosalpinx and pelvic inflammatory disease), uterine disorders (ie, müllerian duct anomaly, adenomyosis, and leiomyoma), and pelvic endometriosis. Although laparoscopy, hysteroscopy, hysterosalpingography, and transvaginal ultrasonography are the most effective techniques for evaluation of pelvic disorders related to female infertility, MR imaging is used in a variety of clinical settings in diagnosis, treatment, and management. The applications of MR imaging include evaluation of the functioning uterus and ovaries, visualization of pituitary adenomas, differentiation of müllerian duct anomalies, and accurate noninvasive diagnosis of adenomyosis, leiomyoma, and endometriosis. In addition, MR imaging helps predict the outcome of conservative treatment for adenomyosis, leiomyoma, and endometriosis and may lead to selection of better treatment plans and management. Finally, MR imaging may serve as an adjunct to diagnostic laparoscopy and hysterosalpingography in patients with hydrosalpinx, peritubal adhesions, or pelvic adhesions related to endometriosis.

Transvaginal sonographic appearance of thrombosed uterine arteries after uterine artery embolization: the "white snake" sign

PURPOSE

The aim of this prospective study was to describe the appearance of thrombosed uterine arteries on transvaginal sonography performed after uterine artery embolization (UAE) and to assess the prognostic value of the "white snake" sign with regard to symptomatic outcome at 12 months.

METHODS

Patients who underwent UAE from January 1, 1999, to July 31, 2000, for the treatment of symptomatic leiomyomas were included in the study. Transvaginal sonography was performed before and at 3, 6, and 12 months after UAE. Patients graded the severity of their symptoms on a scale from 1 to 5, with 1 being the least and 5 the most severe, before and at 12 months after the procedure. The Wilcoxon rank-sum test was used to determine correlations between severity of symptoms and presence of the white snake sign; a p value of less than 0.05 was considered significant.

RESULTS

During the study period, UAE was performed in 19 patients with a mean age of 41 years (range, 32-48 years). UAE was technically successful in all patients. Eighteen patients (95%) reported symptomatic improvement at 12 months: 8 patients (42%) by 4 severity-scale points, 5(26%) by 3 points, and 5 (26%) by 2 points. The 1 patient who did not experience improvement had undergone a hysterectomy at 4 months after the UAE. At the 3-month follow-up, transvaginal sonography demonstrated a tortuous echogenic structure in the adnexa (the white snake sign) in all patients; the finding was still apparent in 10 patients at 6 months but in only 2 patients at 12 months. A direct correlation was found between persistence of the white snake sign and the degree of symptomatic improvement at 6 months (p=0.04) but not at 12 months (p=0.08).

CONCLUSIONS

After UAE, a thrombosed uterine artery appears on transvaginal sonography as an echogenic tortuous structure in the adnexa. Persistence of this white snake sign at 6 months after UAE may suggest a more favorable symptomatic outcome.

Benign myometrial conditions: leiomyomas and adenomyosis

Leiomyomas and adenomyosis are common benign myometrial conditions. Although their symptoms overlap, traditional treatment of these two entities differs; thus, making the correct diagnosis is critical. Specifically, uterine-conserving therapy is well established for many women with symptomatic leiomyomas, whereas hysterectomy is the treatment for debilitating adenomyosis. Magnetic resonance imaging (MRI) is the most accurate modality for identifying leiomyomas and adenomyosis. T2-weighted sequences often are diagnostic. For leiomyomas, MRI reliably identifies their number, size, and location. These features help triage patients to appropriate therapy. For adenomyosis, MRI establishes the diagnosis in cases of equivocal or nondiagnostic ultrasounds. MRI also has been used to confirm an ultrasound diagnosis of adenomyosis when curative surgery is being considered. Intravenous gadolinium chelates are not necessary to make the diagnosis of either adenomyosis or leiomyomas, but it provides useful information about vascularity of lesions, a factor that may impact the type of treatment undertaken.

Embolisation des fibromes utérins : résultats sur 454 cas

OBJECTIVE

To determine the effectiveness of uterine arterial embolization (UAE) as primary treatment in the management of symptomatic leiomyomas.

PATIENTS AND METHOD

UAE was performed on 454 patients (age range: 21-68) with menorrhagia, bulk-related symptoms or both, due to leiomyomas. The effectiveness of this therapy in the control of symptoms and reduction of uterine and leiomyoma volume was measured by clinical and imaging controls at 3, 6 and 9 months after the procedure.

RESULTS

Four hundred and thirty-three patients were evaluated, and 42 failures were observed (9.6%). Six months after the procedure, 391 patients were symptom-free. Follow-up ultrasonic examination showed an average reduction of 55% in dominant myoma volume at 6 months, 70% at 1 year. Twenty-seven women became pregnant (30 pregnancies). Complications related to procedure, and requiring surgery, occurred in three cases. Principal complications are amenorrhoea and fibroid sloughs. Severe complications are rarely found.

DISCUSSION AND CONCLUSION

UAE is an efficient therapy in the management of symptomatic myomas and proves to be a valid alternative to surgical procedure. The future of this mini-invasive and conservative technique appears to be a very promising one.