FEMIC (Fibromes Embolis�s aux MICrosph�res calibr�es): Uterine Fibroid Embolization using Tris-acryl Microspheres. A French Multicenter Study

Current Trends in Gelatin-Based Drug Delivery Systems

Gelatin is a highly versatile natural polymer, which is widely used in healthcare-related sectors due to its advantageous properties, such as biocompatibility, biodegradability, low-cost, and the availability of exposed chemical groups. In the biomedical field, gelatin is used also as a biomaterial for the development of drug delivery systems (DDSs) due to its applicability to several synthesis techniques. In this review, after a brief overview of its chemical and physical properties, the focus is placed on the commonly used techniques for the development of gelatin-based micro- or nano-sized DDSs. We highlight the potential of gelatin as a carrier of many types of bioactive compounds and its ability to tune and control select drugs' release kinetics. The desolvation, nanoprecipitation, coacervation, emulsion, electrospray, and spray drying techniques are described from a methodological and mechanistic point of view, with a careful analysis of the effects of the main variable parameters on the DDSs' properties. Lastly, the outcomes of preclinical and clinical studies involving gelatin-based DDSs are thoroughly discussed.

The comparison of myomectomy, UAE and MRgFUS in the treatment of uterine fibroids: a meta analysis

OBJECTIVE

To compare the re-intervention rates of myomectomy, uterine artery embolization (UAE) and magnetic resonance-guided focused ultrasound surgery (MRgFUS) for uterine fibroids (UFs) in different follow-up time.

METHODS

Two investigators searched PubMed for clinical studies published in English from 1 Jan 2000 to 31 Dec 2020, and independently examined the paper to select qualified studies, extracted relevant information and assessed the risk of bias. Meanwhile, a meta-analysis of 31 studies containing totally 42103 patients was conducted to compare the re-intervention rate of myomectomy, UAE and MRgFUS.

RESULTS

In the meta-analysis of 42103 patients, the 12-month re-intervention rates of myomectomy, UAE and MRgFUS for UFs were 0.06 (95%CI, 0.01-0.11), 0.07 (95%CI, 0.06-0.09), and 0.12 (95%CI, 0.04-0.20) respectively. The 24-month re-intervention rates were 0.10 (95%CI, 0.04-0.16), 0.08 (95%CI, 0.01-0.17), and 0.14 (95%CI, 0.07-0.21) respectively. The 36-month re-intervention rates were 0.09 (95%CI, 0.05-0.13), 0.14 (95%CI, 0.05-0.23), and 0.22 (95%CI, 0.11-0.32) respectively. Additionally, the 60-month re-intervention rates were 0.19 (95%CI, 0.15-0.24), 0.21 (95%CI, 0.17-0.25), and 0.49 (95%CI, 0.21-0.77) respectively.

CONCLUSIONS

The myomectomy has the lowest re-intervention rate of the three regimens in short time and long time while the MRgFUS has the highest. The rate of MRgFUS increased rapidly in the 60th month after the treatment.

Initial experience with HydroPearl microspheres for uterine artery embolization for the treatment of symptomatic uterine fibroids

Background

Uterine Artery Embolization (UAE) is a minimally invasive procedure used to treat symptomatic uterine fibroids. The HydroPearl Microsphere (Terumo Interventional Systems) is an embolic agent approved for UAE and other embolization procedures. The purpose of this article is to describe our initial experience with HydroPearl for UAE in patients with symptomatic uterine fibroids. Twenty-one patients who underwent UAE using HydroPearl Microspheres at a single institution from May 1, 2018 to December 31, 2019 were included in the study. The electronic medical record (EMR) was reviewed for documentation of short- and long-term complications, as well as improvements in menorrhagia and bulk-type symptoms. We also describe unique attributes of the HydroPearl Microsphere that should be considered when utilizing this embolization particle for UAE.

Results

Of the 21 patients, 18 had a 3-month or later post-procedure follow-up documented in the EMR and were included in the analysis. The average time between the UAE procedure and the most recent clinical note was 145 days. Sixteen patients reported symptoms of menorrhagia and 13 reported bulk symptoms prior to the UAE procedure. On follow-up, 13/16 patients (81%) and 12/13 patients (92%) experienced improvement in menorrhagia and bulk symptoms, respectively. The only recorded complication was amenorrhea in 4 patients (22%) who had an average age of 51 years.

Conclusions

Several characteristics of HydroPearl Microsphere may prove helpful when considering these embolic particles for use in UAE. Our initial experience with this embolic agent suggest that the reatment response for menorrhagia and bulk symptoms are largely similar to success rates reported in the literature for other embolic agents. Larger studies are needed to evaluate the safety and efficacy of this embolic particle for this indication.

Significance of changes in inflammatory parameters following uterine artery embolization in pre-menopausal females

The purpose of the present study was to describe the course of changes in laboratory inflammatory markers following bilateral uterine artery embolization (UAE) as a treatment for leiomyomas and adenomyosis. The body temperature was measured and blood samples were collected to determine white blood cell (WBC) count and C-reactive protein (CRP) levels in 270 patients on the day prior to UAE and for up to 4 days post-embolization. Aside from a single case with a non-inflammatory complication, none of the other cases had any complications. Post-UAE leukocytosis with a mean maximum value of 10.8±3.5x10⁹/l (range, 5.9-18.6x10⁹/l) was observed one-year post-intervention. The mean leukocyte numbers were indicated to be higher on day 3 post-UAE. The CRP level was also increased post-UAE, with a mean maximum value of 7.75±3.5 mg/dl. Maximum levels were reached in 8 patients on the 2nd and in 11 patients on the 3rd post-operative day. The maximum pain score was ~5.5 and reached its lowest level at the end of the 12th week post-intervention. The present study did not consider an association between the embolic material used or uterus size with the level of treatment success. No complications were observed post-UAE; however, a significant increase in the WBC count was observed within the first 3 days, indicating mild leukocytosis.

Predisposing factors for predicting the therapeutic response of adenomyosis after uterine artery embolization: serum CA125 levels and accompanying endometriosis

PURPOSE

We aimed to identify predisposing factors that could help predict the therapeutic response of adenomyosis after uterine artery embolization (UAE).

METHODS

This was a retrospective, single-center study of patients admitted to the hospital for adenomyosis between 2013 and 2015. Sixty-eight patients with adenomyosis who underwent UAE with tris-acryl gelatin microspheres were divided into two groups based on their therapeutic response (complete or incomplete necrosis of lesions), and pre- and postprocedural pelvic magnetic resonance imaging (MRI) data. Patients were followed up for 12 months after UAE. Improvements in dysmenorrhea and menorrhagia were evaluated based on the symptom relief criteria. Improvement rates in both groups were analyzed and compared. Multivariate logistic regression analysis was used to identify the predisposing factors from retrospectively gathered baseline data that might affect the therapeutic response, including MRI features, clinical symptoms, biochemical index, and accompanying diseases of adenomyosis. Then, a prognostic model was established, and the receiver operating characteristic (ROC) curve of identified factors was drawn to determine their predictive value.

RESULTS

Following UAE, 46 patients (67.6%) showed complete necrosis, while 22 patients (32.4%) showed incomplete necrosis. At 12-month follow-up, dysmenorrhea symptom improvement was seen in 94.7% of complete necrosis and 50% of incomplete necrosis group (P < 0.001); menorrhagia symptom improvement was seen in 96.2% of complete necrosis and 57.1% of incomplete necrosis groups (P = 0.004). Multivariate logistic regression analysis determined serum cancer antigen 125 (CA125) levels (odds ratio [OR], 1.006; 95% confidence interval [CI], 1.002-1.010; P = 0.005) and accompanying endometriosis (OR, 6.869; 95% CI, 1.881-25.016; P = 0.004) as predisposing factors. The areas under the ROC curve of CA125, endometriosis, and these two indicators combined were 0.785, 0.708, and 0.845, which corresponded to sensitivities of 95.5%, 66.7%, and 68.2% and specificities of 52.2%, 80.0%, and 87.0% at optimal cutoff values, respectively.

CONCLUSION

Symptom relief of dysmenorrhea and menorrhagia for patients with complete necrosis was significantly better than that for patients with incomplete necrosis. Serum CA125 levels and accompanying endometriosis can effectively distinguish complete necrosis from incomplete necrosis.

Uterine artery embolization with trisacryl gelatin microspheres in women treated for leiomyomas: a clinicopathologic analysis of alterations in gynecologic surgical specimens

To characterize the histologic range of alterations due to uterine artery embolization with trisacryl gelatin microspheres in gynecologic specimens containing leiomyomas in detail, we report our clinicopathologic experience with 26 cases (longest postuterine artery embolization interval, 1.9 yr). Microspheres were observed in 85% of cases and could be seen up to 1.9 years after embolization. They were mainly present in leiomyomas and nonneoplastic myometrium but could be found in other nontargeted sites, such as the cervix, endometrium, ovaries, and fallopian tubes; however, infarction (present in 96% of cases) was confined to leiomyomas and did not involve other nonneoplastic tissues. The appearance of the infarcts was correlated with time after embolization, and coagulative necrosis/necrosis of indeterminate type was restricted to the early period after uterine artery embolization (before 10 wk postuterine artery embolization) whereas hyaline necrosis was seen predominantly in the late period (mostly after 10 wk, up to 1.9 yr). Of the 14 hysterectomy specimens with microspheres in extravascular spaces (almost all of which were in close proximity to the arteries), pseudoaneurysms were also focally present in 8 (57%) specimens. Microspheres were usually associated with mild inflammatory reactions, which persisted >1 year after embolization but did not become more severe over time. Morphologic and histochemical features of trisacryl gelatin microspheres were compared with other embolization agents, which can also be encountered in surgical specimens [polyvinyl alcohol (PVA) particles and PVA microspheres]. Trisacryl gelatin microspheres were negative with periodic acid-Schiff and orange-pink with Movat stains whereas PVA was positive with periodic acid-Schiff and black with Movat. Our study, the largest histologic analysis to date, confirms and extends the observations of earlier studies of trisacryl gelatin microspheres. In addition, we conclude that, as expected, the histologic appearance of microsphere-induced infarcts is a function of time, similar to healing of infarcts in nongynecologic sites. Pseudoaneurysms are a likely mechanism for the production of microspheres in extravascular spaces. Inflammation associated with microspheres can persist in gynecologic tissues but does not seem to result in the destruction of nontargeted sites. Finally, trisacryl gelatin microspheres can be distinguished from PVA particles and PVA microspheres based on a combination of morphologic features and histochemical stains.

The role of interventional radiology in obstetric and gynaecology practice

Interventional radiology is continuing to reshape current practice in many specialties of clinical care. It is a relatively new and innovative branch of medicine in which physicians treat diseases non-operatively through small catheters guided to the target by fluoroscopic and other imaging modalities. The aim is to provide image-guided, minimally invasive alternatives to traditional surgical and medical procedures in suitable cohorts of patients. Procedures which previously required major surgery can now be performed by interventional radiologists, sometimes on an outpatient basis, with little patient discomfort. In this review, we highlight the importance of interventional radiology in treating a comprehensive range of obstetric and gynaecological pathologies.

Experimental evaluation of early and long-term effects of microparticle embolization in two different mini-pig models. Part II: liver

PURPOSE

To evaluate trisacryl-gelatin microspheres (40-120 microm) for acute and chronic tissue embolization in mini-pig livers.

METHODS

Thirteen animals were divided into four groups: group 1 (n = 3), total arterial bed occlusion with acute procedure; groups 2 to 4, chronic superselective embolization with follow-up of 1 week (group 2, n = 1), 4 weeks (group 3, n = 4) or 14 weeks (group 4, n = 5). Key endpoints were homogeneity and particle distribution in acute embolizations (group 1) and necrosis and inflammation in chronic embolizations (groups 2-4) as assessed microscopically and angiographically.

RESULTS

After liver embolization, parenchymal necrosis did not occur; only signs of vessel wall disintegration were evident. The bile ducts remained intact. A distinct foreign body reaction with sparse leukocytic infiltration and giant cells was found at 14 weeks, but no signs of major inflammation were found. Particles were seen at the presinusoidal level, but no particle transportation into the sinusoids was observed.

CONCLUSIONS

Embolization in mini-pig livers, using small trisacryl-gelatin microspheres, results in vessel fibrosis without parenchymal or bile duct necrosis. The most likely explanation for preservation of the parenchyma is portal inflow. Small trisacryl-gelatin microspheres may be ideal as an adjunct for chemoembolization.

The impact of uterine artery embolization on fertility and pregnancy outcome

PURPOSE OF REVIEW

Uterine artery embolization for management of symptomatic fibroids is an effective and increasingly popular treatment option. There are several studies evaluating the effects of uterine artery embolization on later pregnancies; however, the effects on fertility are still largely uncertain. This paper reviews the current literature on the effects of this technique on fertility and pregnancy outcome.

RECENT FINDINGS

Two recent studies have reported pregnancy rates following uterine artery embolization in women seeking pregnancy. A small, third study reported preliminary results in a randomized controlled trial comparing uterine artery embolization with myomectomy in women wishing to preserve fertility.

SUMMARY

The body of medical literature supports use of uterine artery embolization as an effective treatment for symptoms of vaginal bleeding and pelvic pressure from uterine fibroids. Patient selection is critical in determining the appropriateness of this treatment option. Myomectomy remains the standard of care for women with symptomatic fibroids seeking fertility preservation.

Preoperative Uterine Artery Embolization (PUAE) Before Uterine Fibroid Myomectomy

PURPOSE

To evaluate the potential of uterine artery embolization to minimize blood loss and facilitate easier removal of fibroids during subsequent myomectomy.

METHODS

This retrospective study included 22 patients (median age 37 years), of whom at least 15 wished to preserve their fertility. They presented with at least one fibroid (mean diameter 85.6 mm) and had undergone preoperative uterine artery embolization (PUAE) with resorbable gelatin sponge.

RESULTS

No complication or technical failure of embolization was identified. Myomectomies were performed during laparoscopy (12 cases) and laparotomy (9 cases). One hysterectomy was performed. The following were noted: easier dissection of fibroids (mean 5.6 per patient, range 1-30); mean intervention time 113 min (range 25-210 min); almost bloodless surgery, with a mean peroperative blood loss of 90 ml (range 0-806 ml); mean hemoglobin pretherapeutically 12.3 g/dl (range 5.9-15.2 g/dl) and post-therapeutically 10.3 g/dl (range 5.6-13.3 g/dl), with no blood transfusion needed. Patients were discharged on day 4 on average and the mean sick leave was 1 month.

CONCLUSION

Preoperative embolization is associated with minimal intraoperative blood loss. It does not increase the complication rate or impair operative dissection, and improves the chances of performing conservative surgery.

Update on uterine artery embolization for symptomatic fibroid disease (uterine artery embolization)

Transcatheter embolization of the uterine arteries for symptomatic fibroid disease has become an increasingly important alternative treatment. It is highly effective and well tolerated by most patients. Most notably, uterine artery embolization is associated with a short recovery period and is uterine sparing. To ensure the best chance for a safe and successful procedure, Interventional Radiologists should have familiarity with uterine artery anatomy, state of the art embolization techniques, and optimal patient selection and post procedure management.

Uterine Artery Embolization as a Treatment Option for Uterine Myomas

Information is still being collected on the long-term clinical responses and appropriate patient selection for UAE. Prospective RCTs have not been performed to compare the clinical results from UAE with more conventional therapies for symptomatic uterine leiomyomata. At least three attempts at conducting such RCTs have been unsuccessful because of poor patient accrual that related to differing patient expectation and desires, clinical bias, insurance coverage, and the tendency that patients who have exhausted other treatment options may be disposed more favorably to less invasive treatments. Other comparative studies have serious limitations. For example, the retrospective study that compared outcomes after abdominal myomectomy with UAE suggested that patients who received UAE were more likely to require further invasive treatment by 3 years than were recipients of myomectomy. Lack of randomization introduced a selection bias because women in the group that underwent UAEwere older and were more likely to have had previous surgeries. A prospective study of "contemporaneous cohorts," which excluded patients who had sub-mucosal and pedunculated subserosal myomas, sought to compare quality of life measures and adverse events in patients who underwent UAE or hysterectomy. The investigators concluded that both treatments resulted in marked improvement in symptoms and quality of life scores, but complications were higher in the group that underwent hysterectomy over 1 year. In this study,however, a greater proportion of patients who underwent hysterectomy had improved pelvic pain scores. Furthermore, hysterectomy eliminates uterine bleeding and the risk for recurrence of myomas. Despite the lack of controlled studies that compared UAE with conventional surgery, and despite limited extended outcome data, UAE has gained rapid acceptance, primarily because the procedure preserves the uterus, is less invasive, and has less short-term morbidity than do most surgical options. The cost of UAE varies by region, but is comparable to the charges for hysterectomy and is less expensive than abdominal myomectomy. The evaluation before UAE may entail additional fees for diagnostic testing, such as MRI, to assess the uterine size and screen for adenomyosis. Other centers have recommended pretreatment ultrasonography, laparoscopy, hysteroscopy, endometrial biopsy, and biopsy of large fibroids to evaluate sarcoma. Generally,after UAE the recovery time and time lost from work are less; however, the potential need for subsequent surgery may be greater when compared with abdominal myomectomy. Any center that offers UAE should adhere to published clinical guidelines,maintain ongoing assessment of quality improvements measures, and observe strict criteria for obtaining procedural privileges. After McLucas advocated that gynecologists learn the skill to perform UAE for managing symptomatic myomas, the Society of Interventional Radiology responded with a precautionary commentary on the level of technical proficiency that is necessary to maintain optimum results from UAE. The complexity of pelvic arterial anatomy, the skill that is required to master modern coaxial microcatheters, and the hazards of significant patient radiation exposure were cited as reasons why sound training and demonstration of expertise be obtained before clinicians are credentialed to perform UAE.A collaboration between the gynecologist and the interventional radiologist is necessary to optimize the safety and efficacy of UAE. The primary candidates for this procedure include women who have symptomatic uterine fibroids who no longer desire fertility, but wish to avoid surgery or are poor surgical risks. The gynecologist is likely to be the primary initial consultant to patients who present with complaints of symptomatic myomas. Therefore, they must be familiar with the indications, exclusions, outcome expectations, and complications of UAE in their particular center. When hysterectomy is the only option, UAE should be considered. Appropriate diagnostic testing should aid in the exclusion of most, but not all, gynecologic cancers and pregnancy. Other contraindications include severe contrast medium allergy, renal insufficiency, and coagulopathy. MRI may be used to screen women before treatment in an attempt to detect those who have adenomyosis; patients should be aware that UAE is less effective in the presence of solitary or coexistent adenomyosis. Because some women may experience ovarian failure after UAE, additional studies to determine basal follicle-stimulating hormone and estradiol before and after the procedure may provide insight into UAE-induced follicle depletion.UAE is a unique new treatment for uterine myomas, and is no longer considered investigational for symptomatic uterine fibroids. There is international recognition that data are needed from RCTs that compare UAE with surgical alternatives. Current efforts to provide prospective objective assessment of treatment outcomes and complications after UAE will help to optimize patient selection and clinical guidelines. FIBROID should provide critical data for the assessment of safety and outcomes measures for women who receive UAE for symptomatic uterine myomas.

Limited Uterine Artery Embolization for Leiomyomas with Tris-Acryl Gelatin Microspheres: 1-Year Follow-up

PURPOSE

To assess the safety and efficacy of uterine artery embolization (UAE) using large calibrated tris-acryl gelatin microspheres.

MATERIALS AND METHODS

One hundred fifty-eight women with symptomatic uterine fibroids underwent UAE. Embosphere was used in 105 women and Embogold microspheres in 53 women. Major and minor complications were assessed. At 12 months, relief of symptoms and patient satisfaction were assessed and volume reductions of the uterus and dominant fibroid were calculated.

RESULTS

Median age of the subjects was 43 years (mean, 42.3 y; range, 23-53 y). Preprocedural symptoms were heavy menstrual bleeding in 89%, pain in 64%, and bulk related symptoms in 57%. At 12 months follow-up, the proportion of women with heavy menstrual bleeding, pain, and bulk-related symptoms had decreased to 9%, 8%, and 8%, respectively. Patient satisfaction was grouped as follows: very satisfied 57%, satisfied 36%, and not satisfied 7%. Mean uterine and dominant fibroid volumes before UAE were 532 cm(3) and 201 cm(3), respectively. At 12-month follow-up MR imaging, mean uterine volume decreased to 260 cm(3) and mean dominant fibroid volume to 78 cm(3). These differences were statistically significant (P < .0001). There were no procedure-related deaths. No emergency hysterectomy was needed. Permanent amenorrhea occurred in 11% of women. Transient amenorrhea occurred in 13% of women, and fibroid expulsion occurred in 10% of women. Twelve women (7.6%) had additional therapy: nine underwent additional embolization and three had hysterectomy.

CONCLUSION

Targeted UAE using large calibrated microspheres is safe and effective in the relief of symptoms in the majority of patients. At 12 months, a marked fibroid and uterine volume reduction is obtained.

Recent advances in uterine fibroid embolization

PURPOSE OF REVIEW

To summarize the literature on uterine embolization for fibroids published in 2004 and 2005.

RECENT FINDINGS

During the last two years, our understanding of the outcome of uterine fibroid embolization has increased. The outcomes are comparable to those that occur after hysterectomy. Health-related quality-of-life studies have confirmed the positive impact of the procedure. Improvement in menorrhagia has been quantified using the alkaline hematin method, objectively confirming the outcome. Recovery is also better understood and quantified, with most patients experiencing only moderate pain over the first few days after embolization. In two pregnancy-outcome studies, an increased frequency of cesarean section occurred and possibly a greater likelihood of abnormal placentation, although the data are too few to draw conclusions at this time. Contrast-enhanced magnetic resonance imaging (MRI) has emerged as the primary tool for assessing the potential of complications following the procedure, and our understanding of vaginal discharge and uterine infarction has been increased as a result of its use.

SUMMARY

Within the last few years, uterine embolization has become an accepted therapy for uterine fibroids. The increase in understanding gained in recent years has helped to confirm the effectiveness and relative tolerability of this therapy.

Mid-term Clinical Results and Patient Satisfaction After Uterine Artery Embolization in Women with Symptomatic Uterine Fibroids

PURPOSE

To evaluate the mid-term clinical results and patient satisfaction following uterine artery embolization (UAE) in women with symptomatic fibroids.

METHODS

Between August 1998 and December 2002, 135 patients had UAE for symptomatic uterine fibroids. All patients were asked to fill in a questionnaire. Questions were aimed at changes in bleeding, pain, and bulk-related symptoms. Symptoms after UAE were scored as disappeared, improved, unchanged or worsened. Adverse events were noted, such as vaginal dryness and discharge, menopausal complaints or fibroid expulsion. Patient satisfaction after UAE was assessed. Patient satisfaction of women embolized with polyvinyl alcohol (PVA) particles was compared with satisfaction of women embolized with calibrated microspheres.

RESULTS

The questionnaire was returned by 110 of 135 women (81%) at a median time interval of 14 months following UAE. In 10 women additional embolization or hysterectomy had been performed. Of the 110 responders, 86 (78%) were satisfied with the result of UAE. The proportion of satisfied women was higher in the group embolized with calibrated microspheres than in women embolized with PVA, although this difference was not statistically significant (p = 0.053).

CONCLUSION

UAE in women with symptomatic uterine fibroids leads to improvement of symptoms and patient satisfaction is good in the vast majority after a median follow-up period of 14 months.

Acquired uterine vascular malformations: radiological and clinical outcome after transcatheter embolotherapy

The purpose of this retrospective study is to assess the radiological and clinical outcome of transcatheter embolization of acquired uterine vascular malformations in patients presenting with secondary postpartum or postabortion vaginal hemorrhage. In a cohort of 17 patients (mean age: 29.7 years; standard deviation: 4.23; range: 25-38 years) 18 embolization procedures were performed. Angiography demonstrated a uterine parenchymal hyperemia with normal drainage into the large pelvic veins ("low-flow uterine vascular malformation") in 83% (n=15) or a direct arteriovenous fistula ("high-flow uterine vascular malformation") in 17% (n=3). Clinically, in all patients the bleeding stopped after embolization but in 1 patient early recurrence of hemorrhage occurred and was treated by hysterectomy. Pathological analysis revealed a choriocarcinoma. During follow-up (mean time period: 18.8 months; range: 1-36 months) 6 patients became pregnant and delivered a healthy child. Transcatheter embolization of the uterine arteries, using microparticles, is safe and highly effective in the treatment of a bleeding acquired uterine vascular malformation. In case of clinical failure, an underlying neoplastic disease should be considered. Future pregnancy is still possible after embolization.