Comparison of Pain After Uterine Artery Embolization Using Tris-Acryl Gelatin Microspheres Versus Polyvinyl Alcohol Particles

When compared in a uterine artery embolization (UAE) animal model, Embospheres (ES) (Biosphere Medical, Rockland, MA) were found to induce less uterine ischemia than polyvinyl alcohol (PVA) particles. Given this finding, we aimed to test the hypothesis that ES is associated with less pain after UAE than PVA in human patients. We performed retrospective analysis on data from 72 consecutive UAE patients, collected from a prospectively acquired database. Patient-controlled analgesia (PCA) pump-delivered morphine sulfate (MS) dosages were compared between patients who received ES versus PVA. Subjective pain scores (SPS) were also compared between the two groups. Secondary outcome measures, including embolic volume and clinical outcome data, were also collected. Linear regression and t-test statistical analyses were performed. Null hypotheses were rejected at the p < 0.05 level. Mean follow-up period in the PVA population was 178 days (range 28–426), versus 96 days (range 24–197) in the ES population. The mean MS doses used by ES and PVA patients were 37.2 (s.d. 23.5) versus 47.1 (s.d. 26.8), respectively. This difference was not significant (p > 0.15). Utilizing a standard 0–10 pain scale, the mean peak SPS for the ES and PVA groups were 5.58 (s.d. 2.77) and 5.07 (s.d. 2.99), respectively. The difference was not significant. The mean amount of embolic material used in each ES and PVA patient was 4.86 cc (s.d. 3.01) and 3.52 cc (s.d. 1.63), respectively. The difference revealed a strong trend toward statistical significance (p = 0.05). There was one treatment failure in each group of patients. Within both patient samples, no significant correlation was found when comparing the volume of embolic used and subsequent MS dose. Despite a strong trend toward a significantly higher volume of ES used per patient, there is no subjective or objective difference in pain after UAE with ES when compared to PVA.     

Superior Rectal Artery Embolization with Tris-Acryl Gelatin Microspheres: A Randomized Comparison of Particle Size

PurposeTo evaluate the safety and efficacy of superior rectal artery embolization (SRAE) with different-sized tris-acryl gelatin microspheres in symptomatic hemorrhoidal disease (HD).Materials and MethodsForty-two patients (male, 30; female, 12; median age, 45 years) with symptomatic HD (2 grade I, 8 grade II, 17 grade III, and 15 grade IV) were divided into 3 experimental arms (500–700 μm, 700–900 μm, and 900–1,200 μm groups; each had 14 patients) in a prospective randomized style to perform SRAE. Follow-up was performed by rectoscopy, clinical examination, and questionnaires. The primary outcome measure was the clinical success rate at 12 months. Secondary outcome measures were technical success rate, recurrence rate, procedure-related mortality, procedure-related complications, and any outcome changes between particle sizes.ResultsNo procedure-related deaths or major morbidities were observed. There was a 54% minor complication rate (n = 23/42) in the treated zone: 45% sustained small superficial ulcerations (n = 19/42), 7% small rectosigmoid junction ulcerations (n = 3/42), and 2% small fibrotic scar tissue (n = 1/42). The clinical success rate was 93%. Of the groups, the best French bleeding score decrease was obtained in the 900–1,200 μm group. There were improvements in the quality of life score and visual analogue scale score after the SRAE procedure, although not in the Goligher score. No recurrent disease was observed.ConclusionsSRAE with tris-acryl gelatin microspheres for symptomatic HD is a safe and efficient treatment, with results favoring the use of larger microspheres.     

Comparison of Polyvinyl Alcohol Microspheres and Tris-Acryl Gelatin Microspheres for Uterine Fibroid Embolization: Results of a Single-Center Randomized Study

PurposeTo assess the efficacy of two embolic agents in the treatment of symptomatic uterine leiomyomas.Materials and MethodsA randomized, prospective, single-center study enrolled 60 women with symptomatic uterine leiomyomas. Uterine artery embolization (UAE) with spherical polyvinyl alcohol (SPVA) microspheres (n = 30; 700–900 μm and 900–1,200 μm; near-stasis or stasis endpoint) and tris-acryl gelatin (TAG) microspheres (n = 30; 500–700 μm; “pruned-tree” endpoint) was performed. Infarction rates were calculated for the dominant tumor and for small (< 2 cm) and large (> 2 cm) nondominant tumors. The primary endpoint was tumor infarction at 24 hours measured by contrast-enhanced magnetic resonance imaging assessed by a blinded reviewer.ResultsBaseline characteristics were similar between groups. The primary endpoint was similar in both treatments (≥ 91% dominant tumor infarction; SPVA. 86.2%; TAG, 93.3%, P = .35). Complete infarction (100%) was also similar between arms at 24 hours and 3 months. Symptom severity was reduced and quality of life improved equally at 3 and 12 months in each treatment group. Complications were minor in both groups.ConclusionsUterine leiomyoma infarction at 24 hours and 3 months after treatment with SPVA or TAG microspheres was comparable when using near-stasis as a procedural endpoint with SPVA microspheres. Symptom relief was maintained for as long as 12 months for both embolic agents.     

Renal and Splenic Micro-Infarctions Following Bronchial Artery Embolization with Tris-Acryl Microspheres

A bronchial artery embolization (BAE) is an important therapeutic method used to control acute and chronic hemoptysis. We report a case of multiple micro-infarcts involving both the kidneys and spleen, following a BAE with 500-700 µm crossed-linked tris-acryl microspheres (Embospheres) in a patient with bronchial artery pulmonary vein shunts. The superior penetration characteristics of the microspheres may have resulted in the greater tendency to cross the bronchial artery pulmonary vein shunts, which subsequently caused the systemic infarcts in our patient. We propose the use of larger sized microspheres (700-900 µm), which may aid in avoiding this complication.     

Comparison of the Efficacy of the Embolic Agents Acrylamido Polyvinyl Alcohol Microspheres and Tris-Acryl Gelatin Microspheres for Uterine Artery Embolization for Leiomyomas: A Prospective Randomized Controlled Trial

Objective  

To evaluate the efficacy of acrylamido polyvinyl alcohol microspheres (a-PVAM) as an embolic agent for uterine artery embolization (UAE) compared with Tris-acryl gelatin microspheres (TAGM).     

Arterial Distribution of Calibrated Tris-Acryl Gelatin and Polyvinyl Alcohol Embolization Microspheres in Sheep Uterus

The purpose of this study was to compare, after embolization, the distribution in the uterine arterial vasculature of tris-acryl gelatin microspheres (TGMS) and polyvinyl alcohol microspheres (PVAMS). A limited bilateral uterine artery embolization was performed in six adult sheep under fluoroscopic control by injecting in each uterine artery 0.25 ml of 500- to 700-μm TGMS of PVAMS suspended in 50/50 saline/contrast medium. Sacrifices were performed 1 week after embolization and uteri were analyzed histologically. The number and size of microspheres and vessels were measured, as well as the histological location according to a classification in four zones of the uterus. One hundred sixty-five vessels (69 vessels occluded with TGMS and 96 vessels occluded with PVAMS) were measured. The size of the occluded vessels decreased significantly from proximal to distal zones of the uterine vasculature (P < 0.0001). The location of TGMS and PVAMS within the vasculature was significantly different (P < 0.0001) since PVAMS blocked significantly more distally than TGMS. Deformation of the microspheres within the tissue was greater for PVAMS (18.0% ± 12.3%) than for TGMS (8.7% ± 9.2%) (P < 0.0001). In conclusion, PVAMS have a more distal distribution in the sheep uterine vasculature, compared to TGMS. Such differences in partition, already described in the kidney embolization model, can ultimately explain the different clinical outcome reported with these two types of microspheres in uterine fibroid embolization.     

Intra-Arterial Lidocaine Administration for Anesthesia after Uterine Artery Embolization with Trisacryl Gelatin Microspheres for Leiomyoma

PurposeTo evaluate whether administration of lidocaine into the uterine artery for anesthesia immediately after uterine artery embolization (UAE) with trisacryl gelatin microspheres (TAGM) for leiomyoma is safe and effective.Materials and MethodsIn a single-institution retrospective study, 100 patients underwent UAE using TAGM with a pruned tree endpoint between June 2014 and April 2019. The first 50 patients (control group) underwent UAE without lidocaine; in the second 50 patients (study group), lidocaine was administered into the uterine artery immediately after UAE. Baseline characteristics and technical and periprocedural outcomes were compared. Visual analog scale (VAS) scores 0, 3, 6, 9, 12, and 18 hours after UAE were compared between the groups with repeated measures analysis of variance. Each multivariate-adjusted VAS score < 24 hours was compared with analysis of covariance.ResultsNo significant differences were observed in baseline characteristics or technical and periprocedural outcomes, including the volume of morphine used (P = .415), between the groups. No significant differences were found in crude or multivariate-adjusted VAS scores at each time point < 24 hours. Only the multivariate-adjusted VAS score 3 hours after UAE was 0.7 lower in the study group (mean ± SE, 2.2 ± 0.3 vs 2.9 ± 0.3); however, no significant difference was noted (P = .070). No adverse events associated with lidocaine were detected.ConclusionsIntra-arterial lidocaine administration immediately after UAE with TAGM for leiomyoma was safe, but did not contribute to significant reductions in pain or volume of narcotic agent administered.     

Bronchial Artery Embolization for Life-Threatening Hemoptysis Using Tris-Acryl Microspheres: Short-Term Result

A prospective study of 70 patients with life-threatening hemoptysis who had bronchial and systemic artery embolization with tris-acryl linked microspheres was performed over 15 months. The procedure was technically successful in 90% of patients and at 24 hr after the procedure (87%). Recurrent hemoptysis occurred in 13% of patients within the first week. Chest pain was experienced following embolization in 7% of patients. The mortality was 10% due to the inclusion of patients with pulmonary metastases. Bronchial artery embolization using microspheres is an effective and well-tolerated treatment for patients with life-threatening hemoptysis who are not surgical candidates.     

The Feasibility of Contrast-Enhanced Ultrasound During Uterine Artery Embolization: A Pilot Study

Purpose To evaluate the feasibility of using contrast-enhanced ultrasound (CEUS) during uterine artery embolization (UAE) in order to define the correct end-point of embolization with complete devascularization of all fibroids. Methods In this prospective study of 10 consecutive women undergoing UAE, CEUS was performed in the angiographic suite during embolization. When the angiographic end-point, defined as the “pruned-tree” appearance of the uterine arteries was reached, CEUS was performed while the angiographic catheters to both uterine arteries were kept in place. The decision whether or not to continue the embolization was based on the findings at CEUS. The results of CEUS were compared with those of contrast-enhanced magnetic resonance imaging (MRI) 1 day as well as 3 months following UAE. Results CEUS was successfully performed in all women. In 4 cases injection of particles was continued based on the findings at CEUS despite angiographically complete embolization. CEUS imaging at completion of UAE correlated well with the findings at MRI. Conclusion The use of CEUS during UAE is feasible and may increase the quality of UAE.     

Midterm Results of Uterine Artery Embolization Using Narrow-Size Calibrated Embozene Microspheres

Purpose  

To evaluate safety and efficacy of uterine artery embolization using narrow-size-range polyphosphazene-coated hydrogel microspheres (Embozene, CeloNova Biosciences, Newnan, GA).     

子宫动脉栓塞治疗子宫肌瘤的临床应用研究

分析子宫动脉栓塞治疗子宫肌瘤的有效性和安全性。材料和方法：５１例子宫肌瘤行子宫通读动脉栓塞治疗,分别于栓塞后１、３、６、１２个月行Ｂ超随访肿瘤体积变化。结果：现例均无子宫坏死一严重并发症。栓塞后６个月,肿瘤体积缩小大于５０％、２０％￣５０％和小于２０％者分别为４１例（占８０．４％）、９例（１７．６％）和１例（占２％）,其中２例肿瘤全部消失。所有病例临床症状减轻或消失。４例自然受孕。结论：子宫动脉栓     

子宫动脉栓塞治疗子宫肌瘤的研究现状

子宫肌瘤是女性生殖系统中最常见的良性肿瘤[1～ 4 ] 。年龄5 0岁左右未闭经的妇女中发病率高达 40 %以上[1 ,2 ,5] 。它是子宫非急性异常出血最常见的原因[1～ 8] 。随着肌瘤体积增大 ,引起下腹部疼痛、腰骶部不适、腹胀、尿频、肾盂积水、性交疼痛、不孕等[1～ 9] 。长期、大量出血引起缺铁性贫血[2 ,4 ,6 ,8] 。传统治疗方法 [手术、冷冻、激光及内分泌 (激素 )等 ]由于存在着各自的缺陷不足 ,临床应用受到限制[2 ,6～ 8] 。子宫动脉栓塞 (ＵＡＥ)治疗子宫肌瘤最初由Ｒａｖｉｎａ等[4 ,1 0 ] 于1995年报道 ,此后 ,该技术得到了广泛开展[2…     

A Novel Resorbable Embolization Microsphere for Transient Uterine Artery Occlusion: A Comparative Study with Trisacryl-Gelatin Microspheres in the Sheep Model

PurposeTo evaluate angiographic recanalization, inflammatory reaction, and uterine damage after sheep uterine artery embolization (UAE) with a novel calibrated resorbable embolization microsphere (REM) and compare the results with control nonresorbable microspheres.Materials and MethodsSix hormonally artificially cycled sheep underwent bilateral UAE until stasis with either REM or trisacryl-gelatin microspheres (TGMS). At 7 days, control angiograms were obtained to assess the residual vascularization at arterial and parenchymal phases. The animals were then sacrificed for analysis of the presence of microspheres, inflammatory foreign body reaction, and surface areas of uterine damage.ResultsMean volume of microspheres injected per uterine artery (UA) or per animal did not differ between groups. At day 7, the flow was normal for six of six UAs that received embolization with REM versus only three of six UAs with TGMS (P = .0455, χ² test). Uterine parenchymography showed no defects in six UAs in the REM group versus five defects in six UAs in the TGMS group (P = .0060, χ² test). No REM or residual fragments of microspheres were observed on histologic analysis. TGMS were observed in tissues and accompanied by a mild inflammatory response. Necrosis rates were not significantly different between the two products, either in endometrium (REM 23.5% ± 28.8% [median 8.1%] vs TGMS 21.8% ± 23.7% [median 14.6%]) or in myometrium (REM 8.2% ± 22.7% [median 0.0%] vs TGMS 8.8% ± 20.8% [median 0.9%]). Endometrium alteration rate was lower with REM than with TGMS (39.7% ± 25.7% [median 34%] vs 60.6% ± 27.1% [median 71%]; P = .0060, Mann-Whitney test). Myometrium alteration rates were not significantly different between REM (45.7% ± 37.1% [median 63.0%]) and TGMS (37.8% ± 34.0% [median 19.1%]).ConclusionsAt 1 week after sheep UAE with REM, the recanalization was complete, the microspheres were completely degraded, and there was no remnant inflammatory response.     

子宫动脉栓塞治疗子宫肌瘤的随访研究

目的探讨子宫动脉栓塞治疗子宫肌瘤的临床疗效。方法对47例子宫肌瘤患者进行选择性子宫动脉造影及栓塞治疗并进行术后随访,观察其子宫肌瘤血供特点、临床疗效、肌瘤复发率。结果子宫肌瘤以一侧子宫动脉供血为主占85.1%,双侧子宫动脉同时供血14.9%,卵巢动脉参与供血6.4%。随访47例患者,治愈17%,显效68%,有效12.7%,无效2.12%,随访6～48个月未发现术后再发肌瘤。结论子宫动脉栓塞治疗子宫肌瘤的方法安全有效,特别是对黏膜下子宫肌瘤可以达到瘤体消失治愈的效果。     

Treatment of Uterine Artery Vasospasm with Transdermal Nitroglycerin Ointment During Uterine Artery Embolization

Uterine artery vasospasm can complicate uterine artery embolization (UAE) by prolonging procedure times or even causing treatment failure. Embolization must be delayed until the spasm improves and adequate antegrade flow in the vessel is restored. Vasospasm can also produce a “false endpoint” to the procedure, where stasis of flow in the vessel is falsely attributed to successful embolization but is actually the result of vasospasm, leading to undertreatment or treatment failure. Traditional treatments for uterine artery vasospasm have included transcatheter intra-arterial vasodilators and catheter withdrawal from the vessel, both of which can yield mixed results. We report a case of uterine artery vasospasm during UAE successfully treated with transdermal nitroglycerine ointment. Case Report     

Management of Symptomatic Vascularized Retained Products of Conception by Proximal Uterine Artery Embolization with Gelatin Sponge Torpedoes

PurposeTo evaluate the effectiveness and safety of temporary proximal uterine artery embolization (UAE) for the treatment of highly vascularized retained products of conception (RPOCs).Materials and MethodsThis retrospective analysis included women who underwent treatment for vaginal bleeding after abortion, miscarriage, or delivery, with highly vascularized RPOCs detected by Doppler ultrasound (US) (ie, presence of an enhanced myometrial vascularity, a low resistance index of <0.5, and a peak systolic velocity of ≥0.7 m/s). A unilateral or bilateral embolization with torpedoes of gelatin foam was performed. From November 2017 to January 2021, 24 women with a median age of 30 years (interquartile range, 26.0–34.5 years) with symptomatic highly vascularized RPOCs were included. Clinical success was defined as bleeding arrest between the UAE and 1-month follow-up. Technical success was defined as the complete obstruction of at least 1 uterine artery supplying vascular abnormalities. The safety of the procedure according to the classification of the Society of Interventional Radiology and evolution of lesions on US were also reported.ResultsTechnical success was achieved in all 24 (100%) patients, with bilateral arterial embolization in 19 (79%) patients and unilateral embolization in 5 (21%) patients. Clinical success was achieved in all 24 (100%) patients. Five patients still had uterine retention at the 1-month follow-up, including 2 patients with highly vascularized RPOCs. Two patients benefited from hysteroscopy, and 3 had noninvasive management. Four minor adverse events were reported (1 patient had infectious endometritis and 3 patients had a postembolization syndrome).ConclusionsProximal UAE with torpedoes of gelatin foam is safe and effective for the management of symptomatic highly vascularized RPOCs.     

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.     

Uterine Artery Embolization with Gelfoam for Acquired Symptomatic Uterine Arteriovenous Shunting

PurposeTo evaluate the technical and clinical success rates and safety of bilateral gelfoam uterine artery embolization (UAE) for symptomatic acquired uterine arteriovenous shunting due to prior obstetric or gynecologic event.Materials and MethodsThis was a retrospective study of consecutive patients of reproductive age who presented with abnormal uterine bleeding after recent gynecologic procedures or obstetric events between January 2013 and February 2018. Bilateral UAE was performed in all patients using gelfoam slurry. Technical success was defined as angiographic resolution of arteriovenous shunting. Clinical success was defined as cessation of symptomatic bleeding, resolution on follow-up imaging, or minimal estimated blood loss (EBL) (<50 ml) on subsequent elective dilation and curettage (D&C) procedure.ResultsEighteen patients (mean age, 32.8 ± 7.1 years) were included. Technical success and clinical success were experienced by 17/18 (94.4%) and 16/17 (94.1%) patients, respectively. Angiography demonstrated arteriovenous shunting in 18/18 (100%) patients, with early venous drainage. Seven of 18 (38.9%) patients underwent subsequent scheduled D&C due to remaining retained products of conception, with an EBL of 17.9 ± 15.6 ml. There was 1 minor complication of a self-limited vascular access groin hematoma (1/18, 5.6%) and 1 major complication (1/18, 5.6%) of a pulmonary embolism detected 3 days after UAE. The length of clinical follow-up was 19.3 ± 15.5 months, in which 41.2% (7/17) of the patients became pregnant.ConclusionsUAE with gelfoam alone for symptomatic uterine arteriovenous shunting is a feasible treatment option that has a high technical and clinical success rate with a low rate of complications.     

Porous Gelatin Particles for Uterine Artery Embolization: An Experimental Study of Intra-Arterial Distribution, Uterine Necrosis, and Inflammation in a Porcine Model

Purpose

We evaluated the location of porous gelatin particles (GP; Gelpart; Nippon Kayaku/Astellas, Tokyo, Japan) within the arterial vasculature and their acute effects on uterine necrosis and inflammation after uterine artery embolization (UAE) in swine.

Materials and Methods

Adult nonpregnant pigs (n = 6) were allocated to either 1- (n = 3) or 2-mm GP (n = 3). Superselective and bilateral embolization of the uterine arteries was performed. All animals were killed 1 week after UAE. Macroscopic and microscopic findings, including the level of arterial occlusion and their effect on uterine necrosis and inflammation, were analyzed.

Results

All UAE procedures were completed without severe complications. The macroscopic necrosis was seen in two animals in the 2-mm group with an extent of <50%. The location of the occluded arteries did not differ significantly between groups. The median diameters of the occluded arteries were 449 μm (95% confidence interval [CI] 417–538 μm) in the 1-mm GP group and 484 μm (95% CI 370–560 μm) in the 2-mm GP group. As for microscopic necrosis, no statistically significant difference was observed. The qualitative inflammatory reaction was significantly greater in the 2-mm GP group than in the 1-mm group (p < 0.001).

Conclusions

Both 1- and 2-mm GP occluded the arteries relevant to the target diameter for UAE in porcine uterus, presumably due to the plastic deformity. Both sizes of GP were associated with limited areas of necrosis; however, evaluation of inflammatory reaction was preliminary. Further study with adequate evaluation of inflammatory reactions is suggested.