Transcatheter arterial embolization with ethylene vinyl alcohol copolymer (Onyx) for the treatment of hemorrhage due to uterine arteriovenous malformations

Embolization with gelatin foam in the management of vascularized retained products of conception: a multicenter study by the French Society of Cardiovascular Imaging

OBJECTIVES

Vascularized retained products of conception (vRPOC) are the most frequent cause of delayed hemorrhage after abortion, spontaneous miscarriage, or delivery. This study evaluated the efficacy of uterine artery embolization (UAE) with gelatin foam in the management of symptomatic of vRPOC.

MATERIALS AND METHODS

This retrospective study included patients who underwent UAE with gelatin foam for vRPOCs with vaginal bleeding between January 2018 and December 2022 in 11 French university hospitals. Embolization was performed using either gelatin foam torpedoes or sludge. The primary endpoint was the clinical success of embolization (cessation of bleeding at approximately 1 month after UAE). The secondary objectives were the success of imaging (no persistent vRPOC at imaging follow-up), the safety of UAE, and the predictive factors of clinical and imaging failure.

RESULTS

Two hundred twenty-four patients (median age, 30.5 years ± 5.7 [standard deviation]) were included. Clinical success was achieved in 212 patients (94.2%). One hundred sixty-five patients had imaging follow-ups, among whom 12 patients (7.3%) had persistent vascularization. According to the SIR classification, 30 patients (13.4%) had minor complications, and two patients (0.8%) had major complications (endometritis n = 1; ischemic uterine necrosis n = 1). No predictive factors of clinical success were found, but the presence of a hypertrophic uterine artery (OR = 0.6 [0.38-0.97], p = 0.045) and the use of gelatin foam torpedoes (OR = 0.57 [0.42-0.77], p = 0.0012) were associated with a greater risk of persistent vRPOC on imaging control.

CONCLUSION

UAE with gelatin foam is safe and effective for treating hemorrhagic vRPOC.

KEY POINTS

Question Uterine vacuity is frequently observed on ultrasound after UAE for vRPOC. Findings A hypertrophic uterine artery and the use of gelatin foam torpedoes are associated with an increased risk of persistent vRPOC. Clinical relevance Embolization with gelatin foam is efficient and safe for treating bleeding in vRPOC.

Case Report of Placenta Accreta Spectrum and Arteriovenous Malformations with Successful Preservation of Fertility After Birth

Uterine arteriovenous malformations (UAVMs) that occur after birth are a rare cause of late postpartum hemorrhage. Acquired UAVMs usually occur in conjunction with pathology of the placenta. In the spectrum of placenta accreta (PAS), subinvolution of the placental bed plays an important role in its pathophysiology. We present a case of UAVM in a pregnant woman with PAS who presented with marked metrorrhagia after delivery, which was treated with classical management. Then, 35 days later, she presented to the emergency room with severe metrorrhagia. As it was suspected that she had placental remnants, an instrumental uterine control was performed, but the bleeding persisted, requiring further uterine packing and blood administration. Later, uterine artery embolization was performed with good results. Color Doppler ultrasound, magnetic resonance imaging, and angiography were the methods with the greatest diagnostic value. The differential diagnosis was as complex as the treatment. We hypothesize that UAVM may develop from minimal residual PAS in this late postpartum period. Moreover, they may recover rapidly after local surgical ablation. Considering the clinical condition, hemodynamic status, and desire to preserve fertility, we were able to avoid a hysterectomy, which is often chosen in such cases of severe, life-threatening bleeding complications.

Immobilized Drugs on Dual-Mode Imaging Ag2S/BaSO4/PVA Embolic Microspheres for Precise Localization, Rapid Embolization, and Local Antitumor Therapy

Transcatheter arterial embolization (TAE) in interventional therapy and tumor embolism therapy plays a significant role. The choice of embolic materials that have good biocompatibility is an essential component of TAE. For this study, we produced a multifunctional PVA embolization material that can simultaneously encapsulate Ag2S quantum dots (Ag2S QDs) and BaSO4 nanoparticles (BaSO4 NPs), exhibiting excellent second near-infrared window (NIR-II) fluorescence imaging and X-ray imaging, breaking through the limitations of traditional embolic microsphere X-ray imaging. To improve the therapeutic effectiveness against tumors, we doped the doxorubicin (DOX) antitumor drug into microspheres and combined it with a clotting peptide (RADA16-I) on the surface of microspheres. Thus, it not only embolizes rapidly during hemostasis but also continues to release and accelerate tumor necrosis. In addition, Ag2S/BaSO4/PVA microspheres (Ag2S/BaSO4/PVA Ms) exhibited good blood compatibility and biocompatibility, and the results of embolization experiments on renal arteries in rabbits revealed good embolic effects and bimodal imaging stability. Therefore, they could serve as a promising medication delivery embolic system and an efficient biomaterial for arterial embolization. Our research work achieves the applicability of NIR-II and X-ray dual-mode images for clinical embolization in biomedical imaging.

Uterine Arteriovenous Malformation: Diagnostic and Therapeutic Challenges

Uterine arteriovenous malformations are a rare cause of puerperal haemorrhage, but their incidence is increasing due to both improved diagnosis and the more frequent use of uterine surgery in recent years. The use of ultrasound, both B-mode and Doppler, is recommended for diagnosis and follow-up, as it has been shown to be the simplest and most cost-effective method. Endometrial thickening associated with an anechoic and vascular intramiometrial structure is very useful for diagnosis and can help to exclude other causes of dysfunctional bleeding. Pulsed Doppler shows low-resistance vessels and high pulsatility indices with a high peak systolic velocity (PSV). In a healthy myometrium, the vessels have a peak systolic velocity of 9-40 cm/s and a resistance index between 0.6 and 0.8, whereas in the case of AVMs, the systolic and diastolic velocities are 4-6 times higher (PSV 25-110 cm/s with a mean of 60 cm/s and a resistance index of 0.27-0.75 with a mean of 0.41). For treatment, we must individualise each case, taking into account haemodynamic stability, the patient's reproductive wishes, and the severity of the AVM as assessed by its size and PSV.

Primary and secondary postpartum haemorrhage: a review for a rationale endovascular approach

Postpartum haemorrhage (PPH) is a significant cause of maternal mortality globally, necessitating prompt and efficient management. This review provides a comprehensive exploration of endovascular treatment dimensions for both primary and secondary PPH, with a focus on uterine atony, trauma, placenta accreta spectrum (PAS), and retained products of conception (RPOC). Primary PPH, occurring within 24 h, often results from uterine atony in 70% of causes, but also from trauma, or PAS. Uterine atony involves inadequate myometrial contraction, addressed through uterine massage, oxytocin, and, if needed, mechanical modalities like balloon tamponade. Trauma-related PPH may stem from perineal injuries or pseudoaneurysm rupture, while PAS involves abnormal placental adherence. PAS demands early detection due to associated life-threatening bleeding during delivery. Secondary PPH, occurring within 24 h to 6 weeks postpartum, frequently arises from RPOC. Medical management may include uterine contraction drugs and hemostatic agents, but invasive procedures like dilation and curettage (D&C) or hysteroscopic resection may be required.Imaging assessments, particularly through ultrasound (US), play a crucial role in the diagnosis and treatment planning of postpartum haemorrhage (PPH), except for uterine atony, where imaging techniques prove to be of limited utility in its management. Computed tomography play an important role in evaluation of trauma related PPH cases and MRI is essential in diagnosing and treatment planning of PAS and RPOC.Uterine artery embolization (UAE) has become a standard intervention for refractory PPH, offering a rapid, effective, and safe alternative to surgery with a success rate exceeding 85% (Rand T. et al. CVIR Endovasc 3:1-12, 2020). The technical approach involves non-selective uterine artery embolization with resorbable gelatine sponge (GS) in semi-liquid or torpedo presentation as the most extended embolic or calibrated microspheres. Selective embolization is warranted in cases with identifiable bleeding points or RPOC with AVM-like angiographic patterns and liquid embolics could be a good option in this scenario. UAE in PAS requires a tailored approach, considering the degree of placental invasion. A thorough understanding of female pelvis vascular anatomy and collateral pathways is essential for accurate and safe UAE.In conclusion, integrating interventional radiology techniques into clinical guidelines for primary and secondary PPH management and co-working during labour is crucial.

Pelvic AVM Embolization: A Tricky Affair-Multicenter Retrospective Experience

PURPOSE

Pelvic arteriovenous malformations (pAVMs) are congenital or acquired vascular anomalies, presenting with hematuria, menometrorrhagia, pelvic pain, and varices; they can be life-threatening in case of rupture. Surgical therapies have been proposed but endovascular embolization has been recognized as the primary modality. The aim of this article was to report a retrospective multicenter experience concerning embolization of pelvic AVMs and provide literature overview.

MATERIALS AND METHODS

We describe 18 patients (14 female and 4 male) diagnosed with pAVM and treated with minimally invasive methods. The pre-procedural imaging evaluation was based on transpelvic and/or transvaginal color Doppler ultrasound, contrast-enhanced computed tomography, and/or magnetic resonance. In 3 cases, the malformation was congenital and in other 15, acquired. Most common symptoms were menometrorrhagia, hematuria, pelvic pain and pressure, and heaviness in the lower abdominal region. In 10 cases (56%), only 1 procedure was required. Eight patients underwent multistage treatment.

RESULTS

Complete occlusion of the lesion in post-procedural angiography was observed in 12 patients (67%). No major periprocedural complications were observed. In 14 cases (78%), both satisfactory embolization and significant clinical improvement was achieved in long-term follow-up. Sixteen patients (88%) were at least satisfied with the clinical outcome. One patient reported subsequent successful pregnancy 5 years after the treatment.

CONCLUSION

Hemodynamics of pAVM are variable and thorough understanding of the vessel anatomy is crucial in planning and choosing proper treatment. Both transarterial and percutaneous direct puncture embolization strategies appear safe, technically feasible, and clinically effective.

CLINICAL IMPACT

In this manuscript, we discuss the role of interventional radiology methods in the treatment of pelvic arteriovenous malformations along with its advantages, limitations and possible complications. In addition to this, we review the current literature and confront our findings with those made by other authors. We believe that modern endovascular methods offer safe and reliable alternative for traditional surgical therapy and should be therefore considered during multidisciplinary treatment of these patients.

Our Experience in Using the Endovascular Therapy in the Management of Hemorrhages in Obstetrics and Gynecology

(1) Background: A quarter of maternal deaths are caused by post-partum hemorrhage; hence obstetric bleeding is a significant cause of morbidity and mortality among women. Pelvic artery embolization (PAE) represents a minimally invasive interventional procedure which plays an important role in conservative management of significant bleeding in Obstetrics and Gynecology. The aim of this study was to evaluate the effect and the complications of PAE in patients with significant vaginal bleeding with different obstetrical and gynecological pathologies. (2) Methods: We conducted an observational, retrospective study on 1135 patients who presented to the University Emergency Hospital of Bucharest with vaginal bleeding of various etiology treated with endovascular therapy. All the patients included in the study presented vaginal hemorrhage that was caused by: uterine leiomyomas, genital tract malignancies, ectopic pregnancy, arterio-venous mal-formations and other obstetrical causes. We excluded patients with uncontrolled high blood pressure, severe hepatic impairment, congestive heart failure, renal failure or ventricular arrhythmias. (3) Results: Bleeding was caused in 88.19% of cases by uterine leiomyomas (n = 1001), 7.84% (n = 89) by cervical cancer, 2.29% by ectopic pregnancy (n = 26), 1.23% by arteriovenous malformation (n = 14) and 0.52% by major hemorrhage of obstetrical causes. Endovascular procedures were used in all the cases. In patients with uterine leiomyomas, supra-selective uterine arteries embolization was used. In 97% (n = 1101) of patients, bleeding was stopped after the first attempt of PAE. 3% (n = 34) needed a second embolization. In 12 of 14 cases of AVM, PAE was successful, two other cases needed reintervention; (4) Conclusions: Endovascular procedures represent a major therapy method for both acute and chronic hemorrhage in Obstetrics and Gynecology. It can be used in post-partum or post-traumatic causes of vaginal bleeding, but also in patients with chronic hemorrhage from uterine leiomyomas or inoperable genital malignancies or even as a preoperative adjuvant in cases of voluminous uterine fibroids or invasive malignant tumors, aiming to reduce intraoperative hemorrhage.

Shape-Anisotropic Microembolics Generated by Microfluidic Synthesis for Transarterial Embolization Treatment

Particulate embolic agents with calibrated sizes, which employ interventional procedures to achieve endovascular embolization, have recently attracted tremendous interest in therapeutic embolotherapies for a wide plethora of diseases. However, the particulate shape effect, which may play a critical role in embolization performances, has been rarely investigated. Here, polyvinyl alcohol (PVA)-based shape-anisotropic microembolics are developed using a facile droplet-based microfluidic fabrication method via heat-accelerated PVA-glutaraldehyde crosslinking reaction at a mild temperature of 38 ^° C. Precise geometrical controls of the microembolics are achieved with a nearly capsule shape through regulating surfactant concentration and flow rate ratio between dispersed phase and continuous phase in the microfluidics. Two specific models are employed, i.e., in vitro decellularized rabbit liver embolization model and in vivo rabbit ear embolization model, to systematically evaluate the embolization behaviors of the nonspherical microembolics. Compared to microspheres of the same volume, the elongated microembolics demonstrated advantageous endovascular navigation capability, penetration depth and embolization stability due to their comparatively smaller radial diameter and their central cylindrical part providing larger contact area with distal vessels. Such nonspherical microembolics present a promising platform to apply shape anisotropy to achieve distinctive therapeutic effects for endovascular treatments.

Temperature-responsive biodegradable injectable polymers with tissue adhesive properties

Injectable polymers (IPs) exhibiting in situ hydrogel formation have attracted attention as vascular embolization and postoperative adhesion prevention materials. While utilizing hydrogels for such purposes, it is essential to ensure that they have appropriate and controllable tissue adhesion property, as it is crucial for them to not detach from their deposited location in the blood vessel or abdominal cavity. Additionally, it is important to maintain gel state in vivo for the desired period at such locations, where large amounts of body fluid exist. We had previously reported on a biodegradable IP system exhibiting temperature-responsive gelation and subsequent covalent cross-link formation. We had utilized triblock copolymers of aliphatic polyester and poly(ethylene glycol) (tri-PCGs) and its derivative containing acrylate group at the termini (tri-PCG-Acryl), exhibiting a longer and more controllable duration time of the gel state. In this study, the introduction of aldehyde groups by the addition of aldehyde-modified Pluronic (PL-CHO) was performed for conferring controllable and appropriate tissue adhesive properties on these IP systems. The IP systems containing PL-CHO, which were not covalently incorporated into the hydrogel network, exhibited tissue adhesive properties through Schiff base formation. The adhesion strength could be controlled by the amount of PL-CHO added. The IP system showed good vascular embolization performance and pressure resistance in the blood vessels. The IP hydrogel remained at the administration site in the abdominal space for 2 days and displayed effective adhesion prevention performance. STATEMENT OF SIGNIFICANCE: Injectable polymers (IPs), which exhibit in situ hydrogel formation, are expected to be utilized as vascular embolization and postoperative adhesion prevention materials. The tissue adhesion properties of hydrogels are important for such applications. We succeeded in conferring tissue adhesion properties onto a previously reported IP system by mixing it with Pluronic modified with aldehyde groups (PL-CHO). The aldehyde groups allowed for the formation of Schiff bases at the tissue surfaces. The tissue adhesion property could be conveniently controlled by altering the amount of PL-CHO. We revealed that the in vitro embolization properties of IPs in blood vessels could be substantially improved by mixing with PL-CHO. The IP system containing PL-CHO also exhibited good in vivo performance for postoperative adhesion prevention.

Peripheral Arteriovenous Malformations: Imaging and Endovascular Management Strategies

The peripheral high-flow vascular malformation (HFVM) comprises arteriovenous malformation (AVM) and fistula (AVF), shows varied clinical presentation (ranging from subtle skin lesion to life-threatening congestive heart failure), and frequently poses diagnostic and therapeutic challenges. Importance of assigning a specific diagnosis to the vascular malformation cannot be overstated, as the treatment strategy is based on the type of vascular anomaly. Although the International Society for the Study of Vascular Anomalies (ISSVA) classification system is the most commonly accepted system for classifying congenital vascular anomalies in clinical practice, the Cho–Do et al classification is of utmost help in guiding optimal mode of treatment in peripheral AVM. Although transarterial approach remains the most commonly employed route for peripheral AVM embolization, the role of transvenous and direct percutaneous approach is ever increasing and the final decision on the approach depends on angioarchitecture of the AVM. In this article, we review various commonly employed classification systems for congenital vascular anomalies, and describe clinical features, imaging and treatment strategies for peripheral arteriovenous malformation (PAVM).

Uterine Arteriovenous Malformations

Uterine arteriovenous malformations are rare but may represent a life-threatening cause of vaginal bleeding. The typical patient affected is a multiparous woman during her thirties. The origin can be congenital or acquired, with the latter being more common after uterine surgery and presenting mainly as arteriovenous fistulous connections into the myometrium supplied by uterine arteries. The correct diagnosis of uterine arteriovenous malformations requires imaging findings of tubular and tortuous structures with mixed signal from arterial and venous flows; transvaginal color-Doppler ultrasound is the initial technique applied, then integrated with contrast-enhanced magnetic resonance or computed tomography. Multiple treatment approaches are available, including conservative-medical, endovascular embolization and surgery. Transarterial embolization represents the most applied, preserving childbearing capacity with negligible procedural complications; clinical and technical success rates are elevated, up to 90%. The goal of embolization is to occlude the point of fistula or the nidus and the application of multiple embolizing agents has been reported: despite there is no clear superiority of one over the others, liquids, especially those related to the dymethil-sulfoxide family, present relevant technical advantages. Surgery is nowadays to be considered when the endovascular approach fails and in these cases hysterectomy remains the common recommendation.

Single institutional experience of peripheral applications of a liquid embolic agent: Ethylene Vinyl Alcohol Copolymer

OBJECTIVE

To evaluate the safety and efficacy of ethylene vinyl alcohol (EVOH) copolymer for the treatment of a variety of peripheral vascular pathologies.

RESULTS

Between October 2010 and October 2017, 43 patients who underwent total 54 EVOH embolization procedures for the treatment of peripheral vascular pathologies were included. The cases which involved the use of EVOH for the treatment of nonvascular, neurologic, ophthalmologic, otolaryngologic or head-neck pathologies were excluded. The demographic data, technical and clinical success rates, and procedure-related details and complications were obtained. The most common indications for EVOH embolization were type II endoleaks (n = 18) and peripheral arteriovenous malformations (n = 14). The majority of cases (62.5%) used EVOH without any adjunct embolic material. The results of this study showed 100% technical success rates and 89% clinical success rates. No events of nontarget embolization or other procedure-related complications were noted. The mortality & morbidity rates were 0%. The loss to follow up rate was 16% (9 /54). The mean follow-up period was 134 days (range, 30 to 522 days).

CONCLUSION

The single institutional experience supports the safety and efficacy of EVOH embolization in the treatment of various peripheral vascular conditions.

Successful pregnancy after uterine artery embolization for uterine arterovenous malformation: a rare case report

Objective

This paper reports on a rare case of pregnancy after uterine artery embolization (UAE) for uterine arteriovenous malformation (AVM). Debate exists about persistence of fertility in women after UAE. Adverse effects of this technique can modify both uterine echostructure, inducing necrosis and infarction, endometrial atrophy and uterine artery rupture, and ovarian reserve, causing persistent amenorrhea. Ovarian reserve appears to be affected by UAE in pre-menopausal women. However, younger ovaries (according to biological ovarian age) exhibit a greater capacity for recovery after ovarian damage. Therefore, larger studies are needed for more conclusive results.

Case report

A 28-year-old woman was admitted to our department due to life-threatening uterine bleeding, resulting in tachycardia, pallor, and sweating. The patient came with a history of two spontaneous miscarriages. After sonography and computed tomography, AVMs were identified at uterine fundus and anterior wall.

Conclusion

The pathogenesis of infertility after UAE is not yet known. The peculiarity of this case was that, only few months later, the patient became pregnant and gave birth to a live fetus at 37 weeks with cesarean delivery.

The Use of Transarterial Approaches in Peripheral Arteriovenous Malformations (AVMs)

Arteriovenous malformations (AVMs) are a subset of congenital vascular malformations (CVMs). They comprise abnormal connections between arterial and venous circulation; treatment approaches are dependent on the angioarchitecture of the AVM, specifically the number and arrangement of the feeder arteries and outflow veins. Various imaging modalities can be used to diagnose and plan treatment. Here we will review the use of transarterial approaches to treat AVMs.

Female Pelvic Vascular Malformations

Vascular malformations are classified primarily according to their flow characteristics, slow flow (lymphatic and venous) or fast flow (arteriovenous). They can occur anywhere in the body but have a unique presentation when affecting the female pelvis. With a detailed clinical history and the proper imaging studies, the correct diagnosis can be made and the best treatment can be initiated. Lymphatic and venous malformations are often treated with sclerotherapy while arteriovenous malformations usually require embolization. At times, surgical intervention of vascular malformations or medical management of lymphatic malformations has been implemented in a multidisciplinary approach to patient care. This review presents an overview of vascular malformations of the female pelvis, their clinical course, diagnostic studies, and treatment options.

Uterine Arteriovenous Fistula with Concomitant Pelvic Varicocele: Endovascular Embolization with Onyx-18®

Uterine arteriovenous fistulas are rare and acquired causes of life-threatening vaginal bleeding. They usually present with intermittent menometrorrhagia in young patients in childbearing age with history of gynecological procedures on uterus. Traditional management is hysterectomy; endovascular embolization represents nowadays an alternative strategy for patients wishing to preserve fertility. Here, the endovascular approach to a 29-year-old woman affected by severe menometrorrhagia caused by a uterine arteriovenous fistula with a concomitant pelvic varicocele is reported; a bilateral uterine arteries embolization with Onyx-18 (ev3, Irvine, CA, USA) has successfully resolved the fistula with clinical success.

Multimodality imaging in secondary postpartum or postabortion hemorrhage: retained products of conception and related conditions

Secondary postpartum hemorrhage (PPH) and postabortion hemorrhage are rare complications. Retained products of conception (RPOC) is among the most common causes of both secondary PPH and postabortion hemorrhage. Other less common causes of secondary PPH are uterine vascular abnormalities such as arteriovenous malformations and pseudoaneurysms. These are usually related to a history of a procedure such as dilation and curettage or cesarean delivery. Subinvolution of the placental site is an idiopathic cause of secondary PPH; this condition may be underrecognized and therefore could have a higher incidence than currently reported. Gestational trophoblastic disease is rare but commonly presents as secondary PPH and resembles RPOC in radiologic appearance. The first-line imaging modality for secondary PPH is ultrasound, but computed tomography and magnetic resonance imaging may be used if the ultrasound findings are indeterminate. Angiography is an important tool for the definitive diagnosis of uterine vascular abnormalities. Appropriate management requires radiologists to be familiar with the multimodality imaging features of secondary PPH or postabortion hemorrhage.