Safety and Effectiveness of Ethylene Vinyl Alcohol Copolymer Embolization of Peripheral High-Flow Arteriovenous Malformations: Results of a Prospective Study

High-Flow Arteriovenous Malformations: Treatment Using a Venous Approach

High-flow arteriovenous malformations (AVMs) are among the rarest and most recalcitrant lesions in medicine. Patients with these anomalies are best managed longitudinally in tertiary referral centers by dedicated multidisciplinary teams that include surgeons, dermatologists, hematologists, geneticists, and interventional radiologists. A significant percentage of these lesions cannot be cured per se and intervention can worsen symptoms or preclude effective future embolization. Existing classification systems help guide treatment, but in nearly all cases, therapy must be individualized based on patient, symptoms, and lesion angioarchitecture. For various reasons, referral to tertiary centers may be impossible for some patients. The purpose of this article is to provide an approach to the evaluation and treatment of these abnormalities.

Complex Arterio-Portal-Venous Malformation of the Liver

A neonatal female patient exhibited a congenital intricate vascular malformation affecting the liver, encompassing anomalies in the arterial, venous, and portal venous systems and notably including an aneurysm within the portal vein. The management strategy involved a staged endovascular approach, initially using retrograde embolization via the venous outflow tract. Subsequently, transarterial embolization was performed to address complications associated with pulmonary and portal hypertension.

Repeat Prostatic Artery Embolization with the Addition of a Liquid Embolic Agent: Short-term Results

RATIONALE AND OBJECTIVES

The long-term effectiveness of prostatic artery embolization (PAE) can be hampered by the recanalization of the previously embolized prostatic arteries (PA). The use of a liquid embolic agent (LEA) could limit this risk. The purpose of this study was to assess the safety and efficacy of repeat PAE (rePAE) using a LEA (Squid Peri) coupled with microspheres in patients experiencing recurring symptoms after initial embolization.

MATERIALS AND METHODS

This retrospective single-center study included all consecutive patients who underwent rePAE using Squid Peri coupled with microspheres. Angiographic patterns of prostatic revascularization were identified. Outcomes were assessed at the 3-month follow-up using the International Prostate Symptom Score (IPSS) and the Quality of Life (QoL) score. The primary endpoint was clinical success defined as an IPSS < 18 with > 25% decrease and a QoL score ≤ 3 with ≥ 1 point decrease. Safety was assessed by using the modified Clavien-Dindo classification.

RESULTS

30 consecutive men (mean age: 67.1 ± 9.5 years) were included. Recanalization of the previously embolized PA was found in 83.3% of patients. Technical success was 93.3%. Median follow-up was 4.9 months [IQR: 3.9 - 9.8]. Clinical success rate was 76.7%, with a mean decrease in IPSS of -9.3 ± 7.3 (p < 0.001) and a median decrease in QoL of -2 [IQR: - 4 - - 1] (p < 0.001). One patient presented with an acute urinary retention requiring readmission (grade IIIa complication).

CONCLUSION

Repeat PAE using Squid Peri coupled with microspheres is safe and effective for patients with recurring symptoms after initial embolization.

Recent advances in nanomaterial-driven strategies for diagnosis and therapy of vascular anomalies

Nanotechnology has demonstrated immense potential in various fields, especially in biomedical field. Among these domains, the development of nanotechnology for diagnosing and treating vascular anomalies has garnered significant attention. Vascular anomalies refer to structural and functional anomalies within the vascular system, which can result in conditions such as vascular malformations and tumors. These anomalies can significantly impact the quality of life of patients and pose significant health concerns. Nanoscale contrast agents have been developed for targeted imaging of blood vessels, enabling more precise identification and characterization of vascular anomalies. These contrast agents can be designed to bind specifically to abnormal blood vessels, providing healthcare professionals with a clearer view of the affected areas. More importantly, nanotechnology also offers promising solutions for targeted therapeutic interventions. Nanoparticles can be engineered to deliver drugs directly to the site of vascular anomalies, maximizing therapeutic effects while minimizing side effects on healthy tissues. Meanwhile, by incorporating functional components into nanoparticles, such as photosensitizers, nanotechnology enables innovative treatment modalities such as photothermal therapy and photodynamic therapy. This review focuses on the applications and potential of nanotechnology in the imaging and therapy of vascular anomalies, as well as discusses the present challenges and future directions.

Coil-assisted ethanol embolotherapy for refractory head and neck arteriovenous malformations with Onyx recrudescence: 10-Year experiences

OBJECTIVE

This study aimed to evaluate the outcomes of coil-assisted ethanol embolotherapy in recanalized head and neck arteriovenous malformations (HNAVMs) with dilated outflowing veins after Onyx treatment.

METHODS

Thirty-six patients with HNAVMs (18 females and 18 males with a mean age of 26.83 years) who experienced recurrence after Onyx embolization from October 2007 to October 2017 were included in this study. All patients underwent complete clinical and angiographic examinations. Further, each patient was classified based on the Schobinger stage before undergoing staged ethanol embolization. All patients were followed up for 5 years in-person at an interval of 3 months after discharge. The Kaplan-Meier method was used to perform the recurrence-free survival analysis.

RESULTS

Sixteen patients (44.4%) had Schobinger stage II HNAVMs, and the remaining patients had Schobinger stage III or IV (20/36 patients [55.6%]) HNAVMs. A total of 116 embolization procedures were performed, coils were applied in 107 procedures (92.2%) among patients with dilated outflowing veins. The dose of absolute ethanol was 16.39 mL per procedure in patients with Schobinger II HNAVMs, and 22.45 mL per procedure in patients with Schobinger III and IV HNAVMs (P = .024, 95% confidence interval, 1.128-5.009). During the 3-month evaluation, complete response was observed in 13 of 36 patients (36.1%), and partial response was observed in 23 of 36 patients (63.9%). The 5-year recurrence-free survival rate for patients who underwent Onyx treatment had improved 58.3% after ethanol embolization (95% confidence interval, 2.853-9.595; P < .0001).

CONCLUSIONS

Coil-assisted ethanol embolotherapy could treat refractory HNAVMs with Onyx recrudescence effectively.

Treatment of Challenging Extracranial Arteriovenous Malformations: A Single-Center Experience and Literature Review

ABSTRACT

Extracranial arteriovenous malformation (AVM) is a high-flow congenital vascular malformation, where direct communication between the arteries and veins impedes perfusion of capillary beds and causes disfigurement of the affected tissue. Surgery and endovascular therapy are currently the main treatment for extracranial AVMs. Nevertheless, management of complex cases is sometimes challenging because of severe complications such as refractory ulceration, life-threatening bleeding, and even cardiac insufficiency. Here, we reviewed the development and potential treatment for extracranial AVMs and shared our single-center experiences of diagnosis and treatment of this challenging disease.

High-flow arteriovenous malformation in the finger with transvenous ethanolamine oleate sclerotherapy using an arterial tourniquet and microballoon occlusion: A case report

Endovascular therapy is an important method of treating high-flow arteriovenous malformations (AVMs). The nidus of AVMs can be treated by transarterial or percutaneous approaches with the use of ethanol as a strong embolic agent; however, treatment outcomes are not always satisfactory and complications including skin necrosis often occur, particularly following the treatment of superficial lesions. Herein, we describe successful transvenous sclerotherapy of high-flow AVMs in the finger of a 47-year-old female patient that were causing erythema and spontaneous pain using ethanolamine oleate (EO) as a safe sclerosant. Dynamic contrast-enhanced computed tomography and angiography revealed a high-flow type Ⅲb AVM according to Yakes classification. Using the transvenous approach, 5% EO with idoxanol was injected into the nidus of the AVM 3 times over 2 sessions. An arterial tourniquet was used to achieve stasis of blood flow at the nidus and microballoon occlusion of the outflow vein was used to ensure the sclerosant effectively reached the nidus. Near-total occlusion of the nidus was achieved leading to improved symptoms. Mild edema lasting 2 weeks occurred as a minor reaction after each session. Finger amputation may have been avoided by using this treatment. Transvenous EO sclerotherapy using an arterial tourniquet and balloon occlusion may have utility in treating AVMs in the extremities.

Clinical Outcome and Quality of Life of Multimodal Treatment of Extracranial Arteriovenous Malformations: The APOLLON Study Protocol

PURPOSE

Arteriovenous malformations (AVMs) as rare diseases are diagnostically and therapeutically challenging. Due to the limited evidence regarding treatment outcome, prospective data are needed on how different treatment regimens affect outcome. The aims of this prospective trial are to determine effectiveness, safety, and clinical outcome of multimodal treatment in patients with extracranial AVMs.

MATERIALS AND METHODS

After clinical and magnetic resonance imaging (MRI)-based diagnosis and informed consent, 146 patients (> 4 years and < 70 years) undergoing multimodal therapy in tertiary care vascular anomalies centers will be included in this prospective observational trial. Treatment options include conservative management, medical therapy, minimally invasive image-guided procedures (embolization, sclerotherapy) and surgery as well as combinations of the latter. The primary outcome is the patient-reported QoL 6 months after completion of treatment using the short form-36 health survey version 2 (SF-36v2) and the corresponding short form-10 health survey (SF-10) for children. In addition, clinical presentation (physician-reported signs), MRI imaging (radiological assessment of devascularization), recurrence rate, and therapeutic safety will be analyzed. Further follow-up will be performed after 12, 24, and 36 months. Moreover, liquid biopsies are being obtained from peripheral blood at multiple time points to investigate potential biomarkers for therapy response and disease progression.

DISCUSSION

The APOLLON trial is a prospective, multicenter, observational open-label trial with unequal study groups to generate prospective evidence for multimodal treatment of AVMs. A multicenter design with the potential to assess larger populations will provide an increased understanding of multimodal therapy outcome in this orphan disease.

TRIAL REGISTRATION

German Clinical Trials Register (identification number: DRKS00021019) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021019 .

Embolization of Recurrent Pulmonary Arteriovenous Malformations by Ethylene Vinyl Alcohol Copolymer (Onyx®) in Hereditary Hemorrhagic Telangiectasia: Safety and Efficacy

Objectives: To evaluate short- and long-term safety and efficacy of embolization with Onyx^® for recurrent pulmonary arteriovenous malformations (PAVMs) in hereditary hemorrhagic telangiectasia (HHT). Methods: In total, 45 consecutive patients (51% women, mean (SD) age 53 (18) years) with HHT referred to a reference center for treatment of recurrent PAVM were retrospectively included from April 2014 to July 2021. Inclusion criteria included evidence of PAVM recurrence on CT or angiography, embolization using Onyx^® and a minimal 1-year-follow-up CT or angiography. Success was defined based on the standard of reference criteria on unenhanced CT or pulmonary angiography if a recurrence was suspected. PAVMs were analyzed in consensus by two radiologists. The absence of safety distance, as defined by a too-short distance for coil/plug deployment, i.e., between 0.5 and 1 cm, between the proximal extremity of the primary embolic material used and a healthy upstream artery branch, was reported. Results: In total, 70 PAVM were analyzed. Mean (SD) follow-up was 3 (1.3) years. Safety distance criteria were missing in 33 (47%) PAVMs. All procedures were technically successful, with a short-term occlusion rate of 100% using a mean (SD) of 0.6 (0.5) mL of Onyx^®. The long-term occlusion rate was 60%. No immediate complication directly related to embolization was reported, nor was any severe long-term complication such as strokes or cerebral abscesses. Conclusions: In HHT, treatment of recurrent PAVM with Onyx^® showed satisfactory safety and efficacy, with an immediate occlusion rate of 100% and a long-term rate of 60%.

Interventional Treatment Options in Children with Extracranial Vascular Malformations

Extracranial vascular malformations vary greatly and belong to the complex field of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic system. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) represents an important guidance for selecting appropriate therapy. Although many of the principles of endovascular treatment, including image-guided sclerotherapy and embolization, are similar in adult and pediatric practice, there are some distinct differences regarding the treatment of vascular malformations of children. Thus, it is crucial to involve longer-term plan about managing these chronic diseases and their impact on a growing child. This review provides a detailed overview over the clinical presentation of venous, lymphatic, and arteriovenous malformations in children and emphasizes the specifics of their interventional treatment options, including distinct pediatric dose limitations and procedure-related side effects.