Ear Necrosis Resulting from the Endovascular Onyx-18 Embolization of a Dural Arteriovenous Fistula Fed by the Posterior Auricular Artery

Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs)

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

Efficacy and Safety of Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs) in Transcatheter Arterial Embolization (TAE) of Acute Non-Neurovascular Bleeding: A Multicenter Retrospective Cohort Study

Background and Objectives: Transcatheter arterial embolization (TAE) is part of the daily practice of most interventional radiologists worldwide. The ideal liquid embolic agent is far from being identified. Non-adhesive liquid embolic agents (NALEA) harden from the outside to the inside, resulting in deep penetration, known as "magma-like" progression, which permits a more distal embolization with good control of the embolic material. This multicenter retrospective cohort study aims to assess the efficacy, feasibility and safety of transcatheter arterial embolization (TAE) with ethylene-vinyl alcohol (EVOH)-based NALEAs (Onyx and Squid) in acute bleeding outside of the neurovascular area. Materials and Methods: This study is a multicenter analysis of retrospectively collected data of consecutive patients who had undergone, from January 2015 to December 2022, transcatheter arterial embolization with non-adhesive EVOH-based agents in the setting of acute non-neurovascular bleeding. Results: Fifty-three patients underwent transcatheter arterial embolization for acute non-neurovascular bleeding. Eight (15.1%) procedures were performed in patients with coagulopathy. The most used concentration of EVOH-based NALEAs was 34 (i.e., 8%), with a mean dose of 0.5 (±0.3) mL. The mean CT-to-groin time, the mean procedure time, the mean CT-to-embolization time and the mean fluoroscopy time were 22.9 (±12.4) min, 27.5 (±7) min, 50.3 (±13.1) min and 7.5 (±2.8) min, respectively. Technical success was achieved in all cases with a 96.2% clinical success rate. Complications were recorded in six (11.3%) patients. No statistically significant differences were observed between the group of patients with coagulopathy and the group of patients without coagulopathy in terms of efficacy and safety endpoints. Conclusions: Transcatheter arterial embolization (TAE) performed with non-adhesive EVOH-based embolic agents is an effective, feasible and safe strategy for the management of acute non-neurovascular bleeding, even in the subgroup of patients with coagulopathy.

Dural Arteriovenous Fistula Arising after Intracranial Surgery in Posterior Fossa of Nondominant Sinus: Two Cases and Literature Review

The results of recent clinical and experimental studies suggest that the most important factor associated with the pathogenesis of dural arteriovenous fistula (AVF) is sinus thrombosis and subsequent venous or intrasinus hypertension. Here, we describe two patients who each developed a dural AVF after a posterior fossa craniotomy on the side of the nondominant or hypoplastic transverse (TS)-sigmoid (SS) sinuses. A 63-year-old female underwent surgical resection of a meningioma in the left cerebellopontine angle. Preoperative subtraction digital angiography (DSA) revealed a hypoplastic, ipsilateral left TS-SS and the sinus occlusion was revealed after surgery. Sixteen months later, she presented with a progressive left retroauricular, pulse-synchronous bruit. An AVF in the left TS-SS region was diagnosed by DSA and treated with transvenous coil embolization. The patient recovered without neurological deterioration. A 56-year-old female underwent surgical removal of an epidermoid tumor in the right cerebellopontine angle. Preoperative DSA revealed severe, ipsilateral right TS stenosis and the sinus occlusion was revealed after surgery. Two years later, she presented with the progressive right retroauricular, pulse-synchronous bruit, which was diagnosed by DSA as dural AVF in the right TS-SS region. She was treated with transvenous coil embolization and recovered without neurological deterioration. Sinus manipulation during intracranial surgery carries a potential risk of dural AVF development and this should be carefully considered, even when the ipsilateral TS-SS is nondominant or appears hypoplastic.

Ethylene vinyl alcohol copolymer (Onyx®) in peripheral interventional radiology: indications, advantages and limitations

Onyx(®) is a remarkable liquid embolizing agent that may allow a well-trained operator to undertake challenging embolization procedures. In multiple interventional radiology indications, the physico-chemical properties of Onyx(®) allow safe embolization. The purpose of this article is to review the advantages and disadvantages of Onyx(®) and identify its main indications.

Safety and Efficacy of Onyx Embolization for Pediatric Cranial and Spinal Vascular Lesions and Tumors

BACKGROUND:

Although Onyx is widely used to embolize vascular lesions in adults, the safety and efficacy of this liquid embolic agent for use in children are not well studied.

OBJECTIVE:

To report our experience using Onyx in pediatric patients for a variety of cranial and spinal vascular lesions and tumors to determine its procedural complication rates, types, and clinical consequences and to highlight the indications for and principles of Onyx embolization in pediatric patients.

METHODS:

All pediatric Onyx embolization cases performed consecutively by the neuroendovascular services at our 2 institutions over a 5-year period were collected retrospectively and analyzed.

RESULTS:

Over the study period, 105 Onyx embolization procedures were performed in 69 pediatric patients with a mean follow-up of 112 days. Fifty-two patients harbored “primary” vascular lesions (malformations, fistulas, etc), whereas 17 patients had tumors. Complications occurred in 25 of 105 procedures (23.8%) and included ischemic infarct (7), asymptomatic nontarget embolization (4), intracerebral hemorrhage (3), microcatheter-related vessel perforation (3), retained microcatheter (2), cerebral edema (2), dimethyl sulfoxide-induced pulmonary edema (2), facial ischemia (1), and contrast-induced bronchospasm (1). Neurological morbidity occurred transiently after 10 procedures (9.5%) and permanently after 2 procedures (1.9%). There were no procedure-related deaths. Statistical analysis revealed no predictors of complications among the multiple potential risk factors evaluated.

CONCLUSION:

Our experience suggests that Onyx can be used effectively for embolization of pediatric cranial and spinal vascular lesions and tumors with low permanent morbidity; however, attention must be paid to the technical nuances of and indications for its use to avoid potential complications.

Long-term outcome in patients treated for benign dural arteriovenous fistulas of the posterior fossa

INTRODUCTION

Dural arteriovenous fistula (dAVF) draining into a dural sinus without recruitment of cortical veins is regarded as relatively benign lesion and treatment is advocated only if the patient is severely affected by the symptoms. The aim of this study was to compare the clinical outcomes in patients who received endovascular treatment or no treatment, respectively.

METHODS

Twenty-one patients presented consecutively with pulsating tinnitus as leading symptom and with angiographically proven dAVF at the transverse or sigmoid sinus (Borden I). Nine patients underwent different types of endovascular embolisation, and 12 patients were not treated. After a median follow-up period of 2.3 years, outcome was evaluated by assessing the patients' symptoms and scores on the mRS, EQ-5D, SF-36 and HIT-6 scales.

RESULTS

Complete long-term closure of the dAFV was achieved in two out of nine cases; subtotal occlusion was found in seven patients. Pulsating tinnitus persisted less frequently in treated than in untreated patients. Neurologic symptoms occurred in both groups. Neither these findings nor the clinical outcome and scores on the quality-of-life scales varied substantially between the two groups.

CONCLUSION

Partial treatment did not resolve the clinical symptoms of patients with "benign" dural AVF in the follow-up and was not clearly superior to conservative management. These results suggest that embolisation should be offered only if there is a possibility of a complete cure without major periinterventional risks. Further studies should be performed to assess the risk-benefit ratio of pursuing more aggressive treatment strategies in patients with unbearable symptoms.