Endovascular embolization of cerebrospinal fluid-venous fistula: a comprehensive systematic review on its efficacy and safety for the management of spontaneous intracranial hypotension.

Cerebrospinal fluid (CSF)-venous fistula can cause spontaneous intracranial hypotension (SIH) and poses a significant diagnostic and management challenge. This study aims to provide a comprehensive overview of the clinical and radiological outcomes of endovascular embolization as a novel treatment approach for CSF-venous fistula in patients with SIH. This systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. The primary outcome was the efficacy of the embolization procedure in occlusion of the CSF-venous fistula, and secondary outcomes included procedural complications and improvement of clinical symptoms and radiological findings. A total of nine studies consisting of 77 patients met the inclusion criteria. Orthostatic and/or Valsalva headache was the most common symptom. The mean age of the patients was 57 ± 8.9 years, and females accounted for 59.7% (46/77) of the cases. Sixty-five (84.4%) patients reported complete resolution or significant improvement in symptoms. The Bern score, Headache Impact Test-6, and the Patient Global Impression of Change scales demonstrated significant improvements in radiological findings and patients' quality of life. Following the procedure, 22 patients (28.6%) experienced rebound intracranial hypertension and 27 patients (35.1%) had transient local pain at the site of the embolization. Our study showed that endovascular embolization is a safe and effective treatment for CSF-venous fistula in patients with SIH, providing complete resolution or significant improvement of clinical symptoms and radiological findings, and positive impacts on patients' quality of life.

Feasibility, safety, and efficacy of endovascular treatment of anterior cranial fossa dural arteriovenous fistulas: a systematic review and meta-analysis with a subanalysis for Onyx.

Dural Arteriovenous Fistulas (dAVFs) of the anterior cranial fossa (ACF) are uncommon but carry a high risk of hemorrhage and pose substantial treatment challenges. Recent advancements in endovascular treatment (EVT), including the introduction of novel liquid embolic agents, have markedly bolstered EVT's role in managing ACF-dAVFs, with notable series published in the last five years. We aimed to assess the feasibility, safety, and efficacy of EVT for ACF-dAVFs. We searched Medline, Scopus, Web of Science, and Cochrane Library databases following PRISMA guidelines. Eligible studies included those with ≥ 5 patients undergoing embolization of ACF-dAVFs, detailing both angiographic and clinical outcomes. We used single proportion analysis with 95% confidence intervals under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Publication bias was assessed by funnel-plot analysis and Egger's test. Outcomes included complete occlusion following embolization, unsuccessful endovascular embolization attempts, incomplete occlusion following embolization, symptom resolution or clinical improvement following embolization, recurrence; procedure-related complications, morbidity, and mortality. Additionally, a subanalysis for studies exclusively utilizing Onyx™ embolic system was done. Eighteen studies comprising 231 ACF-dAVF were included. Unsuccessful endovascular embolization attempts rate was 2%. Complete occlusion rate was 85%, with 4% of complications. Incomplete occlusion rate was 10%. Successfully embolized patients experienced either symptom resolution or clinical improvement in 94% of cases. Morbidity and mortality rates were 1% and 0%, respectively. Onyx subanalyses showed an overall rate of 0% for unsuccessful attempts, 95% for complete occlusion, and 5% for incomplete occlusion. Symptom resolution or clinical improvement was 98% and recurrence rate was 0%. EVT for ACF-dAVF is highly feasible, effective, and safe, with a low rate of complications, morbidity, and mortality. The subanalyses focusing on Onyx embolizations revealed superior efficacy and safety outcomes compared to the findings of the primary analyses involving all included studies.

Facial nerve palsy after ethylene vinyl alcohol arterial embolization of glomus tympanicum in a 57 year old female.

BACKGROUND & OBJECTIVE: Glomus tympanicum and jugulare tumors are highly vascular and are therefore commonly embolized before surgical resection to prevent intra-operative bleeding. We report a case of facial nerve paralysis after pre-operative embolization for a glomus tympanicum tumor with ethylene vinyl alcohol (EVOH also known as Onyx) embolic agent. We discuss the choice of embolic agent in relation to the risk of this complication and potential management strategies. METHODS: A 57F with right glomus tympanicum developed right facial nerve palsy immediately after embolization. She received 24 mg of dexamethasone over the course of 24 h immediately following her embolization, surgical facial nerve decompression concurrent with tumor resection, and a 10-day prednisone taper. Our main outcome measure was facial nerve function on follow-up physical examinations. RESULTS: The patient developed right facial paralysis (HB 6/6) after Onyx embolization of branches of the external carotid artery system, likely due to translocation of embolic agent into facial nerve vasa nervosa as seen on post-embolization CT. No immediate improvement was observed with high dose steroids and decompression, however over the next 6 months her facial nerve function began to improve (HB 3/6). CONCLUSIONS: Surgical excision is the standard of care for glomus jugulare and glomus tympanicum tumors. Due to their propensity to bleed, their arterial feeders (branches of the external carotid) are often embolized prior to surgery, however, facial nerve paralysis is a rare but serious complication. There is a possible relationship between the choice of embolic agent and this complication. Though facial palsy is of sufficient rarity that no standard treatment pathway exists, due to the impact on a patient's quality of life, we recommend aggressive therapy to salvage nerve function.

Onyx®, A New Tool for Intraoperative Localization of Liver Lesions.

BACKGROUND: Precise preoperative localization of liver tumors facilitates successful surgical procedures, Intraoperative ultrasonography is a sensitive imaging modality. However, the presence of small non-palpable isoechoic intraparenchymal lesions may be challenging intraoperatively. METHODOLOGY AND MATERIAL DESCRIPTION: Onyx® is a non-adhesive liquid agent comprised of ethylene-vinyl alcohol usually used dissolved in dimethyl-sulfoxide and suspended micronized tantalum powder to provide contrast for visualization under fluoroscopy and ultrasonography and a macroscopic black shape. This embolization material has been increasingly used for the embolization of intracranial arteriovenous malformations. We present the novel application of Onyx® on liver surgery. CURRENT STATUS: We present the case of a female, 55 years-old, whose medical history revealed an elective sigmoidectomy (pT3N1a). After 17 months of follow up, by PET-CT scan, the patient was diagnosed of a small intraparenchymal hypo-attenuated 13 mm tumor located at segment V consistent with metachronous colorectal liver metastasis. Open metastasectomy was performed, ultrasonography-guided Onyx® infusion was delivered the day after, intraoperative ultrasonography showed a palpable hyperechoic material with a posterior acoustic shadowing artifact around the lesion. Onyx® is a promising new tool, without any previous application on liver surgery, feasible with advantages in small not palpable intraparenchymal liver lesions.

Spontaneous intracranial hypotension: updates from diagnosis to treatment.

Spontaneous intracranial hypotension (SIH) is caused by spinal cerebrospinal fluid (CSF) leaks, which result in continued loss of CSF volume and multiple debilitating clinical manifestations. The estimated annual incidence of SIH is 5/100,000. Diagnostic methods have evolved in recent years due to improved understanding of pathophysiology and implementation of advanced myelographic techniques. Here, we synthesize recent updates and contextualize them in an algorithm for diagnosis and treatment of SIH, highlighting basic principles and points of practice variability or continued debate. This discussion includes finer points of SIH diagnosis, CSF leak classification systems, less common types and variants of CSF leaks, brain MRI Bern scoring, potential SIH complications, key technical considerations, and positioning strategies for different types of dynamic myelography. The roles of conservative measures, non-targeted or targeted blood patches, surgery, and recently developed endovascular techniques are presented.

Enhancing meningioma resection: a comprehensive study on the safety and effectiveness of Onyx™ presurgical embolization.

Presurgical embolization (PE) has emerged as an interesting strategy to help turn brain tumor resection more amenable. This study aims to systematically review the safety and effectiveness of Onyx™ PE in meningioma resection. We followed Cochrane Collaboration and PRISMA for systematic review and meta-analysis, querying PUBMED, Cochrane Library, Web of Science, and Embase databases. Major complications were defined as other artery occlusion, visual deficits due to PE, or non temporary nerve damage, while minor included transitory conditions and others without clinical implications. A total of 186 patients were included, in which 120 were WHO grade I (80%), II (16%), and III (4%). Patient baseline characteristics and complications were distributed in groups without or with individual patient data analysis. Individual Patient Data Meta-Analysis (IPDMA) was performed on the last category, comprising 51 meningiomas that underwent Onyx™ PE. Among available data, 70%, 17%, and 13% were WHO grade I, II, and III, respectively. Considering all studies, tumor characteristics regarding grade underscored a certain homogeneity. Complications occurred at a rate of 9% (95% CI, 4 to 14%; I2 = 35%), with the rate of major complications significantly lower at only 1% (95% CI, 0 to 3%; I2 = 32%), whereas of minor complications was 7% (95% CI, 3 to 10%; I2 = 0%). Mean surgery blood loss was 668.7 (95% CI, 534.9 to 835.8; I2 = 0%) in IPDMA. Onyx™ PE is promising for safer surgical meningioma resection, despite limitations. Further studies are required to validate efficacy, enhance patient selection, and refine techniques.

Outcome and technical evolution of type 2 endoleak embolization with ethylene-vinyl-alcohol copolymer.

PURPOSE: This study aims to evaluate the safety and efficacy of novel approaches to type 2 endoleak access for the purpose of embolization using ethylene-vinyl-alcohol copolymer (EVOH) in patients with abdominal aortic aneurysm (AAA) sac expansion post endovascular abdominal aortic repair (EVAR). METHODS: A retrospective review of 43 consecutive patients (mean age = 80.2 ± 6.7 years) who underwent 52 embolization procedures for type 2 endoleaks using EVOH was performed at a single institution. Catheterization of the endoleaks was achieved using the transarterial (TA) and direct translumbar approaches (DTL), in addition to the novel direct transabdominal (DTA) and perigraft (PG) approaches. Endpoints included technical success of endoleak catheterization, technical success of endoleak embolization, endoleak persistence, endoleak recurrence, AAA sac area change, and adverse events. RESULTS: The TA, DTL, DTA, and PG approaches were used 25, 2, 14, and 19 times respectively, including nine procedures where a combination of approaches was used. The technical success rate of endoleak embolization was 98%. Five patients developed recurrent type 2 endoleaks, while five patients developed a type 1 endoleak. The persistent endoleak rate at a mean initial follow-up of 3 months was 34%. At a mean follow-up of 18 months, 58% of patients demonstrated absence of an endoleak, and 71% showed freedom from AAA sac enlargement. No major adverse events were recorded. CONCLUSION: The DTA and PG approaches were safe and effective in this cohort of patients undergoing embolization of type 2 endoleaks with EVOH.

Delayed Migration of Onyx Embolic Agent after Preoperative Embolization of an Arteriovenous Malformation in a Pediatric Patient: A Case Report and Review of the Literature.

INTRODUCTION: Brain arteriovenous malformations (AVMs) are increasingly being treated with Onyx liquid embolic agent (Onyx, Medtronic, Inc.). The phenomenon of delayed Onyx migration is not well documented in the literature. Moreover, the clinical presentation associated with Onyx migration is not well understood. CASE PRESENTATION: A pediatric patient with a history of neonatal seizures was referred to our institution upon experiencing daily headaches with photophobia, phonophobia, and sleep disturbance. Cerebral angiography revealed an AVM of the medial left cerebellar hemisphere. Preoperative embolization with Onyx liquid embolic achieved 25% closure of the AVM nidus. Upon developing worsening headaches the following day, new perinidal parenchymal edema was revealed on MRI, and urgent angiography demonstrated delayed migration of Onyx into the venous drainage. The patient underwent emergency resection of the AVM due to the risk of hemorrhage resulting from venous outflow obstruction. CONCLUSION: Our report and literature review demonstrate that while the delayed, unexpected migration of Onyx embolic material has been alluded to in a handful of papers, this phenomenon is not well documented. Future research is needed to understand the frequency of delayed Onyx migration from brain AVMs and the possible clinical presentations to look for. The sudden development of headaches and other signs of perilesional edema, in particular, should prompt repeat angiographic examination due to the possibility of delayed liquid embolic migration.

Pancreatic Ducts Obliteration With Controlled Injection of Onyx®: A Proposal of New Onyx® Pancreatic Ducts Obliteration Scoring System.

BACKGROUND: The aim of this study was confirm the efficacy and feasibility of Onyx injection for pancreatic stump management after pancreaticoduodenectomy (PD) and investigate a new Onyx® Pancreatic Ducts Obliteration (OPDO) scoring system of pancreatic duct obliteration (PDOb) in patients with high risk of Post-Operative Pancreatic Fistula (POPF). STUDY DESIGN: We enrolled ten patients undergoing PDOb with Onyx® intraoperative controlled injection after elective PD. RESULTS: PDOb with Onyx® controlled injection was classified according to the OPDO scoring system in three degrees: complete 5/10 (50%), medium 2/10 (20%) and bad 3/10 (30%). Increased amylase in abdominal drainage was identified in two patients (20%) with a degree II and III, and resolved spontaneously within a week. A "clinically relevant" POPF (CR-POPF) was observed in one patient (10%) with a degree III and none in the patients with degree I and II. DISCUSSION: We confirm that intraoperative injection of Onyx® is a valid solution in high-risk POPF patients and our OPDO scoring system allows obtain an intraoperative classification of the degree of PDO to prevent the CR-POPOF; furthermore, it may be suggested that the viscosity of the injected product (Onyx®) reduce parenchymal fibrosis.

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.

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.

[Spontaneous retroperitoneal hemorrhage].

A 50-year old male presented to our emergency department with sudden abdominal pain. Upon arrival he was diaphoretic, pale and tachycardic. A CT showed retroperitoneal hemorrhage with suspected tumor at the left adrenal gland. He was quickly stabilized with intravenous fluids and blood transfusion. Rebleed occurs roughly a week after discharge and a new CT showed a visceral pseudoaneurysm from the left middle adrenal artery. The pseudoaneurysm was embolized and the patient discharged in good condition. Follow-up MRI depicted reabsorption of the hematoma and no adrenal tumor. Thus, the etiology of the previous retroperitonal hemorrhage is considered spontaneous.

Embolization in pelvic venous disorders using ethylene vinyl alcohol copolymer (Onyx®) and Aetoxysclerol: a prospective evaluation of safety and long-term efficacy.

OBJECTIVES: To prospectively evaluate the safety and efficacy of embolization using ethylene vinyl alcohol copolymer (Onyx®) and Aetoxysclerol for treatment of pelvic venous disorders (PeVD). METHODS: This prospective study was approved by the institutional ethics review board. Ten clinical parameters were retained for evaluation of PeVD (pelvic pain, dyspareunia, post-coital pain, menstruation pain, lower limbs pain, difficulty walking, aesthetic discomfort, impact on daily working life, psychological impact and impact on daily life), measured on a visual analogue scale (VAS) between 0 and 10, and a global score out of 100 was noted before embolization, after 3 months during the imaging follow-up, and at the end of follow-up by phone call. The main criterion was clinical efficacy of embolization defined by an impairment score < 40/100 and a 50% decrease in overall score. Complications were recorded. Visualization of Onyx® on MRI 3 months after embolization was noted. RESULTS: Between July 2017 and May 2019, 73 consecutive women (mean age ± SD [range]: 41 ± 11 years [25-77]) treated by embolization with Onyx® and Aetoxysclerol were included. The median follow-up was 28 months [Q1-Q3: 24.0-29.2] (range: 18.1-34.5). The median initial VAS impairment score was 39/100 [29.75-48.50] (12-58). Clinical efficacy was obtained for 70 patients (70/73, 95.9%), and the median VAS impairment score at the end of follow-up was significantly lower at 3 [0.00-7.25] (0-73) (p < 0.0001). Four minor complications occurred. Onyx® was visualized on DIXON sequence of MRI for all patients. CONCLUSION: Embolization using Onyx® and Aetoxysclerol for PeVD is safe and effective. KEY POINTS: • Embolization using Onyx® and Aetoxysclerol for pelvic venous disorders is safe and effective. • Imaging follow-up is facilitated by visualization of Onyx® on MRI DIXON sequences.

Onyx™ Cast Fragmentation After Embolization of Endoleaks.

PURPOSE: Endoleaks are common following endovascular aneurysm repair (EVAR), and the liquid embolic material Onyx has been widely used in their treatment. We report our experience of long-term morphological changes of Onyx casts on surveillance imaging. MATERIALS AND METHODS: We identified 10 patients over 10 years who underwent Onyx embolization in our institution. Morphological changes of Onyx casts were assessed on surveillance radiographs and computed tomography (CT) scans. Relevant outcome data and sequelae were obtained via electronic patient records. RESULTS: Twelve procedures were performed on 10 cases, 9 for type 2, and 1 for a type 1a endoleak. Five cases showed evidence of Onyx fragmentation on follow-up imaging ranging from a single fracture to gross fragmentation with migration of fragments. Of these 5, 3 had achieved primary success but 2 went on to develop recurrence of endoleak. Onyx volume ranged from 4 to 46.5 ml (median 10.5 ml) per patient with larger volumes demonstrating the most marked fragmentation on follow-up. Follow-up ranged from 9 months to 8 years (median 2.25 years). CONCLUSION: To our knowledge, this is the first report of Onyx fragmentation after endoleak embolization. If long-term morphological stability of the Onyx cast is necessary to maintain aneurysm seal, then Onyx may not offer a permanent solution to some patients with post-EVAR endoleaks. Our study cannot ascertain whether the observed changes were the cause or the effect of ongoing aneurysm growth, persistent endoleak, and/or other forces acting on the solidified polymer, but it raises important questions on the use of Onyx in this setting.

Management of Dural Arteriovenous Fistulas.

Dural arteriovenous fistula (DAVF) is an acquired lesion. The dural arteries connect with the dural veins within the dura mater in the histopathological study. Sinus type involves the cavernous sinus, transverse-sigmoid sinus, superior sagittal sinus, and anterior condylar confluence (or condylar canal). Non-sinus type involves the anterior cranial base, falcotentorial region, craniocervical junction, convexity, and spinal dura mater.Radical treatment is to obliterate the draining veins in any treatment modalities including endovascular treatment or surgical treatment. Radiosurgery is the last choice. Transvenous embolization plays a main role in the DAVF of the cavernous sinus and anterior condylar confluence. Transarterial embolization with Onyx has dramatically improved the obliteration rate of the transverse-sigmoid, superior sagittal sinuses, and other non-sinus lesions. Transarterial NBCA injection is still the gold standard in the endovascular treatment of the spinal dural and epidural AVFs. Understanding of the functional microvascular anatomy is mandatory, especially in the transarterial liquid injection (Onyx and NBCA). Surgical treatment in the DAVF of the anterior cranial base, craniocervical junction, tentorial region, and spine is a safe and radical treatment. Postoperative follow-up is necessary from the viewpoint of chronological and spacial multi-occurrence of this disease.

Scepter dual-lumen balloon catheter for Onyx embolization for dural arteriovenous fistula.

BACKGROUND: This study aimed to evaluate the efficacy and safety of Scepter dual-lumen balloon catheter for transarterial Onyx embolization of dural arteriovenous fistula (DAVF). METHODS: Transarterial Onyx embolization using a Scepter dual-lumen balloon catheter (Scepter-assisted Onyx embolization) for DAVF was attempted in a total of 35 patients (mean age, 52.5 years; M:F = 24:11) between October 2012 and December 2018. The results of Scepter-assisted Onyx embolization were evaluated with respect to total procedural and Onyx injection times, the types and number of feeders requiring embolization, angiographic and clinical outcomes, and treatment-related complications. RESULTS: Initial presentations were non-hemorrhagic neurological deficits in 10, intracranial hemorrhage in 8, seizure in 7, headache in 7, and intractable tinnitus in 3. All DAVF were aggressive type (Borden type 2, 14.3 %; type 3, 85.7 %). Scepter-assisted Onyx embolization resulted in immediately complete occlusion in 33 patients (94.3 %) and near complete occlusion in 2 patients. Middle meningeal artery (51.4 %) was the most commonly used for Scepter-assisted technique, followed by occipital artery (42.9 %), ascending pharyngeal artery (2.9 %) and superficial temporal artery (2.9 %). There was no difference in complete occlusion rate between middle meningeal artery and the other arteries (94.4 % versus 94.1 %). The median number of total feeders embolized was 1 (range, 1-3). The median total procedural time was 45 minutes (range, 21 minutes - 127 minutes) and the median Onyx injection time was 11 minutes (range, 3 minutes - 25 minutes). All patients recovered completely (n = 31) or partially (n = 4) from presenting symptoms. Treatment-related complications occurred in 2 patients, of whom one had a permanent morbidity (2.8 %, ipsilateral facial nerve palsy). No patient showed a recurrence on follow-up imaging (median, 15 months; range, 3-56 months). CONCLUSIONS: Scepter-assisted transarterial Onyx embolization showed a very high complete occlusion rate with a low morbidity and no recurrence in aggressive type DAVF. Scepter dual-lumen balloon catheter seems to be a useful tool for transarterial Onyx embolization of DAVF.

The Preoperative Functional Downgrading of Brain AVMs.

The actual role of preoperative embolization of brain arteriovenous malformations (AVMs) is undervalued.The present study aims to describe the effectiveness, safety, technics, and results of the endovascular-based functional downgrading of brain AVMs.Data regarding 31 Spetzler-Martin (SM) grade III AVMs that consecutively underwent a combined endovascular-surgical treatment were reviewed. Clinical and radiological outcomes were evaluated according to modified Ranking Scale score (mRS) and postoperative angiography, respectively.Low-density Onyx was used in all cases, and the timeframe between the embolizations was 10-15 days. Procedures were 1.6 (±0.6) on average. Superselective nidal catheterization was essential to reach the deepest parts of the AVMs, which were the targets. Onyx made the nidus compact and easier to dissect. The Average obliteration rate was 29.6%, with negligible morbidity. Surgery was performed after 3.7 days on average and the AVM exclusion was complete in 83.4% of cases. An mRS score between 0 and 2 was reported in 77.5% of patients, while the best outcome was achieved in small and medium-deep malformations.An effective and safe functional downgrading of brain AVMs must be based upon specific technical key aspects, which make surgery easier and, ultimately, allow for the achievement of the best outcome.

Direct percutaneous embolization of aneurysm sac: a safe and effective procedure to treat post-EVAR type II endoleaks.

PURPOSE: To report safety and effectiveness of type II endoleak embolization, with percutaneous direct aneurysm sac puncture. MATERIALS AND METHODS: Fifty patients, 31 male (mean age 55 ± 5), with post-EVAR type-II endoleak underwent direct percutaneous sac puncture for embolization. Procedures were performed, under local anesthesia. Sac puncture was done using a 20G needle under rotational angiography guidance. A coaxial system (4 Fr catheter + 2.7 microcatheter) was used to navigate the sac. During the follow-up period, all patients underwent contrast-enhanced ultrasound (CEUS) at 6 and 12 months. RESULTS: Technical success, with complete exclusion of the aneurysm sac, was achieved in all cases. Time of procedure varied between 36 and 68 min (mean 51.36 min). Mean fluoroscopy time was 16.7 min. A posterior left access was used in 41 cases, posterior right access in 6 cases, and an anterior approach in 3. In 19 cases (38%), one or more feeding vessels were visualized and embolized. Sac embolization was done using Onyx plus micro-coils in 31 cases (62%) and Onyx alone in 19 cases (38%). Mean amount of Onyx was 6 ml. No complications, correlated with the direct percutaneous sac puncture, or to Onyx injection occurred. After 1-year follow-up, sac shrinkage occurred in 34 cases (68%), while in 16 patients (32%) sac size remained stable without evidence of sac perfusion. CONCLUSION: Percutaneous direct sac embolization using Onyx in combination or not with microcoils represents a safe and valid technique to solve post-EVAR type II endoleaks.

A Damp-and-Push Technique for the Copolymer (Onyx) Embolization of Dural Arteriovenous Fistula.

BACKGROUND: Copolymer (Onyx) embolization is an effective treatment for dural arteriovenous fistula (dAVF), however, some dAVFs have multiple, high-flow feeding vessels, resulting in insufficient embolization. For the treatment of such patients, we have developed a novel flow-control technique, the 'damp-and-push technique'. The purpose of this study was to evaluate the technical efficiency and safety of this technique. METHODS: Seven patients who had been diagnosed with intracranial dAVF were treated by transarterial Onyx embolization using the damp-and-push technique between 2016 and 2019. This technique was designed to reduce blood flow to the shunt site using a balloon catheter in the major feeding vessel other than the one injected with Onyx, leading to better Onyx penetration and enabling more controlled embolization of complex dAVFs. Retrospectively collected data were reviewed to assess the occlusion rates and clinical outcomes. RESULTS: The dAVF was at a transverse sinus-sigmoid sinus junction in four patients, in the superior sagittal sinus in two, and in the tentorium in one. Five cases were Cognard type Ⅱb and two cases were Cognard type Ⅳ. All the patients were treated by transarterial Onyx injection via the main feeding vessel, combined with flow reduction in the other main feeding vessel using a balloon catheter. Complete occlusion was achieved in six patients and elimination of cerebral venous reflux was achieved in all the patients. There were no immediate or delayed post-interventional complications. CONCLUSIONS: Transarterial Onyx embolization of dAVF using the damp-and-push technique is safe and yields a high complete occlusion rate.

Ethylene Vinyl Alcohol Copolymer Embolization for Acute Renal Hemorrhage: Initial Experience in 24 Cases.

OBJECTIVE. The purpose of this study was to assess the efficacy and safety of ethylene vinyl alcohol (EVOH) copolymer (Onyx, Medtronic) for embolization for acute renal hemorrhage. MATERIALS AND METHODS. Between October 2006 and June 2018, 24 consecutive patients were treated by embolization with EVOH copolymer for acute renal hemorrhage at Hôpital Bichat-Claude-Bernard. CT angiography was performed in all patients before treatment. Technical success was defined as the complete occlusion of the bleeding artery on final renal angiogram. Clinical success was defined as the absence of rebleeding after embolization. Complications mid procedure, infarcted renal area on final angiogram, and renal function 1 week after embolization were retrospectively analyzed. RESULTS. Active bleeding was observed in all cases. The causes of acute renal hemorrhage were iatrogenic in 12 patients, vascular malformation in four patients, renal tumor in four patients, and unknown in four patients. EVOH copolymer was the sole embolic agent used in 16 patients. In eight patients, EVOH copolymer was used after persistent bleeding after embolization with coils. Technical and clinical success rates were 100%. No patient required surgery or new embolization during a mean follow-up period of 35 months (range, 6-86 months). No serious complications were attributable to EVOH copolymer. The mean infarcted renal area was 10% (range, 5-30%). Renal function, available for 16 (67%) patients, was not altered 1 week after embolization. CONCLUSION. EVOH copolymer is safe and effective for embolization of acute renal hemorrhage, either as a first-line embolic agent or after failure of coil embolization.