Technique and impact on first pass effect primary results of the ASSIST global registry.

BACKGROUND: Patients treated with mechanical thrombectomy (MT) for acute ischemic strokes from large vessel occlusion (LVO) have better outcomes with effective reperfusion. However, it is unknown which technique leads to better technical and clinical success. We aimed to determine which technique yields the most effective first pass reperfusion during MT. METHODS: In a prospective, multicenter global registry we enrolled patients treated with operator preferred MT technique at 71 hospitals from January 2019 to January 2022. Three techniques were assessed: SR Classic with stent retriever (SR) and balloon guide catheter (BGC); SR Combination which employed SR with contact aspiration with or without BGC; and direct aspiration (DA) with or without BGC. The primary outcome was achieving an expanded Thrombolysis In Cerebral Infarction (eTICI) score of 2c or 3 on the first pass, with the primary technique as adjudicated by core lab. The primary clinical outcome measure was a 90-day modified Rankin Scale (mRS) score of 0-2. RESULTS: A total of 1492 patients were enrolled. Patients treated with SR Classic or SR Combination were more likely to achieve first pass eTICI 2c or 3 reperfusion (P=0.01). There was no significant difference in mRS 0-2 (P=0.46) or safety endpoints. CONCLUSIONS: The use of SR Classic or SR Combination was more likely to achieve first pass eTICI 2c or 3 reperfusion. There were no significant differences in clinical outcomes and safety endpoints.

Penumbral Rescue by normobaric O = O administration in patients with ischemic stroke and target mismatch proFile (PROOF): Study protocol of a phase IIb trial.

RATIONALE: Oxygen is essential for cellular energy metabolism. Neurons are particularly vulnerable to hypoxia. Increasing oxygen supply shortly after stroke onset could preserve the ischemic penumbra until revascularization occurs. AIMS: PROOF investigates the use of normobaric oxygen (NBO) therapy within 6 h of symptom onset/notice for brain-protective bridging until endovascular revascularization of acute intracranial anterior-circulation occlusion. METHODS AND DESIGN: Randomized (1:1), standard treatment-controlled, open-label, blinded endpoint, multicenter adaptive phase IIb trial. STUDY OUTCOMES: Primary outcome is ischemic core growth (mL) from baseline to 24 h (intention-to-treat analysis). Secondary efficacy outcomes include change in NIHSS from baseline to 24 h, mRS at 90 days, cognitive and emotional function, and quality of life. Safety outcomes include mortality, intracranial hemorrhage, and respiratory failure. Exploratory analyses of imaging and blood biomarkers will be conducted. SAMPLE SIZE: Using an adaptive design with interim analysis at 80 patients per arm, up to 456 participants (228 per arm) would be needed for 80% power (one-sided alpha 0.05) to detect a mean reduction of ischemic core growth by 6.68 mL, assuming 21.4 mL standard deviation. DISCUSSION: By enrolling endovascular thrombectomy candidates in an early time window, the trial replicates insights from preclinical studies in which NBO showed beneficial effects, namely early initiation of near 100% inspired oxygen during short temporary ischemia. Primary outcome assessment at 24 h on follow-up imaging reduces variability due to withdrawal of care and early clinical confounders such as delayed extubation and aspiration pneumonia. TRIAL REGISTRATIONS: ClinicalTrials.gov: NCT03500939; EudraCT: 2017-001355-31.

Pre-emptive transjugular intrahepatic portosystemic shunt in pediatric cystic fibrosis-related liver disease and portal hypertension: prospective long-term results.

PURPOSE: Portal hypertension (PHT) and its sequelae are the most clinically important manifestations in cystic fibrosis-related liver disease (CFLD). This paper aimed to evaluate the safety and efficacy of a pre-emptive transjugular intrahepatic portosystemic shunt (TIPS) to prevent PHT-related complications in pediatric patients with CFLD. METHODS: This was a prospective single-arm study on pediatric patients with CFLD, signs of PHT, and preserved liver function who underwent a pre-emptive TIPS in a single tertiary CF center between 2007 and 2012. The long-term safety and clinical efficacy were assessed. RESULTS: A pre-emptive TIPS was performed on seven patients with a mean age of 9.2 years (± standard deviation: 2.2). The procedure was technically successful in all patients, with an estimated median primary patency of 10.7 years [interquartile range (IQR) 0.5-10.7)]. No variceal bleeding was observed during the median follow-up of 9 years (IQR 8.1-12.9). In two patients with advanced PHT and rapidly progressive liver disease, severe thrombocytopenia could not be stopped. Subsequent liver transplantation revealed biliary cirrhosis in both patients. In the remaining patients with early PHT and milder porto-sinusoidal vascular disease, symptomatic hypersplenism did not occur, and liver function remained stable until the end of the follow-up. Inclusion for pre-emptive TIPS was discontinued in 2013 following an episode of severe hepatic encephalopathy. CONCLUSION: TIPS is a feasible treatment with encouraging long-term primary patency to avoid variceal bleeding in selected patients with CF and PHT. However, as the progression of liver fibrosis, thrombocytopenia, and splenomegaly is inevitable, the clinical benefits due to pre-emptive placement appear to be minor.

Cerebral Proliferative Angiopathy in a Child, Five Years after an Intraventricular Hemorrhage and Negative Catheter Angiography.

Cerebral proliferative angiopathy (CPA) is a rare cerebrovascular disease comprised of a diffuse network of blood vessels, often spread over several lobes. Due to the presence of normal brain tissue within the malformation, complete resection is not desirable. Several imaging characteristics help to distinguish CPA from brain arteriovenous malformations. We report the case of a patient diagnosed with CPA five years after a spontaneous intraventricular hemorrhage and an initial negative angiogram. Teaching Point: The radiologist should be able to differentiate CPA from brain AVM to prevent potentially harmful treatment.

Transjugular Intrahepatic Portosystemic Shunts in Pediatric Portal Hypertension: A Systematic Review and Meta-Analysis.

PURPOSE: To investigate the technical outcome, clinical outcome, and patency of transjugular intrahepatic portosystemic shunt (TIPS) in pediatric portal hypertension (PHT). METHODS: A systematic search of MEDLINE/PubMed, EMBASE, Cochrane databases, ClinicalTrials.gov, and WHO ICTRP registries was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. An a priori protocol was registered at the PROSPERO database. Original full-text articles on pediatric patients (sample size of ≥5 patients with upper age limit of 21 years) with PHT who underwent TIPS creation for any indication were included. RESULTS: Seventeen studies with 284 patients (average-weighted age of 10.1 years) were included, with an average-weighted follow-up of 3.6 years. TIPS was technically successful in 93.3% (95% confidence interval [CI], 88.5%-97.1%) of patients, with a major adverse event rate of 3.2% (95% CI, 0.7-6.9) and adjusted hepatic encephalopathy rate of 2.9% (95% CI, 0.6-6.3). The pooled 2-year primary and secondary patency rates were 61.8% (95% CI, 50.0-72.4) and 99.8% (95% CI, 96.2%-100.0%), respectively. Stent type (P = .002) and age (P = .04) were identified as a significant source of heterogeneity for clinical success. In subgroup analysis, the clinical success rate was 85.9% (95% CI, 77.8-91.4) in studies with a majority of covered stents, and 87.6% (95% CI, 74.1-94.6) in studies with a median age of 12 years or older. CONCLUSIONS: This systematic review and meta-analysis demonstrates that a TIPS is a feasible and safe treatment for pediatric PHT. To improve clinical outcome and patency on the long term, the use of covered stents should be encouraged.

Empirical transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients.

BACKGROUND: Recently, an empiric Cone-beam Computed Tomography (CBCT)-guided transarterial embolization (TAE) technique has been investigated for lower gastrointestinal bleeding (LGIB). Although this empirical strategy reduced the rate of rebleeding in hemodynamically unstable patients compared to a 'wait and see' strategy, the specified technique is challenging and time-consuming. CASE PRESENTATION: We present two methods to perform a prompt empiric TAE in LGIB when catheter angiography is negative. Based on the pre-procedural Computed Tomography Angiography bleeding site and using vessel detection and navigation software tools that are integrated in contemporary angiosuites, the culprit bleeding artery could be targeted with only one selective intraprocedural CBCT acquisition. CONCLUSION: The proposed techniques are promising to reduce procedure time and facilitate the implementation of empiric CBCT-guided TAE in clinical practice when angiography is negative.

Video-assisted thoracic surgery in critically ill COVID-19 patients on venovenous extracorporeal membrane oxygenation.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) leads to thoracic complications requiring surgery. This is challenging, particularly in patients supported with venovenous extracorporeal membrane oxygenation (VV-ECMO) due to the need for continuous therapeutic anticoagulation. We aim to share our experience regarding the safety and perioperative management of video-assisted thoracic surgery for this specific population. METHODS: Retrospective, single-center study between November 2020 and January 2022 at the ICU department of a 1.061-bed tertiary care and VV-ECMO referral center during the COVID-19 pandemic. RESULTS: 48 COVID-19 patients were supported with VV-ECMO. A total of 14 video-assisted thoracic surgery (VATS) procedures were performed in seven patients. Indications were mostly hemothorax (85.7%). In eight procedures heparin was stopped at least 1 h before incision. A total of 10 circuit changes due to clot formation or oxygen transfer failure were required in six patients (85.7%). One circuit replacement seemed related to the preceding VATS procedure, although polytransfusion might be a contributing factor. None of the mechanical complications was fatal. Four VATS-patients (57.1%) died, of which two (50%) immediately perioperatively due to uncontrollable bleeding. All three survivors were treated with additional transarterial embolization. CONCLUSION: (1) Thoracic complications in COVID-19 patients on VV-ECMO are common. (2) Indication for VATS is mostly hemothorax (3) Perioperative mortality is high, mostly due to uncontrollable bleeding. (4) Preoperative withdrawal of anticoagulation is not directly related to a higher rate of ECMO circuit-related complications, but a prolonged duration of VV-ECMO support and polytransfusion might be. (5) Additional transarterial embolization to control postoperative bleeding may further improve outcomes.

90Y Radioembolization versus Drug-eluting Bead Chemoembolization for Unresectable Hepatocellular Carcinoma: Results from the TRACE Phase II Randomized Controlled Trial.

Background Transarterial chemoembolization (TACE) is the recommended treatment for intermediate hepatocellular carcinoma (HCC) according to the Barcelona Clinic Liver Cancer guidelines. Prospective uncontrolled studies suggest that yttrium 90 (90Y) transarterial radioembolization (TARE) is a safe and effective alternative. Purpose To compare the efficacy and safety of TARE with TACE for unresectable HCC. Materials and Methods In this single-center prospective randomized controlled trial (TRACE), 90Y glass TARE was compared with doxorubicin drug-eluting bead (DEB) TACE in participants with intermediate-stage HCC, extended to Eastern Cooperative Oncology Group performance status 1 and those with early-stage HCC not eligible for surgery or thermoablation. Participants were recruited between September 2011 and March 2018. The primary end point was time to overall tumor progression (TTP) (Kaplan-Meier analysis) in the intention-to-treat (ITT) and per-protocol (PP) groups. Results At interim analysis, 38 participants (median age, 67 years; IQR, 63-72 years; 33 men) were randomized to the TARE arm and 34 (median age, 68 years; IQR, 61-71 years; 30 men) to the DEB-TACE arm (ITT group). Median TTP was 17.1 months in the TARE arm versus 9.5 months in the DEB-TACE arm (ITT group hazard ratio [HR], 0.36; 95% CI: 0.18, 0.70; P = .002) (PP group, 32 and 34 participants, respectively, in each arm; HR, 0.29; 95% CI: 0.14, 0.60; P < .001). Median overall survival was 30.2 months after TARE and 15.6 months after DEB-TACE (ITT group HR, 0.48; 95% CI: 0.28, 0.82; P = .006). Serious adverse events grade 3 or higher (13 of 33 participants [39%] vs 19 of 36 [53%] after TARE and DEB-TACE, respectively; P = .47) and 30-day mortality (0 of 33 participants [0%] vs three of 36 [8.3%]; P = .24) were similar in the safety groups. At the interim, the HR for the primary end point, TTP, was less than 0.39, meeting the criteria to halt the study. Conclusion With similar safety profile, yttrium 90 radioembolization conferred superior tumor control and survival compared with chemoembolization using drug-eluting beads in selected participants with early or intermediate hepatocellular carcinoma. Clinical trial registration no. NCT01381211 © RSNA, 2022 Online supplemental material is available for this article.

Dural Arteriovenous Fistula Presenting As Pulsatile Tinnitus.

Teaching point: We report magnetic resonance imaging characteristics of a dural arteriovenous fistula (dAVF), a possible cause of pulsatile tinnitus.

Empiric cone-beam CT-guided embolization in acute lower gastrointestinal bleeding.

OBJECTIVES: To evaluate the clinical effect and safety of cone-beam CT (CBCT)-guided empirical embolization for acute lower gastrointestinal bleeding (LGIB) in patients with a positive CT angiography (CTA) but subsequent negative digital subtraction angiography (DSA). METHODS: A retrospective study of consecutive LGIB patients with a positive CTA who received a DSA within 24 h from January 2008 to July 2019. Patients with a positive DSA were treated with targeted embolization (TE group). Patients with a negative DSA underwent an empiric CBCT-guided embolization of the assumed ruptured vas rectum (EE group) or no embolization (NE group). Recurrent bleeding, major ischemic complications, and in-hospital mortality were compared by means of Fisher's exact test. Further subgroup analysis was performed on hemodynamic instability. RESULTS: Eighty-five patients (67.6 years ± 15.7, 52 men) were included (TE group, n = 47; EE group, n = 19; NE group, n = 19). If DSA was positive, technical success of targeted embolization was 100% (47/47). If DSA was negative and the intention to treat by empiric CBCT-guided embolization, technical success was 100% (19/19). Recurrent bleeding rates in the TE group, EE group, and NE group were 17.0% (8/47), 21.1% (4/19), and 52.6% (10/19) respectively. Empiric CBCT-guided embolization reduced rebleeding significantly in patients with a negative DSA and hemodynamic instability (EE group, 3/10 vs NE group, 10/12, p = .027). Major ischemic complications occurred in one patient (TE group). Overall, the in-hospital mortality rate was 7.1% (6/85). CONCLUSION: Empiric cone-beam CT-guided embolization proved to be a feasible, effective, and safe treatment strategy to reduce rebleeding and improve clinical success in hemodynamically unstable patients with acute LGIB, positive CTA but negative DSA. KEY POINTS: • A novel transarterial embolization technique guided by cone-beam CT could be developed extending the "empiric" embolization strategy to lower gastrointestinal bleeding. • By implementing the empiric treatment strategy, nearly all patients with an active lower gastrointestinal bleeding on CTA will be eligible for a superselective empiric embolization, even if subsequent catheter angiography is negative. • In patients with a negative catheter angiography, empiric embolization reduces the rebleeding rate and, particularly in hemodynamically unstable patients, improves clinical success compared with a conservative "wait-and-see" management.

Correction to: No evidence of improved efficacy of covered stents over uncovered stents in percutaneous palliation of malignant hilar biliary obstruction: results of a prospective randomized trial.

On request from the Editors, the authors would like to clarify the following: the patient cohorts in the publications "No evidence of improved efficacy of covered stents over uncovered stents in percutaneous palliation of malignant hilar biliary obstruction: results of a prospective randomized trial".

CT Perfusion as a Selection Tool for Mechanical Thrombectomy, a Single-Centre Study.

BACKGROUND: Recently, CT perfusion (CTP) has been proposed as a selection tool for stroke patients to be treated with endovascular thrombectomy. We investigated whether functional outcome following endovascular treatment was improved after the introduction of CTP. METHODS: This retrospective single-centre study includes all patients with a major vessel occlusion in the anterior circulation that received a CTP and underwent a mechanical thrombectomy from 2014 up to 2015. CTP were visually evaluated. Demographics, stroke and time data, procedural data, functional outcomes as measured by the modified Rankin Scale (mRS) and the association between these variables were studied. A comparison was made with the results of a similar local retrospective study from before the CTP "era". RESULTS: Eighty-nine patients were included in this study. Median National Institutes of Health Stroke Scale (NIHSS) was 16 (Interquartile range 6). At three months, good functional outcome (GFO; mRS 0-2) was achieved in 48.4% and excellent functional outcome (EFO; mRS 0-1) in 34.4% of patients. The mortality rate at three months was 14.5%. GFO at one year was 44.8%, EFO was 31.3% and mortality 21.1%. The duration of the thrombectomy procedure and the EFO were associated (p = 0.032). The outcome improvement achieved with CTP was higher compared to the reference study (GFO 48.4% versus 44%; EFO 34.4% versus 29%) but remained below the statistical significance. CONCLUSIONS: Mechanical thrombectomy for anterior circulation strokes based on CTP did not result in a significant functional outcome improvement. The duration of the thrombectomy procedure was the sole time-interval related to improved functional outcome.

No evidence of improved efficacy of covered stents over uncovered stents in percutaneous palliation of malignant hilar biliary obstruction: results of a prospective randomized trial.

OBJECTIVE: To investigate whether covered stents show a higher efficacy than uncovered stents in percutaneous treatment of malignant hilar biliary obstruction. METHODS: Patients with obstructive jaundice caused by an unresectable hilar malignancy were included after failed endoscopic intervention in a prospective randomized trial comparing expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE-FEP)-covered nitinol stents with uncovered nitinol stents. Exclusion criteria were as follows: primary tumors existing more than 3 months, a biliodigestive anastomosis, previous stenting, and a Karnofsky score of less than 50. Safety, clinical success, and adjuvant chemotherapy were compared as well as occlusion rate, patency, and survival. RESULTS: A total of 120 patients were included. One patient was post hoc excluded. Fourteen patients who died within 7 days and one patient without patency data were excluded from patency analysis. Serious adverse events (p = 0.4), 30-day mortality (p = 0.5), and clinical success (p = 0.8) were equivalent for both stent groups. Twenty-one out of 61 (34%) patients in the covered and 24/58 (41%) in the uncovered stent groups received adjuvant chemotherapy (p = 0.5). Occlusion rate was 54% (27/50) in the covered stent group and 57% (31/54) in the uncovered stent group (p = 0.8). Median patency was 229 days (95% CI 113-345) for covered stents and 130 days (95% CI 75-185) for uncovered stents (p = 0.1). Median survival in patients with covered stents was 79 days (95% CI 52-106) and with uncovered stents 92 days (95% CI 60-124) (p = 0.3). CONCLUSION: In malignant hilar biliary obstruction, there is no evidence that ePTFE-FEP-covered stents are superior to uncovered stents in terms of safety, clinical success, adjuvant chemotherapy, patency, or survival. KEY POINTS: • Percutaneous palliation of hilar biliary obstruction is feasible with both uncovered and covered stents. • Clinical success in terms of bilirubin decrease and adjuvant chemotherapy is achievable with both stents. • Thirty-day mortality is considerable when stenting is also offered to patients with a low performance status.

No Advantage of Expanded Polytetrafluoroethylene and Fluorinated Ethylene Propylene-Covered Stents over Uncovered Nitinol Stents for Percutaneous Palliation of Malignant Infrahilar Biliary Obstruction: Results of a Single-Center Prospective Randomized Trial.

PURPOSE: To prove that covered stents are more efficacious than uncovered stents regarding patency, safety, enabling of chemotherapy, and survival in percutaneous palliation of malignant infrahilar biliary obstruction. MATERIALS AND METHODS: After failed endoscopic treatment, 154 patients with obstructive jaundice caused by unresectable infrahilar malignancy were randomly allocated to receive an expanded polytetrafluoroethylene and fluorinated ethylene propylene-covered or an uncovered nitinol stent. Occlusion rate, patency, and survival were assessed. Safety and clinical success in terms of chemotherapy were compared. RESULTS: Three patients were excluded post hoc. Fifteen patients died within 7 d and were excluded from patency analysis. Occlusion rates were 32% (21 of 66) for covered and 29% (20 of 70) for uncovered stents (P = .7). Estimated median patency durations were 308 d (95% confidence interval [CI], 178-438 d) for covered and 442 d (95% CI, 172-712 d) for uncovered stents (P = .1). Serious adverse events (P = 1.0) and 30-day mortality (P = .5) were equivalent between groups. At hospital discharge, median bilirubin reduction of 8 mg/dL was found in both groups (P < .001). In the covered stent group, 35 patients (48%) received palliative chemotherapy, vs 29 (37%) in the uncovered stent group (P = .2). Estimated median survival times were 96 days (95% CI, 68-124 d) with covered stents and 75 days (95% CI, 42-108 d) with uncovered stents (P = .6). CONCLUSIONS: In malignant infrahilar biliary obstruction not amenable to endoscopy, no improvement in patency or survival with percutaneously placed covered stents could be confirmed. Covered and uncovered stent types exhibit similar safety profiles and clinical success rates.

Benign anastomotic biliary strictures untreatable by ERCP: a novel percutaneous balloon dilatation technique avoiding indwelling catheters.

OBJECTIVE: To evaluate long-term patency rates of a novel percutaneous threefold balloon dilatation protocol in benign anastomotic biliary strictures. METHODS: Patients with a benign biliary stricture after hepatobiliary surgery or liver transplantation, untreatable with endoscopy, underwent a percutaneous treatment cycle consisting of a 20-min balloon dilatation session on day one, repeated on days three and five. No catheters were left behind after the last dilatation session. Technical and clinical success as well as complications were analysed. Mean primary and secondary patency times were assessed. Cumulative primary and secondary patency rates at 6 months and 1, 2 and 3 years were determined. RESULTS: Seventy patients underwent 135 dilatation treatment cycles (mean 1.9) with a technical success rate of 99%. Clinical success was achieved in 87% of the patients. Fifty-eight of 135 (43%) patients had minor and 15/135 (11%) had major complications. Mean primary and secondary patency times were 26 months and 46 months, respectively, with a median follow-up of 69 months. Cumulative primary patency rate at 6 months was 67%, at 1 year 56%, at 2 years 41% and at 3 years 36%. The cumulative secondary patency rate at 6 months was 83%, at 1 year 79%, at 2 years 70% and at 3 years 64%. CONCLUSION: In benign anastomotic biliary strictures, a percutaneous threefold balloon dilatation treatment is effective. As long indwelling catheters are avoided, patient comfort improves. KEY POINTS: • Percutaneous threefold balloon dilatation treatment is effective in benign anastomotic biliary strictures. • As indwelling catheters after dilatation are avoided, patient comfort improves. • The dilatation protocol can be repeated efficiently in case of recurrent stricture.

Model for end-stage liver disease score and hemodynamic instability as a predictor of poor outcome in early transjugular intrahepatic portosystemic shunt treatment for acute variceal hemorrhage.

OBJECTIVE: To evaluate the outcome of early transjugular portosystemic shunt (TIPS) treatment in patients with a trial-compatible high-risk variceal bleeding and secondly to disclose other predictors of early mortality. MATERIALS AND METHODS: A cohort study was conducted on patients referred for a TIPS procedure with or without combined variceal embolization to control acute esophageal variceal bleeding. A total of 32 patients with Child-Pugh C score less than 14 or Child-Pugh B plus active bleeding at endoscopy, admitted for early-TIPS treatment (<72 h), were included. RESULTS: We noted one (3.7%) failure to control bleeding and no rebleeding during 1-year follow-up. Ten (31.3%) patients died within 6 weeks after TIPS placement. Early mortality was associated with model for end-stage liver disease (MELD) score (P=0.025), MELD score of at least 19 (P=0.008) and hemodynamic instability at time of admission (P=0.001). If hemodynamic instability is associated with a high MELD score, the 6-week mortality peaks at 77.8% (P=0.000). CONCLUSION: This study confirms the excellent survival results of early-TIPS treatment for acute variceal bleeding in a selected patient group with a low MELD score. Poor survival in hemodynamically unstable patients with high MELD scores (≥19) contests the guidelines that patients with Child-Pugh class C cirrhosis or Child-Pugh class B with active bleeding on endoscopy should deliberately receive preemptive TIPS treatment after endoscopic haemostasis.

Unruptured Brain Arteriovenous Malformations: Primary ONYX Embolization in ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations)-Eligible Patients.

BACKGROUND AND PURPOSE: In light of evidence from ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations), neurovascular specialists had to reconsider deliberate treatment of unruptured brain arteriovenous malformations (uBAVMs). Our objective was to determine the outcomes of uBAVM treated with primary embolization using ethylene vinyl alcohol (ONYX). METHODS: Patients with uBAVM who met the inclusion criteria of ARUBA and were treated with primary Onyx embolization were assigned to this retrospective study. The primary outcome was the modified Rankin Scale score. Secondary outcomes were stroke or death because of uBAVM or intervention and uBAVM obliteration. RESULTS: Sixty-one patients (mean age, 38 years) were included. The median observation period was 60 months. Patients were treated by embolization alone (41.0%), embolization and radiosurgery (57.4%), or embolization and excision (1.6%). Occlusion was achieved in 44 of 57 patients with completed treatment (77.2%). Forty-seven patients (77.1%) had no clinical impairment at the end of observation (modified Rankin Scale score of <2). Twelve patients (19.7%) reached the outcome of stroke or death because of uBAVM or intervention. Treatment-related mortality was 6.6% (4 patients). CONCLUSIONS: In uBAVM, Onyx embolization alone or combined with stereotactic radiosurgery achieves a high occlusion rate. Morbidity remains a challenge, even if it seems lower than in the ARUBA trial.