Management of distal aneurysm of the superior mesenteric artery by percutaneous ultrasound-guided Onyx injection: A case report.

OBJECTIVES: The aim of this article is to report an alternative approach for the management of a distal aneurysm of superior mesenteric artery using direct percutaneous ultrasound-guided Onyx injection. METHODS: We report a rare case of symptomatic superior mesenteric artery aneurysm. A 78-year-old man presents with pain and pulsating mass in the right umbilical region of the abdomen. The patient was treated by percutaneous ultrasound-guided Onyx injection after several failing transarterial embolization attempts. RESULTS: The procedure was successful without any complication, and the patient wasdischarged to home the day after procedure. Follow-up at 60 months confirmed the complete thrombosis of the aneurysm sac. Ultrasound-guided Onyx injection for distal superior mesenteric artery aneurysm could provide an alternative to transcatheter arterial embolization or open surgery. Anatomical assessment of collaterals and knowledge of abdomen anatomy could play important roles in preventing bowel ischemia and minimizing the risk of procedural complication. CONCLUSION: Ultrasound-guided Onyx injection of superior mesenteric artery aneurysm is a feasible, effective, and cost-saving technique that can be used when endovascular approach is not possible or has failed.

Outcomes of Onyx® Embolization of Type II Endoleaks After Endovascular Repair of Abdominal Aortic Aneurysms.

BACKGROUND: Type II endoleaks (T2ELs) are common following endovascular repair of abdominal aortic aneurysms (EVAR). Embolization with ethylene vinyl alcohol copolymer (Onyx) may present an effective treatment alternative for T2ELs. Due to limited data supporting its use, we sought to analyze outcomes of Onyx embolization for T2ELs. METHODS: Retrospective review of consecutive patients treated for T2ELs utilizing Onyx embolization agent from 2009-2018. All pre- and post-Onyx intervention CT scans were analyzed for diameter and volume changes with 3D reconstruction software. The primary outcomes were change in maximum AAA diameter and volume. Secondary outcomes included additional interventions, rupture, and mortality. A subset analysis was performed with patients with isolated T2ELs (no other types of endoleaks present). RESULTS: We identified 85 patients (73 males, mean age 77.6 ± 7.6 years) who underwent 112 Onyx interventions. Average time to first Onyx intervention after index EVAR was 3.3 ± 2.6 years and average sac growth was 6.3 ± 6.7 mm. Patients underwent mean 1.3 Onyx interventions using a mean of 4.9 ± 4.7 ml for treatment. Three complications occurred (Onyx extravasation, colon ischemia, and access site hematoma). Mean follow-up was 2.5 ± 2.1 years after initial Onyx treatment. At the most recent follow-up, sac diameter stabilization was seen in 47% and reduction >5 mm was seen in 19%. Sac growth of >5 mm was seen in 34% of patients following the first Onyx intervention. In our subset of isolated T2EL, 72% had sac stabilization or reduction >5 mm. Four patients experienced a ruptured aneurysm (3 had active type 1 endoleaks). Rupture-free survival was 95% at 5 years, and overall survival was 54% at 5 years. Notably, increasing Onyx interventions were not associated with sac stabilization or reduction (OR 0.6, P = 0.1). On multivariable analysis, AAA sac diameter stabilization or reduction was independently associated with BMI >30 kg/m2 (OR 4.2, P = 0.01) and having only 1 Onyx intervention (OR 3.8, P = 0.02). CONCLUSIONS: Onyx for embolization of T2ELs resulted in AAA sac diameter stabilization or reduction in 66% of patients, and up to 72% in isolated T2ELs. Further, increasing Onyx interventions were not associated with either aneurysm sac stabilization or reduction. Given its similar outcomes to other embolization strategies in the literature, Onyx embolization for management of T2ELs needs to be judiciously considered, particularly for T2ELs persisting after an initial Onyx embolization intervention.

Dynamic airway constriction in rats: heterogeneity and response to deep inspiration.

Airway narrowing due to hyperresponsiveness severely limits gas exchange in patients with asthma. Imaging studies in humans and animals have shown that bronchoconstriction causes patchy patterns of ventilation defects throughout the lungs, and several computational models have predicted that these regions are due to constriction of smaller airways. However, these imaging approaches are often limited in their ability to capture dynamic changes in small airways, and the patterns of constriction are heterogeneous. To directly investigate regional variations in airway narrowing and the response to deep inspirations (DIs), we utilized tantalum dust and microfocal X-ray imaging of rat lungs to obtain dynamic images of airways in an intact animal model. Airway resistance was simultaneously measured using the flexiVent system. Custom-developed software was used to track changes in airway diameters up to generation 19 (~0.3-3 mm). Changes in diameter during bronchoconstriction were then measured in response to methacholine (MCh) challenge. In contrast with the model predictions, we observed significantly greater percent constriction in larger airways in response to MCh challenge. Although there was a dose-dependent increase in total respiratory resistance with MCh, the percent change in airway diameters was similar for increasing doses. A single DI following MCh caused a significant reduction in resistance but did not cause a significant increase in airway diameters. Multiple DIs did, however, cause significant increases in airway diameters. These measurements allowed us to directly quantify dynamic changes in airways during bronchoconstriction and demonstrated greater constriction in larger airways.

Embolization of brain arteriovenous malformations with the diluted Onyx technique: initial experience.

PURPOSE: Insufficient nidus occlusion is a matter of great concern to routine Onyx embolization of brain arteriovenous malformations (AVMs). This paper described an efficient method which using the diluted Onyx embolization technique to treat brain AVM. METHODS: The diluted Onyx technique was performed in a series of 15 patients with brain AVMs (10 males, 5 females; age range, 11-44 years). It consists of initial embolization with routine Onyx-18, followed by the diluted Onyx (1.5 mL of Onyx-18 diluted with 0.5 mL of DMSO) through the same microcatheter. The technical skills and angiographic and clinical outcomes were analyzed. RESULTS: A total of 15 embolization sessions were performed with diluted Onyx via 16 arterial feeders in these 15 patients. Each patient underwent one attempt of diluted Onyx through a single feeder except one patient. In this patient, the AVM was simultaneously embolized with diluted Onyx through double microcatheters which were placed in two feeders. When the length of reflux reached to 2 cm (or close to the determined length) and the embolic material could not move distally any more despite some rounds of "injection-reflux-waiting," regular Onyx 18 was changed to diluted Onyx. Antegrade flow of embolic material into the nidus was observed in 12 cases but failed in 3. An average of 90% (range 55-100%) estimated size reduction was achieved, and 6 AVMs were completely obliterated. No functionally relevant complications occurred. CONCLUSION: The diluted Onyx technique could be a useful adjunct to routine Onyx embolization which may offer more embolic material penetrating into the nidus of AVM, but additional work is needed to validate this technique.

Carotid-Cavernous Sinus Fistula caused by Persistent Primitive Trigeminal Artery Aneurysm rupture: A case report.

Carotid-Cavernous sinus fistula (CCF) caused by a ruptured aneurysm of persistent primitive trigeminal artery (PPTA) is exceptionally rare. Herein, we reported the case of a 64-year-old female who presented with headache, pulsatile tinnitus, and diplopia. Angiography showed a PPTA and CCF. Three-dimensional digital subtraction angiograms revealed a direct shunt between the PPTA aneurysm and the left cavernous sinus. The trigeminal carotid fistula was successfully treated with detachable coils and Onyx, and the PPTA was preserved. Hence, coil and Onyx occlusion of the cavernous sinus is a safe and effective treatment for trigeminal carotid fistula.

Vagal Nerve Palsy After Transarterial Embolization of Transverse-Sigmoid Dural Arteriovenous Fistula Using Onyx.

OBJECTIVE: We report a case of a 70-year-old man who developed a transverse-sigmoid dural arteriovenous fistula (TS-DAVF) that was successfully treated by transarterial embolization (TAE) with Onyx. CASE PRESENTATION: The patient presented with sudden and progressive disturbance of consciousness and left hemiparesis. Magnetic resonance imaging (MRI) revealed venous infarction and hemorrhagic changes with brain swelling in the right parietal lobe. Angiography revealed a right TS-DAVF and multiple occlusions with retrograde leptomeningeal venous drainage into the cortical veins. The TS-DAVF was graded as Borden type III and Cognard type IIa+b. Because of its progressive clinical nature and wide distribution of DAVF in the occluded sinus wall, he underwent emergent TAE with liquid embolic materials including n-butyl cyanoacrylate and Onyx under informed consent by his family. Complete obliteration of the TS-DAVF was achieved, leading to a marked amelioration of symptoms, and MRI after treatment confirmed a decrease in the brain swelling. However, he suffered transient dysphagia due to right vagal nerve palsy caused by occlusion of vasa nervorum of ascending pharyngeal artery. He returned home 5 months later with a modified Rankin Scale of 1. CONCLUSIONS: TAE with Onyx appears to be effective for aggressive TS-DAVF with a widely distributed shunt. However, the blood supply to the cranial nerves and potentially dangerous anastomoses between the external-internal carotid artery and vertebral artery should be taken into account to avoid serious complications.

An Intravascular Tantalum Oxide-based CT Contrast Agent: Preclinical Evaluation Emulating Overweight and Obese Patient Size.

Purpose To compare the CT imaging performance of a carboxybetaine zwitterionic-coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated contrast agent in a swine model meant to simulate overweight and obese patients. Materials and Methods Four swine were evaluated inside three different-sized adipose-equivalent encasements emulating abdominal girths of 102, 119, and 137 cm. Imaging was performed with a 64-detector row CT scanner at six scan delays after intravenous injection of 240 mg element (Ta or I) per kilogram of body weight of TaCZ or iopromide. For each time point, contrast enhancement of the aorta and liver were measured by using regions of interest. Two readers independently recorded the clarity of vasculature using a five-point Likert scale. Findings were compared by using paired t tests and Wilcoxon signed-rank tests. Results Mean peak enhancement was higher for TaCZ than for iopromide in the aorta (270 HU [σ = 24.5] vs 199 HU [σ = 10.2], P < .001) and liver (61.3 HU [σ = 11.7] vs 45.2 HU [σ = 8], P < .001). Vascular clarity was higher for TaCZ than for iopromide in 63% (132 of 208), 82% (170 of 208), and 86% (178 of 208) of the individual vessels at the 102-, 119-, and 137-cm girths, respectively (P < .01). Arterial clarity scores were higher for TaCZ than for iopromide in 62% (208 of 336) of vessels. Venous clarity scores were higher for TaCZ than for iopromide in 89% (128 of 144) of the veins in the venous phase and in 100% (144 of 144) of veins in the delayed phase (P < .01). No vessel showed higher clarity score with iopromide than with TaCZ. Conclusion An experimental tantalum nanoparticle-based contrast agent showed greater contrast enhancement compared with iopromide in swine models meant to simulate overweight and obese patients. © RSNA, 2018.

Septal reduction therapy using nonalcohol agent in hypertrophic obstructive cardiomyopathy: Single center experience.

AIMS: Percutaneous septal reduction therapy by either alcohol or nonalcohol agents is an alternative approach to surgery in drug-refractory symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). Nonalcohol agents have some advantages and disadvantages over alcohol during the procedure. Nowadays, a novel non-alcohol agent, named as Ethylene-vinyl alcohol (EVOH) copolymer (Onyx® and Squid® ), is used during septal ablation. Thus, in this study, we aimed to evaluate both acute and long-term efficacy and safety profile of EVOH during septal ablation in HOCM. METHODS AND RESULTS: A total of 25 patients (52% female; mean age: 55.8 ± 17.1 years) with symptomatic HOCM were enrolled in the study. All subjects underwent clinical and laboratory assessment before and after the procedure. Peak left ventricular outflow tract (LVOT) gradient was significantly reduced just after the procedure (68 vs. 20 mmHg; P < 0.001). Peak serum creatine kinase-myocardial band and troponin I levels were 112 (35-282) ng/ml and 11 (4-93) ng/ml. EVOH embolization to diagonal artery was observed in 1 patient (4%) and the complete atrioventricular block was noted in 2 (8%) patients. During the 12-month follow-up, there was no mortality. There was a significant improvement in New York Heart Association functional class of the subjects P < 0.001). Both interventricular septum thickness and LVOT gradient showed a significant reduction during follow-up (P < 0.05). However, there was no reduction in the LVOT gradient of 3 patients (12%). CONCLUSIONS: In conclusion, our small-sized preliminary study results showed that septal reduction therapy using EVOH is an effective alternative option in reducing symptoms and LVOT gradient in HOCM.

What is the rate of patients undergoing a total hip arthroplasty after core decompression and insertion of a tantalum rod in osteonecrosis of the femoral head: a systematic review.

PURPOSE: Core decompression (CD) may be effective when performed during the early stages of osteonecrosis of the femoral head (ONFH). Tantalum may be added as a rod that would allow putting some mechanical constraints on the femoral head. We aimed to estimate the rate of total hip arthroplasty after CD and insertion of a tantalum rod during early stages of OFNH. METHODS: We searched systematically Medline via PubMed and the Cochrane Library. Our primary endpoint was the rate of patients undergoing a total hip arthroplasty after CD and insertion of a tantalum rod. Secondary endpoints were the delay between the initial surgery and the arthroplasty, the functional improvement, and the rate of complications. RESULTS: We included seven  studies reporting the results of 232 patients (297 hips) that were operated on by CD and insertion of a tantalum rod. At a mean follow-up of 26.97 months, 24.63% of the included hips underwent a hip arthroplasty (6-56%, SD = 17.34%). The mean delay between the initial surgery and the arthroplasty was 14.94 months (10.20-22.90; SD = 5.25), the mean improvement of Harris Hip Score was 27.66 (20.20-36.90; SD = 6.48), and the mean rate of femoral fracture was 2.43% (0-13%, SD = 4.89%). CONCLUSION: CD and insertion of a tantalum rod may represent a solution in order to improve the mechanical support and to give a rate of conversion in arthroplasty that is acceptable.

Real-time computerised tomography assisted porous tantalum implant in ARCO stage I-II non-traumatic osteonecrosis of the femoral head: minimum five-year follow up.

PURPOSES: This study was established to investigate the medium-term clinical effect of real-time CT assisted porous tantalum implant for the treatment of ARCO stage I-II non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: This study comprised 24 ONFH patients (29 hips) who were treated with intra-operative real-time CT accurate rapid positioning assisted drilling decompression, lesion removal and porous tantalum implant. Harris score, VAS score and imaging in pre-operation and follow-up period were recorded. RESULTS: The average operative time and intra-operative blood loss were 72.6 min and 158.8 ml, respectively. The mean follow-up was 5.4 years. No femoral head penetrating, wound infection, and death occurred. Harris and VAS score improved significantly (73.78 vs. 88.11; 7.13 vs. 2.66) at last follow-up (P < 0.05). The functional improvement and pain relief rate was 100% at six months after operation. The effective rate was 86.21% at 12 months after operation and last follow-up. Five pre-operative ARCO stage I hips had no radiographic progress. Meanwhile, four among the 24 ARCO stage II hips progressed into stage III between eight and 12 months after surgery, among which two progressed into stage IV and two remained in stage III at the last follow-up. The average value of Kerboul combined necrotic angle was 263.24°. There was no progress in Kerboul combined necrotic angle among the grades 2 and 3 patients. However, among the six cases at grade 4, four cases with post-operative progress, two patients converted to THA. CONCLUSIONS: Our technique is safety and effective in the treatment of ARCO stage I-II non-traumatic ONFH.

Early and midterm outcomes after transcatheter embolization of type I endoleaks in 25 patients.

OBJECTIVE: This study reports the technical success and follow-up results of transcatheter embolization of type I endoleak (ELI) in 25 patients after endovascular aortic repair (EVAR). METHODS: Twenty-five patients with ELI (20 men, five women; mean age 80 years; range, 64-96 years) underwent embolization of abdominal ELI (23 proximal, 2 distal endoleaks) after EVAR. All patients were unsuitable for standard endovascular methods for treatment of ELI. The average aneurysm sac size before embolization was 8.2 cm (range, 5.3-12.9 cm). The average time between EVAR and endoleak diagnosis was 685 days (range, 1-4220 days) and from endoleak diagnosis to embolization was 27 days (range, 2-94 days). Onyx (ev3 Endovascular, Inc, Plymouth, Minn) alone or with detachable coils was used for embolization. RESULTS: A total of 27 embolization procedures were performed, with two patients having undergone a repeat procedure. Onyx alone was used in 16 cases and Onyx and coils were used in 11. Immediate technical success with complete isolation of the endoleak on completion angiography was achieved in all procedures. Six procedural complications occurred: three puncture site hematomas and three cases of non-target Onyx embolization. None of the complications had long term sequelae. During the follow-up period (average, 311 days; range, 1-1357 days), seven patients (28%) developed endoleak recurrence, and two underwent a second embolization procedure. Of these, one has had no further endoleak recurrence, but the other developed a recurrent endoleak and died of sac rupture. Two of the other five cases of endoleak recurrence were successfully managed by other procedures, one had a persistent endoleak despite aortic cuff placement, and the other two were deemed unsuitable for further intervention. Three of the four patients with persistent endoleaks died of sac rupture. At the average follow-up time of 311 days, freedom from endoleak recurrence was 80%, and freedom from sac growth was 85%. CONCLUSIONS: Transcatheter embolization of ELI offers a safe, feasible, and sustainable treatment option for patients who are unsuitable for standard methods of ELI treatment. Additional coil embolization before Onyx injection may result in better outcome.

Long-term results of intra-arterial onyx injection for type II endoleaks following endovascular aneurysm repair.

Purpose The aim of this paper is to report our experience of type II endoleak treatment after endovascular aneurysm repair with intra-arterial injection of the embolizing liquid material, Onyx liquid embolic system. Methods From 2005 to 2012, we performed a retrospective review of 600 patients, who underwent endovascular repair of an abdominal aortic aneurysm. During this period, 18 patients were treated with Onyx for type II endoleaks. Principal findings The source of the endoleak was the internal iliac artery in seven cases, inferior mesenteric artery in seven cases and lumbar arteries in four cases. Immediate technical success was achieved in all patients and no endoleak from the treated vessel recurred. During a mean follow-up of 19 months, no major morbidity or mortality occurred, and one-year survival was 100%. Conclusions Treatment of type II endoleaks with Onyx is safe and effective over a significant time period.

Development of Dural Arteriovenous Fistulas After Cerebral Venous Sinus Thrombosis.

A 57-year-old man presented with papilledema due to partially recanalized dural sinus thrombosis and was treated with anticoagulation and acetazolamide. One year after treatment and resolution of his symptoms, he had an increase in his optic disc edema accompanied by headaches. Subsequent neuroimaging indicated development of arteriovenous fistulas resulting in cortical and deep venous reflux. Given the high risk of mortality from intracranial hemorrhage, the patient underwent urgent treatment with a liquid embolic agent, which resulted in the resolution of his optic disc edema. Our case is unique in that recurrence of bilateral optic disc edema led to discovery of the rare complication of dural arteriovenous fistulas developing after dural sinus thrombosis. Ongoing monitoring of patients after cerebral venous sinus thrombosis is, therefore, important.

Endovascular Treatment of Two High-Flow Brain Arteriovenous Fistulas with a Combination of Detachable Coils and Onyx in an Infant: Case Report and Review of Literature.

Congenital brain arteriovenous fistulas (BAVFs) are rare neurovascular lesions of the brain, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. Here, we present a case of 2 high-flow BAVFs occurring in a 12-month-old boy. Standard techniques of digital subtraction angiography were used, and dimethyl sulfoxide-compatible microcatheters were delivered and entered into a distal feeding artery as closely as possible to the fistulas. Then, a combination of detachable coils and Onyx was used. After the treatment of the 2 high-flow BAVFs, a complete percutaneous embolization of the fistulas was obtained. The fistulas remained closed, as ascertained by follow-up angiograms. No new neurological deficit related to the procedure was detected, and the infant was asymptomatic and in good health 4 years after the surgery. Our case shows that the endovascular treatment of high-flow BAVFs with a combination of detachable coils and Onyx in an infant is safe and effective.

Novel intravascular tantalum oxide-based contrast agent achieves improved vascular contrast enhancement and conspicuity compared to Iopamidol in an animal multiphase CT protocol.

BACKGROUND: To assess thoracic vascular computed tomography (CT) contrast enhancement of a novel intravenous tantalum oxide nanoparticle contrast agent (carboxybetaine zwitterionic tantalum oxide, TaCZ) compared to a conventional iodinated contrast agent (Iopamidol) in a rabbit multiphase protocol. METHODS: Five rabbits were scanned inside a human-torso-sized encasement on a clinical CT system at various scan delays after intravenous injection of 540 mg element (Ta or I) per kg of bodyweight of TaCZ or Iopamidol. Net contrast enhancement of various arteries and veins, as well as image noise, were measured. Randomized scan series were reviewed by three independent readers on a clinical workstation and assessed for vascular conspicuity and image artifacts on 5-point Likert scales. RESULTS: Overall, net vascular contrast enhancement achieved with TaCZ was superior to Iopamidol (p ≤ 0.036 with the exception of the inferior vena cava at 6 s (p = 0.131). Vascular contrast enhancement achieved with TaCZ at delays of 6 s, 40 s, and 75 s was superior to optimum achieved Iopamidol contrast enhancement at 6 s (p ≤ 0.036. Vascular conspicuity was higher for TaCZ in 269 of 300 (89.7%) arterial and 269 of 300 (89.7%) venous vessel assessments, respectively (p ≤ 0.005), with substantial inter-reader reliability (κ = 0.61; p < 0.001) and strong positive monotonic correlation between conspicuity scores and contrast enhancement measurements (ρ = 0.828; p < 0.001). CONCLUSION: TaCZ provides absolute and relative contrast advantages compared to Iopamidol for improved visualization of thoracic arteries and veins in a multiphase CT protocol. RELEVANCE STATEMENT: The tantalum-oxide nanoparticle is an experimental intravenous CT contrast agent with superior cardiovascular and venous contrast capacity per injected elemental mass in an animal model, providing improved maximum contrast enhancement and prolonged contrast conspicuity. Further translational research on promising high-Z and nanoparticle contrast agents is warranted. KEY POINTS: There have been no major advancements in intravenous CT contrast agents over decades. Iodinated CT contrast agents require optimal timing for angiography and phlebography. Tantalum-oxide demonstrated increased CT attenuation per elemental mass compared to Iopamidol. Nanoparticle contrast agent design facilitates prolonged vascular conspicuity.

Quantification and reduction of reflux during embolotherapy using an antireflux catheter and tantalum microspheres: ex vivo analysis.

PURPOSE: To demonstrate in a porcine model that reflux during embolotherapy can be relatively quantified (ie, as embolization efficiency) and that nontarget embolization can be eliminated by using an antireflux microcatheter. MATERIALS AND METHODS: Renal artery embolization was performed with radiopaque tantalum microspheres (concentration of 1 g/20 mL) in three swine. Second-order right renal arteries (n = 3) underwent embolization with a 3-F antireflux catheter, and second-order left renal arteries (n = 3) underwent embolization with a 4-F end-hole catheter as a control. After embolization, kidneys were explanted and underwent micro-computed tomographic (microCT) imaging. Three-dimensional volumetric and multiplanar imaging of the kidneys was performed to assess vascular distribution. Digital Imaging and Communications in Medicine data were analyzed, with a threshold algorithm used to create binary images. The number of positive values in a region of interest in the target embolized tissue (upper pole or lower pole) and the nontarget adjacent tissue was determined, and embolization efficiency was calculated. Wilcoxon rank-sum statistical analysis was performed to compare nontarget embolization between infusion catheters. RESULTS: All renal arteries underwent successful embolization with tantalum microspheres, with 20 mL (1 g) administered in all dose deliveries. MicroCT provided high-resolution visualization of the renal parenchyma at 70-µm resolution. In control renal arteries, a standard 4-F end-hole catheter had an embolization efficiency of 72%± 13. In experimental renal arteries, the antireflux microcatheter had an embolization efficiency of 99.9%± 1.0 (P< . 05). CONCLUSIONS: A significant decrease in nontarget embolization (ie, reduction in reflux) was possible with an antireflux microcatheter compared with a conventional end-hole catheter.

Transcatheter embolisation of type 1 endoleaks after endovascular aortic aneurysm repair with Onyx: when no other treatment option is feasible.

Type 1 endoleaks following endovascular aortic aneurysm repair are associated with poor outcomes and re-intervention is recommended as soon as possible after diagnosis. When standard endovascular or surgical treatment options are unsuitable due to severe co-morbidity or adverse anatomic factors, patients can be treated by transcatheter embolisation of the endoleak itself. We describe six such patients with proximal and distal type 1 endoleaks, who have been successfully treated by transcatheter embolisation with Onyx. The embolisation technique, advantages of using this relatively novel liquid embolic agent and potential pitfalls are discussed.