Paediatric intracranial dural arteriovenous fistulas: clinical characteristics, treatment outcomes and prognosis

BACKGROUND

Compared with dural arteriovenous fistulas (DAVFs) in adult, paediatric DAVFs are notable for distinct clinical manifestations, low cure rate and poor prognosis. However, due to the limitations of small sample sizes, the long-term prognosis and follow-up data have not been described.

METHODS

Clinical data from 43 consecutive paediatric DAVFs were documented and analysed between 2002 and 2022 at the author's institution. They were divided into infantile (Lasjaunias classification) and non-infantile (adult type and dural sinus malformation (DSM)) type DAVFs based on prognosis differences.

RESULTS

Their mean age at first symptoms was 8.4±6.0 years. 29 boys and 14 girls presented between at birth and 18 years of age. 5 of 10 patients ≤1 year of age presented with asymptomatic cardiomegaly compared with 5/33 patients >1 year of age (p=0.022). 42 (88.4%) patients received endovascular treatment alone, while 9.3% underwent radiosurgery, burr hole embolisation or surgery. 28 (65.1%) patients experienced DAVF obliteration by the end of treatment. Among them, 26 cases underwent embolisation alone, one case had embolisation in conjunction with surgery, and one case underwent burr hole embolisation. The overall complication rate among patients was 9.3%, all resulting from endovascular treatment. According to the Lasjaunias Classification, there were 18 cases of adult type, 17 cases of infantile type and 8 cases of DSM. Compared with non-infantile-type DAVFs, infantile-type DAVFs showed more times of treatment, lower cure rate and worse prognosis (p<0.001, 0.003 and 0.021, respectively). The average follow-up duration was 41.4±36.2 months (3-228 months). 8 (22.9%) patients died.

CONCLUSIONS

Most adult-type DAVFs and DSMs can now be effectively treated with embolisation, resulting in good outcomes and prognosis. However, there are still challenges in treating infantile-type DAVFs, and the prognosis is frequently poor.

'An eye for an eye' therapeutic strategy for cavernous sinus dural arteriovenous fistula: a single-center experience

BACKGROUND

In cavernous sinus dural arteriovenous fistulas (CS-DAVF), ophthalmological symptoms are usually the main clinical presentation, caused by abnormal drainage of the superior ophthalmic vein (SOV). Early opacification of the SOV during cerebral angiography inevitably signifies the fistula's shunt point at the confluence of the SOV and CS. We aimed to leverage this anatomical feature to achieve precise embolization, thereby enhancing the embolization success rate and preventing CS-related symptoms and complications resulting from overpacking.

METHODS

This single-center, case series study was conducted between May 2017 and September 2023, and included the largest sample of CS-DAVF patients treated via the transfemoral vein-SOV approach. We retrospectively reviewed the data of 32 CS-DAVF patients with inferior petrosal sinus (IPS) occlusion.

RESULTS

The study demonstrated an excellent immediate postoperative complete embolization rate (31/32, 97%). Only three patients (3/32, 9%) developed temporary endovascular treatment-related complications. The average operation time was 131.6±61.6 min, with an average of 1.2±1.1 coils and 1.8±1.2 mL Onyx glue used per patient. CS-DAVF-associated ophthalmological symptoms resolved in all patients. We also identified a rare anatomical variation, where 77% of the patients had a facial vein draining into the external jugular vein.

CONCLUSIONS

Transfemoral vein-SOV embolization should be considered a crucial alternative approach in CS-DAVF patients with occluded IPS and predominantly SOV drainage. This approach showed an excellent immediate postoperative complete embolization rate and satisfactory long-term outcomes along with clinical safety. We therefore strongly advocate for this 'an eye for an eye' treatment strategy.

Efficacy and safety of the PHIL embolic agent in the treatment of intracranial dural arteriovenous fistulas: results of the PHIL-dAVF study

BACKGROUND AND PURPOSE

Embolization is the first-line treatment for dural arteriovenous fistulas (dAVF). The precipitating hydrophobic injectable liquid (PHIL) embolic agent is a non-adhesive copolymer with specific features and endovascular behavior. This study assessed its safety and efficacy in a prospective real-life cohort.

METHODS

The PHIL-dAVF study was a prospective single-arm open-label observational multicenter study conducted between October 2017 and November 2019 in 14 European centers. Patients with a single intracranial dAVF intended for PHIL embolization were included. Previously partially treated or multiple dAVFs were excluded. Additional devices and embolic agents were permitted as complementary techniques or second-line strategies. Primary endpoints were functional outcome changes from baseline and complete cure rate at 3-6 months after the last embolization. Safety was assessed by adverse events (AE) incidence.

RESULTS

A total of 67 patients (77 endovascular procedures; 70.1% men, mean age 61±14 years) were included. Most DAVFs were unruptured (71.6%), located in the transverse/sigmoid sinus (53.7%) and Cognard grade III or IV (56.7%). Sixty patients (89.6%) received one single embolization. Additional devices were used in 31.2% of procedures. Complete angiographic cure rate was 86.9% at the 3-6 month DSA follow-up after the last endovascular treatment. At least one AE was recorded in 37.3% of patients during follow-up, of which 52.9% were related to the procedure. The procedural rates of AE and serious AE were 32.5% and 15.6%, respectively. Five AEs were related to PHIL. Transient functional deterioration occurred in three patients (4.5%), all resolved by the last follow-up.

CONCLUSION

The PHIL-dAVF study provides evidence about the efficacy and safety of PHIL in the treatment of intracranial dAVFs, with outcomes comparable to existing liquid embolic agents reported in the literature.

Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas Cognard Type V With Direct Drainage Into the Perimedullary Veins: Case Report and Literature Review

BACKGROUND AND IMPORTANCE

Cognard type V fistula (CVF) is a rare type of dural arteriovenous fistula characterized by spinal perimedullary venous drainage. Owing to the lack of pathognomonic findings, misdiagnosis is common. Patients often undergo multiple spinal angiograms negative for spinal vascular malformations. Digital subtraction angiography is the gold standard diagnostic tool. The preferred treatment option is endovascular management with embolization through a transarterial, transvenous, or combined approach. Other options include open surgery, stereotactic radiosurgery, or a combination of both.

CLINICAL PRESENTATION

The patient from case # 1 presented with progressive weakness and hypoesthesia in the bilateral lower extremities, with urinary and bowel incontinence. The DSA identified a CVF fed by the meningohypophyseal trunk and a draining perimedullary vein. Embolization with 0.1 ccs of Onyx-18 was performed with complete fistula occlusion. The patient from case # 2 developed bilateral lower extremity weakness, diffuse numbness, and urinary incontinence. The DSA showed a CVF fed by tributaries from the ascending pharyngeal artery and posterior meningeal artery branches of the V3 segment, draining into a perimedullary vein. Embolization with 0.3 cc of Onyx-18 was performed with 100% occlusion of the fistula. A 1-year follow-up angiogram confirmed complete fistula occlusion. Both patients consented to the procedure.

CONCLUSION

Even if a patient only presents symptoms of myelopathy, CVF should be considered. Herein, we present 2 cases of CVF with direct drainage into the perimedullary veins which presented exclusively with myelopathy syndrome and describe treatment with trasarterial embolization with Onyx.

Bailout using NBCA for incomplete onyx embolization of tentorial dural arteriovenous fistula

Transarterial embolization using Onyx (Medtronic, Irvine, CA, USA) results in a high cure rate for complete obliteration of dural arteriovenous fistulas. However, incomplete obliteration occurs in some cases. Reports on the use of bailout therapy in such cases are limited. A 79-year-old man was diagnosed with Borden type III tentorial dural arteriovenous fistulas during a check-up for a headache. We first performed transarterial embolization with Onyx from a tentorial artery, but the fistula was not completely obliterated. We then performed an additional transarterial embolization with n-butyl-2-cyanoacrylate from the same artery in a single session, and the fistula was successfully bailed out, resulting in complete obliteration. Combining different liquid embolic materials, Onyx and n-butyl-2-cyanoacrylate, is an effective strategy for achieving complete obliteration in incomplete transarterial embolization treatment of dural arteriovenous fistulas.

Safety and efficacy of newer liquid embolic agents Squid and PHIL in endovascular embolization of cerebral arteriovenous malformations and dural arteriovenous fistulas: A systematic review and meta-analysis

BACKGROUND

A wide range of liquid embolic agents has been used in endovascular treatment (EVT) of dural arteriovenous fistulas (dAVFs) and cerebral arteriovenous malformations (cAVMs). Newer liquid embolics, Squid (Balt) and PHIL (MicroVention), aim to improve the safety and efficacy of EVT of dAVFs and cAVMs.

OBJECTIVE

To assess the safety and efficacy of EVT of cAVMs and dAVFs using Squid or PHIL as an embolic agent.

METHODS

We searched major databases following PRISMA guidelines and included studies with ≥ five patients reporting on EVT of dAVFs and/or cAVMs using Squid or PHIL as embolic agent. We analyzed efficacy outcomes including complete occlusion, incomplete occlusion, and recurrence at follow up, and safety outcomes including procedure-related complications, morbidity, and mortality with a random-effects meta-analysis. Separate analyses were performed for cAVMs and dAVFs. Subanalyses were conducted for studies exclusively utilizing PHIL and those exclusively utilizing Squid, for both cAVMs and dAVFs.

RESULTS

Ten studies, comprising 214 patients (53.7% male), were found. Of these, 113 patients had 113 dAVFs, while 101 patients had 101 cAVMs. Complete occlusion rates following embolization were 91% for dAVFs and 32% for cAVMs. A subanalysis of dAVFs embolized solely with Squid and PHIL identified 93% and 86% complete occlusion rates, respectively. The overall procedure-related permanent morbidity rate was 3% for dAVFs and 7% for cAVMs. There was only one procedure-related mortality, which developed in a cAVM case, across 214 cases.

CONCLUSION

Squid and PHIL are safe and effective embolic agents for treatment of dAVFs and cAVMs.

Comparison of a Novel Liquid Embolic System with Commonly Used Embolic Agents in the Endovascular Treatment of Intracranial Dural Arteriovenous Fistulas: A Single-Center Experience

Background/Objectives: Endovascular embolization is an effective treatment option for cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (DAVFs). The objective of this study was to assess the safety and efficacy of MenoxTM in patients with cranial dural arteriovenous fistulas. Methods: From January 2021 to January 2023, 19 patients with intracranial DAVFs underwent embolization procedures. All patients were treated by embolization with MenoxTM or/and in combination with other embolization products such as Onyx (Covidien, Irvine, California), PHIL (MicroVention, Tustin, California), and Squid (Balt Extrusion, Montmorency, France). Treatment approaches were selected depending on the anatomical location of the fistula. Patients were monitored and followed-up for 12 months. Results: The patients' mean age was 56.26 ± 16.49 years. Of these 19 patients, 58% (n = 11) were treated with the MenoxTM liquid embolizing agent (LEA) alone or in combination with different LEAs, while n = 7 were treated with other LEAs and 1 patient was treated solely with coils. Complete occlusion of DAVFs with MenoxTM and other agents was evident in 68.4% (n = 13/19) of patients. Complete occlusion (100%) was observed in the sinus rectus, transverse sinus, and diploic veins of the orbital roof, while complete occlusion was observed in 50% of falcotentorial patients and 60% of superior sagittal sinus patients. The lowest rate of complete fistula obliteration was observed in the dural carotid cavernous fistula (CCF) group (25%). An intra-procedural adverse event occurred in one patient. No other post-procedural adverse events were noted. Furthermore, in patients treated with MenoxTM, total occlusion was achieved in 72.7% (n = 8) of patients, whereas the non-MenoxTM group had 62.5% (n = 5) of patients with 100% occlusion and 37.5% (n = 3) of patients with subtotal occlusion. Conclusions: Outcomes using MenoxTM alone and in combination with other agents were effective, and it is safe for the treatment of dural arteriovenous fistulas.

Transarterial embolization in non-cavernous and cavernous sinus dural arteriovenous fistulas: A systematic review and meta-analysis of proportions

BACKGROUND

Transarterial embolization (TAE) is pivotal in managing non-cavernous and cavernous sinus dural arteriovenous fistulas (CSDAVFs).

METHODS

Systematic searches were conducted across ScienceDirect, Medline, and Cochrane databases for longitudinal studies on TAE outcomes in non-CSDAVFs and CSDAVFs. Post-procedural outcomes, including complete, incomplete, and failed AVFs obliteration, and end-study outcomes were analyzed.

RESULTS

Our meta-analysis involved 27 studies with 643 patients and 736 fistulas. Symptoms in both groups included tinnitus (29.74 %), ocular/visual symptoms (29.12 %), hemorrhage (19.42 %), and headache (19.11 %). Feeding arteries mainly originated from the meningeal arteries (49.16 %). In non-CSDAVFs cases, fistula locations were within sinus complexes (69.23 %) and specific dural areas (28.31 %). Complete AVFs obliteration was 81 % (95 %CI: 70 % - 90 %), slightly higher in non-CSDAVFs (82 %, 95 % CI: 69 % - 92 %) than CSDAVFs (79 %, 95 %CI: 58 % - 95 %). Incomplete obliteration occurred in 14 % (95 %CI: 5 % - 39 %), with rates of 11 % (95 %CI: 2 % - 26 %) in non-CSDAVFs and 19 % (95 % CI: 5 % - 39 %) in CSDAVFs. Failed obliteration was rare (1 %, 95 %CI: 0 % - 3 %), with similar rates in both groups. At end-study follow-up, resolution of AVFs was achieved in 97 % of cases (95 %CI: 92 % - 100 %). However, complications occurred in 17 % of cases (95 %CI: 10 % - 25 %), with a higher incidence in CSDAVFs (22 %, 95 %CI: 9 % - 37 %) compared to non-CSDAVFs (13 %, 95 %CI: 6 % - 23 %).

CONCLUSIONS

TAE with embolic agents demonstrates favorable outcomes in non-CSDAVFs and CSDAVFs, with high rates of AVFs obliteration and resolution. Complications, particularly in CSDAVFs, warrant careful consideration in treatment decisions.

Initial clinical experience with N-hexyl cyanoacrylate for neuroendovascular embolization

OBJECTIVE

To report our initial clinical experience with N-hexyl cyanoacrylate (NHCA), a novel liquid agent for neurovascular embolization.

METHODS

Four paragangliomas were treated with percutaneous embolization using NHCA as the sole embolic material. In one dural arteriovenous fistula (dAVF), NHCA was used in combination with other embolic materials. Procedural specifics, complications and angiographic results were retrospectively evaluated.

RESULTS

Total or subtotal devascularization was obtained in 3 of the 4 paragangliomas. In the largest tumor, only partial devascularization could be achieved. The dAVF was completely occluded. Catheter entrapment did not occur. After dAVF treatment, the patient had an asymptomatic lacunar infarction, while there was no procedural morbidity related to paraganglioma treatment.

CONCLUSIONS

In this series, neurovascular embolization with NHCA was feasible and effective. It may be particularly beneficial for small and tortuous vessels that require low-profile catheterization and a slow and controlled polymerization. Further studies are necessary to prove the benefits of NHCA over established embolic agents.

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.

A First-in-Human Trial of a New Aqueous Ionic Liquid Embolic Material in Distal Embolization Applications

PURPOSE

A prospective, single-arm, open-label, multicenter, first-in-human, early feasibility study was completed to evaluate the safety and performance of the GPX Embolic Device (Fluidx, Salt Lake City, Utah), a novel liquid embolic agent, for use in the peripheral vasculature when deep distal embolization is desired.

MATERIALS AND METHODS

The early feasibility study evaluated the use of the device in the peripheral vasculature. Enrollment consisted of 17 patients with diverse embolization needs requiring deep distal vessel/vessel bed occlusion. Technical success, freedom from adverse events (AEs), and handling/performance characteristics were assessed with follow-up at 30 days.

RESULTS

The trial enrolled 17 patients requiring distal vascular penetration of the embolic agent, including 7 with renal angiomyolipomas, 4 with renal cell carcinomas (primary and secondary), 4 with portal veins needing embolization, 1 with pelvic sarcoma, and 1 with polycystic kidney. In all cases (100%), technical success was achieved with target regions fully occluded on the first angiogram (taken immediately after delivery). Furthermore, the material received high usability ratings, as measured by a postprocedural investigator questionnaire. Most patients (15/17, 88.2%) were free from device-related severe AEs, and there were no unanticipated AEs during the study. Each patient completed a 30-day follow-up evaluation, and sites remained fully occluded in each case where imaging was available (6 [35.3%] of 17 patients had follow-up imaging where all sites were deemed occluded [100%] with a mean of 30.2 days after the procedure).

CONCLUSIONS

The results of this first-in-human, early feasibility study demonstrate that the GPX Embolic Device may provide safe and effective embolization for arterial or venous applications where deep distal penetration is desired.

LIQUID - Treatment of high-grade dural arteriovenous fistulas with Squid liquid embolic agent: a prospective, observational multicenter study

BACKGROUND

Endovascular embolization is a feasible treatment for cranial dural arteriovenous fistulas (DAVFs). New embolic agents aim to improve the success of DAVF embolization.

OBJECTIVE

To assess the safety, efficacy, and short-term outcome of the treatment of DAVFs using the new liquid embolic agent Squid.

METHODS

The LIQUID study is a prospective, observational multicenter study on the treatment of high-grade (Cognard type ≥3) DAVFs with the embolic agent Squid. The primary outcome measures were safety (ie, morbidity and mortality), as well as the occlusion rate 90 to 180 days after treatment.

RESULTS

In eight centers, 53 patients (mean age 59.8 years, 22.6% female) were treated in 55 treatment sessions. Of the DAVFs, 56.6% were Cognard type III, 41.5% type IV, and 18.9% were ruptured. Squid 18 was used in 83.6% and Squid 12 in 32.7% of the treatments. The overall rate of intraprocedural or postprocedural adverse events (AEs) was 18.2%. Procedure-related AEs resulting in permanent morbidity were observed in 3.6%. One patient (1.8%) died unrelated to the procedure due to pulmonary embolism. The final complete occlusion rate at 90 to 180 days was 93.2%. After a mean follow-up of 5.5 months, the modified Rankin Scale (mRS) score was stable or improved in 93.0%. In one of the patients, worsening of the mRS score was related to the procedure (1.8%).

CONCLUSION

Squid is a safe and effective liquid embolic agent for the treatment of high-grade DAVFs.

Copolymer liquid embolization of dural arteriovenous fistulas: A 20-year single-center experience

BACKGROUND AND PURPOSE

Dural arteriovenous fistulas (DAVFs) with cortical venous drainage (CVD) carry significant risks of cerebral ischemia and intracranial hemorrhage. Endovascular treatment (EVT) using Onyx, a copolymer-based liquid embolic material, has become the preferred approach. However, the optimal treatment strategy for anterior cranial fossa DAVFs remains debated.

METHODS

This retrospective study analyzed outcomes of EVT for DAVFs in a single center from 2002 to 2023. Patient data including demographics, clinical status, angiographic findings, embolization techniques, and outcomes were recorded. The results of the anterior fossa malformations were analyzed separately afterward.

RESULTS

A total of 195 DAVFs were included in the study. The most common presenting symptom was hemorrhage (41%), most fistulas were located in the transverse and sigmoid sinus region (48%), and the majority of DAVFs had direct CVD (78%). Transarterial embolization with Onyx was the preferred treatment strategy in majority of cases (92%). Overall, 94% of patients showed improvement or stability on the modified Rankin Scale. Two patients died due to rebleeding after partial DAVF embolization. Onyx demonstrated higher immediate complete occlusion rate compared to other embolic materials (88% vs. 35%). Overall, 91% of fistulas were closed at the last follow-up. Ten anterior fossa DAVFs were treated, resulting in clinical improvement and complete occlusion in all cases.

CONCLUSION

Based on the results of our study, we believe that a cure of DAVFs, including those in the anterior fossa, can be achieved in more than 90% of cases through transarterial Onyx embolization, given long-term clinical experience.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Endovascular Treatment of Borden Type III Transverse-sigmoid Sinus Dural Arteriovenous Fistulas: a Single-center 12-year Experience

PURPOSE

The objective of this study was to evaluate our 12-year experience in treating Borden type III transverse-sigmoid sinus (TSS) dural arteriovenous fistulas (DAVFs) and discuss the technical aspects of ipsilateral and contralateral transvenous embolization (TVE) approaches.

METHODS

We retrospectively reviewed charts of consecutive patients with TSS DAVF treated with multimodal treatment between April 2008 and March 2020. The baseline patient characteristics, imaging data, details of procedure, data sets of sinus pressure monitoring, and clinical results were systematically collected.

RESULTS

Of 44 patients with TSS DAVF who were treated during study periods, 23 patients of Borden type III were extracted. Among the 23 patients, 18 with transfemoral TVE were included for analysis. TVE was performed using an ipsilateral approach in 8 patients and a contralateral approach in 10. Pressure monitoring data revealed that initial mean sinus pressure (43.5 mmHg vs. 29.5 mmHg; P = 0.033), maximum sinus pressure during the procedure (69.0 mmHg vs. 40.5 mmHg; P = 0.011), and sinus pressure gradient (22.5 mmHg vs. 5.5 mmHg; P = 0.021) were significantly higher in the ipsilateral approach group. The complete obliteration rate by primary embolization was 94% in our cohort with the recurrence rate of 5.6% with a median follow-up period of 57 months.

CONCLUSION

Our study showed the durability of TVE for patients with Borden type III TSS DAVF. TVE performed via the contralateral approach might prevent a potentially dangerous increase in intraprocedural sinus pressure and cortical venous reflux.

Middle meningeal artery: An effective pathway for achieving complete obliteration following transarterial Ethylene Vinyl Copolymer (Onyx) embolization of dural arteriovenous fistulas

Objective

Transarterial Onyx embolization is the mainstay of intracranial non-cavernous dural arteriovenous fistulas (dAVFs) treatment. Although the dural arterial supply varies depending on the location, the impact of arterial access on treatment outcomes has remained unclear. The aim of this study was to characterize factors as sociated with complete obliteration following transarterial Onyx embolization, with a special focus on arterial access routes and dAVF location.

Methods

A retrospective analysis of the patients who underwent transarterial Onyx embolization for intracranial dAVFs at two academic institutions was performed. Patients with angiographic follow-up were considered eligible to investigate the impact of the arterial access on achieving complete obliteration.

Results

Sixty-eight patients underwent transarterial Onyx embolization of intracranial dAVFs. Complete obliteration was achieved in 65% of all treated patients and in 75% of those with cortical venous reflux. Multivariable analysis identified middle meningeal artery (MMA) access to be a significant independent predictive factor for complete obliteration (OR, 2.32; 95% CI, 1.06-5.06; p=0.034). Subgroup analysis showed that supratentorial and lateral cerebellar convexity dAVFs (OR, 5.72, 95% CI, 1.89-17.33, p=0.002), and Borden type III classification at pre-treatment (OR, 3.13, 95% CI, 1.05- 9.35, p=0.041), were independent predictive factors for complete obliteration following embolization through the MMA.

Conclusions

MMA access is an independent predictive factor for complete obliteration following transarterial Onyx embolization for intracranial non-cavernous dAVFs. It is particularly effective for supratentorial and lateral cerebellar convexity dAVFs and those that are Borden type III.

Analysis of the Pial Arterial Supply as a Cause of Intraprocedural Hemorrhage During Transarterial Liquid Embolization of Tentorial Dural Arteriovenous Fistulas

OBJECTIVE

Tentorial dural arteriovenous fistulas (AVFs) are bridging vein shunts, and are therefore sometimes supplied by the pial artery as well as the dural artery. Recently, intraprocedural hemorrhage from the pial artery was reported, and we experienced 2 tentorial dural AVFs with the same complication. Pure pial artery has a glomus-like structure and forms direct shunts along the draining vein, and is likely to bleed after restriction of the draining vein caused by the transarterial embolization. This study investigated the characteristics of the pial arterial supply as a cause of hemorrhage.

METHODS

Twenty-six tentorial dural AVFs in 25 patients treated in our institute were retrospectively investigated and the characteristics of the pial feeders responsible for bleeding were analyzed.

RESULTS

Thirteen pial arterial feeders (pure pial feeder in 7, dilated dural branch of the pial artery in 4, and undefined in 2) were identified in 10 of the 26 tentorial dural AVFs. Pure pial feeders were responsible for bleeding in 2 tentorial dural AVFs.

CONCLUSIONS

To prevent intraprocedural hemorrhage, differentiation of the pure pial supply from the dural branch of the pial artery is important. The infratentorial artery will supply supratentorial fistula as the dural branch after passing through the tentorium. In contrast, the supratentorial artery can supply supratentorial fistula not only as a dural branch but also as a pure pial feeder. Therefore, attribution of the fistula and the pial supply, supratentorial or infratentorial, is useful in identifying pure pial supply.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas: A Systematic Review and Meta-Analysis and International Stereotactic Radiosurgery Society Practice Guidelines

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are often treated with stereotactic radiosurgery (SRS) to achieve complete obliteration (CO), prevent future hemorrhages, and ameliorate neurological symptoms.

OBJECTIVE

To summarize outcomes after SRS for dAVFs and propose relevant practice recommendations.

METHODS

Using a PICOS/PRISMA/MOOSE protocol, we included patients with dAVFs treated with SRS and data for at least one of the outcomes of the study. Relevant outcomes were CO, symptom improvement and cure, and post-SRS hemorrhage or permanent neurological deficits (PNDs). Estimated outcome effect sizes were determined using weighted random-effects meta-analyses using DerSimonian and Laird methods. To assess potential relationships between patient and lesion characteristics and clinical outcomes, mixed-effects weighted regression models were used.

RESULTS

Across 21 published studies, we identified 705 patients with 721 dAVFs treated with SRS. The CO rate was 68.6% (95% CI 60.7%-76.5%) with symptom improvement and cure rates of 97.2% (95% CI 93.2%-100%) and 78.8% (95% CI 69.3%-88.2%), respectively. Estimated incidences of post-SRS hemorrhage and PNDs were 1.1% (95% CI 0.6%-1.6%) and 1.3% (95% CI 0.8%-1.8%), respectively. Noncavernous sinus (NCS) dAVFs were associated with lower CO (P = .03) and symptom cure rates (P = .001). Higher grade was also associated with lower symptom cure rates (P = .04), whereas previous embolization was associated with higher symptom cure rates (P = .01).

CONCLUSION

SRS for dAVFs results in CO in the majority of patients with excellent symptom improvement rates with minimal toxicity. Patients with NCS and/or higher-grade dAVFs have poorer symptom cure rates. Combined therapy with embolization and SRS is recommended when feasible for clinically aggressive dAVFs or those refractory to embolization to maximize the likelihood of symptom cure.

Feasibility of Metal Artifact Reduction on CT Angiography for Planning Direct Surgery of Tentorial dAVF after Onyx Embolization

Although Onyx is approved as an embolic material for arteriovenous malformation (AVM) and dural arteriovenous fistula (dAVF), metal artifacts due to Onyx on CT remain problematic. We report the feasibility of a metal artifact reduction (MAR) algorithm on CT angiography (CTA) in the planning of direct surgery of dAVF after transarterial Onyx embolization. A 45-year-old male patient presented with right pulsatile tinnitus, and cerebral angiography demonstrated right tentorial dAVF. As the dAVF had not completely disappeared even after Onyx transarterial embolization, we planned direct surgery. Evaluation of the lesion was difficult on normal preoperative CTA because of Onyx artifacts, but CTA using MAR enabled a detailed planning of direct surgery. Direct surgery was performed through right retrosigmoid craniotomy. Referencing CTA using MAR, we identified the draining veins originating from the main drainer, which were coagulated and cut, achieving complete occlusion of the dAVF. His symptoms disappeared with no postoperative complications. CT angiography using MAR was useful for planning direct surgery after Onyx embolization. As the incidence of direct surgery after transarterial Onyx embolization for AVM or dAVF is increasing, MAR on CTA will become more important.

Intervention for unruptured high-grade intracranial dural arteriovenous fistulas: a multicenter study

OBJECTIVE

The risk-to-benefit profile of treating an unruptured high-grade dural arteriovenous fistula (dAVF) is not clearly defined. The aim of this multicenter retrospective cohort study was to compare the outcomes of different interventions with observation for unruptured high-grade dAVFs.

METHODS

The authors retrospectively reviewed dAVF patients from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with unruptured high-grade (Borden type II or III) dAVFs were included and categorized into four groups (observation, embolization, surgery, and stereotactic radiosurgery [SRS]) based on the initial management. The primary outcome was defined as the modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were good outcome (mRS scores 0-2) at final follow-up, symptomatic improvement, all-cause mortality, and dAVF obliteration. The outcomes of each intervention group were compared against those of the observation group as a reference, with adjustment for differences in baseline characteristics.

RESULTS

The study included 415 dAVF patients, accounting for 29, 324, 43, and 19 in the observation, embolization, surgery, and SRS groups, respectively. The mean radiological and clinical follow-up durations were 21 and 25 months, respectively. Functional outcomes were similar for embolization, surgery, and SRS compared with observation. With observation as a reference, obliteration rates were higher after embolization (adjusted OR [aOR] 7.147, p = 0.010) and surgery (aOR 33.803, p < 0.001) and all-cause mortality was lower after embolization (imputed, aOR 0.171, p = 0.040). Hemorrhage rates per 1000 patient-years were 101 for observation versus 9, 22, and 0 for embolization (p = 0.022), surgery (p = 0.245), and SRS (p = 0.077), respectively. Nonhemorrhagic neurological deficit rates were similar between each intervention group versus observation.

CONCLUSIONS

Embolization and surgery for unruptured high-grade dAVFs afforded a greater likelihood of obliteration than did observation. Embolization also reduced the risk of death and dAVF-associated hemorrhage compared with conservative management over a modest follow-up period. These findings support embolization as the first-line treatment of choice for appropriately selected unruptured Borden type II and III dAVFs.

Glue, Onyx, Squid or PHIL? Liquid Embolic Agents for the Embolization of Cerebral Arteriovenous Malformations and Dural Arteriovenous Fistulas

Background

Endovascular embolization is an effective treatment option for cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs). A variety of liquid embolic agents have been and are currently used for embolization of AVMs and DAVFs. Knowledge of the special properties of the agent which is used is crucial for an effective and safe embolization procedure.

Material and Methods

This article describes the properties and indications of the liquid embolic agents which are currently available: cyanoacrylates (also called glues), and the copolymers Onyx, Squid and PHIL, as well as their respective subtypes.

Results

Cyanoacrylates were the predominantly used agents in the 1980s and 1990s. They are currently still used in specific situations, for example for the occlusion of macro-shunts, for the pressure cooker technique or in cases in which microcatheters are used that are not compatible with dimethyl-sulfoxide. The first broadly used copolymer-based embolic agent Onyx benefits from a large amount of available experience and data, which demonstrated its safety and efficacy in the treatment of cerebral vascular malformations, while its drawbacks include temporary loss of visibility during longer injections and artifacts in cross-sectional imaging. The more recently introduced agents Squid and PHIL aim to overcome these shortcomings and to improve the success rate of endovascular embolization. Novelties of these newer agents with potential advantages include extra-low viscosity versions, more stable visibility, and a lower degree of imaging artifacts.

Conclusion

All the available liquid embolic agents feature specific potential advantages and disadvantages over each other. The choice of the most appropriate embolic agent must be made based on the specific material characteristics of the agent, related to the specific anatomical characteristics of the target pathology.

Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas

BACKGROUND

Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial.

OBJECTIVE

To compare the outcomes of observation versus intervention for low-grade dAVFs.

METHODS

We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up.

RESULTS

The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively.

CONCLUSION

Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Long-term stability of Onyx: is there any indication for repeated angiography after dural arteriovenous fistula embolization?

OBJECTIVE

The natural course of dural arteriovenous fistulas (DAVFs) is unfavorable. Transarterial embolization with Onyx is currently the therapeutic method of choice, although the long-term stability of Onyx has been questioned. The literature reports a significant difference in the recurrence rate after complete DAVF occlusion and lacks larger series with long-term follow-up. The authors present the largest series to date with a long-term follow-up to determine the stability of Onyx, prospectively comparing magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) as follow-up diagnostic methods.

METHODS

Demographics, clinical symptomatology, length of follow-up, diagnostic methods, and angiographic findings of DAVFs were recorded and retrospectively evaluated in 112 patients. A prospective group of 15 patients with more than 5 years of follow-up after complete DAVF occlusion was established. All 15 patients in the prospective group underwent a clinical examination and MRA; 10 of these patients also underwent DSA. The recurrences and the correlation between the two diagnostic methods were evaluated.

RESULTS

Among the 112 patients, 71 were men and 41 were women, with an average age of 60 years. Intracranial hemorrhage (40%) was the most common clinical presentation of DAVF. At the last follow-up, 73% of the patients experienced clinical improvement, 21% remained unchanged, and 6% worsened. Overall, 87.5% of the DAVFs were occluded entirely with endovascular treatment, and 93% of the DAVFs were classified as cured at the last follow-up (i.e., completely embolized DAVFs and DAVFs that thrombosed spontaneously or after Gamma Knife surgery). Two recurrences of DAVFs were recorded in the entire series. Both were first diagnosed by MRA and confirmed with DSA. The mean follow-up was 27.7 months. In the prospective group, a small asymptomatic recurrence was diagnosed. The mean follow-up of the prospective group was 96 months.

CONCLUSIONS

Onyx is a stable embolic material, although recurrence of seemingly completely occluded DAVFs may develop because of postembolization hemodynamic changes that accentuate primarily graphically absent residual fistula. These residuals can be diagnosed with MRA at follow-up. The authors' data suggest that MRA could be sufficient as the follow-up diagnostic method after complete DAVF occlusion with Onyx. However, larger prospective studies on this topic are needed.

Role of Surgical Intervention for Intracranial Dural Arteriovenous Fistulas With Cortical Venous Drainage in an Endovascular Era: A Case Series

BACKGROUND

Intracranial dural arteriovenous fistulae (dAVFs) with cortical venous drainage (CVD) require treatment because of their aggressive clinical presentation and natural history. Although endovascular treatment is effective for the majority of these lesions in the current endovascular era, surgical management has been required if the lesions are not amenable to or fail endovascular treatments.

OBJECTIVE

To demonstrate the angioarchitecture that may necessitate surgical intervention.

METHODS

A retrospective review of the patients with intracranial dAVFs with CVD treated at 2 academic institutions between January 1, 2009, and July 31, 2019 was performed. Patients who required surgical intervention were selected in this study, and angiographic findings were analyzed.

RESULTS

A total of 81 dAVFs in 80 patients were treated during the study period. Endovascular treatments were attempted for 72 (88.9%) dAVFs, resulting in complete obliteration in 55 (76.4%). Surgical interventions were performed in 18 (22.2%) dAVFs, resulting in complete obliteration in all lesions. Overall, complete obliteration was achieved in 74 (93.7%) of 79 dAVFs with follow-up. In the surgically treated dAVFs, curative transarterial embolization was deterred by the angioarchitecture, which included dominant feeding vessels from the ophthalmic artery, meningohypophyseal trunk, posterior meningeal artery, pial artery, or ascending pharyngeal artery. Drainage through tortuous cortical vein, deep venous system, or isolated sinus made transvenous approach challenging.

CONCLUSION

Despite continued improvement in endovascular technology, surgical approaches to dAVFs are still of great value as initial and salvage treatment of dAVFs with angioarchitecture hampering endovascular treatment.

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.

A Case of Dural Arteriovenous Fistula in the Falx with Prominent Falcine Venous Plexus

Objective

The falx cerebri is known to have venous plexuses. Although some cases of dural arteriovenous fistula (DAVF) associated with falcine sinus have been reported, DAVF in the falx with prominent falcine venous plexus has not previously been reported.

Case Presentation

A 59-year-old male was hospitalized with head trauma. MRI incidentally showed a possible occipital DAVF. CTA and DSA revealed a DAVF in the flax with prominent falcine venous plexus. We performed a selective transarterial embolization with glue and particle, obtaining a complete occlusion of the fistula.

Conclusion

We report a rare case of DAVF in the flax with prominent falcine venous plexus that was successfully treated by a transarterial embolization.

A comparison of dual-lumen balloon and simple microcatheters in the embolization of DAVFs and AVMs using onyx

Endovascular embolization of arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) has become the mainstay in treatment for these pathologies. Traditional techniques required the formation of a proximal plug of Onyx around the microcatheter prior to embolization to avoid reflux. Recently, dual-lumen balloon catheters have been introduced as a potential solution to this issue. We sought to compare our institutional experience with dual-lumen balloons to traditional microcatheters in the endovascular embolization of AVMs and DAVFs. A retrospective analysis of consecutive patients treated with Scepter between 2016 and 2020 was obtained. A control cohort treated with Marathon between 2012 and 2020 was also obtained. Variables collected included patient demographics, procedure times, pedicles treated, operative complications, obliteration rate, and retreatment rate. A total of 44 trial (30 DAVFs and 14 AVMs) and 25 control (15 DAVFs and 10 AVMs) subjects were identified. Average Scepter procedure times were 66.0 and 68.0 min for DAVFs and AVMs, respectively. Average Scepter volume of Onyx injected was 2.2 and 1.4 mL for DAVFs and AVMs, respectively. Complete angiographic occlusion Scepter rate was 86.7% and 50.0% for DAVFs and AVMs, respectively. The Scepter retreatment rate was 13.3% and 50.0% for DAVFs and AVMs, respectively. Predictors of angiographic occlusion included the number of pedicles (OR 0.54, 95%CI 0.30-0.97, p = 0.04). Predictors of retreatment included DAVF (OR 0.16, 95%CI 0.04-0.66, p = 0.01) and Marathon (OR 3.34, 95%CI 1.00-11.56, p = 0.05). Our study shows that dual-lumen balloon catheters are a viable option in the embolization of DAVFs and AVMs.

Long-term follow-up of transarterial balloon-assisted Onyx embolization for endovascular treatment of dural arteriovenous fistulas: A single-institution case series and literature review

OBJECTIVE

Dural arteriovenous fistulas (DAVFs)-specifically, symptomatic DAVFs with cortical venous reflux-are aggressive lesions with a poor prognosis. Intra-arterial endovascular closure is considered the optional treatment for DAVFs and is currently performed at several international centers. However, long-term outcomes remain unknown. This study investigated the long-term efficacy and safety of transarterial balloon-assisted Onyx embolization in the treatment of DAVFs.

METHODS

A total of 14 consecutive patients who underwent endovascular treatment for DAVFs were treated by balloon-assisted Onyx embolization. Additionally, we retrospectively reviewed all cases reported in the literature and compared the outcomes of patients treated with single- vs dual-lumen microcatheters.

RESULTS

The patients at our institution were followed-up for 114.57 ± 33.52 months. Embolization was performed by balloon-assisted Onyx injection via a single feeding artery. Complete occlusion was achieved in 13 cases and partial occlusion in 1 case. At the final follow-up, all patients were functionally independent (Modified Rankin Scale score of 0-2), with no recurrence. In our review of 70 published cases of DAVFs that underwent endovascular treatment by balloon-assisted Onyx embolization, single- and dual-lumen balloon catheters were used in 33 and 37 patients, respectively. In the former group, there was complete or near-complete occlusion in 32 cases and partial occlusion in 1 case; and in the latter, there was complete or near-complete occlusion in 35 cases and partial occlusion in 2 cases. There were no deaths following endovascular treatment.

CONCLUSION

Measurable and durable outcomes can be achieved by endovascular treatment of DAVFs with the transarterial balloon-assisted Onyx embolization technique, especially in cases with small, distal, and circuitous feeding arteries.

Hemorrhagic risk factors of endovascular onyx embolization of intracranial dural arteriovenous fistulas

BACKGROUND AND PURPOSE

Hemorrhagic complication is a disastrous complication of intracranial dural arteriovenous fistulas (DAVFs) embolization. This study was to analyze the possible risk factors for the hemorrhagic complication caused by endovascular embolization of DAVFs.

METHODS

From January 2012 to July 2016, a total of 267 patients with intracranial DAVFs received endovascular Onyx embolization at our hospital. The demographic information, clinical presentation, angiographic features, endovascular treatment and hemorrhagic complications were reviewed. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors contributing to the post-procedural hemorrhagic complications.

RESULTS

In 267 patients of DAVF treated with endovascular embolization, procedure-related hemorrhagic complication occurred in 12 (4.5%) patients. Univariate and multivariate logistic regression analyses showed that the pial arterial supplier (OR 13.630; 95% CI, 1.556-119.368; P = 0.018), giant venous aneurysm (OR 15.196; 95% CI, 2.505-92.183; P = 0.003) and Onyx volume ≥ 6 ml (OR 1.138; 95% CI, 1.006-1.288; P = 0.040) were significant factors associated with these hemorrhagic complications.

CONCLUSIONS

Hemorrhagic complications associated with endovascular DAVF embolization are not negligible. The pial arterial supplier, giant venous aneurysm and higher Onyx volume in one session may be risk factors for endovascular DAVF embolization.

Endovascular treatment of cerebral dural arteriovenous fistulas with SQUID 12

BACKGROUND

Endovascular therapy with liquid embolic agents (LEAs) is the gold standard for the treatment of cerebral dural arteriovenous fistulas (cDAVFs). The aim of the study is to retrospectively evaluate effectiveness, safety, and midterm follow-up results of endovascular treatment of cDAVFs using SQUID 12.

METHODS

Between June 2017 and January 2020 the authors retrospectively reviewed clinical, demographic and embolization data of 19 consecutive patients with cDAVF who underwent embolization using SQUID 12. The number of arteries catheterized for each procedure, the total amount of embolic agent, the occlusion rate, the injection time, any technical and/or clinical complications were recorded. Mid-term follow-up with DSA was reviewed.

RESULTS

20 procedures were performed in 19 patients. A transarterial approach was accomplished in 19 procedure; a combined transvenous-transarterial approach was realized in 1 treatment. The average time of injection was 33 minutes (2-82 minutes), and the average amount of SQUID 12 was 2.8 mL (0.5-6 mL). Complete angiographic cure at the end of the procedure was achieved in 17 patients. No major periprocedural adverse events were recorded. Mid-term follow-up was achieved in 15 out of 19 patients and confirmed complete occlusion of the cDAVFs in 13/15 patients (87%); in 2 of the initially cured patients a small relapse was detected.

CONCLUSIONS

The treatment of the cDAVFs using SQUID 12 was effective and safe. The lower viscosity seems to allow an easier penetration of the agent with a high rate of complete occlusion of the cDAVFs.

Complication rate, cure rate, and long-term outcomes of microsurgery for intracranial dural arteriovenous fistulae: a multicenter series and systematic review

Although microsurgery is an established treatment modality for intracranial dural arteriovenous fistula (dAVF), data regarding the perioperative complication rate, cure rate, and long-term outcomes remain scarce. The aims of this study were to describe our original experience with microsurgery, including the surgical complications and pitfalls, and conduct a systematic review of the relevant literature. A multicenter cohort of patients with dAVF treated by microsurgery was retrospectively assessed. In addition, the PubMed database was searched for published studies involving microsurgery for dAVF, and the complication rate, cure rate, and long-term outcomes were estimated. The total number of patients in our multicenter series and published articles was 553 (593 surgeries). The overall rates of transient complications, permanent complications, death, and incomplete treatment were 11.4, 4.0, 1.2, and 6.5%, respectively. A favorable outcome was achieved for 90.1% patients, even though almost half of the patients presented with intracranial hemorrhage. Of note, the incidence of recurrence was only one per 8241 patient-months of postoperative follow-up. Surgeries for anterior cranial fossa dAVF were associated with a lower complication rate, whereas those for tentorial dAVF were associated with higher complication and incomplete treatment rates. The complication and incomplete treatment rates were lower with simple disconnection of cortical venous drainage than with radical occlusion/resection of dural shunts. Our findings suggest that the cure rate, complication rates, and outcomes of microsurgery for dAVF are acceptable; thus, it could be a feasible second-line treatment option for dAVF. However, surgeons should be aware of the specific adverse events of microsurgery.

The Influence of Angioarchitectural Features on the Success of Endovascular Embolization of Cranial Dural Arteriovenous Fistulas with Onyx

BACKGROUND AND PURPOSE

Endovascular embolization can be an effective treatment for cranial dural arteriovenous fistulas. However, a considerable number of dural arteriovenous fistulas still cannot be treated sufficiently. The purpose of this study was to report our single-center experience of endovascular embolization of dural arteriovenous fistulas with Onyx, including the investigation of the influence of angioarchitectural features on the treatment success.

MATERIALS AND METHODS

Clinical data, angioarchitectural features, complications, treatment success (defined as complete symptom remission for low-grade dural arteriovenous fistulas and complete occlusion for high-grade dural arteriovenous fistulas), and occlusion rates were assessed. The influence of various angioarchitectural features (including location, pattern of venous drainage, and quantity and origin of feeding arteries) was investigated using multivariable backward logistic regression.

RESULTS

One hundred four patients with 110 dural arteriovenous fistulas were treated in 132 treatment procedures. Treatment success and complete occlusion rates were 81.8% and 90.9%, respectively. After a mean follow-up of 23.6 months, 95.5% of the patients showed complete symptom remission or symptom relief. The overall complication rate was 8.3% (4.5% asymptomatic, 2.3% transient, and 1.5% permanent complications). Logistic regression showed that ≥10 feeding arteries (P = .041) and involvement of the ascending pharyngeal artery (P = .039) significantly lowered the probability of treatment success. Treatment success tended to be lower for low-grade dural arteriovenous fistulas, Cognard type I dural arteriovenous fistulas, and dural arteriovenous fistulas with involvement of dural branches of the internal carotid artery, however without reaching statistical significance in the multivariable model.

CONCLUSIONS

The presence of multiple feeding arteries and involvement of the pharyngeal artery negatively influence the treatment success of endovascular embolization of cranial dural arteriovenous fistulas with Onyx.

Future liver remnant growth after various portal vein embolization regimens: a quantitative comparison

Purpose: To compare the efficacy of right portal vein embolization using ethylene vinyl alcohol (EVOH-PVE) compared to other embolic agents and surgical right portal vein ligation (PVL).Material and methods: Patients with right sided liver malignancies scheduled for extensive surgery and receiving induction of liver hypertrophy via right portal vein embolization/ligature between 2010-2016 were retrospectively evaluated. Treatments included were ethylene vinyl alcohol copolymer (Onyx®, EVOH-PVE), ethiodized oil (Lipiodol^®, Lipiodol/PVA-PVE), polyvinyl alcohol (PVA-PVE) or surgical ligature (PVL). Liver segments S2/3 were used to assess hypertrophy. Primary outcome was future liver remnant growth in ml/day.Results: Forty-one patients were included (EVOH-PVE n = 11; Lipiodol/PVA-PVE n = 10; PVA-PVE n = 8; PVL n = 12), the majority presenting with cholangiocarcinoma and colorectal metastases (n = 11; n = 27). Pre-interventional liver volumes were comparable (p = .095). Liver hypertrophy was successfully induced in all but one patient receiving Lipiodol/PVA-PVE. Liver segment S2/3 growth was largest for EVOH-PVE (5.38 ml/d) followed by PVA-PVE (2.5 ml/d), with significantly higher growth rates than PVL (1.24 ml/d; p < .001; p = .007). No significant difference was evident for Lipiodol/PVA-PVE (1.43 ml/d, p = .809).Conclusions: Portal vein embolization using EVOH demonstrates fastest S2/3 growth rates compared to other embolic agents and PVL, potentially due to its permanent portal vein embolization and induction of hepatic inflammation.

Transcatheter embolization with Squid, combined with other embolic agents or alone, in different abdominal diseases: a single-center experience in 30 patients

Background

Squid, as Onyx, is an ethylene-vinyl alcohol copolymer (EVOH)-based liquid embolic agent developed for neuroradiologic interventions with poor application in abdominal district. Our aim was to evaluate safety, complications, and efficacy of transcatheter embolization using the two available formulations Squid-18 and 12, in 30 patients affected by different abdominal diseases.

Results

Transcatheter embolization with Squid, combined with other embolic agents, as poly vinyl alcohol (PVA) particles, coils and amplatzer plugs, or alone (type 2 endoleak), was performed in 30 patients, as follows: 10 portal vein embolizations (PVEs), 6 arteriovenous malformations (AVMs), 5 visceral artery aneurysms (VAAs), 4 type 2 endoleaks, 3 preoperative embolizations, 1 acute arterial bleeding, 1 female varicocele. Squid was always administered using dimethyl sulfoxide (DMSO) compatible microcatheters. Technical success, 30-day clinical success and complications were assessed.

Technical success was 90%. 3 patients (2 AVMs, 1 VAA) required re-intervention successfully performed in all cases. Major complications, cases of microcatheter entrapment and DMSO-related poor pain control were not recorded. 30-day clinical success was 93.3%: in 2 patients submitted to PVE a sufficient future liver remnant (FLR) hypertrophy was not achieved.

Conclusion

Squid was successfully used with low complication rate in many abdominal diseases showing a valid embolic action either combined with other embolic agents or alone in type 2 endoleak. The availability of different formulations (Squid-18 and Squid-12) variable for viscosity makes Squid preferable to Onyx as EVOH-based liquid embolic agent, even though comparable studies in different abdominal districts with a larger cohort of patients will be necessary.

Endovascular Treatment of Transverse-Sigmoid Sinus Dural Arteriovenous Fistulas: A Single-Center Experience with Long-Term Follow-Up

BACKGROUND

Endovascular treatment of transverse-sigmoid sinus dural arteriovenous fistulas (TSDAVFs) remains challenging because of their complex anatomic factors. The aim of our study was to evaluate the long-term efficacy and safety of endovascular treatment of TSDAVFs.

METHODS

From January 2008 to December 2014, 44 patients with TSDAVFs were treated endovascularly at our institution. The clinical and angiographic data were retrospectively collected, and the occlusion rate, complications, and clinical outcomes were analyzed.

RESULTS

Overall, 44 patients (26 males and 18 females) were identified, with a mean age of 47 years (range, 13-68 years). Of the 44 patients, 5 presented with Cognard type I fistula, 12 with type IIa, 6 with type IIb, 13 with type IIa+IIb, 2 with type III, and 6 with type IV. Complete (n = 29) or near-complete (n = 7) occlusion of the fistula was achieved in 36 patients (82%). Two patients experienced a transient neurological deficit (cranial nerve VII). In 31 patients with angiographic follow-up (range, 2-40 months) data available, the occlusion remained in 25, 2 previously minimal residual fistulas were completely occluded, 3 residual fistulas were unchanged, and 1 fistula recurred. Two patients with cortical venous reflux who had received incomplete treatment died of intracranial hemorrhage during the follow-up period. Of the 37 patients with clinical follow-up (mean, 33.6 months) data available, clinical cure was achieved in 29, residual symptoms remained unchanged in 7, and symptoms had deteriorated in 1.

CONCLUSIONS

Favorable and durable outcomes were achieved with endovascular treatment of TSDAVFs. TSDAVFs with cortical venous reflux carry a high risk of hemorrhage and require curative treatment.