Complete Obliteration Rate Research Articles

Dural arteriovenous fistulas at the craniocervical junction: a systematic review and meta-analysis.

The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management. Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes. We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2-64.5), 58.8 years (95%CI: 48.4-69.2), and 63.8 years (95%CI: 60.1-67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3-88.2%) in the microsurgery group and 54.9% (95%CI:30.7-77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7-34.5%) in the embolization group, 11.6% (95%CI:3.8-30.4%) in the microsurgery group, and 7.7% (95%CI:1.1-39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1-80.8%), embolization: 51.9% (95%CI:30.8-72.4%), and conservative: 11.6% (95%CI:4.4-27.4%)]. In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics.

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.

Shortened Cerebral Circulation Time Predicts Resistance to Obliteration in High-Flow Brain Arteriovenous Malformations After Stereotactic Radiosurgery.

Treatment selection for brain arteriovenous malformations (BAVMs) is complicated by BAVM size, location, and hemodynamics. Quantitative digital subtraction angiography is used to quantify the hemodynamic impact of BAVMs on cerebral circulation. This study investigated the association between cerebral circulation time and the complete obliteration (CO) rate of BAVMs after stereotactic radiosurgery (SRS). We analyzed the data of 143 patients who underwent SRS for BAVMs between January 2011 and December 2019 in our institute. Their pre-SRS magnetic resonance imaging and angiography images were analyzed to acquire BAVM characteristics and quantitative digital subtraction angiography parameters. Modified cerebral circulation time (mCCT) was defined as the time difference between the bolus arrival time of the ipsilateral cavernous internal carotid artery and that of the parietal vein, as determined from the lateral view of images obtained using digital subtraction angiography. Cox regression with hazard ratios and Kaplan-Meier analyses were conducted to determine the associations between the parameters and BAVM CO after SRS. Of the 143 patients, 101 (70.6%) achieved BAVM CO. According to the multivariate analyses, an increased mCCT (hazard ratio: 1.24, P = .041) was the independent factor associated with BAVM CO after adjustment for age, sex, hemorrhagic presentation, a BAVM volume of >5 cm3, and a margin dose of >18 Gy. Individuals with an mCCT of ≤2.32 s had a lower 36-month probability of BAVM CO than did those with an mCCT of >2.32 s (44.1% ± 6.8% vs 63.3% ± 5.6%, P = .034). The hemodynamic impact of high-flow BAVM demonstrated by a shortened mCCT is associated with a lower BAVM CO rate after SRS.

Embolization Prior to Radiosurgery in Treatment of Arteriovenous Malformations: Defining Radiosurgery Target Dose with Nidal Volume Reduction

IntroductionArteriovenous malformations (AVMs) can be treated with observation, surgery, embolization, stereotactic radiosurgery (SRS) or a combination of therapies. SRS has been used for AVMs that pose a high risk of surgery, such as in deep or eloquent anatomic locations. Smaller AVMs, < 3cm, have been shown to have higher rates of complete obliteration after SRS. For AVMs that are a larger size, embolization prior to SRS has been used to reduce the size of the AVM nidus. In this study we analyzed embolization prior to SRS to reduce nidal volume and describe imaging techniques to target for SRS post embolization. MethodsWe retrospectively reviewed all patients at a single academic institution treated with embolization prior to SRS for treatment of AVMs. We then used contrast enhanced magnetic resonance imaging (MRI) to contour AVM volumes based on pre-embolization imaging and compared to post-embolization imaging. Planned AVM volume prior to embolization was then compared to actual treated AVM volume. ResultsWe identified 11 patients treated with embolization prior to SRS from 2011-2023. Median AVM nidal volume prior to embolization was 7.69cc and post embolization was 3.61cc (p<0.01). There was a 45.5% obliteration rate at follow up in our series with 2 minor complications related to radiosurgery. ConclusionIn our cohort, embolization prior to SRS resulted in a statistically significant reduction in AVM nidal volume. Therefore, embolization prior to SRS can result in dose reduction at time of SRS treatment allowing for decreased risk of SRS complications without higher embolization complication rates.

The natural course, treatment outcomes, and long-term prognosis of cervical spinal cord arteriovenous shunts.

The highly intricate nature of the cervical spinal cord can cause arteriovenous shunts in these segments that may be associated with heightened clinical risks and treatment complexities. In this article, the authors aimed to provide a comprehensive analysis of the detailed natural course, treatment, and clinical outcomes of cervical spinal cord arteriovenous shunts (SCAVSs) based on the largest cohort to date. Two hundred forty consecutive patients were included. Data on clinical presentation, angioarchitecture, treatment, and follow-up were retrospectively reviewed. The cohort demonstrated a greater prevalence of acute onset (63.3% vs 36.7%). Spontaneous recovery was observed in 63.7% of patients after onset, with a significantly elevated recovery rate observed among patients experiencing acute onset (72.4% vs 48.9%, p < 0.001). The risks of acute and gradual clinical deterioration after onset was 11.9%/year and 13.4%/year, respectively. Microsurgery was performed in 39.6% of patients, while the remaining 60.4% exclusively underwent embolization. The complete obliteration rate was 65.3% after microsurgery and 21.4% after embolization. The rate of treatment-related deterioration was 14.7% after microsurgery and 6.2% after embolization. After partial treatment, the acute and gradual deterioration rates were 4.1%/year and 6.6%/year, respectively. Lack of spontaneous recovery after onset was an independent predictor of embolization-related deterioration (OR 17.905, p = 0.007) and long-term gradual deterioration after partial treatment (HR 2.325, p = 0.021). After a median follow-up period of 32.55 months, prognosis was unfavorable in 16.7% of patients, with the sole independent risk factor being the absence of spontaneous recovery after onset (OR 2.476, p = 0.018). The outcomes of patients with cervical SCAVS were generally favorable, even in patients with only partial obliteration of the lesions. However, patients who did not show a trend toward spontaneous recovery after onset had a significantly elevated risk of unfavorable prognosis, highlighting the need for prompt clinical intervention.

Safety and efficacy of stent-assisted coil embolization with periprocedural dual antiplatelet therapy for the treatment of acutely ruptured intracranial aneurysms.

Despite growing evidence for the effectiveness of stent-assisted coil embolization (SAC) in treating acutely ruptured aneurysms, the safety of stent placement in acute phase remains controversial because of concerns for stent-induced thromboembolism and hemorrhagic events attributable to the necessity of antiplatelet therapy. Therefore, we investigated the safety and efficacy of SAC with periprocedural dual antiplatelet therapy (DAPT) compared with the coiling-only technique to determine whether it is a promising treatment strategy for ruptured aneurysms. We retrospectively evaluated 203 enrolled patients with acutely ruptured aneurysms, categorizing them into two groups: SAC and coiling-only groups. Comparative analyses between the two groups regarding angiographic results, clinical outcomes, and procedure-related complications were performed. A subgroup analysis of procedural complications was conducted on patients who did not receive chronic antithrombotic medications to alleviate their influence before hospitalization. 130 (64.0%) patients were treated using the coiling-only technique, whereas 73 (36.0%) underwent SAC. There was a trend to a higher complete obliteration rate (p = 0.061) and significantly lower recanalization rate (p = 0.030) at angiographic follow-up in the SAC group compared to the coiling-only group. Postprocedural cerebral infarction occurred less frequently in the SAC group (8.2%) than in the coiling-only group (17.7%), showing a significant difference (p = 0.044). Although the ventriculostomy-related hemorrhage rate was significantly higher in the SAC group than in the coiling-only group (26.2% vs. 9.3%, p = 0.031), the incidence of symptomatic ventriculostomy-related hemorrhage was comparable. Subgroup analysis excluding patients receiving chronic antithrombotic medications showed similar results. SACwith periprocedural DAPT could be a safe and effective treatment strategy for acutely ruptured aneurysms. Moreover, it might have a protective effect on postprocedural cerebral infarction without increasing the risk of symptomatic hemorrhagic complications.

Extended thoracic endovascular aortic repair is optimal therapy in acute complicated type B dissection

BackgroundThoracic endovascular aortic repair (TEVAR) represents optimal therapy for complicated acute type B aortic dissection (aTBAD). Persistent knowledge gaps remain, including the optimal length of aortic coverage, impact on distal aortic remodeling, and fate of the dissected abdominal aorta. MethodsReview of the Emory Aortic Database identified 92 patients who underwent TEVAR for complicated aTBAD from 2012 to 2018. Standard TEVAR covered aortic zones 3 and 4 (from the left subclavian to the mid-descending thoracic aorta). Extended TEVAR fully covered aortic zones 3 though 5 (from the left subclavian to the celiac artery). Long-term imaging, clinical follow-up, and overall and aortic-specific mortality were reviewed. ResultsExtended TEVAR (n = 52) required a greater length of coverage vs standard TEVAR (n = 40) (240 ± 32 mm vs 183 ± 23 mm; P < .01). In-hospital mortality occurred in 5.4% of patients (7.7% vs 2.5%; P = .27) owing to mesenteric malperfusion (n = 3) or rupture (n = 2). The overall incidences of postoperative stroke, transient paraparesis, paraplegia, and dialysis were 5.4% (3.9% vs 7.5%; P = .38), 3.2% (5.8% vs 0%; P = .18), 0%, and 0% respectively, equivalent between groups. Follow-up was 96.6% complete to a mean of 6.1 years (interquartile range, 3.5-8.6 years). There were significantly higher rates of complete thrombosis or obliteration of the entire thoracic false lumen after Extended TEVAR (82.2% vs 51.5%; P = .04). Distal aortic reinterventions were less frequent after extended TEVAR (5.8% vs 20%; P = .04). Late aorta-specific survival was 98.1% after extended TEVAR vs 92.3% for standard TEVAR (P = .32). ConclusionsExtended TEVAR for complicated aTBAD is safe, results in a high rate of total thoracic false lumen thrombosis/obliteration, and reduces distal reinterventions. Longer-term follow-up will be needed to demonstrate a survival benefit compared to limited aortic coverage.

Stratified assessment of treatment approach for craniocervical junction arteriovenous fistulas: a multicenter cohort study and literature review.

Craniocervical junction arteriovenous fistulas (CCJ-AVFs) are complex vascular shunts that present a challenge for treatment. The aim of this study was to compare the clinical outcomes of microsurgery and endovascular embolization for CCJ-AVFs and to determine whether the treatment approach affected the obliteration rate and neurological improvement. The authors conducted a retrospective analysis of 64 patients who had undergone microsurgery or endovascular embolization for CCJ-AVF at one of two neurosurgical centers from January 2014 to February 2022. Additionally, a pooled analysis of 68 patients from 38 studies was performed. Baseline characteristics, angioarchitectural features, and clinical outcomes were compared between two treatment groups. A subgroup analysis of CCJ-AVFs with carotid artery (CA) feeders was also performed. In the multicenter cohort, the complete obliteration rate was 95.1% with microsurgery, 81.8% with embolization via the CA, and 50.0% with embolization via the vertebral artery (VA). After adjusting for baseline and confounding features, the occlusion rate was significantly lower in the VA embolization group (adjusted OR 41.06, 95% CI 2.37-711.9, p = 0.01). No new-onset infarctions occurred in the microsurgical group, whereas 1 patient each in the CA and VA embolization groups experienced posttreatment infarction. Microsurgery demonstrated a neurological improvement rate similar to that in the CA embolization group (65.9% vs 63.6%, respectively). In the subgroup analysis of CCJ-AVF with CA feeders in the multicenter cohort, the occlusion rate and neurological improvement in the CA embolization group were comparable to those in the microsurgery group. The subgroup analysis in the pooled analysis revealed complete obliteration rates of 100.0% in the microsurgical group, 88.9% in the CA embolization group, and 66.7% in the VA embolization group. This study supports microsurgery as the best treatment modality for CCJ-AVFs, exhibiting the highest rates of complete obliteration. Conversely, embolization via the VA can result in a lower occlusion rate and less neurological improvement. In CCJ-AVFs with CA feeders, embolization via the CA can be a safe and effective alternative to microsurgery.

688 Stratified Assessment of Treatment Approach for Craniocervical Junction Arteriovenous Fistulas: A Multicenter Cohort and Pool Analysis

INTRODUCTION: Cranio-cervical junction arteriovenous fistulas (CCJ-AVFs) are complex vascular shunts that present a challenge for treatment. METHODS: We conducted a retrospective analysis of 132 patients who underwent microsurgery or endovascular embolization for CCJ-AVF. The baseline characteristics, angioarchitectural features, and clinical outcomes were compared between the two treatment groups. A subgroup analysis was also performed in CCJ-AVF with carotid artery feeders. RESULTS: The complete obliteration rate was 97.1% in the microsurgery group, 85.3% in the embolization via carotid artery (CA) approach group, and 62.5% in the embolization via vertebral artery (VA) approach group. After adjusting for baseline and confounding features, the occlusion rate was significantly lower in embolization via VA approach (adjusted OR, 0.04; 95% CI, 0.005-0.40, p = 0.006). None of the patients in the microsurgical group appeared new-onset infarction, while 1 (2.9%) in CA embolization and 3 (12.5%) in VA embolization suffered new-onset infarction after treatment. The neurological improvement rate of microsurgery was similar to that of embolization via CA approach. Embolization via VA was associated with less neurological improvement (adjusted OR, 0.11; 95% CI, 0.03-0.38, p = 0.001). In the subgroup analysis of CCJ-AVF with CA feeders, the occlusion rate and neurological improvement of embolization via CA approach were comparable to those of microsurgery. CONCLUSIONS: Our study suggests that microsurgery and embolization via CA approach can achieve similar clinical outcomes for CCJ-AVF. Embolization via VA approach may result in a lower occlusion rate and less neurological improvement. In CCJ-AVF with CA feeders, embolization via CA approach may be a safe and effective alternative to microsurgery.

Microsurgical versus endovascular treatment of ethmoidal dural arteriovenous fistulas: systematic review and meta-analysis with a single-center case series.

Ethmoidal dural arteriovenous fistulas (DAVFs) are often associated with cortical venous drainage (CVD) and a higher incidence of hemorrhage compared with DAVFs in other locations. They may be treated with open surgical disconnection or with endovascular treatment (EVT). In this systematic review and meta-analysis, the authors compare the outcomes of ethmoidal DAVFs treated with open microsurgery versus EVT and report four additional cases of ethmoidal DAVFs treated with open microsurgery in their institution. A literature search of the PubMed and Scopus databases was conducted between December 2021 and May 2022 to identify relevant articles published between 1990 and 2021 using the PRISMA guidelines. References were reviewed and screened by two authors independently, and disagreements were resolved through consensus. Exclusion criteria included non-English-language studies, those with an incorrect study design, those reporting DAVFs in a nonethmoidal location, and studies whose outcomes were not stratified based on DAVF location. Inclusion criteria were any studies reporting on ethmoidal DAVFs treated by either microsurgery or EVT. A risk of bias assessment was performed using the Newcastle-Ottawa Scale. The authors performed a pooled proportional meta-analysis to compare patient outcomes. Twenty studies were included for analysis. Of 224 patients, 142 were treated with surgery, while 103 were treated with EVT. Seventy percent (148/210) of the patients were symptomatic at presentation, with hemorrhage being the most common presentation (48%). CVD was present in 98% of patients and venous ectasia in 61%. The rates of complete DAVF obliteration with surgery and EVT were 89% and 70%, respectively (95% CI -30% to -10%, p < 0.03). Twenty percent (21/103) of endovascularly treated fistulas required subsequent surgery. Procedure-related complications occurred in 10% of the surgical cases, compared with 13% of the EVT cases. The authors' case series included 4 patients with ethmoidal DAVFs treated surgically with complete obliteration, without any postoperative complications. The complete obliteration rates of ethmoidal DAVF appear to be higher and more definitive with microsurgical intervention than with EVT. While complication rates between the two procedures seem similar, patients treated with EVT may require further interventions for definitive treatment. The limitations of this study include its retrospective nature, the quality of studies included, and the continued evolving technologies of EVT. Future studies should focus on the association between venous drainage pattern and the proclivity toward venous ectasia or rate of hemorrhage at presentation.

Transvenous embolization of noncavernous dural arteriovenous fistulas (dAVFs): A systematic review and meta-analysis.

Intracranial dural arteriovenous fistulas (dAVFs) are abnormal connections between arteries and veins within the dura mater. Various treatment modalities, such as surgical ligation, endovascular intervention, and radiosurgery, aim to close the fistulous connection. Although transvenous embolization (TVE) is the preferred method for carotid-cavernous fistulas, its description and outcomes for noncavernous dAVFs vary. This has prompted a systematic review and meta-analysis to comprehensively assess the effectiveness of TVE in treating noncavernous dAVFs, addressing variations in outcomes and techniques. We searched PubMed and Embase, spanning from the earliest records to December 2022, to identify pertinent English-language articles detailing the utilization of TVE. We focused on specific procedural details, outcomes, and complications in patients older than 18 years. The data collected and analyzed comprised the sample size, number of fistulas, publication specifics, presenting symptoms, fistula grades, and pooled rates of embolizations, outcomes, follow-up information, and complications. From a total of 565 screened articles, 15 retrospective articles encompassing 166 patients spanning across seven countries met the inclusion criteria. Their Newcastle-Ottawa scores ranged from 6 to 8. Intraprocedural complication rate was 10% (95% confidence interval [CI] = 5.9-17.1) and in-hospital postprocedural complication rate was 5.4% (95% CI = 2.8-10.6). Prevalence of in-hospital mortality was 5.5% (95% CI = 2.9-10.6). Complication rate during follow-up was 8.6% (95% CI = 4.7-15.7) with fistula rupture occurring in 5.5% (95% CI = 2.6-11.6) of patients. Complete obliteration rate at final angiographic follow-up was 94.9% (95% CI = 90.3-99.9). Symptoms improved in 95% (95% CI = 89.8-100) of patients at final follow-up. To our knowledge, we present the first meta-analysis assessing obliteration rates, outcomes, and complications of TVE for dAVFs. Our analysis highlights the higher (>90%) complete obliteration rates. Large prospective multicenter studies are needed to better define the utility of TVE for noncavernous dAVFs.

Endovascular Treatments for Aneurysms Involving a Major Branch.

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

Six-month Outcomes after PulseRider- and Conventional Single Stent-assisted Embolization for Bifurcation Aneurysms: A Propensity-adjusted Comparison.

Endovascular treatment of wide-necked bifurcation aneurysms (WNBAs) remains challenging despite using a stent. PulseRider is a novel device specifically designed to treat WNBAs, protecting both daughter branches, but the outcomes have not been compared with conventional single stent-assisted embolization. This study aimed to compare the six-month outcomes of PulseRider and single stent-assisted embolization for intracranial unruptured WNBAs using propensity score adjustment. Between February 2012 and October 2021, 46 unruptured WNBAs (34 basilar and 12 middle cerebral arteries) smaller than 10 mm in diameter were treated with PulseRider-assisted embolization (n = 17) or single stent-assisted embolization (n = 29). The immediate and six-month outcomes were compared using inverse probability of treatment weighting analysis. The immediate adequate occlusion rates for the PulseRider- and single stent-assisted embolization were similar (47.1% vs. 62.1%). At six months, adequate occlusion rates for the two groups were also similar (94.1% vs. 86.2%). However, the complete obliteration rate was significantly high after PulseRider-assisted embolization (88.2% vs. 41.4%, adjusted OR 10.54, 95% CI 1.93-57.63). The angiographical improvement rate was also significantly high after PulseRider-assisted embolization (70.6% vs. 37.9%, adjusted OR 6.06, 95% CI 1.54-23.76). The neurologic thromboembolic complication rate was 0% after PulseRider-assisted embolization and 3.4% after single stent-assisted embolization. PulseRider-assisted embolization of WNBAs smaller than 10 mm in diameter was associated with complete obliteration and angiographical improvement at six months. The unique shape of the PulseRider might contribute to the improved midterm aneurysm occlusion.

Feasibility of Gamma Knife Radiosurgery for Brain Arteriovenous Malformations According to Nidus Type.

Gamma Knife radiosurgery (GKRS) is an effective and noninvasive treatment for high-risk arteriovenous malformations (AVMs). Since differences in GKRS outcomes by nidus type are unknown, this study evaluated GKRS feasibility and safety in patients with brain AVMs. This single-center retrospective study included patients with AVM who underwent GKRS between 2008 and 2021. Patients were divided into compact- and diffuse-type groups according to nidus characteristics. We excluded patients who performed GKRS and did not follow-up evaluation with magnetic resonance imaging or digital subtraction angiography within 36 months from the study. We used univariate and multivariate analyses to characterize associations of nidus type with obliteration rate and GKRS-related complications. We enrolled 154 patients (mean age, 32.14±17.17 years; mean post-GKRS follow-up, 52.10±33.67 months) of whom 131 (85.1%) had compact- and 23 (14.9%) diffuse-type nidus AVMs. Of all AVMs, 89 (57.8%) were unruptured, and 65 (42.2%) had ruptured. The mean Spetzler-Martin AVM grades were 2.03±0.95 and 3.39±1.23 for the compact- and diffuse-type groups, respectively (p<0.001). During the follow-up period, AVM-related hemorrhages occurred in four individuals (2.6%), three of whom had compact nidi. Substantial radiation-induced changes and cyst formation were observed in 21 (13.6%) and one patient (0.6%), respectively. The AVM complete obliteration rate was 46.1% across both groups. Post-GKRS complication and complete obliteration rates were not significantly different between nidus types. For diffuse-type nidus AVMs, larger AVM size and volume (p<0.001), lower radiation dose (p<0.001), eloquent area location (p=0.015), and higher Spetzler-Martin grade (p<0.001) were observed. GKRS is a safe and feasible treatment for brain AVMs characterized by both diffuse- and compact-type nidi.

CyberKnife based fractionated stereotactic radiotherapy as an upfront treatment for cerebral arteriovenous malformation

BackgroundTo explore the therapeutic outcomes of CyberKnife based fractionated stereotactic radiotherapy (CKFRT) for patients with cerebral arteriovenous malformations (AVM). MethodsBetween January 2008 and October 2020, 45 patients underwent CKFRT for cerebral AVMs as a first treatment. The delineation of AVM targets included AVM nidus. The mean target volume was 4.07 cm3, and 9 lesions (20%) were larger than 10.0 cm3. The mean marginal dose was 24 Gy (range, 20–35 Gy). CKFRT was delivered in median 3 fractions (range, 2 ∼ 5 fractions). AVM obliteration following CKFRT was confirmed by magnetic resonance imaging or angiography. ResultsDuring a median follow-up of 47 (5–148) months, complete obliteration and partial obliteration of AVM after CKFRT were obtained in 23 (51%) and 13 (29%) patients, respectively. Median time to complete obliteration was 39 (15–63) months. The cumulative probability of complete obliteration rate at 3 years was 47%. Complete obliteration rate of AVM was associated with Radiosurgery-based AVM score, which was consisted of AVM volume, patients age, and AVM location. One (2%) patient had hemorrhage during the follow-up period. ConclusionsCKFRT is an effective primary treatment for patients with cerebral AVMs with a low hemorrhage risk.

Endovascular Treatment of Brain Arteriovenous Malformations in Pediatric Patients: A Single Center Experience and Review of the Literature.

Brain arteriovenous malformations (bAVMs) are abnormal vascular connections with direct arteriovenous shunts, generally symptomatic in the adult life. However, a small number of bAVMs may manifest in pediatric patients, with higher bleeding risk and mortality rates when compared to adults. The purpose of this study is to review our experience with endovascular treatment of bAVMs in pediatric patients. This is a retrospective analysis of all bAVMs in pediatric patients (0-18 years) who underwent diagnostic digital subtraction angiography (DSA) at our institution from January 2010 to June 2021. Twenty-six patients met the inclusion criteria, of which 12 underwent endovascular treatment. Treated patients had a mean age of 10.25 years and 58% were females. Complete angiographic exclusion was achieved in five (42%) patients with endovascular treatment. Five patients with residual bAVM after embolization needed adjuvant therapy with surgery (n = 3) or stereotactic radiosurgery (SRS; n = 2). Two patients are still undergoing embolization sessions. Procedure-related complications occurred in two patients (17%) and included small vessel perforation and an occipital ischemic stroke. Two patients showed bAVM recurrence on follow-up (17%) and subsequently underwent SRS (n = 1) or surgery (n = 1), both resulting in complete bAVM exclusion. All patients had a modified Rankin scale (mRS) score of 0 to 2 on follow-up. Our experience supports the effectiveness and safety of endovascular treatment of bAVM in selected pediatric patients. A multidisciplinary approach combining surgery and SRS is warranted to achieve higher complete bAVM obliteration rates. Long-term follow-up is important as these lesions may show recurrence over time, especially in the pediatric population.

Comparison Between the Efficacy of a Flow Diverter and Interventional Trapping with Bypass in the Treatment of Unruptured Large- or Giant-Sized ICA Aneurysms

Management of large- or giant-sized internal carotid artery aneurysms (LICAAs) remains challenging. Whether a flow diverter device (FDD) or interventional trapping with extracranial-intracranial bypass (ITB) is better, remains unclear. We conducted a multicenter retrospective analysis of unruptured LICAA patients treated with FDD or ITB at 3 medical centers. Both the effectiveness and safety results of FDD and ITB were compared. In total, 101 aneurysms in 95 patients treated with FDDs and 36 aneurysms in 36 patients managed with ITBs were included (September 2014-June 2021). There was no significant difference between the groups in the complete obliteration rate 1year after surgery (P=0.101). There were 2 relapse cases (2.0%) and 4 retreated cases (4.0%) in the FDD group and 1 relapse case (2.8%) and 2 retreated cases (5.6%) in the ITB group. Neither the relapse rates nor retreat rates between groups were significantly different. The neurological morbidity rates were 4.0% (4/101) and 2.8% (1/36) in the FDD group and ITB group, respectively, and were not significantly different. There was 1 mortality case in each group, and the mortality rates were not significantly different (P=0.443). Both the perioperative and overall (perioperative plus long-term) complication rates in the FDD group were significantly lower than those in the ITB group (P=0.033, P=0.039). FDD had comparable surgical efficacy and a significantly lower postoperative complication rate to traditional ITB. FDD might be preferable to ITB as a treatment modality for LICAA.

Gamma Knife Radiosurgery for Spetzler-Martin Grade III Brain Arteriovenous Malformations

Spetzler-Martin (SM) grade III AVMs exhibit angioarchitecture heterogeneity and lack a clearly defined treatment strategy. This study aims to evaluate outcomes following treatment of SM grade III AVMs with Gamma Knife Radiosurgery (GKRS). A single-institution retrospective analysis was conducted of 307 patients with SM grade III AVMs undergoing GKRS between October 2006 to December 2020 with follow-up times of at least 24 months. SM grade III AVMs were classified into four subtypes: IIIA (S1E1V1), IIIB (S2E0V1), subtype IIIC (S2E1V0), and IIID (S3E0V0). Over a median follow-up time of 50.3 months, complete AVM obliteration was achieved in 211 patients (68.7%). Complete obliteration rates in subtypes IIIA, IIIB, IIIC, and IIID were 80.8%, 55.4%, 53.4%, and 25.0%, respectively. Annual post-GKRS hemorrhage risk was 0.8%. Significant radiosurgery-induced imaging changes occurred in 7 patients (2.3%). Three variables were identified as predictors of obliteration in final forward stepwise regression models, including volume of AVM (B= -0.011, p <0.001), age (B= -0.004, p =0.024) and prior AVM hemorrhage (B= 0.187, p = 0.077). GKRS is a safe and effective treatment for SM grade III AVMs, particularly subtype IIIA (S1E1V1). AVM volume is the key predictor of post-GKRS obliteration.

Application of the pressure cooker technique for transarterial embolization of brain arteriovenous malformations: Factors affecting obliteration and outcomes.

The typical pressure cooker technique (PCT) and several modifications with similar mechanisms have been introduced to enhance the embolization of brain arteriovenous malformations (bAVMs). This study aimed to assess the effectiveness of transarterial embolization of bAVMs with the PCT. From January 2019 to December 2021, 125 consecutive patients with bAVM managed by transarterial embolization in the prospective database on cerebral vascular diseases of a single center were retrospectively reviewed. Patient data and lesion characteristics were collected. According to the treatment strategy, the patients were assigned to the PCT group (46 patients) and conventional embolization technique (CET) group (79 patients). Baseline patient features were comparable between the two groups. After the first procedure, complete obliteration immediately was observed in 61 and 42% of patients in the PCT and CET groups, respectively. The rate was markedly elevated in the PCT group (p = 0.04). In subgroup analysis, the rate of immediate complete obliteration was starkly increased in PCT group patients with Spetzler-Martin grade I/II bAVM (86 and 53% in the PCT and CET groups, respectively; p = 0.0036). The overall complication rates were similar in the two groups (13 and 10% in the PCT and CET groups, respectively; p = 0.77). In multivariable analysis, nidus size >3 cm (OR = 8.826, 95% CI: 1.250-62.312; p = 0.03) and deep location (OR = 8.576, 95% CI: 1.480-49.690; p = 0.02) were significant factors affecting complete obliteration in the PCT group. The PCT may yield a higher rate of immediate complete obliteration with transarterial embolization of bAVMs, without increasing the rate of procedure-related complications.

Spinal Extramedullary Arteriovenous Fistulas: A 15-Year Endovascular Treatment Experience in a Tertiary Care Hospital in Thailand.

Spinal arteriovenous shunts are rare diseases. Different classifications have been proposed, but the most widely used are those classified by locations. Different locations (i.e., intramedullary and extramedullary) have different treatment outcomes and different posttreatment angiographical results. Our study presents the 15-year endovascular treatment outcomes of patients who had spinal extramedullary arteriovenous fistulas (AVFs) at Ramathibodi Hospital, which is a tertiary care hospital in Thailand. A retrospective medical record and imaging review of all patients with spinal extramedullary AVFs, which were confirmed by a diagnostic spinal angiogram in our institute from January 2006 to December 2020, were performed. The angiographic complete obliteration rate in the first session of endovascular treatment, clinical outcomes of the patients, and complications of the procedures for all eligible patients were analyzed. Sixty-eight eligible patients were included in the study. The most common diagnosis was spinal dural AVF (45.6%). The most common presenting symptoms were weakness, numbness, and bowel-bladder involvement (70.6%, 67.6%, and 57.4%, respectively). Ninety-four percent had spinal cord edema in preoperative magnetic resonance imaging. All patients had pial venous reflux. Sixty-four patients (94.1%) received endovascular treatment as the first option. The complete obliteration rate in the first session of endovascular treatment was 75% and was high in all subgroups except for the perimedullary AVF group. The overall intraoperative complication of endovascular treatment was 9.4%. Follow-up imaging showed no residual AVF in 50 patients (87.7%). Most of the patients (57.4%) had improvement of neurological functions at 3- to 6-month follow-up. Treatment results of spinal extramedullary AVFs were good in terms of angiographic aspects and clinical outcomes. This may have resulted from the locations of the AVFs, which mostly did not involve the spinal cord arterial supply, with the exception of perimedullary AVFs. Although perimedullary AVF is difficult to treat, it can be cured by careful catherization and embolization.