Endovascular Treatment for Low-Grade (Spetzler-Martin I-II) Brain Arteriovenous Malformations

Transvenous Approach for the Treatment of Cerebral Arteriovenous Malformations: A Randomized Comparison With Transarterial Embolization

BACKGROUND

Transvenous embolization (TVE) is a new treatment of brain arteriovenous malformations (AVMs). The safety and efficacy of TVE have not been compared with transarterial embolization (TAE). The primary hypothesis of this trial was that TVE would increase the proportion of AVM occlusion from 40% to 80%.

METHODS

The TATAM (Transvenous Approach for the Treatment of Cerebral AVMs) was an investigator-initiated, multicenter, prospective, phase 2, open-label, controlled randomized trial comparing TVE versus TAE alone (1:1). Patients with symptomatic or asymptomatic AVMs considered curable with 2 endovascular sessions were reviewed by a case selection committee. Participating centers were experienced (>20 cases) or proctored by experts. The primary outcome was complete occlusion of the AVM, confirmed by catheter angiography at 3 to 6 months. There was no blinding. Primary analyses were intent-to-treat.

RESULTS

From May 2019 to April 2023, 77 patients were recruited in 7 French and 2 Canadian centers. After exclusions, results from 69 patients were analyzed; 35 were allocated TVE and 34 TAE. The mean age of participants was 43.3 years; 29 of 69 (42%) were female. There were 2 crossovers. The primary outcome was reached in 29 of 35 patients with TVE (83% [95% CI, 67%-92%]) compared with 20 of 34 patients allocated TAE (59% [95% CI, 42%-74%]; P=0.036). Poor outcomes (modified Rankin Scale score >2 at 3-6 months) occurred in 7 of 35 patients with TVE (20% [95% CI, 10%-36%]) and 9 of 34 patients with TAE (27% [95% CI, 15%-43%]; P=0.513) and related serious adverse events in 12 of 35 patients with TVE (34% [95% CI, 21%-51%]) and 14 of 34 patients with TAE (41% [95% CI, 26%-58%]; P=0.624).

CONCLUSIONS

TVE was more effective than TAE in terms of angiographic results at 3 to 6 months. Morbidity was similar but high for both groups. More studies are needed to determine the role of curative embolization in managing patients with brain AVM.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03691870.

Comparing stand-alone endovascular embolization versus stereotactic radiosurgery in the treatment of arteriovenous malformations with Spetzler-Martin grades I-III: a propensity score matched study

BACKGROUND

Arteriovenous malformations (AVMs) are uncommon cerebral lesions that can cause significant neurological complications. Surgical resection is the gold standard for treatment, but endovascular embolization and stereotactic radiosurgery (SRS) are viable alternatives.

OBJECTIVE

To compare the outcomes of endovascular embolization versus SRS in the treatment of AVMs with Spetzler-Martin grades I-III.

METHODS

This study combined retrospective data from 10 academic institutions in North America and Europe. Patients aged 1 to 90 years who underwent endovascular embolization or SRS for AVMs with Spetzler-Martin grades I-III between January 2010 and December 2023 were included.

RESULTS

The study included 244 patients, including 84 who had endovascular embolization and 160 who had SRS. Before propensity score matching (PSM), complete obliteration at the last follow-up was achieved in 74.5% of the SRS group compared with 57.8% of the embolization group (OR=0.47; 95% CI 0.26 to 0.48; P=0.01). After propensity score matching, SRS still achieved significantly higher occlusion rates at last follow-up (78.9% vs 55.3%; OR=0.32; 95% CI 0.12 to 0.90; P=0.03).Hemorrhagic complications were higher in the embolization group than in the SRS group, although this difference did not reach statistical significance after PSM (13.2% vs 2.6%; OR=5.6; 95% CI 0.62 to 50.47; P=0.12). Similarly, re-treatment rate was higher in the embolization group (10.5% vs 5.3%; OR=2.11; 95% CI 0.36 to 12.31; P=0.40) compared with the SRS group.

CONCLUSION

Our findings indicate that SRS has a significantly higher obliteration rate at last follow-up compared with endovascular embolization. Also, SRS has a higher tendency for fewer hemorrhagic complications and lower re-treatment rate. Further prospective studies are needed.

Adenosine-assisted embolization of cerebral arteriovenous malformations: a systematic review and meta-analysis

BACKGROUND

Cerebral arteriovenous malformations (AVMs) are complex lesions that can cause hemorrhagic stroke and significant neurological disability. Adenosine induces cardiac standstill and hypotension, which are thought to be useful during cerebral AVM embolization. Herein, we conducted a systematic review and meta-analysis of the technique's safety.

METHODS

Following PRISMA guidelines, four databases were queried for studies describing the use of adenosine-assisted embolization of cerebral AVMs. Adenosine-related intraoperative complications, permanent neurological outcomes, morbidity, and mortality assessed the technique's safety. Single proportion analysis under a random-effects model was performed. Heterogeneity was assessed using I² statistics, and publication bias was evaluated through funnel plot analysis and Egger's regression test.

RESULTS

Ten studies were included, involving 79 patients (55.7% male) with 79 AVMs (54.4% unruptured and 70.9% Spetzler-Martin grade III-V) who underwent 123 embolizations (80.4% and 5.9% under transarterial and transvenous approaches, respectively) with n-butyl cyanoacrylate (80.4%), ethylene vinyl alcohol (14.4%), or both (5.2%). The incidence of transient adenosine-related intraoperative complications was 0% (95% CI 0% to 3%, I2=24%). Besides, the incidence of adenosine-related morbidity, mortality, and permanent outcomes was 0% (95% CI 0% to 3%, I2=0%). During follow-up, good functional outcomes were reported for 64 patients (81%).

CONCLUSIONS

Adenosine's effects on blood flow control can facilitate embolization and mitigate the risk of AVM rupture and embolic agent migration. Although current evidence stems from observational studies, the results of this meta-analysis suggest a safe drug profile due to minimal associated morbidity and mortality. Further research from larger randomized and controlled studies is warranted to attain a higher level of evidence.

PROSPERO REGISTRY NUMBER

CRD42023494116.

Transarterial Embolization for the Management of Brain Arteriovenous Malformations: A Systematic Review

Objective

The authors aimed for a systematic review to clarify the current role of transarterial embolization (TAE) in the management of brain arteriovenous malformations (BAVMs).

Methods

A search was conducted on PubMed, using the following terms; "brain arteriovenous malformation," "cerebral arteriovenous malformation," "endovascular treatment," and "transarterial embolization." Studies reporting the efficacy and safety of endovascular treatment for BAVMs, performed either as a standalone treatment or in conjunction with surgery or radiosurgery, were included. The final search was conducted in December 2023. Only articles written in English were reviewed. The references of publications of interest were also screened. Studies on transvenous embolization were excluded. More than 100 articles on the treatment of BAVMs were reviewed.

Results

Advances in endovascular techniques and devices have enabled TAE as a treatment modality for BAVMs, to achieve higher embolization rates. Thus, curative TAE for some BAVMs with suitable angioarchitecture has become possible. The efficacy of presurgical TAE in the treatment of low Spetzler-Martin grade BAVMs is limited; however, TAE is effective for intermediate grade BAVMs. Several reports using propensity-matched analyses reevaluated the therapeutic efficacy of pre-/post-radiosurgical TAE for BAVMs with radiosurgery-resistant lesions such as large nidus, fistulous components, and associated aneurysms. The complication rate of TAEs as a treatment modality for BAVMs is approximately 10%, and hemorrhagic complications occur in approximately 5% of cases. Despite recent advances, substantial improvements have not been observed in the morbidity and mortality associated with TAEs for the treatment of BAVMs.

Conclusion

TAE for the treatment of BAVMs is primarily performed in an adjuvant manner; however, recent advances have made standalone embolization possible. A multidisciplinary team should evaluate each case independently. Furthermore, as per recent studies, inclusive of meta-analyses, the efficacy and safety of TAEs for the treatment of BAVMs have not been elucidated. Thus, the manifestations and characteristics of BAVMs, in addition to the objective of performing a TAE, should be deliberated carefully before the endovascular procedure, to avoid complications.

Surgical Results with Low-Grade Arteriovenous Malformations : A Single Center 14-Year Experience

OBJECTIVE

Advancements in AVM surgical techniques for cerebral arteriovenous malformation (AVM) underscore its efficacy. Our research aims to showcase the positive outcomes of treating low-grade AVMs surgically, focusing on safety and effectiveness.

METHODS

We retrospectively reviewed 55 patients (36 males and 19 females; average age 37.4 years) with Spetzler-Martin (S-M) grade 1 and 2 AVMs who underwent surgical resection between January 2009 and December 2022.

RESULTS

In our study, 55 patients with S-M grade 1 and 2 AVMs underwent surgical resection, evenly divided between grades 1 (50.9%) and 2 (49.1%). Intracranial hemorrhage was the primary symptom in 74.5% of cases. Pre-operative Glasgow coma scale (GCS) scores revealed 69.1% of patients scored above 13, with 18% below 8. Successful resection was achieved in 87.3%. Postoperatively, 95.5% of ruptured and 90.9% of unruptured AVM patients showed lower or same modified Rankin scale scores. Poorer outcomes were significantly linked to lower GCS scores and intranidal/flow-related aneurysms through multivariate logistic regression. Postoperative seizures noted in nine patients, were exclusive to the ruptured AVM group.

CONCLUSION

Our findings indicate surgical resection as a beneficial treatment for low-grade AVMs, yielding high cure rates and positive functional outcomes in both ruptured and unruptured cases. Preoperative GCS scores and the presence of associated aneurysms are predictive of postoperative functional status. Additionally, managing postoperative seizures effectively is key to enhancing prognosis.

Surgical outcomes and risk factors for overall mortality in brain arteriovenous malformations patients: a retrospective analysis

Background

Brain arteriovenous malformations (AVMs) are challenging vascular lesions. Extensive follow-up studies are necessary to refine the therapeutic algorithm, and to improve long-term survival in these patients. The aim of the study was to assess surgical outcomes, and to evaluate overall long-term mortality in patients treated for brain AVMs.

Methods

This retrospective single-center study included 191 patients with brain AVMs, admitted between 2012 and 2022. Clinical and angiographical particularities have been analyzed, to identify factors that might influence early outcome and overall long-term mortality.

Results

Out of 79 patients undergoing surgery, 51 had ruptured AVMs with total resection achieved in 68 cases (86.1%). Deep venous drainage was associated with incomplete resection. Female sex, admission modified Rankin Scale (mRS) > 2, and eloquent location were independent predictors of poor outcomes. Multiple venous drainage was associated with a higher risk of worsened early outcome. Eloquent brain region involvement, conservative treatment, increasing age, admission mRS > 2, and comorbidities significantly decrease survival in brain AVM patients. Patients treated with interventional treatments had significantly better survival than the conservatively managed ones, when adjusting for age and admission mRS.

Conclusion

The study identified female sex, poor neurologic status on admission and eloquence as independent prognostic factors for a negative outcome after surgery. Patients who received interventional treatment had significantly better survival than patients managed conservatively. We recommend employing tailored, proactive management strategies as they significantly enhance long-term survival in brain AVM patients.

Endovascular embolization of Spetzler-Martin Grade I brain arteriovenous malformations: A case report on patient-centered neurointervention

Brain arteriovenous malformations (AVM) present complex treatment decisions, particularly for low-grade AVM where surgical resection is often considered the standard. This case report emphasizes the importance of patient preferences and cultural considerations in selecting endovascular embolization over traditional surgical approaches for Spetzler-Martin Grade I AVM management, highlighting the evolving practice of patient-centered care in neurointervention. A 30-year-old male presented with recurrent seizures, characterized by a sudden onset of headache followed by speech arrest, without any preceding medical history of neurological deficits. Initial physical examination revealed no focal neurological deficits. Non-contrast computed tomography, magnetic resonance imaging, and magnetic resonance angiography suggested an AVM involving the cortical-subcortical regions of the left frontal lobe, measuring approximately 1.7 × 2.6 × 1.5 cm, fed by the left middle cerebral artery M3 segment, and draining into the superior sagittal sinus. Spetzler-Martin Grade I classification was confirmed via digital subtraction angiography. Given the patient's strong preference against invasive procedures, driven by personal and cultural beliefs, endovascular embolization was selected as the treatment strategy. Post-embolization, the patient showed marked symptomatic improvement with no evidence of residual AVM on follow-up imaging, and no postprocedure complications were reported. This case highlights the importance of considering patient preferences in AVM treatment planning, illustrating that endovascular embolization can be an effective and less invasive alternative to surgery in selected patients, reinforcing the need for personalized, patient-centered approaches in neurointerventional care.

Preoperative embolization of brain arteriovenous malformation and efficacy in intraoperative blood loss reduction: a quantitative study

BACKGROUND

Embolization of brain arteriovenous malformations (bAVMs) is often used as adjuvant therapy to microsurgical resection to reduce the high-risk features of bAVMs such as large size and high flow. However, the effect of preoperative embolization on surgical performance and patient outcome has shown mixed results. Heterogeneity in treatment goals, selection criteria, and unpredictable changes in bAVM hemodynamics after partial embolization may account for these uncertain findings. In this study we use an objective quantitative technique to assess the impact of preoperative embolization on intraoperative blood loss (IBL).

METHODS

Patients with bAVM treated with microsurgical resection only or in combination with preoperative embolization from 2012 to 2022 were retrospectively reviewed. Patients were included if quantitative magnetic resonance angiography was performed prior to any treatment. Correlation of baseline bAVM flow, volume, and IBL was evaluated between the two groups. Additionally, bAVM flow prior to and after embolization was compared.

RESULTS

Forty-three patients were included, 31 of whom required preoperative embolization (20 had more than one session). Mean bAVM initial flow (362.3 mL/min vs 89.6 mL/min, p=0.001) and volume (9.6 mL vs 2.8 mL, p=0.001) were significantly higher in the preoperative embolization group; flow decreased significantly after embolization (408.0 mL/min vs 139.5 mL/min, p<0.001). IBL was comparable between the two groups (258.6 mL vs 141.3 mL, p=0.17). Linear regression continued to show a significant difference in initial bAVM flow (p=0.03) but no significant difference in IBL (p=0.53).

CONCLUSION

Patients with larger bAVMs who underwent preoperative embolization had comparable IBL to those with smaller bAVMs undergoing only surgical treatment. Preoperative embolization of high-flow bAVMs facilitates surgical resection, reducing the risk of IBL.

Primary endovascular embolisation of intracranial arteriovenous malformations (AVM)-UK single centre experience

PURPOSE

Intracranial arteriovenous malformations (AVMs) treated at our institution with modern techniques of endovascular intervention were analysed for the rate of complete occlusion, associated morbidity, and mortality. To our knowledge, this is the first series from the UK evaluating the effectiveness of endovascular embolisation as a primary treatment for selected cases.

METHODS

All newly referred AVMs between January 2017 and June 2022 were reviewed and those treated with primary endovascular intervention were identified. Details of the endovascular procedures were retrospectively reviewed.

RESULTS

In 5½ years, 41.1% of AVMs referred to our institution have been triaged for primary endovascular intervention. Sixty-eight AVMs were embolised and followed-up: 44 ruptured and 24 unruptured. Spetzler-Martin grading varied from I to III, and a single AVM was grade IV. The approach was arterial in 73.5%, solely venous in 7.4%, and combined in 19.1%. The mean follow-up was 18 months for imaging and 26 months for clinical assessment. Complete obliteration was achieved in 95.6%. Ruptured AVM cohort: The rate of functional deterioration was 13.6%. Unruptured AVM cohort: The rate of functional deterioration secondary to complications from embolisation was 4.2%.

CONCLUSIONS

Endovascular embolisation may be a favourable option for primary AVM treatment in carefully selected patients. However, selection criteria need to be better delineated for more specialists to consider this as a primary therapy.

Current perspectives and trends in the treatment of brain arteriovenous malformations: a review and bibliometric analysis

Background

Currently, there is a lack of intuitive analysis regarding the development trend, main authors, and research hotspots in the field of cerebral arteriovenous malformation treatment, as well as a detailed elaboration of possible research hotspots.

Methods

A bibliometric analysis was conducted on data retrieved from the Web of Science core collection database between 2000 and 2022. The analysis was performed using R, VOSviewer, CiteSpace software, and an online bibliometric platform.

Results

A total of 1,356 articles were collected, and the number of publications has increased over time. The United States and the University of Pittsburgh are the most prolific countries and institutions in the field. The top three cited authors are Kondziolka D, Sheehan JP, and Lunsford LD. The Journal of Neurosurgery and Neurosurgery are two of the most influential journals in the field of brain arteriovenous malformation treatment research, with higher H-index, total citations, and number of publications. Furthermore, the analysis of keywords indicates that "aruba trial," "randomised trial," "microsurgery," "onyx embolization," and "Spetzler-Martin grade" may become research focal points. Additionally, this paper discusses the current research status, existing issues, and potential future research directions for the treatment of brain arteriovenous malformations.

Conclusion

This bibliometric study comprehensively analyses the publication trend of cerebral arteriovenous malformation treatment in the past 20 years. It covers the trend of international cooperation, publications, and research hotspots. This information provides an important reference for scholars to further study cerebral arteriovenous malformation.

Endovascular NBCA treatment of a ruptured arteriovenous malformation with venous pseudoaneurysm in a young child

We reported imaging findings of arterio-venous malformation complicated by hemorrhage and venous pseudoaneurysm in a young child consulting for headache and emesis: to our knowledge venous pseudoaneurysm in association with ruptured arteriovenous malformation is a rare complication reported in the literature. We present the indications for endovascular treatment, especially with NBCA (N-butyl cyanoacrylate).

Management of Brain Arteriovenous Malformations: A Review

Brain arteriovenous malformations (bAVM) are vascular malformations of the brain affecting all ages. The optimum management strategy is essentially devoid of high-quality evidence and is highly nuanced and embedded in local customs. This study summarizes the frequently employed management strategies, drawing conclusions on the utility of each method of treatment and delving into controversies surrounding them. A literature search on PubMed and Medline was done on January 3^rd, 2022. 11,767 articles were found, and abstracts were reviewed. Full-text review of 153 articles led to chapters from three books and 71 articles incorporated into a summative discussion. Spetzler-Ponce (S-P) Class A patients may be offered surgery if they are good surgical candidates and have a good number of high-quality years of life left. The exception is diffuse Spetzler-Martin (S-M) grade 2 in a patient older than 40 years: radiosurgery for unruptured and embolization for ruptured. S-P Class B may be offered surgery if a compact nidus or if younger than 40 years. If diffuse or age greater than 40, radiosurgery may be preferred if the Pollock-Flickinger score is less than 2.5. For the remainder of S-P Class B, conservative management may be preferred. S-P Class C is generally not treated unless young or those patients with poorly controlled seizures affecting their quality of life are willing to risk permanent neurological deficits. While the quality of studies is generally high, the level of evidence is concerning with only one randomized controlled trial (RCT). Most research output hails from high-income countries, i.e., perhaps not universally applicable to all settings owing to possible genetic, environmental, and resource differences. More research is needed: large volume studies in the pregnant population, validation of scoring systems in pediatric age groups, clinical trials focused on combination multi-staged treatment modalities, and studies originating from the developing world.

State of the Art in the Role of Endovascular Embolization in the Management of Brain Arteriovenous Malformations-A Systematic Review

As a significant cause of intracerebral hemorrhages, seizures, and neurological decline, brain arteriovenous malformations (bAVMs) are a rare group of complex vascular lesions with devastating implications for patients' quality of life. Although the concerted effort of the scientific community has improved our understanding of bAVM biology, the exact mechanism continues to be elucidated. Furthermore, to this day, due to the high heterogeneity of bAVMs as well as the lack of objective data brought by the lack of evaluative and comparative studies, there is no clear consensus on the treatment of this life-threatening and dynamic disease. As a consequence, patients often fall short of obtaining the optimal treatment. Endovascular embolization is an inherent part of multidisciplinary bAVM management that can be used in various clinical scenarios, each with different objectives. Well-trained neuro-interventional centers are proficient at curing bAVMs that are smaller than 3 cm; are located superficially in noneloquent areas; and have fewer, larger, and less tortuous feeding arteries. The transvenous approach is an emerging effective and safe technique that potentially offers a chance to cure previously untreatable bAVMs. This review provides the state of the art in all aspects of endovascular embolization in the management of bAVMs.

Untangling the Modern Treatment Paradigm for Unruptured Brain Arteriovenous Malformations

Brain arteriovenous malformations (AVMs) often present treatment challenges. Patients with unruptured AVMs must consider not only whether they want to be treated, but what treatment modality they would prefer. Vascular neurosurgeons, neurointerventional surgeons, and stereotactic radiosurgeons must in turn guide their patients through the most appropriate treatment course considering the risk of AVM rupture, an individual AVM’s characteristics, and patient preferences. In this review we will look at how the clinical trial “A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA)” has influenced the approach to unruptured brain AVMs and the treatment modalities available to clinicians to deal with these formidable lesions.

Exclusion treatment of ruptured and unruptured low-grade brain arteriovenous malformations: a systematic review

PURPOSE

To assess the obliteration rate, functional outcome, hemorrhagic complication, and mortality rates of exclusion treatment of low-grade brain arteriovenous malformations (BAVMs) (Spetzler and Martin grades (SMGs) 1 and 2), either ruptured or unruptured.

METHODS

Electronic databases-Ovid MEDLINE and PubMed-were searched for studies in which there was evidence of exclusion treatment of low-grade BAVMs treated either by endovascular, surgical, radiosurgical, or multimodality treatment. The primary outcome of interest was angiographic obliteration post-treatment and at follow-up. The secondary outcomes of interest were functional outcome (mRS), mortality rate, and hemorrhagic complication. Descriptive statistics were used to calculate rates and means.

RESULTS

Eleven studies involving 1809 patients with low-grade BAVMs were included. Among these, 1790 patients treated by either endovascular, surgical, radiosurgical, or multimodality treatment were included in this analysis. Seventy-two percent of BAVMs were Spetzler-Martin grade II. The overall (i.e., including all exclusion treatment modalities) complete obliteration rate ranged from 36.5 to 100%. The overall symptomatic hemorrhagic complication rate ranged from 0 to 7.3%; procedure-related mortality ranged from 0 to 4.7%.

CONCLUSION

Our systematic review of the literature reveals a high overall obliteration rate for low-grade BAVMs, either ruptured or unruptured, with low mortality rate and an acceptable post-treatment hemorrhagic complication rate. These results suggest that exclusion treatment of low-grade BAVMs may be safe and effective, regardless of the treatment modality chosen.

Elective intervention for unruptured cranial arteriovenous malformations in relation to ARUBA trial: a National Inpatient Sample study

BACKGROUND

In 2014, A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) concluded that medical management alone for cranial arteriovenous malformations (AVMs) had better clinical outcomes than interventional treatment. The impact of the ARUBA study on changes in the rates of intervention and outcomes is unknown. Thus, we investigated whether the conclusions from ARUBA may have influenced treatment modalities and outcomes of unruptured AVMs.

METHODS

The National Inpatient Sample (NIS) was queried between 2006 and 2018, for adult patients with an AVM who were admitted on an elective basis. Interventions included open, endovascular, and stereotactic surgeries. Join-point regression was used to assess differences in slopes of treatment rate for each modality before and after the time-point. Logistic regression was used to assess the odds of non-routine discharge and hemorrhage between the two time-points for each treatment modality. Linear regression was used to assess the mean length of stay (LOS) for each treatment modality between the two time-points.

RESULTS

A total of 40,285 elective admissions for AVMs were identified between 2006 and 2018. The rate of intervention was higher pre-ARUBA (n = 15,848; 63.8%) compared to post-ARUBA (n = 6985; 45.2%; difference in slope - 8.24%, p < 0.001). The rate of open surgery decreased, while endovascular and stereotactic surgeries remained the same, after the ARUBA trial time-point (difference in slopes - 8.24%, p < 0.001; - 1.74%, p = 0.055; 0.20%, p = 0.22, respectively). For admissions involving interventions, the odds of non-routine discharge were higher post-ARUBA (OR 1.24; p = 0.043); the odds of hemorrhage were lower post-ARUBA (OR 0.69; p = 0.025). There was no statistical difference in length of stay between the two time-points (p = 0.22).

CONCLUSION

The rate of intervention decreased, the rate of non-routine discharge increased, and rate of hemorrhage decreased post-ARUBA, suggesting that it may have influenced treatment practices for unruptured AVMs.

Treatments of unruptured brain arteriovenous malformations: A systematic review and meta-analysis

BACKGROUND

The best therapeutic option for unruptured brain arteriovenous malformations (bAVMs) patients is disputed.

OBJECTIVE

To assess the occurrence of obliteration and complications of patients with unruptured bAVMs after various treatments.

METHODS

A systematic literature search was performed in PubMed, EMBASE, Web of Science, and so on to identify studies fulfilling predefined inclusion criteria. Baseline, treatment, and outcomes data were extracted for statistical analysis.

RESULTS

We identified 28 eligible studies totaling 5852 patients. The obliteration rates were 98% in microsurgery group (95% confidence interval (CI): 96%-99%, I2 = 74.5%), 97% in surgery group (95%CI: 95%-99%, I2 = 18.3%), 87% in endovascular treatment group (95%CI: 80%-93%, I2 = 0.0%), and 68% in radiosurgery group (95%CI: 66%-69%, I2 = 92.0%). The stroke or death rates were 1% in microsurgery group (95%CI: 0%-2%, I2 = 0.0%), 0% in surgery group (95%CI: 0%-1%, I2 = 0.0%), 4% in endovascular treatment group (95%CI: 0%-8%, I2 = 85.8%), and 3% in radiosurgery group (95%CI: 3%-4%, I2 = 82.9%). In addition, the proportions of hemorrhage were 2% in microsurgery group (95%CI: 1%-4%, I2 = 0.0%), 23% in endovascular treatment group (95%CI: 7%-39%), and 12% in radiosurgery group (95%CI: 12%-13%, I2 = 99.2%). As to neurological deficit, the occurrence was 9% in microsurgery group (95%CI: 6%-11%, I2 = 94.1%), 20% in surgery group (95%CI: 13%-27%, I2 = 0.0%), 14% in endovascular treatment group (95%CI: 10%-18%, I2 = 64.0%), and 8% in radiosurgery group (95%CI: 7%-9%, I2 = 66.6%).

CONCLUSIONS

We found that microsurgery might provide lasting clinical benefits in some unruptured bAVMs patients for its high obliteration rates and low hemorrhage. These findings are helpful to provide a reference basis for neurosurgeons to choose the treatment of patients with unruptured bAVMs.

The SMART Registry: Long-Term Results on the Utility of the Penumbra SMART COIL System for Treatment of Intracranial Aneurysms and Other Malformations

Introduction: Penumbra SMART COIL® (SMART) System is a novel generation embolic coil with varying stiffness. The study purpose was to report real-world usage of the SMART System in patients with intracranial aneurysms (ICA) and non-aneurysm vascular lesions. Materials and Methods: The SMART Registry is a post-market, prospective, multicenter registry requiring ≥75% Penumbra Coils, including SMART, PC400, and/or POD coils. The primary efficacy endpoint was retreatment rate at 1-year and the primary safety endpoint was the procedural device-related serious adverse event rate. Results: Between June 2016 and August 2018, 995 patients (mean age 59.6 years, 72.1% female) were enrolled at 68 sites in the U.S. and Canada. Target lesions were intracranial aneurysms in 91.0% of patients; 63.5% were wide-neck and 31.8% were ruptured. Adjunctive devices were used in 55.2% of patients. Mean packing density was 32.3%. Procedural device-related serious adverse events occurred in 2.6% of patients. The rate of immediate post-procedure adequate occlusion was 97.1% in aneurysms and the rate of complete occlusion was 85.2% in non-aneurysms. At 1-year, the retreatment rate was 6.8%, Raymond Roy Occlusion Classification (RROC) I or II was 90.0% for aneurysms, and Modified Rankin Scale (mRS) 0-2 was achieved in 83.1% of all patients. Predictors of 1-year for RROC III or retreatment (incomplete occlusion) were rupture status (P < 0.0001), balloon-assisted coiling (P = 0.0354), aneurysm size (P = 0.0071), and RROC III immediate post-procedure (P = 0.0086) in a model that also included bifurcation aneurysm (P = 0.7788). Predictors of aneurysm retreatment at 1-year was rupture status (P < 0.0001). Conclusions: Lesions treated with SMART System coils achieved low long-term retreatment rates. Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier NCT02729740.

Arteriovenous Malformations in the Setting of Osler-Weber-Rendu: What the Radiologist Needs to Know

Osler-Weber-Rendu, also known as Hereditary Hemorrhagic Telangiectasia, is an autosomal dominant disease with phenotypic manifestations that include pulmonary, cerebrospinal, hepatic, and other visceral arteriovenous malformations (AVMs). Pulmonary AVMs can result in hypoxemia, hemoptysis, or stroke due to paradoxical embolism. The mainstay of treatment is transcatheter embolization. Central nervous system and abdominal visceral AVMs contribute to morbidity of the disease. Radiologists should be familiar with the imaging manifestations and treatment algorithm of AVMs in Osler-Weber-Rendu to effectively guide patient care.

Update Onyx embolization for plexiform arteriovenous malformation: Ante-grade drifting technique

OBJECTIVE

The conventional arteriovenous malformation (AVM) Onyx embolization technique is the extrusion Onyx injection technique, with blood-flow control after a certain distance casting through the head end of the microcatheter. This method has elevated periprocedural AVM bleeding complications. In this study, the authors reported safety and efficacy of an updated ante-grade drifting Onyx injection for plexiform AVM embolization.

METHODS

Between January 2016 and December 2018, 101 consecutive patients with plexiform AVMs were treated with ante-grade drifting Onyx injection. The patients' clinical status was classified using the modified Rankin Scale (mRS). To measure associations, logistic univariate or multivariate regression analyses were used.

RESULTS

Complete AVM obliteration was achieved in 51.2% (52/101) of patients. Two (2/101, 2.0%) arterial perforations occurred without causing neurological deficits. In univariate and multivariate logistic regression analyses, younger patient age (odds ratio (OR) = 1.06, 95% confidence interval (CI) 1.01-1.12, p = 0.014), haemorrhagic presentation at admission (OR = 7.14, 95% CI 1.52-33.33, p = 0.013) and low Spetzler-Martin grade (OR = 10.00, 95% CI 3.45-25.00, p < 0.001) were significantly correlated with complete obliteration. Pretreatment mRS was correlated with perforation complication (OR = 3.44, 95% CI 1.05-11.29, p = 0.041) in univariate logistic regression analysis but not in multivariate logistic regression analysis (OR = 2.956, 95%CI 0.745, 11.731, p = 0.123). Patients' clinical status was significantly improved after endovascular AVM embolization.

CONCLUSIONS

With ante-grade drifting Onyx injection, it was possible to prevent serious bleeding complications and elevated complete embolization rate in plexiform AVMs. Younger patient age, haemorrhagic presentation at admission and low AVM Spetzler-Martin grade were significantly correlated with complete obliteration. Although there is not enough statistical power to show that the pretreatment mRS and the arterial perforation complication have a significant correlation, but its OR value is large, and there may be more data in the future to obtain further conclusion.

Endovascular treatment as the main approach for Spetzler-Martin grade III brain arteriovenous malformations

BACKGROUND

Because Spetzler-Martin (SM) grade III brain arteriovenous malformations (bAVMs) constitute a heterogeneous group of lesions with various combination of sizes, eloquence, and venous drainage patterns, their management is usually challenging. The aim of this study is to evaluate the clinical/imaging outcomes and the procedural safety of endovascular approach as the main treatment for the cure of SM grade III bAVMs.

METHODS

In this retrospective study, prospectively collected data of SM grade III bAVMs treated by endovascular techniques between 2010 and 2018 at our hospital were reviewed. Patients older than 16 years with angiographic follow-up of at least 6 months after endovascular treatment were entered in the study. The patients had a mean follow-up of 12 months. The data were assessed for clinical outcome (modified Rankin Scale), permanent neurological deficit, post-operative complications, and optimal imaging outcome, defined by complete exclusion of AVM. The independent predictive variables of poor outcome or hemorrhagic complication were assessed using binary logistic regression.

RESULTS

Sixty-five patients with 65 AVMs were included in the study. Mean age of the patients was 40.0±14.4. Most common presentation was hemorrhage (61.5%). The patients underwent one to eight endovascular procedures (median=2). Mean nidus diameter was 30.2±13.0. A complete obliteration of AVM was achieved in 57 patients (87.7%). Post-procedure significant hemorrhagic and ischemic complications were seen in 13 (20%) and five (7.7%) patients respectively, leading to five (7.7%) transient and four (6.2%) permanent neurological deficits. Eight patients (12.3%) experienced worsening of mRS after embolization. Ten patients (15.4%) had poor outcome (mRS 3-5) at follow-up and two (3%) died.

CONCLUSIONS

Endovascular treatment can achieve a high rate of complete exclusion of grade III AVM but may be associated (as in other treatment modalities) with significant important complications.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02879071.