Endovascular and microsurgical treatment of cerebral arteriovenous malformations: Current recommendations

Microsurgery of Cerebral Arteriovenous Malformations in a Resource-Limited Setting: The First Case-Series from Iraq

BACKGROUND

Cerebral arteriovenous malformations (AVMs) can lead to significant morbidity and are particularly challenging to manage in resource-limited settings where endovascular treatment modalities are unaffordable for most patients.

OBJECTIVE

To describe the first case series of AVM from Iraq with an analysis of the related clinicoradiologic characteristics, operative features, and outcomes.

METHODS

A single-center database from October 2018 to December 2022 was reviewed to analyze the characteristics of cerebral AVMs who underwent surgical treatment in Baghdad, Iraq. We collected patient demographics, clinical, radiologic, operative, and the follow-up combined outcome results (modified Rankin Scale score and the presence of AVM remnants).

RESULTS

Of the 54 AVM patients treated with microsurgery, the majority of lesions have Spetzler-Martin grade of 3 (31.5%), followed by grade 1 (29.6%). The parietal lobe was the most common location of AVM in 25.9% of the cases, and the temporal location had better outcomes. The mean duration of surgery was 8.5 hours, ranging from 3 to 14 hours, with 20.3% of cases having undergone preoperative stereotactic radiosurgery, and just one patient received preoperative embolization. Good combined outcome (modified Rankin Scale 0-2 and no AVM remnant) was associated with lower SM grades (P=0.003); location in the nondominant hemisphere (P=0.036), and noneloquent regions (P=0.006); absence of deep venous drainage (P=0.042) and no intraoperative brain swelling (P=0.004). The mortality rate in our series was 5.5%.

CONCLUSIONS

Good clinicoradiologic outcomes can be achieved through microsurgery in a setting where endovascular treatment is inaccessible to patients due to limited resources.

Pilot Trial on Awake Surgery for Low-Grade Arteriovenous Malformations in Speech Area and Systematic Review of the Literature

OBJECTIVE

One of the pressing constraints in the treatment of arteriovenous malformations (AVM) is the potential development of new neurologic deficits, mainly when the AVM is in an eloquent area. The risk of ischemia when an en passage arterial supply is present is not negligible. In this regard, awake surgery holds promise in increasing the safety of low-grade AVM resection.

METHODS

We conducted a pilot trial on 3 patients with low-grade AVMs affecting speech areas to evaluate the safety of awake craniotomy using Conscious Sedation. Each feeder was temporarily clipped before the section. Also, we performed a systematic review to analyze the existing data about the impact of awake surgery in eloquent AVM resection.

RESULTS

None of the 3 patients presented with neurologic deficits after the procedure. Awake craniotomy was useful in 1 case, as it allowed the detection of speech arrest during the temporal clipping of 1 of the feeders. This vessel was identified as an en passage vessel, closer to the nidus. The second attempt revealed the feeder of the AVM, which was sectioned. Systematic review yielded 7 studies meeting our inclusion criteria. Twenty-six of 33 patients included in these studies presented with AVM affecting speech area. Only 2 studies included the motor evoked potentials. Six studies used direct cortical and subcortical stimulation. In all studies the asleep-awake-asleep technique was used.

CONCLUSIONS

Awake craniotomies are safe procedures and may be helpful in avoiding ischemic complications in low-grade AVMs, either affecting eloquent areas and/or when en passage feeders are present.

Enhancing the quality of evidence, comparability, and reproducibility in brain arteriovenous malformations treated with open surgery research: a systematic review and proposal of a reporting guideline for surgical and clinical outcomes

Brain Arteriovenous Malformations (bAVMs) are rare but high-risk developmental anomalies of the vascular system. Microsurgery through craniotomy is believed to be the mainstay standard treatment for many grades of bAVMs. However, a significant challenge emerges in the existing body of clinical studies on open surgery for bAVMs: the lack of reproducibility and comparability. This study aims to assess the quality of studies reporting clinical and surgical outcomes for bAVMs treated by open surgery and develop a reporting guideline checklist focusing on essential elements to ensure comparability and reproducibility. This is a systematic literature review that followed the PRISMA guidelines with the search in Medline, Embase, and Web of Science databases, for studies published between January 1, 2018, and December 1, 2023. Included studies were scrutinized focusing on seven domains: (1) Assessment of How Studies Reported on the Baseline Characteristics of the Patient Sample; (2) Assessment and reporting on bAVMs grading, anatomical characteristics, and radiological aspects; (3) Angioarchitecture Assessment and Reporting; (4) Reporting on Pivotal Concepts Definitions; (5) Reporting on Neurosurgeon(s) and Staff Characteristics; (6) Reporting on Surgical Details; (7) Assessing and Reporting Clinical and Surgical Outcomes and AEs. A total of 47 studies comprising 5,884 patients were included. The scrutiny of the studies identified that the current literature in bAVM open surgery is deficient in many aspects, ranging from fundamental pieces of information of methodology to baseline characteristics of included patients and data reporting. Included studies demonstrated a lack of reproducibility that hinders building cumulative evidence. A bAVM Open Surgery Reporting Guideline with 65 items distributed across eight domains was developed and is proposed in this study aiming to address these shortcomings. This systematic review identified that the available literature regarding microsurgery for bAVM treatment, particularly in studies reporting clinical and surgical outcomes, lacks rigorous scientific methodology and quality in reporting. The proposed bAVM Open Surgery Reporting Guideline covers all essential aspects and is a potential solution to address these shortcomings and increase transparency, comparability, and reproducibility in this scenario. This proposal aims to advance the level of evidence and enhance knowledge regarding the Open Surgery treatment for bAVMs.

Deliberately Staged Combined Endovascular Embolization and Subsequent Microsurgery Resection for the Treatment of Cerebral Arteriovenous Malformations

OBJECTIVE

Complex cerebral arteriovenous malformations (AVMs) require a combined therapy of endovascular embolization and microsurgical resection to eliminate the lesion and maximize neurological protection, while a deliberate time interval might contribute to optimal clinical outcomes. The present study aimed to explore the feasibility of this paradigm.

METHODS

All patients who underwent deliberately planned presurgery embolization and microsurgery resection between 2015 and 2023 were reviewed, with baseline data, postoperative complications, and follow-up outcomes recorded. The modified Rankin scale (mRS) was used to evaluate clinical outcomes, with mRS 0-2 defined as good.

RESULTS

A total of 30 patients were included in the study (15 were ruptured AVMs). The median Spetzler-Martin grade of baseline AVMs was 3 (interquartile range: 2-3). The median interval between the last embolization and microsurgery was 5 days (interquartile range: 2.25-7). The complete removal rate was 100%, and the overall permanent complication rate was 16.67%. At the last follow-up, 26 patients achieved mRS 0-2, while 28 had improved or unaltered mRS. The last follow-up mRS significantly improved from baseline and discharge (P = 0.0006 and P = 0.006). The last follow-up mRS decreased by 0.65 for each additional day of time interval before the 4.4-day inflection point (β = -0.65, P = 0.02) in the AVM ruptured cohort.

CONCLUSIONS

The deliberately staged combined procedure of embolization and microsurgery might be a safe and efficacious strategy for Spetzler-Martin grade 2-5 AVMs, 4-5 days might be an appropriate staged time interval for ruptured AVMs, although further studies are needed to substantiate these findings.

Worldwide Research Trends on Transvenous Embolization of Brain Arteriovenous Malformations: A Bibliometric and Visualized Study

BACKGROUND

Transvenous embolization (TVE) of brain arteriovenous malformations (bAVMs) is an emerging endovascular technique that has shown high cure rates in selected cases. The rationale of our study was to determine authorship and worldwide institutional trends and contributions to the knowledge in this topic.

METHODS

Web of Science database was used. A total of 63 articles were included based on predefined inclusion criteria, which were manually reviewed. The bibliometric analysis involved the use of quantitative bibliometric indicators and network analysis with co-authorship and co-occurrence of terms, which were performed using the bibliometrix package in R and VOSviewer, respectively.

RESULTS

The first article was published in 2010, with the largest number of articles published in 2022 (10 articles). The average number of citations per document was 11.38, and the annual growth rate was 14.35%. The top 10 authors with the most scientific production on TVE of bAVMs were from France, and the most cited study was published by Iosif C in 2015, followed by Consoli A in 2013, and Chen CJ in 2018. Journal of Neurointerventional Surgery was the journal with the most articles published. The most commonly used keywords were dural arteriovenous fistula, Onyx, vascular disorders, and neurological surgery around 2016, and intervention around 2021.

CONCLUSIONS

TVE of bAVMs is an emerging technique. Our search identified some scientific articles, without randomized clinical trials, but many case series from single institutions. French and German institutions are the pioneers in the field, and further research is required in specialized endovascular centers.

Intraoperative Monitoring Cerebral Blood Flow During the Treatment of Brain Arteriovenous Malformations in Hybrid Operating Room by Laser Speckle Contrast Imaging

Background

Hemodynamic changes caused by hybrid surgery for brain arteriovenous malformations (bAVM) are usually related to long-term lesions from "blood stealing". There are currently no viable low-cost, noninvasive procedures for assessing cerebral perfusion in the operating room. This study aims to investigate the use of intraoperative laser speckle contrast image (LSCI) software in AVM surgery.

Methods

In Zhongnan Hospital of Wuhan University, 14 patients who underwent surgery with LSCI were collected. To analyze the hemodynamic features of AVM and the influence on the peripheral cortex of AVM embolization and resection, we assessed the transit time between feeding arteries and drainage veins by intraoperative digital subtraction angiography (DSA). Meanwhile, LSCI was performed at pre-embolization, post-embolization, and after complete resection of bAVM.

Results

In this study, the transit time of bAVM before and after embolization was compared, the transit time before embolization was significantly shorter than that after embolization (p < 0.05). We also got good visualization of relative CBF, in addition, to flow imaging in the cortical vasculature round bAVM with LSCI. The flux of post-surgery was significantly higher than pre-embolization (p < 0.01).

Conclusion

Hemodynamic variable assessment plays an important role in the resection of AVM in the hybrid operative room and LSCI can be used to visualize and evaluate cortical cerebral blood flow to detect pathological hyperperfusion in real-time with a good spatial-temporal resolution in a sensitive and continuous, non-invasive mode.

Endovascular treatment in the multimodality management of brain arteriovenous malformations: report of the Society of NeuroInterventional Surgery Standards and Guidelines Committee

BACKGROUND

The purpose of this review is to summarize the data available for the role of angiography and embolization in the comprehensive multidisciplinary management of brain arteriovenous malformations (AVMs METHODS: We performed a structured literature review for studies examining the indications, efficacy, and outcomes for patients undergoing endovascular therapy in the context of brain AVM management. We graded the quality of the evidence. Recommendations were arrived at through a consensus conference of the authors, then with additional input from the full Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee and the SNIS Board of Directors.

RESULTS

The multidisciplinary evaluation and treatment of brain AVMs continues to evolve. Recommendations include: (1) Digital subtraction catheter cerebral angiography (DSA)-including 2D, 3D, and reformatted cross-sectional views when appropriate-is recommended in the pre-treatment assessment of cerebral AVMs. (I, B-NR) . (2) It is recommended that endovascular embolization of cerebral arteriovenous malformations be performed in the context of a complete multidisciplinary treatment plan aiming for obliteration of the AVM and cure. (I, B-NR) . (3) Embolization of brain AVMs before surgical resection can be useful to reduce intraoperative blood loss, morbidity, and surgical complexity. (IIa, B-NR) . (4) The role of primary curative embolization of cerebral arteriovenous malformations is uncertain, particularly as compared with microsurgery and radiosurgery with or without adjunctive embolization. Further research is needed, particularly with regard to risk for AVM recurrence. (III equivocal, C-LD) . (5) Targeted embolization of high-risk features of ruptured brain AVMs may be considered to reduce the risk for recurrent hemorrhage. (IIb, C-LD) . (6) Palliative embolization may be useful to treat symptomatic AVMs in which curative therapy is otherwise not possible. (IIb, B-NR) . (7) The role of AVM embolization as an adjunct to radiosurgery is not well-established. Further research is needed. (III equivocal, C-LD) . (8) Imaging follow-up after apparent cure of brain AVMs is recommended to assess for recurrence. Although non-invasive imaging may be used for longitudinal follow-up, DSA remains the gold standard for residual or recurrent AVM detection in patients with concerning imaging and/or clinical findings. (I, C-LD) . (9) Improved national and international reporting of patients of all ages with brain AVMs, their treatments, side effects from treatment, and their long-term outcomes would enhance the ability to perform clinical trials and improve the rigor of research into this rare condition. (I, C-EO) .

CONCLUSIONS

Although the quality of evidence is lower than for more common conditions subjected to multiple randomized controlled trials, endovascular therapy has an important role in the management of brain AVMs. Prospective studies are needed to strengthen the data supporting these recommendations.

Microsurgical Treatment of Deep and Eloquent AVMs

Over the past 30 years, the treatment of deep and eloquent arteriovenous malformations (AVMs) has moved away from microneurosurgical resection and towards medical management and the so-called minimally invasive techniques, such as endovascular embolization and radiosurgery. The Spetzler-Martin grading system (and subsequent modifications) has done much to aid in risk stratification for surgical intervention; however, the system does not predict the risk of hemorrhage nor risk from other interventions. In more recent years, the ARUBA trial has suggested that unruptured AVMs should be medically managed. In our experience, although these eloquent regions of the brain should be discussed with patients in assessing the risks and benefits of intervention, we believe each AVM should be assessed based on the characteristics of the patient and the angio-architecture of the AVM, in particular venous hypertension, which may guide us to treat even high-grade AVMs when we believe we can (and need to) to benefit the patient. Advances in imaging and intraoperative adjuncts have helped us in decision making, preoperative planning, and ensuring good outcomes for our patients. Here, we present several cases to illustrate our primary points that treating low-grade AVMs can be more difficult than treating high-grade ones, mismanagement of deep and eloquent AVMs at the behest of dogma can harm patients, and the treatment of any AVM should be tailored to the individual patient and that patient's lesion.

Radiosurgery as a microsurgical adjunct: outcomes after microsurgical resection of intracranial arteriovenous malformations previously treated with stereotactic radiosurgery

OBJECTIVE

Microsurgical resection of arteriovenous malformations (AVMs) can be aided by staged treatment consisting of stereotactic radiosurgery followed by resection in a delayed fashion. This approach is particularly useful for high Spetzler-Martin (SM) grade lesions because radiosurgery can reduce flow through the AVM, downgrade the SM rating, and induce histopathological changes that additively render the AVM more manageable for resection. The authors present their 28-year experience in managing AVMs with adjunctive radiosurgery followed by resection.

METHODS

The authors retrospectively reviewed records of patients treated for cerebral AVMs at their institution between January 1990 and August 2019. All patients who underwent stereotactic radiosurgery (with or without embolization), followed by resection, were included in the study. Of 1245 patients, 95 met the eligibility criteria. Univariate and multivariate regression analyses were performed to assess relationships between key variables and clinical outcomes.

RESULTS

The majority of lesions treated (53.9%) were high grade (SM grade IV-V), 31.5% were intermediate (SM grade III), and 16.6% were low grade (SM grade I-II). Hemorrhage was the initial presenting sign in half of all patients (49.5%). Complete resection was achieved among 84% of patients, whereas 16% had partial resection, the majority of whom received additional radiosurgery. Modified Rankin Scale (mRS) scores of 0-2 were achieved in 79.8% of patients, and 20.2% had poor (mRS scores 3-6) outcomes. Improved (44.8%) or stable (19%) mRS scores were observed among 63.8% of patients, whereas 36.2% had a decline in mRS scores. This includes 22 patients (23.4%) with AVM hemorrhage and 6 deaths (6.7%) outside the perioperative period but prior to AVM obliteration.

CONCLUSIONS

Stereotactic radiosurgery is a useful adjunct in the presurgical management of cerebral AVMs. Multimodal therapy allowed for high rates of AVM obliteration and acceptable morbidity rates, despite the predominance of high-grade lesions in this series of patients.

Transpacific Aeromedical Evacuation for a Ruptured Brain Arteriovenous Malformation During the COVID-19 Pandemic

The COVID-19 pandemic has altered preexisting patient treatment algorithms and referral patterns, which has affected neurosurgical care worldwide. Brain arteriovenous malformations are complex vascular lesions that frequently present with intracerebral hemorrhage. Care for these patients is best performed at large medical centers by specialists with high volumes. The authors describe the care of a patient who presented in extremis to a resource-limited, community-sized military treatment facility (MTF) in Southeast Asia. In the MTF, the patient underwent emergent neurosurgical therapy. However, given newly implemented restrictions enacted to mitigate COVID-19 spread, local transfer for definitive care to a tertiary care facility was not possible. In order to attain definitive care for the patient, a transpacific aeromedical evacuation augmented with a critical care air transport team was utilized for transfer to a tertiary care, teaching hospital. This case demonstrates the safe treatment of a patient with hemorrhagic arteriovenous malformations and postoperative management under limited conditions in an MTF outside the CONUS. Given the unique circumstances and challenges the pandemic presented, the authors feel that this patient's outcome was only possible by leveraging all the capability military medicine has to offer.

Targeted Embolization of Aneurysms Associated With Brain Arteriovenous Malformations at High Risk for Surgical Resection: A Case-Control Study

BACKGROUND

High-risk components of brain arteriovenous malformations (BAVMs) can be targeted to reduce the risk of lesion rupture.

OBJECTIVE

To evaluate targeted embolization of aneurysms against other means of treatment with a case-control analysis; we previously investigated this approach associated with BAVMs.

METHODS

Retrospective analysis of patients with BAVMs was performed, identifying patients treated with intention to occlude only an aneurysm associated with a BAVM. For each targeted aneurysm embolization (TAE) patient identified, 4 control patients were randomly selected, controlling for rupture status, age, and Spetzler-Martin plus Lawton-Young supplemental score. Analysis was performed to compare rates of adverse events (hemorrhage, new seizure, and death) between the 2 groups.

RESULTS

Thirty-two patients met inclusion criteria, and 128 control patients were identified, out of 1103 patients treated during the study period. Thirty-four adverse events occurred (15 ruptures, 15 new seizures, and 11 deaths) during the follow-up period (mean 1157 d for the TAE cohort and 1036 d for the non-TAE cohort). Statistically lower associations were noted for the TAE group for any adverse event (hazard ratio 0.28, P = .037) and the composite outcome of hemorrhage or new seizure (hazard ratio 0.20, P = .029).

CONCLUSION

For BAVMs at high risk for surgical resection, TAE can be performed safely and effectively. Patients treated with TAE had better outcomes than matched patients undergoing other combinations of treatment. TAE can be considered for BAVMs with high operative risk prior to radiosurgery or when no other treatment options are available.

Endovascular treatment of small cerebral arteriovenous malformations as a primary therapy

Purpose

The patient population that would benefit most from endovascular curative treatment of intracranial arteriovenous malformations is not clearly established. The aim of the study was to determine the effect of curative embolization of cerebral arteriovenous malformations with special regard to radiographic and clinical outcomes and procedure-related complications.

Material and methods

Between January 2009 and December 2014, 18 patients with intracranial arteriovenous malformations were embolized with Onyx with intent to cure. There were 4 women and 14 men with a mean age of 40 years (range 10-62 years). Inclusion criteria were: maximal diameter of the lesions ≤ 3 cm and arterial supply consisting of no more than 2 major arteries. There were 5 (27.8 %) patients with ruptured and 13 (72.2%) with unruptured lesions. Mean arteriovenous malformations size was 2.3 cm (range 1.5-2.9 cm).

Results

Thirty-three procedures were performed in 18 patients. Total obliteration was achieved in 5 patients (27.8%). The most common reason for initial incomplete angiographic occlusion were unfavorable angioarchitectural features of arteriovenous malformations with the rate of 44.4%. The mean follow-up of patients with complete occlusion was 35.2 months (range 18-60 months). Complication rate was 12.1%. One patient had permanent neurological deficit with resulting morbidity of 5.6%. There were no deaths.

Conclusions

Embolization of intracranial arteriovenous malformations plays a limited role as a sole therapeutic modality even in terms of small lesions with two or less arterial feeders, although larger prospective series are necessary to confirm your findings. Associated complications are not trivial and should be considered when choosing this form of treatment.

Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs must be tailored specifically to the lesion, with surgical resection being the gold standard for small, accessible lesions. Pre-operative embolization of AVMs can reduce nidal blood flow and remove high-risk AVM features such as intranidal or venous aneurysms, thereby simplifying a challenging neurosurgical procedure. Herein, we describe our approach for the staged endovascular embolization and open resection of AVMs, and highlight the advantages of having a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. This includes planning the craniotomy and resection to immediately follow the final embolization stage, thereby using a single session of anesthesia for aggressive embolization, and rapid resection. Finally, we provide a representative case of a 22-year-old female with an unruptured right frontal AVM diagnosed during a seizure workup, who was successfully treated via staged embolizations followed by open surgical resection.

[Surgical treatment of a pregnant female with AVM hemorrhage]

Hemorrhages from arteriovenous malformations (AVMs) in pregnant females are rare, but they are known to lead to high maternal and infant mortality. There are no standards for AVM treatment in pregnant females. Many authors believe that AVM resection before delivery improves the prognosis for life and health of the mother and fetus. In this paper, we present a case of successful surgical treatment of a female patient with AVM hemorrhage at 20 weeks and address management issues of these patients.

Microsurgery for ARUBA Trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformation)-Eligible Unruptured Brain Arteriovenous Malformations

BACKGROUND AND PURPOSE

The management of unruptured brain arteriovenous malformations (ubAVMs) remains controversial despite ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformation), a controlled trial that suggested superiority of conservative management over intervention. However, microsurgery occurred in only 14.9% of ARUBA intervention cases, raising concerns about the study's generalizability. Our purpose was to evaluate whether, in a larger ARUBA-eligible ubAVM population, microsurgery produces acceptable outcomes.

METHODS

Demographic data, AVM characteristics, and treatment outcomes were evaluated in 155 ARUBA-eligible bAVMs treated with microsurgery between 1994 and 2014. Outcomes were rates of early disabling deficits and permanent disabling deficits with modified Rankin Scale score ≥3 or any permanent neurological deficits with modified Rankin Scale score ≥1. Covariates associated with outcomes were determined by regression analysis.

RESULTS

Of 977 AVM patients, 155 ARUBA-eligible patients had microsurgical resection (71.6% surgery only and 25.2% with preoperative embolization). Mean follow-up was 36.1 months. Complete obliteration was achieved in 94.2% after initial surgery and 98.1% on final angiography. Early disabling deficits and permanent disabling deficits occurred in 12.3% and 4.5%, respectively, whereas any permanent neurological deficit (modified Rankin Scale score ≥1) occurred in 16.1%. Among ubAVM of Spetzler-Martin grades 1 and 2, complete obliteration occurred in 99.2%, with early disabling deficits and permanent disabling deficits occurring in 9.3% and 3.4%, respectively. Major bleeding was the only significant predictor of early disabling deficits on multivariate analysis (P<0.001).

CONCLUSIONS

Microsurgery in this cohort produced less disabling deficits than ARUBA with similar morbidity and AVM obliteration as other cohort series. This disparity between our results and ARUBA suggests that future controlled trials should focus on the safety and efficacy of microsurgery with or without adjunctive embolization in carefully selected ubAVM patients.

Less can be more: Targeted embolization of aneurysms associated with arteriovenous malformations unsuitable for surgical resection

INTRODUCTION

To mitigate risks of hemorrhage, high-risk features of brain arteriovenous malformations (BAVMs) can be targeted to reduce the risk of rupture. Previous investigation has examined embolization of a pedicle supplying a high-risk feature; this study examines embolization targeted specifically at aneurysms associated with BAVMs.

MATERIALS AND METHODS

Patients with BAVMs treated at two high-volume neurointerventional services were retrospectively reviewed. Patients treated with intention to occlude only the associated aneurysm itself were analyzed. Demographic and lesion characteristics were identified, as were technical and clinical outcomes. Adverse events were defined as hemorrhage, new seizure, and death.

RESULTS

Thirty-two patients met inclusion criteria out of 1103 patients treated during the study period. Twenty-seven (84.4%) BAVMs were acutely ruptured, all with the aneurysm identified as the hemorrhage source. Twenty-four (75.0%) lesions involved eloquent territory. There were equal numbers of feeding artery and nidus aneurysms. Follow-up data were available for a total of 101.3 patient-years for a mean follow-up time of 2.9 years. One patient died; the remaining 31 patients had improved functional status at last contact. Annualized rate of hemorrhage after treatment was 1.0%; rate of adverse events after treatment was 3.0%. Excluding time after confirmed occlusion following radiosurgery, annualized rates were 1.4% and 4.8%, respectively.

CONCLUSION

In inoperable BAVMs, targeted embolization of associated aneurysms can be performed safely and effectively. This should be considered in high-risk lesions prior to radiosurgery or in cases when no other treatment options are available. Such intervention warrants further investigation.