Effect of A Randomized trial of Unruptured Brain Arteriovenous Malformation on Interventional Treatment Rates for Unruptured Arteriovenous Malformations

Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

National reduction in cerebral arteriovenous malformation treatment correlated with increased rupture incidence

BACKGROUND

Recently, there has been a shift in management of unruptured cerebral arteriovenous malformations (AVMs) following studies suggesting that medical management alone was superior to interventional therapy.

OBJECTIVE

To evaluate the influence of contemporary AVM management on AVM rupture patterns in the United States.

METHODS

154 297 AVM admissions were identified between 2003 and 2017 in the National Inpatient Sample. Annual AVM intervention and rupture rates were computed and multivariable logistic regression assessed the likelihood of AVM intervention pre- and post-2014. Segmented regression identified significant change points and fitted segmented linear models for annual intervention and rupture rates. Correlation coefficients assessed the relationship between annual AVM intervention and rupture rates.

RESULTS

For unruptured AVMs, intervention likelihood and proportion decreased after 2014 (28.1% to 22.3%, p<0.0001; adjusted OR=0.857, 95% CI 0.751 to 0.977, p=0.02). Ruptured AVM admissions increased from 14.7% to 18.6% after 2014 (p<0.0001). Between 2003 and 2017, segmented linear regression identified one significant change point in intervention rate between 2014 and 2015. Average annual percent change for rupture incidence and intervention rate increased by 0.49% (p=0.0001) and decreased by 1.17% (p=0.0001), respectively. Annual AVM intervention rates were inversely correlated with annual AVM rupture incidence (Pearson coefficient=-0.82, p=0.0002). In 2017, the annual AVM rupture rate (20.6%) surpassed the annual AVM intervention rate (19.7%).

CONCLUSIONS

After 2014, the likelihood of intervention for unruptured AVMs decreased while the incidence of ruptured AVMs increased. These findings suggest that fewer unruptured AVM treatments may lead to increases in AVM rupture incidence.

Outcomes of Unruptured Low-Grade Brain Arteriovenous Malformations Using TOBAS (Treatment of Brain Arteriovenous Malformations Study) Criteria

BACKGROUND

Treatment of an unruptured brain arteriovenous malformation (bAVM) is a matter of debate, especially for low-grade bAVM (Spetzler-Martin grade I and II). The aim is to compare the outcomes of patients with low-grade unruptured bAVM after interventional or medical management in a pragmatic manner.

METHODS

Adults with unruptured low-grade bAVM diagnosed between 2006 and 2016 were included. The primary end points were death from all causes and disabling stroke that resulted in a modified Rankin Scale (mRS) score >2 at last follow-up.

RESULTS

Eighty-four patients presented with an unruptured Spetzler-Martin low-grade bAVM. Among these patients, 55 (65.5%) were treated and 29 (34.5%) were untreated, with no differences regarding clinical and radiologic characteristics. The modality of treatment was embolization in 25.5%, radiosurgery (alone, 30.9%; with embolization, 18.2%), and surgery (alone, 5.5%; with embolization, 20%). The rupture rate was 6.7% person-year in the untreated group; 12.7% (n = 7) of treated and 16.7% (n = 5) of untreated patients achieved the primary evaluation criteria (P = 0.744). Using a Kaplan-Meier curve, the probability of reaching this criterion at 5 years was not different between groups (P = 0.07). Complications resulting in an mRS score >2 at last follow-up occurred in 9.1%, in 80% of cases after embolization.

CONCLUSIONS

This study shows no differences between treated and untreated low-grade bAVM. Embolization seems to carry a high risk of complication and should be used with caution. The small number of cases must encourage cautious interpretations especially because of the spontaneous high-rupture rate. One major interest is to investigate center habits in pathology when treatment standards are limited.

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.

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.

Brain Arteriovenous Malformations: The Role of Imaging in Treatment Planning and Monitoring Response

Brain arteriovenous malformations (AVMs) are characterized by shunting between pial arteries and cortical or deep veins, with the presence of an intervening nidus of tortuous blood vessels. These lesions present a therapeutic challenge, because their natural history entails a risk of intracranial hemorrhage, but treatment may cause significant morbidity. In this article, imaging features of AVMs on MR imaging and catheter angiography are reviewed to stratify the risk of hemorrhage and guide appropriate management. The angioarchitecture of AVMs may evolve over time, spontaneously or in response to treatment, necessitating ongoing imaging surveillance.

Unruptured Arteriovenous Malformations: Do We Have an Answer After the Final Follow-Up of ARUBA? A Bayesian Viewpoint

Brain arteriovenous malformations (bAVMs) are vascular lesions that carry significant morbidity and mortality risk upon rupture. bAVM rupture causes either intracerebral or intraventricular hemorrhage, or both. In 2014, the first results of the ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) were published in The Lancet, causing a paradigm shift in clinical practice and suggesting the superiority of medical treatment in terms of mortality or stroke compared with any intervention designed to obliterate the AVM. In 2020, the final results of the ARUBA trial were published. In this Viewpoint, we critically review the clinical equipoise behind the trial, highlight issues regarding external validity, and place the results of the trial in the context of other results in scientific literature of bAVMs using Bayesian inference. ARUBA is a trial of decision-making, and only proper knowledge of the nuances of its interpretation within the broader context of bAVM research can lead to proper decision-making when confronted with patients with unruptured bAVMs.

Radiotherapeutic management of brain tumours during the COVID-19 pandemic

Aim:

The coronavirus disease (COVID-19) pandemic is bound to put tremendous pressure on the existing healthcare system. This aim of this technical note is to help in triaging patients with brain tumours who are sent for radiotherapy during this pandemic and to provide safe and evidence-based care.

Materials and Methods:

Published data for this review were identified by systematically searching PubMed database from November 2007 onwards with the following Medical Subject Heading (Mesh) terms ‘Brain tumours’, ‘COVID-19’, ‘coronavirus’, ‘SARS-nCoV-2’, ‘Radiotherapy’, ‘Guidelines’ ‘hypofractionation’ using Boolean search algorithm. Articles in English language were reviewed.

Results:

We tried to apply the as low as reasonable achievable (ALARA) principle in triaging and management of patients for radiotherapy. We identified protocols which have hypofractionated regimens (reducing patient visits to hospital, time spent in treatment console) with similar outcomes when compared to conventional fractionated regimens and not overburdening the healthcare facility. We also identified the tumours for which we could safely avoid or delay the initiation of radiotherapy.

Conclusion:

Treatment decisions made during the COVID-19 pandemic rely on the safety first/do no harm principle and evidence-based prioritisation of cases for triage. This article is a tool to aid in triaging and prioritising brain tumour patient management. This is for consideration during the pandemic only and certainly not as a strategy for permanent practice change.