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Journal Club

Cerebrovascular

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

Journal of Neurosurgery | 2023

Rapid review note

Journal Club is a rapid, AI-assisted appraisal layer. It highlights study design, effect estimates, and practice relevance, but it is still a briefing, not a replacement for the paper.

For education only. Not medical advice.

Paper snapshot

Rapid study overview

Open paper

DOI

10.3171/2022.9.JNS22987

PMID

N/A

PICO

Population

TOBAS registry patients with ruptured and unruptured brain AVMs selected for curative or pre-embolization strategies

Intervention

Endovascular embolization as curative intent or pre-embolization before surgery or SRS

Comparator

No randomized comparator within this registry report

Outcomes

mRS >2 at follow-up, angiographic occlusion, serious adverse events, treatment-related disability

Design

Type

Prospective multicenter registry nested in a pragmatic randomized trial platform

Randomized

No

Multicenter

Yes

Blinded

N/A

Follow-up

Mean follow-up 22 months in curative registry and 24 months in pre-embolization registry

Primary endpoint

Death or dependency defined as mRS >2 at last follow-up

Secondary endpoints

  • Angiographic occlusion rates
  • Serious adverse events
  • Permanent treatment-related complications with mRS >2

Practice impact

What this means

This TOBAS registry report highlights that AVM embolization often did not achieve complete cure and carried substantial hemorrhagic risk. It supports careful case selection and preference for trial-based care when available.

Bottom line

Registry outcomes show modest occlusion and frequent hemorrhagic complications, so endovascular AVM therapy should remain selective and trial-oriented when possible.

Strength of evidence

low

Recommendation

do not change

Why it matters

  • High SAE rates and limited complete occlusion in many cases.
  • Nonrandomized registry design limits causal conclusions.
  • Authors recommend offering treatment in randomized trial contexts when feasible.

What would change my mind

  • Randomized evidence showing superior disability-free outcomes for specific embolization strategies.
  • Consistent multicenter data with lower hemorrhage rates and higher confirmed cure rates.
  • Robust subgroup modeling identifying low-risk high-benefit embolization phenotypes.

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Registry allocation was based on clinician choice, creating substantial selection bias risk.

Confounding

No randomized comparison in this report, and rupture status and grade mix strongly influence outcomes.

Missing data

Outcomes were unavailable for a subset of enrolled patients in both registries.

Multiplicity

Multiple subgroup percentages are descriptive and vulnerable to unstable inference.

Notes

  • Pragmatic registry structure improves real-world relevance but limits causal attribution.
  • Safety event rates include both periprocedural and delayed hemorrhagic events.

Stats check

NNT

N/A

Effect sizes

  • Curative registry mRS >2: 15/106 (14%, 95% CI 8-22)
  • Pre-embolization registry mRS >2: 9/77 (12%, 95% CI 6-21)
  • Confirmed AVM occlusion: 32/106 (30%) curative and 9/77 (12%) pre-embolization
  • SAEs: 28/106 (26%) curative and 18/77 (23%) pre-embolization

Absolute effects

  • Symptomatic hemorrhage in curative registry: 21/106 (20%)
  • Symptomatic hemorrhage in pre-embolization registry: 12/77 (16%)

Concerns

  • No control arm prevents net-benefit estimation.
  • Incomplete occlusion rates question curative reliability for many lesions.

External validity

Who it applies to

Specialized centers using endovascular AVM therapy within multidisciplinary treatment pathways.

Who it does not

Centers without high-volume AVM expertise or patients not considered for invasive treatment.

Generalizability notes

  • Registry includes ruptured and unruptured AVMs, reflecting heterogeneous practice.
  • Outcome interpretation must account for selection and lesion complexity.

Evidence trace

Source trace and metadata

Citations (5)

claim_id

methods_critique.selection

locator

p. 2 Methods

claim_id

methods_critique.missing_data

locator

p. 2 Results

claim_id

stats_check.primary_outcome

locator

p. 2 Results

claim_id

stats_check.occlusion

locator

Table 2

claim_id

practice_impact.conclusion

locator

p. 2 Conclusions

Metadata

Generated at

2026-03-04T03:09:55Z

Version

v1