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Journal Club

Cerebrovascular

Surgical 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

10.3171/2022.7.JNS22813

PMID

N/A

PICO

Population

TOBAS surgical registry patients with ruptured and unruptured AVMs selected for surgery

Intervention

Microsurgical treatment with or without preoperative embolization

Comparator

No randomized comparator within this registry report

Outcomes

mRS >2 at follow-up, angiographic cure, serious adverse events, permanent disabling complications

Design

Type

Prospective multicenter surgical registry within pragmatic trial platform

Randomized

No

Multicenter

Yes

Blinded

N/A

Follow-up

Mean follow-up 18.1 months

Primary endpoint

mRS >2 at last follow-up

Secondary endpoints

  • Surgical angiographic cure
  • Serious adverse events
  • Permanent treatment-related complications with mRS >2

Practice impact

What this means

In TOBAS surgical registry patients, microsurgery delivered high cure rates, especially for low-grade AVMs, with nontrivial complication burden that was partly linked to adjunct embolization. Use this as supportive but nondefinitive evidence pending stronger randomized data.

Bottom line

Microsurgery achieved high angiographic cure in selected TOBAS registry patients, but safety outcomes depend heavily on case mix and adjunct embolization risk.

Strength of evidence

low

Recommendation

consider change

Why it matters

  • High cure rates, particularly in low-grade AVMs.
  • Permanent disabling complication rate was lower than overall SAE rate.
  • Nonrandomized design means treatment selection may explain part of observed performance.

What would change my mind

  • Randomized surgery-versus-observation outcomes for clearly defined unruptured AVM subgroups.
  • Prospective comparative data isolating effect of adjunct preoperative embolization.
  • Longer follow-up confirming durable functional benefit, not only angiographic cure.

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Selection into registry occurred when surgery was chosen and observation deemed unreasonable, increasing selection bias.

Confounding

Rupture status, AVM grade, and adjunct embolization likely confound observed safety and efficacy.

Missing data

Some initially selected surgical patients were excluded before analysis.

Multiplicity

Multiple subgroup percentages are descriptive without randomized control in this report.

Notes

  • High proportion of ruptured AVMs in registry shifts risk profile.
  • Many poor outcomes occurred in patients with high baseline disability from prior rupture.

Stats check

NNT

N/A

Effect sizes

  • Surgical cure: 123/139 (89%, 95% CI 82-93)
  • Low-grade cure: 105/110 (95%, 95% CI 90-98)
  • Primary safety outcome mRS >2: 16/139 (12%, 95% CI 7-18)
  • Permanent treatment-related mRS >2 complications: 6/139 (4%, 95% CI 2-9)
  • SAEs: 29/139 (21%, 95% CI 15-28)

Absolute effects

  • Difference between all-grade and low-grade cure rates: 6 percentage points
  • Most permanent disabling complications were linked to preoperative embolization

Concerns

  • No control arm to estimate net comparative benefit.
  • Event interpretation is sensitive to baseline rupture-related disability.

External validity

Who it applies to

Specialized AVM centers considering surgery, especially for low-grade lesions.

Who it does not

Patients managed in non-specialist settings or those not selected for surgery by multidisciplinary teams.

Generalizability notes

  • Real-world multicenter registry supports practical relevance.
  • Selection criteria and high rupture prevalence limit extrapolation to all unruptured AVMs.

Evidence trace

Source trace and metadata

Citations (5)

claim_id

methods_critique.selection

locator

p. 2 Methods

claim_id

methods_critique.confounding

locator

Table 1

claim_id

stats_check.cure

locator

p. 2 Results

claim_id

stats_check.safety

locator

Table 2

claim_id

practice_impact.conclusion

locator

p. 2 Conclusions

Metadata

Generated at

2026-03-04T03:09:55Z

Version

v1