The Neurosurgery Signal — Signal, Not Noise

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

10.1016/S1474-4422(09)70080-8

PMID

19329361

PICO

Population

Patients with ruptured intracranial aneurysms

Intervention

Endovascular coiling

Comparator

Neurosurgical clipping

Outcomes

Long-term risks of death, disability, and rebleeding

Design

Type

Randomized controlled trial

Randomized

Yes

Multicenter

Yes

Blinded

Not applicable: outcomes were objective events (death, rebleeding)

Follow-up

Mean 9 years (range 6-14 years)

Primary endpoint

Risk of death at 5 years

Secondary endpoints

Risk of rebleeding from treated aneurysm
Proportion of survivors independent at 5 years
Standardized mortality ratio

Practice impact

What this means

ISAT long-term follow-up shows coiling reduces 5-year mortality compared to clipping for ruptured aneurysms (RR 0.77). Rebleeding from treated aneurysms was higher with coiling (10 vs 3 events) but absolute risk small. No difference in independence among survivors at 5 years. Overall mortality remains elevated compared to general population (SMR 1.57).

Bottom line

Coiling reduces 5-year mortality compared to clipping for ruptured aneurysms, with small increased rebleeding risk but no difference in independence among survivors.

Strength of evidence

high

Recommendation

consider change

Why it matters

Large RCT with long-term follow-up
Consistent mortality benefit
Small absolute rebleeding risk difference (10 vs 3 events)

What would change my mind

Modern coiling techniques (flow diversion, stent-assisted) showing different durability
Longer-term data (>10 years) showing divergence in rebleeding rates
Subgroup analyses showing specific aneurysm types where clipping remains superior

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Low risk: randomized design, intention-to-treat analysis, complete loss to follow-up only 2.7% at mean 9 years

Confounding

Minimal: randomization balanced baseline characteristics; some non-UK centers stopped follow-up after 5 years

Missing data

Well-handled: only 2.7% lost to follow-up; UK patients flagged with national death registry

Multiplicity

Multiple endpoints reported but primary endpoint clearly defined; no adjustment for multiple comparisons noted

Notes

Long-term follow-up of landmark ISAT trial
Analysis by both allocation and treatment received

Stats check

NNT

33 (for death at 5 years, based on 3% absolute risk reduction)

Effect sizes

Relative risk of death at 5 years: 0.77 (95% CI 0.61-0.98)
Standardized mortality ratio: 1.57 (95% CI 1.32-1.82)

Absolute effects

Death at 5 years: coiling 11% (112/1046), clipping 14% (144/1041)
Independent survivors at 5 years: coiling 83% (626/755), clipping 82% (584/713)

Concerns

Rebleeding analysis underpowered: only 13 events from treated aneurysms
Log-rank p=0.06 for rebleeding by intention-to-treat

External validity

Who it applies to

Patients with ruptured intracranial aneurysms similar to ISAT population (mean age 52, mostly good-grade SAH)

Who it does not

Patients with unruptured aneurysms, complex/giant aneurysms, or poor-grade SAH (WFNS 4-5)

Generalizability notes

43 centers internationally
Enrolled 1994-2002; coiling technology has evolved
Mostly anterior circulation aneurysms

Evidence trace

Source trace and metadata

Citations (3)

claim_id

methods_critique.risk_of_bias

locator

p. 2 Methods

quote

2143 patients with ruptured intracranial aneurysms were enrolled between 1994 and 2002 at 43 neurosurgical centres and randomly assigned to clipping or coiling.

claim_id

stats_check.effect_sizes

locator

p. 3 Findings

quote

The risk of death at 5 years was significantly lower in the coiling group than in the clipping group (relative risk 0·77, 95% CI 0·61–0·98; p=0·03)

claim_id

practice_impact.bottom_line

locator

p. 3 Interpretation

quote

There was an increased risk of recurrent bleeding from a coiled aneurysm compared with a clipped aneurysm, but the risks were small. The risk of death at 5 years was significantly lower in the coiled group than it was in the clipped group.

Metadata

Generated at

2026-03-06T13:41:29.251Z

Version

top 100 cited in past 20 years