CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-23). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1501 · Search date 2026-07-23 · Methodology v0.6

Endovascular coil embolization,
does it really help with Reduced death or dependency at one year in ruptured intracranial aneurysms suitable for either coiling or clipping?

30-Second Summary
B
Evidence Grade B · 78 · Safety unknown
In selected ruptured aneurysms, coiling reduced early death or dependency versus clipping but required more retreatment and had more late rebleeding
What the
research shows
Endovascular coiling is graded B because it reduced death or dependency at one year versus clipping in patients with ruptured intracranial aneurysms judged suitable for either procedure. In the final ISAT report, the composite outcome occurred in 23.5% versus 30.9%, and a survival advantage persisted in long-term follow-up. This was superiority over another effective procedure rather than placebo or no treatment, and randomized patients were a selected fraction of those screened. More late rebleeding and retreatment after coiling also qualify its durability.
What the
ads claim
Descriptions can turn coiling into a uniformly superior and recurrence-free procedure for every aneurysm. The randomized evidence directly applies to patients with rupture for whom both treatments were technically feasible and clinical equipoise existed.
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Useful facts when choosing a product

  • Coil embolization is a hospital-based prescription procedure that advances a catheter into the aneurysm and uses platinum coils or related devices to obstruct blood flow.
  • The direct comparator in ISAT was surgical clipping through craniotomy.
  • The evidence is most direct for ruptured intracranial aneurysms judged suitable for either coiling or clipping by experienced teams.
  • Intraprocedural rupture, thromboembolism, cerebral infarction, and hemorrhage can occur; incomplete occlusion or recanalization can require imaging surveillance and retreatment.
Gap Measurement · Verdict 1501 · B 78
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

The 2005 final ISAT report randomized 2,143 patients at 43 centers to coiling or clipping and reported one-year death or dependency of 23.5% versus 30.9%. The 2009 long-term follow-up found lower mortality after assignment to coiling but more late rebleeding from the treated aneurysm. A 2007 analysis also found more retreatment after coiling. This evidence concerns coiling for ruptured aneurysm and is distinct from decompressive hemicraniectomy or alteplase for acute ischemic stroke.

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Why this is classified as B (78)

A large randomized ISAT comparison reduced one-year death or dependency and long-term mortality. Because this was superiority over active clipping in a selected population and rebleeding and retreatment were more frequent after coiling, the verdict is B with 78 points.

Counterpoint. The absolute frequency of late rebleeding was low and disability-free long-term survival favored coiling. Durability and early clinical benefit are separate outcomes that should be retained together.

Rejudgment record. New verdict — Accepted randomized ISAT reductions in one-year death or dependency and long-term mortality versus active clipping, while applying the B ceiling for active-control superiority in a population selected for suitability for both procedures and retaining higher late rebleeding and retreatment after coiling

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Reduced death or dependency at one yearBISAT reported 23.5% with coiling versus 30.9% with clipping, but this was an active-procedure comparison in a selected population.
Reduced long-term mortalityBLong-term follow-up of the randomized cohort found lower mortality after assignment to coiling.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Molyneux AJ et al. ISAT 2005Multicenter randomized active comparison of coiling versus clipping2,143Public and nonprofit support including the UK Medical Research CouncilDeath or dependency at one yearThe outcome occurred in 23.5% with coiling and 30.9% with clipping, an absolute difference of 7.4 percentage points favoring coiling.Key large randomized active-control evidence
Molyneux AJ et al. ISAT long-term follow-up 2009Long-term follow-up of the randomized ISAT cohort2,143Public and nonprofit supportLong-term death, dependency, and rebleedingMortality was lower after assignment to coiling, while late rebleeding from the treated aneurysm was more frequent after coiling.Long-term clinical and durability evidence
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-23).

Molyneux AJ, Kerr RSC, Yu LM, et al. International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion. Lancet. 2005;366(9488):809-817. PMID: 16139655. DOI: 10.1016/S0140-6736(05)67214-5.
checked
Molyneux AJ, Kerr RSC, Birks J, et al. Risk of recurrent subarachnoid haemorrhage, death, or dependence and standardised mortality ratios after clipping or coiling of an intracranial aneurysm in ISAT: long-term follow-up. Lancet Neurol. 2009;8(5):427-433. PMID: 19329361. PMCID: PMC2669592. DOI: 10.1016/S1474-4422(09)70080-8.
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Campi A, Ramzi N, Molyneux AJ, et al. Retreatment of ruptured cerebral aneurysms in patients randomized by coiling or clipping in ISAT. Stroke. 2007;38(5):1538-1544. PMID: 17395870. DOI: 10.1161/STROKEAHA.106.466987.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-23 · Corrections: none

Cite this verdict

Endovascular coil embolization x reduced death or dependency after ruptured intracranial aneurysm Evidence Grade B card
[Chamgap] Endovascular coil embolization x reduced death or dependency after ruptured intracranial aneurysm — Evidence Grade B·78. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/cognition/endovascular-coil-embolization-ruptured-intracranial-aneurysm/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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