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Original research
Clinical outcome after surgical clipping or endovascular coiling for cerebral aneurysms: a pragmatic meta-analysis of randomized and non-randomized trials with short- and long-term follow-up
  1. Alberto Falk Delgado1,
  2. Tommy Andersson2,3,4,
  3. Anna Falk Delgado2,3
  1. 1Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
  2. 2Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
  3. 3Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
  4. 4Department of Medical Imaging, AZ Groeninge, Kortrijk, Belgium
  1. Correspondence to Dr Alberto Falk Delgado, Department of Surgical Sciences, Uppsala University, Ing 78/79, Akademiska sjukhuset, Uppsala 75185, Sweden; alberto.falk-delgado{at}


Background Two randomized trials have evaluated clipping and coiling in patients with ruptured aneurysms. Aggregated evidence for management of ruptured and unruptured aneurysms is missing.

Objective To conduct a meta-analysis evaluating clinical outcome after aneurysm treatment.

Methods PubMed, Cochrane Central Register of Controlled Trials, and were searched for studies evaluating aneurysm treatment. The primary outcome measure was an independent clinical outcome (modified Rankin scale 0–2, Glasgow Outcome Scale 4–5, or equivalent). Secondary outcomes were poor outcome and mortality. ORs were calculated on an intention-to-treat basis with 95% CIs. Outcome heterogeneity was evaluated with Cochrane's Q test (significance level cut-off value at <0.10) and I2 (significance cut-off value >50%) with the Mantel–Haenszel method for dichotomous outcomes. A p value <0.05 was regarded as statistically significant.

Results Searches yielded 18 802 articles. All titles were assessed, 403 abstracts were evaluated, and 183 full-text articles were read. One-hundred and fifty articles were qualitatively assessed and 85 articles were included in the meta-analysis. Patients treated with coiling (randomized controlled trials (RCTs)) had higher independent outcome at short-term follow-up (OR=0.67, 95% CI 0.57 to 0.79). Independent outcome was favored for coiling at intermediate and long-term follow-up (RCTs and observational studies combined—OR=0.80, 0.68 to 0.94 and OR=0.81, 0.71 to 0.93, respectively). Independent outcome and lower mortality was favored after coiling in unruptured aneurysms (database registry studies) at short-term follow-up (OR=0.34, 0.29 to 0.41 and OR=1.74, 1.52 to 1.98, respectively).

Conclusions This meta-analysis evaluating clinical outcome after coiling or clipping for intracranial aneurysms, indicates a higher independent outcome and lower mortality after coiling.

  • Aneurysm
  • Coil
  • Hemorrhage
  • Intervention

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  • Contributors AlFD and AnFD contributed equally to this study. AlFD and AnFD planned the work and were responsible for data collection, analysis and interpretation, and writing of the manuscript. TA interpreted the data and critically revised the manuscript. All authors approved the final version and agreed on the integrity of the work.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.