Endovascular Coiling Versus Neurosurgical Clipping for Aneurysmal Subarachnoid Haemorrhage

A Cochrane review [Abstract] 1 included 3 studies with a total of 2 272 subjects. Most of the patients were in good clinical condition and had an aneurysm on the anterior circulation. The evidence comes mainly from one large trial 2 3.

After one year of follow up, the relative risk (RR) of poor outcome for coiling versus clipping was 0.76 (95% confidence interval (CI) 0.67 to 0.88). The absolute risk reduction was 7% (95% CI 4% to 11%). In the worst-case scenario analysis for poor outcome overall, the relative risk for coiling versus clipping was 0.81 (95% CI 0.70 to 0.92) and the absolute risk reduction was 6% (95% CI 2% to 10%). For patients with anterior circulation aneurysm the relative risk of poor outcome was 0.78 (95% CI 0.68 to 0.90) and the absolute risk decrease was 7% (95% CI 3% to 10%). For those with a posterior circulation aneurysm the relative risk was 0.41 (95% CI 0.19 to 0.92) and the absolute decrease in risk 27% (95% CI 6% to 48%).

Authors' conclusion: For patients in good clinical condition with ruptured aneurysms of either the anterior or posterior circulation we have firm evidence that, if the aneurysm is considered suitable for both surgical clipping and endovascular treatment, coiling is associated with a better outcome.

Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in results in different populations).

References

• van der Schaaf I, Algra A, Wermer M, Molyneux A, Clarke M, van Gijn J, Rinkel G. Endovascular coiling versus neurosurgical clipping for patients with aneurysmal subarachnoid haemorrhage. Cochrane Database Syst Rev 2005 Oct 19;(4):CD003085. [PubMed]
• Molyneux A, Kerr R, Stratton I, Sandercock P, Clarke M, Shrimpton J, Holman R, International Subarachnoid Aneurysm Trial (ISAT) Collaborative Group. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial. Lancet 2002 Oct 26;360(9342):1267-74. [PubMed]
• Molyneux AJ, Kerr RS, Yu LM, Clarke M, Sneade M, Yarnold JA, Sandercock P, International Subarachnoid Aneurysm Trial (ISAT) Collaborative Group. 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 Sep 3-9;366(9488):809-17. [PubMed]