Long-term outcomes of endovascular simple coiling versus neurosurgical clipping of unruptured intracranial aneurysms: A systematic review and meta-analysis.

BACKGROUND

Previous studies on ruptured intracranial aneurysms have shown favourable long-term outcomes of patients undergoing endovascular coiling compared to neurosurgical clipping. We aimed to evaluate if these results also apply to patients with unruptured intracranial aneurysms (UIAs).

METHODS

Embase, PubMed, and Cochrane Library were systematically searched for all studies reporting long-term (≥3 years) follow-up after coiling or clipping of UIAs. Thirteen studies involving 16,622 coiled patients and 13,606 clipped patients were included. Short-term outcome was defined as death ≤30 days after treatment. Long-term outcomes (>3 years) included all-cause mortality, morbidity (defined as modified Rankin Score 3-5 or Glasgow Outcome Score 2-3), cerebrovascular accident, intracerebral haemorrhage, additional repairs, and lost to follow-up. We calculated relative risk (RR), incidence and mortality rates (IR and MR), together with incidence and mortality rate ratio (IRR and MRR).

RESULTS

Patients treated with simple coiling had lower short-term mortality than clipped patients (RR = 0.62 (95%CI 0.42-0.91)), but this difference disappeared after long-term follow-up ((MRR) = 0.89 (95%CI: 0.78-1.02). Coiled patients had higher retreatment rates than clipped patients (IRR = 1.70 (95%CI 1.50-1.93)).

CONCLUSIONS

This systematic review and meta-analysis reports benefits and drawbacks of simple coiling versus neurosurgical clipping of UIAs. Future studies with longer follow-up time should account for differences in coiling techniques and confounding factors such as size and location of UIAs.