Endovascular coiling versus microsurgical clipping for extremely small intracranial aneurysms: a comparative analysis of treatment strategies, complications, and clinical outcomes.

Background: Generally, extremely small intracranial aneurysms (ESIAs) are defined as having a maximum diameter of less than 2 mm. Despite technological improvement, treating ESIAs remains challenging for neurosurgery specialists. ESIA treatment has long been controversial owing to the high risk of complications associated with both endovascular coiling (EC) and microsurgical clipping (MC). This retrospective cohort study assessed postoperative complications, angiographic outcomes, and long-term clinical efficacy in ESIAs patients receiving EC or MC interventions. The objective was to evaluate the effectiveness of different surgical interventions for patients diagnosed with ESIAs. Methods: Patients who underwent EC or MC between February 2013 and December 2023 were retrospectively analyzed. A total of 153 patients were included in this study, encompassing both ruptured and unruptured cases of ESIAs. Notably, unruptured cases were associated with larger ipsilateral aneurysms, which were either ruptured or at a significant risk of rupture. Imaging follow-up evaluations were conducted using computed tomography angiography (CTA) or digital subtraction angiography (DSA), whereas patient recovery outcomes were assessed using the Glasgow Outcome Scale (GOS). The primary outcome measure was the GOS score recorded 6 months post-treatment. Secondary outcomes included the GOS score at discharge, the embolization rate 6 months after treatment, and postoperative complications such as cerebral infarction, hydrocephalus, and postoperative rebleeding. Results: This study included 153 patients, 84 of whom were treated with EC and 69 with MC. In the EC group, 28 cases of unruptured aneurysms were identified, whereas the MC group had 20 cases of unruptured aneurysms. EC treatment demonstrated slight benefits in clinical outcomes at discharge, with statistically significant differences 6 months after treatment. The EC group had a shorter hospital stay compared with the MC group (14.40±6.57 Conclusions: Both EC and MC treatments are suitable for patients with ESIAs. However, the EC group exhibited fewer hospitalization days than the MC group, whereas the latter demonstrated a higher occlusion rate. Female patients may have better long-term outcomes with EC treatment. Further confirmation through large-sample, multi-center trials is needed.