Objective: Coil embolization for the treatment of internal carotid artery–posterior communicating artery aneurysms (PComAAn) associated with oculomotor nerve palsy (ONP) remains controversial in terms of the therapeutic effect to improve ONP. Patients with PComAAn treated in our hospital were retrospectively analyzed to evaluate the effectiveness of coil embolization on ONP.

Methods: Twenty-three patients who had coil embolization for PComAAn with ONP were included in the analysis. In the evaluation of postoperative outcome of ONP, complete resolution of all symptoms was considered as a total recovery. ONP with a few residual symptoms that are stable and not disabling was considered as a subtotal recovery and that with only a slight improvement as a partial recovery.

Results: Preoperative ONP was complete palsy in 14 and partial palsy in nine cases. The mean maximum diameter of the aneurysms was 9.1 ± 3.5 mm (3–17 mm), and the mean time from the onset to treatment was 46.3 ± 98.4 days (0–300 days). The embolization state immediately after the procedure was complete occlusion in seven, neck remnant in eight, and body filling (BF) in eight cases. Total recovery was observed in nine, subtotal recovery in 11, and partial recovery in three cases. The mean time to any improvement in ONP was 6.0 ± 6.0 months (0.5–25 months). Comparing 20 cases with total plus subtotal recovery and three cases with partial recovery, five (25.0%) and three (100%) cases showed BF immediately after the procedure, respectively, which was statistically significant (P = 0.015).

Conclusion: The analysis indicated that coil embolization for the treatment of PComAAn with ONP resulted in satisfactory recovery of ONP in 87% of the cases and the outcome of aneurysm embolization was related to improvement in ONP.