Resolution of Oculomotor Nerve Palsy Secondary to Posterior Communicating Artery Aneurysms: Comparison between Clipping and Coiling

Introduction: Posterior communicating artery aneurysm (PCoA) induced oculomotor nerve palsy (ONP) is a well-established entity. Previous studies have attempted to address the effectiveness of clip ligation or coil embolization on the rate and completeness of ONP resolution, but they have been limited by small sample sizes. Methods: In this multicentered study, 84 patients with ruptured and unruptured PCoA and acute ONP from January 1991 to October 2013 were reviewed. Included patients had angiographically confirmed PCoA and complete or partial ONP on admission. Treatment option was based on physician discretion. Rate of resolution of ONP was determined from treatment date to last known follow-up and was defined as complete versus partial or no resolution. Aneurysm characteristic and resolution data on 322 similarly treated patients were extracted from the literature and combined to increase sample size. Outcomes and treatment groups were directly compared. Complete primary data from the literature were not available for all patients and thus for certain groups the number of patients reviewed were not equal to the total number of patients available. Results: Overall, 399 patients were compared (205 clipped and 194 coiled). In both groups, there was no difference between the size of the aneurysm (7.7 ± 2.7 vs. 7.7 ± 3.4 mm), time from symptom onset to treatment (4.5 vs. 6.0 days), percentage of complete ONP at presentation (60 vs. 51.6%), percentage of partial ONP at presentation (40 vs. 48.5%), and percentage of ruptured aneurysms (50.5vs. 62%) and unruptured aneurysms (49.5vs. 38%) in the clipped and coiled groups, respectively. Overall, in the 399 patients, 56.1% of those who underwent clipping had full ONP recovery versus 45.5% in the coiling group (OR, 1.54; p = 0.032). Of the 223 patients who presented with complete ONP those who underwent clipping had a 45.5% full ONP recovery versus 29.0% in the coiling group (OR, 2.05; p = 0.012). Of the 176 patients who presented with partial ONP 75.6% who underwent clipping had a full recovery versus 58.5% in the coiling group (OR, 2.20; p = 0.014). In the ruptured aneurysm group ( n = 130), 70.9% of those who underwent clipping had full recovery versus 49.7% in the coiling group (OR, 2.50; p = 0.014). In the unruptured aneurysm group ( n = 100), 59.3% who underwent clipping had full recovery versus 45.7% in the coiling group (OR, 1.73; p = 0.174). Median time to full recovery, regardless of degree of presenting ONP, was 153 days (range, 54–369 days) in the clipped group versus 90 days (range, 36–240 days) in the coiled group ( p = 0.421). Conclusion: In our series of treated aneurysm patients who presented with either partial or complete ONP secondary to PCoA aneurysms, those who underwent clip ligation were much more likely to achieve full recovery compared with those undergoing coil embolization. It appears that those who are clipped have a longer recovery time compared with the coiled group, but ultimately recovery more completely. Across all patients, there was no difference in presenting characteristics including size of aneurysm, degree of palsy, time to treatment, and percentage ruptured versus nonruptured aneurysms.