Is clipping better than coiling in the treatment of patients with oculomotor nerve palsies induced by posterior communicating artery aneurysms? A systematic review and meta-analysis.

OBJECTIVE: Posterior communicating artery aneurysms (PcomAAs) are the second most common aneurysm, accounting for 25% of all aneurysms and 50% of internal carotid artery aneurysms. It has been estimated that oculomotor nerve palsy (ONP) occurs in up to one-third of patients with posterior communicating artery (PcomA) aneurysms. Recent research showed a better outcome of ONP in patients with PcomAA after surgical clipping when compared to endovascular coiling. We compared the effect of clipping and coiling on recovery of ONP in the management of patients with PcomAAs.

METHODS: A meta-analysis of studies that compared surgical clipping with endovascular coiling was conducted by searching the literature via Pubmed, Embase and Cochrane Library databases without restricting the publication year. We extracted the following information: author names and publication year; clinical outcome (number of complete and incomplete recovery of ONP); perioperative data (number of pre-operatively complete or incomplete ONP, subarachnoid hemorrhage or not, number of complications (hydrocephalus, recurrence of PcomAA)). Except for author names and publication year, the data was pooled to perform a mean effect size estimate. The effects of two treatment modalities were then analyzed.

RESULTS: Nine published reports of eligible studies involving 297 participants met the inclusion criteria. Overall, compared with endovascular coiling, surgical clipping had no statistically significant difference on the complete recovery of ONP, although there was an obvious trend in favor of clipping [RR=1.48, 95%CI (0.95, 2.29), p=0.08]. There was no significant difference in the total efficiency (any degree of change) on ONP [RR=1.08, 95%CI (0.94, 1.25), p>0.05], the overall complications [RR=0.60, 95%CI (0.33, 1.10), p>0.05], the efficacy on the complete recovery of ONP in patients without SAH [RR=0.83, 95%CI (0.53, 1.31), p>0.05], the effect on the complete recovery of ONP in patients with pre-operatively complete or incomplete ONP [RR=1.12, 95%CI (0.68, 1.85), p>0.05], [RR=1.12, 95%CI (0.79, 1.59), p>0.05]. In a comparison of a small cohort of patients that had suffered an SAH (17 vs. 22) there was a significant difference on the effect on complete recovery of ONP between clipping and coiling [RR=1.70, 95%CI (1.08, 2.67), p<0.05].

CONCLUSIONS: A superiority of clipping over coiling for the complete recovery of oculomotor nerve palsy in patients that had suffered an SAH from a ruptured aneurysm of the posterior communicating artery was found in the present meta-analysis. Limited by the relatively small sample sizes included, there were no significant differences observed in the clinical outcome between coiling and clipping in the treatment of unruptured PcomAA causing ONP. More evidence from advanced multi-center studies of large scale is needed to provide insight into the optimal treatment for outcome of ONP caused by PcomAAs.