Introduction: Oculomotor nerve palsy (ONP) is a well-known presentation of posterior communicating artery (PCOM) aneurysms. Surgical clipping has been the treatment of choice for improved clinical outcome. Reports on recovery of ONP with endovascular coiling have been limited to small case-series. This is the largest study to date investigating the clinical outcome of ONP with different endovascular embolization techniques and predictors of complete recovery.
Methods: 37 patients with ONP and available clinical follow-up underwent endovascular treatment in our institution between 2005-2011. Medical charts, operative reports, and office follow-up records were reviewed to determine the degree of nerve recovery after endovascular therapy.
Results: 19 patients (51.4%) presented with complete ONP and 18 (48.6%) with partial ONP. 17 patients (45.9%) were treated in the setting of subarachnoid hemorrhage. Mean aneurysm size was 7.6 mm. Conventional coiling was performed in 31 (83.8%) patients, stent-assisted coiling in 4 (10.8%), and balloon remodeling in 2 (5.4%). There was 1 (2.7%) procedural complication (a transient thromboembolic event). 27 (73%) patients were treated within 3 days from symptom onset. Mean follow-up time was 11.3 months. At the last available clinical follow-up, ONP resolution was complete in 14 (37.8%) patients and partial in 19 (51.4%). Only 4 (10.8%) patients showed no signs of nerve recovery. Complete nerve recovery occurred in 50% (9/18) of patients with initial partial ONP versus 21% (4/19, p=0.01) with initial complete ONP. In multivariate analysis, partial ONP, younger age, and longer follow-up durations were independent predictors of complete nerve recovery. Treatment timing, type of endovascular embolization, subarachnoid hemorrhage, and initial degree of aneurysm occlusion were not predictors of nerve recovery.
Conclusions: Endovascular therapy is a safe and efficient treatment for PCOM aneurysms with ONP, with nerve recovery rates almost comparable to surgical clipping. Partial nerve palsy and young patient age carry a more favorable clinical outcome.
Patient Care: This is the largest study to date to assess the safety and efficacy of endovascular therapy in promoting oculomotor nerve recovery. The data provided will help neurosurgeons make evidence-based clinical decisions for these patients and optimize their management.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Discuss the advantages and limitations of endovascular therapy in the treatment of PC aneurysms with ONP. 2) Discuss the factors that may influence recovery of ONP after endovascular treatment 3) Optimize the treatment options for patients presenting with PC aneurysms causing ONP.