Factors Predicting the Oculomotor Nerve Palsy following Surgical Clipping of Distal Vertebrobasilar Aneurysms: A Single-Institution Experience.

Background The aim of our study was to identify various clinical and radiologic factors that correlate with the oculomotor nerve palsy following clipping of distal vertebrobasilar aneurysms. Methods A total of 48 patients with 51 aneurysms were included in this retrospective study . Patient's age, gender, size, location, and projection of the aneurysm, preoperative Hunt and Hess (H&H) grade, presence of subarachnoid hemorrhage (SAH), temporary clipping, preoperative third nerve palsy, and Glasgow Outcome Scale were included in the model for analysis. Results A total of 15 patients (31.25%) developed oculomotor nerve palsy following clipping of basilar apex aneurysms. 38 patients (79.2%) presented with SAH and 35 patients (72.9%) had poor H&H grades at presentation. The size of the aneurysm (p = 0.03), preoperative H&H grade (p = 0.04), preoperative oculomotor nerve dysfunction (p = 0.007), and projection of an aneurysm (p = 0.004) had shown a significant correlation with the oculomotor nerve palsy. The size of the aneurysm (p = 0.030, odds ratio: 0.381; 95% confidence interval, 0.175-0.827] was an independent predictor of postoperative nerve dysfunction. Conclusion The size of the aneurysm, clinical grade at presentation, and projection of the aneurysm correlated with the oculomotor nerve dysfunction following clipping. These clinical and radiologic parameters can be used to predict the oculomotor nerve outcome.