Presigmoid Approach to Vertebrobasilar Artery Aneurysms: A Series of 31 Patients and Review of the Literature.

OBJECTIVE: The presigmoid approach can be used to treat vertebrobasilar artery aneurysms when circumstances require more operative exposure. High morbidity and mortality in these cases have been reported. In this study, we describe our modified presigmoid approach for vertebrobasilar artery aneurysms and our clinical results. METHODS: This series includes patients with vertebrobasilar aneurysms clipped via the modified presigmoid approach at the Department of Neurosurgery at Helsinki University Hospital from 1998 to 2014. Data were collected from the operating record books, patients' medical records, and a radiologic database server. RESULTS: Thirty-three presigmoid procedures of 31 patients were performed to treat 34 aneurysms (14 ruptured, 20 unruptured). The aneurysms had a mean distance from the posterior clinoid process to the aneurysm neck of 12.2 mm (range, 0-26.6 mm). A favorable outcome was achieved in 21 patients (64%). A favorable outcome was achieved in 74% of unruptured and good-grade patients, whereas favorable outcome was achieved in only 36% of poor-grade patients. Complete or near-complete occlusion was achieved in 79%. Larger aneurysms, fusiform morphology, and anterior dome projection had lower occlusion rates. CONCLUSIONS: We have described our experiences of using the presigmoid approach to treat vertebrobasilar aneurysms. The clinical and radiographic results are acceptable given the complex location and configuration of the treated aneurysms. Unfavorable outcomes are related to the poor admission Hunt and Hess grade, aneurysm morphology, and aneurysm size.

Factors Determining Surgical Approaches to Basilar Bifurcation Aneurysms and Its Surgical Outcomes.

BACKGROUND: The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective. OBJECTIVE: To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes. METHODS: A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05. RESULTS: One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size. CONCLUSION: Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome.