Predictors of Intraoperative Aneurysm Rupture, Aneurysm Remnant, and Brain Ischemia following Microsurgical Clipping of Intracranial Aneurysms: Single-Center, Retrospective Cohort Study

Background and Study Aims Complete microsurgical clip occlusion of an aneurysm is one of the most important challenges in cerebrovascular surgery. Incorrect position of clip blades as well as intraoperative aneurysm rupture can expose the patient to serious complications such as rebleeding in case of aneurysm remnant and cerebral ischemia in case of occlusion of branching arteries or perforators. The aim of this study was to identify independent predictors of surgery-derived complications (aneurysm remnant and brain ischemia) as well as intraoperative aneurysm rupture in an institutional series of patients. Material and Methods This is a single-institution, retrospective cohort study including 147 patients with 162 aneurysms that were selected for microsurgical clipping due to intracranial aneurysm in a 5-year period. Bivariate and multivariate analyses were performed to identify independent predictors among demographic, clinical, and radiographic factors. Results Increasing aneurysm size with a cutoff value at 9 mm (p = 0.009; odds ratio [OR]: 0.644) and irregular dome shape (p = 0.003; OR: 4.242) were independently associated with brain ischemia and aneurysm remnants that occurred in 13.6 and 17.3% of patients in our group, respectively. Intraoperative rupture was encountered in 27% of patients and its predictors were patient's age (p = 0.002; OR: 1.073) and increasing aneurysm size with a cutoff value at 7 mm (p = 0.003; OR: 1.205). Conclusion Aneurysm size, patient's age, and irregular dome shape were the most important risk factors of aneurysm remnant, brain ischemia, and intraoperative aneurysm rupture in our series of patients. We were not able to define a cutoff value for patient's age, but our results showed that with increasing age the risk of intraoperative aneurysm rupture increased.