Residual lesions in patients undergoing microsurgical clipping of cerebral aneurysms in a reference university hospital.

[OBJECTIVES] This study aimed to analyze the incidence and epidemiological, angiographic, and surgical aspects associated with incomplete clipping of brain aneurysms in a cohort of patients undergoing microsurgical treatment.

[METHODS] The medical record data of patients who underwent microsurgery for cerebral aneurysm treatment and postoperative digital subtraction angiography, treated at the same teaching hospital between 2014 and 2019, were retrospectively analyzed. The studied variables involved epidemiological and clinical data, as well as neurological status and findings on neuroimaging. The time elapsed between hemorrhage and microsurgical treatment, data on the neurosurgical procedure employed for aneurysm occlusion, and factors associated with the treated aneurysm, specifically location and size, were also evaluated.

[RESULTS] One hundred and seventeen patients were submitted to 139 neurosurgical procedures, in which 167 aneurysms were clipped. The overall rate of residual injury was 23%. Smoking (odds ratio [OR]: 3.38, 95% confidence interval [CI95%]: 1.372-8.300, p=0.008), lesion size >10 mm (OR: 5.136, CI95%: 2.240-11.779, p<0.001) and surgery duration >6 h (OR: 8.667, CI95%: 2.713-27.681, p<0.001) were found to significantly impact incomplete aneurysm occlusion in the univariate analyses.

[CONCLUSION] Incomplete microsurgical aneurysm occlusion is associated with aneurysm size, complexity, and current smoking status. Currently, there is no consensus on postoperative assessment of clipped aneurysms, hindering the correct assessment of treatment outcomes.