Stability of unruptured intracranial aneurysms in the anterior circulation: nomogram models for risk assessment

Abstract

OBJECTIVE The probable stability of the lesion is critical in guiding treatment decisions in unruptured intracranial aneurysms (IAs). The authors aimed to develop multidimensional predictive models for the stability of unruptured IAs. METHODS Patients with unruptured IAs in the anterior circulation were prospectively enrolled and regularly followed up. Clinical data were collected, IA morphological features were assessed, and adjacent hemodynamic features were quantified with patient-specific computational fluid dynamics modeling. Based on multivariate logistic regression analyses, nomograms incorporating these factors were developed in a primary cohort (patients enrolled between January 2017 and February 2018) to predict aneurysm rupture or growth within 2 years. The predictive accuracies of the nomograms were compared with the population, hypertension, age, size, earlier rupture, and site (PHASES) and earlier subarachnoid hemorrhage, location, age, population, size, and shape (ELAPSS) scores and validated in the validation cohort (patients enrolled between March and October 2018). RESULTS Among 231 patients with 272 unruptured IAs in the primary cohort, hypertension, aneurysm location, irregular shape, size ratio, normalized wall shear stress average, and relative resident time were independently related to the 2-year stability of unruptured IAs. The nomogram including clinical, morphological, and hemodynamic features (C+M+H nomogram) had the highest predictive accuracy (c-statistic 0.94), followed by the nomogram including clinical and morphological features (C+M nomogram; c-statistic 0.89), PHASES score (c-statistic 0.68), and ELAPSS score (c-statistic 0.58). Similarly, the C+M+H nomogram had the highest predictive accuracy (c-statistic 0.94) in the validation cohort (85 patients with 97 unruptured IAs). CONCLUSIONS Hemodynamics have predictive values for 2-year stability of unruptured IAs treated conservatively. Multidimensional nomograms have significantly higher predictive accuracies than conventional risk prediction scores.

Nomograms for assessing the rupture risk of anterior choroid artery aneurysms based on clinical, morphological, and hemodynamic features

“…The derived regression equations yielded an AUC of 0.89 for the comprehensive model, incorporating hemodynamic parameters, marking the highest predictive accuracy ( 41 ). Moreover, Liu et al ( 4 ) categorized the rupture risk concerning the stability of IAs in the anterior circulation. The C-indices for the models (C + M + H), (C + M), and PHASES scores were 0.94, 0.89, and 0.68, respectively.…”

“…Utilizing a time step of 0.001 s generates 800 solutions for 3 cardiac cycles. The last simulated cardiac cycle is utilized for post-processing hemodynamic parameters ( 4 ). Finally, morphological and hemodynamic outcomes are exported together.…”

“…In this investigation, we meticulously recorded and computed four crucial hemodynamic parameters: normalized wall shear stress (NWSS), average oscillatory shear index (OSI ave ), low shear area (LSA), and relative residence time (RRT). Comprehensive insights into the calculation methods can be gleaned from the seminal works of Liu et al ( 4 ) and Retarekar et al ( 24 ).…”

“…The occurrence of anterior choroidal artery (AChA) aneurysms is relatively low, constituting only 2-5% of all cerebral aneurysms (1). While the incidence of rupture in AChA aneurysms is elevated within the realm of medical care (2), the PHASES score scale (considering population, hypertension, age, size, prior subarachnoid hemorrhage, and location) indicated relatively lower scores for these small aneurysms (3)(4)(5). Furthermore, earlier research showed that the majority of ruptured intracranial aneurysms (IAs) exhibit a diameter of less than 7 mm (6), with approximately 35-47% of all IAs being small and ruptured (7,8).…”