{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T14:20:08Z","timestamp":1789395608679,"version":"build-2803163510"},"reference-count":26,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sci.","Brain Sciences"],"abstract":"<jats:p>Background: Unruptured intracranial aneurysms (UIAs) represent a major challenge in neurosurgical practice. Rupture risk assessment traditionally relies on qualitative parameters, such as aneurysm size and shape, combined with surgical judgment and clinical expertise. However, these approaches may fail to account for the complex interplay between vascular morphology and hemodynamic forces that leads to aneurysm growth and rupture. Therefore, the development of reliable and quantitative parameters is essential to support neurosurgeons in balancing the risks of intervention against the natural history of the disease, thus optimizing decision-making for surgery. Methods: We developed an integrative framework based on a novel morphological parameter (MP), integrating multiple geometric descriptors into a single quantifiable index. To complement morphological assessment, patient-specific computational fluid dynamics (CFD) simulations were performed to evaluate hemodynamic factors known to influence aneurysm progression, thus analyzing structural and flow-related determinants of rupture risk. Results: In a cohort of 60 consecutive patients with MCA UIAs, MP showed strong concordance with the treatment decision made by an expert neurosurgeon regarding the indication for surgical clipping of aneurysms considered at risk of imminent rupture, providing an indirect, objective measure of UIA rupture risk stratification. CFD analyses confirmed that adverse hemodynamic conditions, including elevated intra-aneurysmal pressures and heterogeneous distribution of wall shear stress, correlated with unfavorable morphological features that were considered to indicate a higher risk of rupture by an expert neurosurgeon. Moreover, the integration of expert clinical judgment with quantitative indices may enhance the discrimination between aneurysms requiring early surgical intervention and those suitable for conservative management. Conclusions: This proof-of-concept study highlights the potential added value of combining morphological modelling and patient-specific hemodynamic analysis to support, rather than replace, expert neurosurgical judgment regarding the surgical management of unruptured MCA aneurysms. The proposed parameter (MP) shows concordance with expert operability decisions and may complement current neurosurgical evaluation as an ancillary decision-support tool, potentially contributing to safer operative strategies, more individualized patient management, and ultimately improved patient outcomes in the treatment of unruptured intracranial aneurysms.<\/jats:p>","DOI":"10.3390\/brainsci16090970","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T13:05:26Z","timestamp":1789391126000},"page":"970","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Improving Risk Stratification and Surgical Decision-Making for Unruptured Cerebral Aneurysm: A Proof-of-Concept of Novel Morphological Parameters and Computational Hemodynamics"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6309-8963","authenticated-orcid":false,"given":"Giuseppe Roberto","family":"Giammalva","sequence":"first","affiliation":[{"name":"Unit of Neurosurgery, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriele","family":"Costantino","sequence":"additional","affiliation":[{"name":"Unit of Neurosurgery, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Umberto Emanuele","family":"Benigno","sequence":"additional","affiliation":[{"name":"Unit of Neurosurgery, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1487-6292","authenticated-orcid":false,"given":"Lapo","family":"Bonosi","sequence":"additional","affiliation":[{"name":"Unit of Neurosurgery, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-9304-9926","authenticated-orcid":false,"given":"Micol","family":"Tantillo","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Palermo, 90100 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5156-1559","authenticated-orcid":false,"given":"Antonino","family":"Cirello","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Palermo, 90100 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1975-8167","authenticated-orcid":false,"given":"Vito","family":"Ricotta","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Palermo, 90100 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tommaso","family":"Ingrassia","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Palermo, 90100 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giuseppe","family":"Craparo","sequence":"additional","affiliation":[{"name":"Unit of Neuroradiology, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1493-4034","authenticated-orcid":false,"given":"Giovanni","family":"Tringali","sequence":"additional","affiliation":[{"name":"Unit of Neurosurgery, ARNAS Civico Di Cristina Benfratelli, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2505","DOI":"10.1161\/STROKEAHA.120.030590","article-title":"Pathophysiology of Intracranial Aneurysms","volume":"51","author":"Rodemerk","year":"2020","journal-title":"Stroke"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1007\/s12017-019-08537-7","article-title":"Intracranial Aneurysms: Pathology, Genetics, and Molecular Mechanisms","volume":"21","author":"Xu","year":"2019","journal-title":"Neuromol. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2357","DOI":"10.1056\/NEJMcp2409371","article-title":"Unruptured Intracranial Aneurysms","volume":"392","author":"Ogilvy","year":"2025","journal-title":"N. Engl. J. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1970","DOI":"10.1016\/j.mayocp.2021.01.005","article-title":"Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage","volume":"96","author":"Tawk","year":"2021","journal-title":"Mayo Clin. Proc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1625","DOI":"10.1007\/s10143-020-01356-6","article-title":"Management of Unruptured Intracranial Aneurysms: Correlation of UIATS, ELAPSS, and PHASES with Referral Center Practice","volume":"44","author":"Feghali","year":"2021","journal-title":"Neurosurg. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/S1474-4422(13)70263-1","article-title":"Development of the PHASES Score for Prediction of Risk of Rupture of Intracranial Aneurysms: A Pooled Analysis of Six Prospective Cohort Studies","volume":"13","author":"Greving","year":"2014","journal-title":"Lancet Neurol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"(1998). The International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured Intracranial Aneurysms\u2014Risk of Rupture and Risks of Surgical Intervention. N. Engl. J. Med., 339, 1725\u20131733.","DOI":"10.1056\/NEJM199812103392401"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1007\/s00701-020-04602-4","article-title":"Small Intracranial Aneurysms in the Barrow Ruptured Aneurysm Trial (BRAT)","volume":"163","author":"Catapano","year":"2021","journal-title":"Acta Neurochir."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1161\/STROKEAHA.107.495747","article-title":"Predictors of Rehemorrhage After Treatment of Ruptured Intracranial Aneurysms","volume":"39","author":"Johnston","year":"2008","journal-title":"Stroke"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1093\/neuros\/nyy600","article-title":"External Validation of the Subarachnoid Hemorrhage International Trialists (SAHIT) Predictive Model Using the Barrow Ruptured Aneurysm Trial (BRAT) Cohort","volume":"86","author":"Mascitelli","year":"2020","journal-title":"Neurosurgery"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2497","DOI":"10.1161\/STROKEAHA.107.512756","article-title":"Immediate Clinical Outcome of Patients Harboring Unruptured Intracranial Aneurysms Treated by Endovascular Approach","volume":"39","author":"Pierot","year":"2008","journal-title":"Stroke"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Tantillo, M., Craparo, G., Cirello, A., Costantino, G., Di Martino, A., Ingrassia, T., Marannano, G.V., Mirulla, A.I., Tringali, G., and Ricotta, V. (2025). Development of a Morphological Parameter and Hemodynamic Analysis to Assess Aneurysm Operability. Int. J. Interact. Des. Manuf.","DOI":"10.1007\/s12008-025-02371-x"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"145","DOI":"10.3174\/ajnr.A2419","article-title":"Quantitative Characterization of the Hemodynamic Environment in Ruptured and Unruptured Brain Aneurysms","volume":"32","author":"Cebral","year":"2011","journal-title":"Am. J. Neuroradiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1161\/STROKEAHA.110.592923","article-title":"Hemodynamic\u2013Morphologic Discriminants for Intracranial Aneurysm Rupture","volume":"42","author":"Xiang","year":"2011","journal-title":"Stroke"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1254","DOI":"10.3174\/ajnr.A3558","article-title":"High WSS or Low WSS? Complex Interactions of Hemodynamics with Intracranial Aneurysm Initiation, Growth, and Rupture: Toward a Unifying Hypothesis","volume":"35","author":"Meng","year":"2014","journal-title":"Am. J. Neuroradiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1161\/STROKEAHA.108.521674","article-title":"Unruptured Intracranial Aneurysms","volume":"40","author":"Ishibashi","year":"2009","journal-title":"Stroke"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"317","DOI":"10.3233\/THC-161132","article-title":"Experimental and CFD Flow Studies in an Intracranial Aneurysm Model with Newtonian and Non-Newtonian Fluids","volume":"24","author":"Frolov","year":"2016","journal-title":"Technol. Health Care"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"416","DOI":"10.3174\/ajnr.A7418","article-title":"Relationship between 3D Morphologic Change and 2D and 3D Growth of Unruptured Intracranial Aneurysms","volume":"43","author":"Timmins","year":"2022","journal-title":"Am. J. Neuroradiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1136\/neurintsurg-2011-010089","article-title":"Newtonian Viscosity Model Could Overestimate Wall Shear Stress in Intracranial Aneurysm Domes and Underestimate Rupture Risk","volume":"4","author":"Xiang","year":"2012","journal-title":"J. NeuroInterv. Surg."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"536","DOI":"10.3174\/ajnr.A3793","article-title":"Mind the Gap: Impact of Computational Fluid Dynamics Solution Strategy on Prediction of Intracranial Aneurysm Hemodynamics and Rupture Status Indicators","volume":"35","author":"Steinman","year":"2014","journal-title":"Am. J. Neuroradiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1177\/0954411920917531","article-title":"Computational Fluid Dynamics Simulations of Cerebral Aneurysm Using Newtonian, Power-Law and Quasi-Mechanistic Blood Viscosity Models","volume":"234","author":"Saqr","year":"2020","journal-title":"Proc. Inst. Mech. Eng. Part H J. Eng. Med."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"071006","DOI":"10.1115\/1.4050539","article-title":"Non-Newtonian Blood Modeling in Intracranial Aneurysm Hemodynamics: Impact on the Wall Shear Stress and Oscillatory Shear Index Metrics for Ruptured and Unruptured Cases","volume":"143","author":"Oliveira","year":"2021","journal-title":"J. Biomech. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1159\/000339678","article-title":"Local Hemodynamics at the Rupture Point of Cerebral Aneurysms Determined by Computational Fluid Dynamics Analysis","volume":"34","author":"Omodaka","year":"2012","journal-title":"Cerebrovasc. Dis."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1227\/01.NEU.0000197332.55054.C8","article-title":"Growth Factor Receptor Expression and Remodeling of Saccular Cerebral Artery Aneurysm Walls: Implications for Biological Therapy Preventing Rupture","volume":"58","author":"Piippo","year":"2006","journal-title":"Neurosurgery"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.1227\/01.NEU.0000245598.84698.26","article-title":"Complement activation associates with saccular cerebral artery aneurysm wall degeneration and rupture","volume":"59","author":"Tulamo","year":"2006","journal-title":"Neurosurgery"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1061","DOI":"10.1227\/NEU.0000000000000137","article-title":"Computational Fluid Dynamic Analysis of Intracranial Aneurysmal Bleb Formation","volume":"73","author":"Russell","year":"2013","journal-title":"Neurosurgery"}],"container-title":["Brain Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3425\/16\/9\/970\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T13:38:59Z","timestamp":1789393139000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3425\/16\/9\/970"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,14]]},"references-count":26,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["brainsci16090970"],"URL":"https:\/\/doi.org\/10.3390\/brainsci16090970","relation":{},"ISSN":["2076-3425"],"issn-type":[{"value":"2076-3425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,14]]}}}