Small intracranial aneurysms of the anterior circulation: A negligible risk?

Thiemo Florin Dinger; Jonas Peschke; Mehdi Chihi; Meltem Gümüs; Maryam Said; Alejandro Nicolas Santos; Jan Rodemerk; Anna Michel; Marvin Darkwah Oppong; Yan Li; Cornelius Deuschl; Karsten Henning Wrede; Philipp René Dammann; Benedikt Frank; Christoph Kleinschnitz; Michael Forsting; Ulrich Sure; Ramazan Jabbarli

doi:10.1111/ene.15625

Small intracranial aneurysms of the anterior circulation: A negligible risk?

Eur J Neurol. 2023 Feb;30(2):389-398. doi: 10.1111/ene.15625. Epub 2022 Nov 21.

Authors

Thiemo Florin Dinger¹, Jonas Peschke¹, Mehdi Chihi¹, Meltem Gümüs¹, Maryam Said¹, Alejandro Nicolas Santos¹, Jan Rodemerk¹, Anna Michel¹, Marvin Darkwah Oppong¹, Yan Li², Cornelius Deuschl², Karsten Henning Wrede¹, Philipp René Dammann¹, Benedikt Frank³, Christoph Kleinschnitz³, Michael Forsting², Ulrich Sure¹, Ramazan Jabbarli¹

Affiliations

¹ Department of Neurosurgery and Spine Surgery, and Center for Translational Neuroscience and Behavioral Science, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.
² Institute for Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
³ Department of Neurology and Center for Translational Neuroscience and Behavioral Science, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.

PMID: 36333955
DOI: 10.1111/ene.15625

Abstract

Background and purpose: According to the International Study of Unruptured Intracranial Aneurysms, small (<7 mm) unruptured intracranial aneurysms (IAs) of the anterior circulation (aC) carry a neglectable 5-year rupture risk. In contrast, some studies report frequencies of >20% of all ruptured IAs being small IAs of the aC. This contradiction was addressed in this study by analyzing the rates and risk factors for rupture of small IAs within the aC.

Methods: Of the institutional observational cohort, 1676 small IAs of the aC were included. Different demographic, clinical, laboratory, and radiographic characteristics were collected. A rupture risk score was established using all independent prognostic factors. The score performance was checked using receiver operating characteristic curve analysis.

Results: Of all registered small IAs of the aC, 20.1% were ruptured. The developed small IAs of the aC (SIAAC) score (range = -4 to +13 points) contained five major risk factors: IA location and size, arterial hypertension, alcohol abuse, and chronic renal failure. In addition, three putative protective factors were also included in the score: hypothyroidism, dyslipidemia, and peripheral arterial disease. Increasing rates of ruptured IA with increasing SIAAC scores were observed, from 0% (≤-1 points) through >50% (≥8 points) and up to 100% in patients scoring ≥12 points. The SIAAC score achieved excellent discrimination (area under the curve_SIAAC = 0.803) and performed better than the PHASES (Population,Hypertension, Age, Size of the aneurysm, Earlier SAH from another aneurysm, Site of aneurysm) score.

Conclusions: Small IAs of the aC carry a considerable rupture risk. After external validation, the proposed rupture risk score might provide a basis for better decision-making regarding the treatment of small unruptured IAs of the aC.

Keywords: ISUIA; SAH; anterior circulation; risk factors; rupture risk score; small intracranial aneurysms.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aneurysm, Ruptured* / diagnostic imaging
Aneurysm, Ruptured* / epidemiology
Humans
Hypertension*
Intracranial Aneurysm* / diagnostic imaging
Intracranial Aneurysm* / epidemiology
ROC Curve
Risk Factors