Retrospective Application of Risk Scores to Unruptured Anterior Communicating Artery Aneurysms

Introduction: The management of unruptured intracranial aneurysms (UIA), particularly those involving the anterior communicating artery (AComA), remains a challenging task. Clinical scales, such as UIATS and PHASES, have been developed to aid in decision-making process. This study aims to compare the recommendations provided by these scales for AComA UIAs and assess their alignment with real-world clinical management.

Methods: This retrospective, single-center study analyzed 129 observed or treated AComA UIAs, evaluating the concordance between PHASES and UIATS scores with actual decisions. A PHASES score of >9 indicated high risk.

Results: We observed 46.5% (60) and treated 53.5% (69) of patients. The range in PHASES scale was 4-9 in observed group and 4-15 in treated group.
PHASES scores were significantly higher in treated group (median±IQR=8±5 in treated vs 5±1 in observed, p=0.00002). Only non-high-risk aneurysms were observed, while as many as 39.5% (51) of these were treated. Our management was consistent with PHASES in 60.5% of cases.
According to the UIATS, treatment was favored for 19.4% (23) and observation for 34.8% (45); the recommendation was not definitive in 41.8% (56) of patients. Interestingly, there were no significant differences in distribution of UIATS recommendations among observed and treated patients (p=0.925, chi-square test). 56% of patients with UIATS treatment recommendation were treated. Similarly, 46% of patients with an observation recommendation were in fact observed. Our management was consistent with the UIATS recommendations in 50% of cases.
The concordance of UIATS and PHASES scales was 60.3%. There were no hemorrhages from observed aneurysms. Mortality for all patients with available follow-up was 2.4% (3/124), and permanent morbidity was 1.6% (2/124) over a mean follow-up of 64.2 months.

Conclusion : In major proportion, discordant suggestions from PHASES and UIATS were obtained. This indicates that therapeutic decisions are still primarily based on the center's experience and an individual assessment.