PHASES score
The PHASES (Population, Hypertension, Age, Size, Earlier subarachnoid hemorrhage, Site) score was developed to facilitate risk stratification for the unruptured intracranial aneurysm management.
Go to the calculator https://qxmd.com/calculate/calculator_464/phases-score
see also Unruptured intracranial aneurysm treatment score.
5 year Ruptured intracranial aneurysm FROM Unruptured intracranial aneurysm.
see also ISUIA calculator
see also UCAS Calculator
Indicators
Population
0 points: North American, European (other than Finnish)
3 points: Japanese
5 points: Finnish
Hypertension
0 points: No
1 point: Yes
Age
0 points: < 70 years
1 point: ≥ 70 years
Size of aneurysm
0 points: < 7.0 mm
3 points: 7.0 - 9.9 mm
6 points: 10.0 - 19.9 mm
10 points: ≥ 20 mm
Earlier SAH from another aneurysm
0 points: No
1 point: Yes
Site of aneurysm
0 points: ICA
2 points: MCA
4 points: ACA / Pcom / posterior
5yr rupture risk
(based on cumulative risk score)
≤ 2 points: 0.4%
3 points: 0.7%
4 points: 0.9%
5 points: 1.3%
6 points: 1.7%
7 points: 2.4%
8 points: 3.2%
9 points: 4.3%
10 points: 5.3%
11 points: 7.2%
≥ 12 points: 17.8% 1).
Higher PHASES scores were associated with an increased risk of aneurysm growth. Because higher PHASES scores also predict aneurysm rupture, the findings suggest that aneurysm growth can be used as surrogate outcome measure of aneurysm rupture in follow-up studies on risk prediction or interventions aimed to reduce the risk of rupture 2).
A reasonable percentage of ruptured aneurysms have a low calculated PHASES score and these aneurysms may have been managed conservatively should they have presented incidentally prior to rupture. The majority of ruptured aneurysms also had a low ELAPSS score and were at low risk of future growth. The use PHASES score and ELAPSS score alone when making treatment decisions could result in many aneurysms being treated conservatively or undergoing remote surveillance despite rupture potential 3).
Smoking and family history are risk factors for sIA formation and aneurysmal SAH at young age. Young aneurysmal SAH patients had lower PHASES scores and often rupture from a small sIA, suggesting need for more aggressive management 4).
Wang et al. analyzed 1514 sIAs in a Chinese cohort of 1216 patients, including 651 ruptured and 863 unruptured sIAs. Median aneurysm size was 5.7 mm for ruptured aneurysms, with 66.1% <7 mm in maximal diameter, and 40.2% measuring <5 mm. The median PHASES score of ruptured sIAs was 5. In multivariate analysis, male sex, hypertension, locations other than the internal carotid artery, irregularity (lobulated or with blebs), and higher AR were independently associated with rupture status (OR for irregularity, 2.88, 95% CI 2.20 to 3.77, p<0.001; OR for AR, 1.12, 95% CI 1.01 to 1.24, p=0.036). However, the maximal diameter was not significantly associated with rupture status (p=0.72).
In this cohort, ruptured saccular intracranial aneurysm were frequently smaller than 7 mm. Shape-related features, such as irregularity and higher AR, were associated with the ruptured status of sIAs, irrespective of diameter. PHASES seems to be inadequate in sIA risk stratification. Shape related parameters may be further investigated in prospective studies 5).