A model for predicting the growth of unruptured intracranial aneurysms

Performance of Aneurysm Wall Enhancement Compared with Clinical Predictive Scales: PHASES, ELAPSS, and UIATS

OBJECTIVE

To correlate the presence of objectively measured wall enhancement on high-resolution vessel wall imaging (HR-VWI) with the clinical predictive scales PHASES, ELAPSS, and UIATS.

METHODS

Patients with unruptured intracranial aneurysm (UIAs) prospectively underwent HR-VWI on a 3-T magnetic resonance imaging scanner at diagnosis. Aneurysmal wall enhancement was objectively quantified on T1 postcontrast magnetic resonance imaging using signal intensity values adjusted for the pituitary stalk to calculate a contrast ratio (CR_stalk). UIAs with CR_stalk ≥0.60 were considered "enhancing." Patients' demographics, comorbidities, and aneurysm morphology were reviewed to calculate PHASES, ELAPSS, and UIATS scores. Pearson coefficients were applied for statistical correlation. Univariable and multivariable logistic regressions were performed to assess for confounders.

RESULTS

One-hundred and twenty-three patients harboring 178 UIAs underwent HR-VWI. A total of 101 patients with 135 UIAs were analyzed. Enhancing UIAs were larger (8.4 ± 5.5 mm vs. 5.5 ± 2.3 mm; P < 0.001), had higher aspect ratio (2.3 ± 1.5 vs. 1.8 ± 0.7; P = 0.008), higher size ratio (3.0 ± 1.8 vs. 2.4 ± 1.1; P = 0.016), scored higher on PHASES (5.6 ± 3.9 vs. 4.4 ± 2.6; P = 0.04) and ELAPSS (19.4 ± 8.9 vs. 15.4 ± 7.3; P = 0.006) compared with nonenhancing UIAs. Treatment allocation as defined by UIATS was measured independently to enhancement status. No significant differences were found for UIATS between enhancing and nonenhancing UIAs (P = 0.63). Multivariable regression showed that size was the only independent factor significantly associated with UIA enhancement (odds ratio, 1.76; P = 0.005).

CONCLUSIONS

Enhancing UIAs score higher in PHASES and ELAPSS scales. This association is largely explained by aneurysm size, aspect, and size ratios. Morphologic UIA features should be accounted for in clinical predictive scales of aneurysm instability.

SMART coils for intracranial aneurysm embolization: Follow-up outcomes

The SMART coil (Penumbra Inc., Alameda, CA, USA) is a new microcoil designed to enhance deliverability. Although prior studies have described its perioperative safety and efficacy, the follow-up outcomes after embolization of intracranial aneurysms using SMART coils have not been reported. Therefore, the aim of this retrospective cohort study is to assess the angiographic outcomes at interim follow-up after aneurysm embolization with SMART coils. We reviewed data from consecutive patients with intracranial aneurysms who underwent endovascular treatment using SMART coils between June 2016 and August 2017. Baseline data and follow-up angiographic outcomes using the modified Raymond-Roy classification (MRRC) were recorded. The study cohort comprised 33 patients with 34 aneurysms who underwent SMART coil embolization and had sufficient follow-up data. The mean age was 57 years, and 82% were female. The mean aneurysm maximum diameter and neck width were 6.1 ± 2.2 mm and 3.2 ± 1.2 mm, respectively, and 14.7% of aneurysms were ruptured. The overall complication rate was 12%. Initial mean coil packing density was 26%, and the initial MRRC was I, II, IIIa, and IIIb in 24%, 26%, 35%, and 15%, respectively. At last follow-up (mean duration 7.7 ± 3.2 months), the MRRC was I, II, IIIa, and IIIb in 62%, 26%, 3%, and 9%, respectively. The retreatment rate was 14.7%. The SMART coil is efficacious for the treatment of appropriately selected aneurysms, with an acceptable risk profile. The majority of residual aneurysms after the initial embolization procedure will progress to complete or near-complete occlusion at interim follow-up.