Predictors of recanalization after endovascular treatment of posterior circulation aneurysms

Posterior circulation aneurysms account for approximately 30% of all intracranial aneurysms, and their rupture often causes aneurysmal subarachnoid hemorrhage (aSAH). Because surgical treatment of posterior circulation aneurysms is difficult, endovascular treatment is commonly indicated. However, simple coil embolization is associated with a high rate of recanalization. Our goal was to investigate morphometric aneurysmal features assessed on pre-embolization computed tomography angiography (CTA) as predictors of recanalization in patients with posterior circulation aneurysms.

We retrospectively analyzed data of 24 patients who underwent coil embolization due to rupture of saccular posterior circulation aneurysms. The morphometric features of aneurysms were measured based on pre-embolization 3D-CTA-aneurysm models, and aneurysmal size and volume were measured on digital subtraction angiography (DSA) images. The effectiveness of initial endovascular treatment was determined visually with the modified Raymond Roy classification directly after embolization and on follow-up DSAs. Recanalization was diagnosed when, compared to the primary embolization aneurysm appearance, compaction and filling of the aneurysm occurred. Statistical analysis was performed with Statistica 13.1 software.

Higher maximal aneurysm height perpendicular to the aneurysmal neck was associated with a greater aneurysm recanalization risk (12.12±5.13mm vs. 7.41±3.97mm, p=0.039), and this relationship remained significant after adjustment for patient's age, sex and aneurysm localization (OR=1.26, 95%CI: 1.01-1.60, p=0.047). Maximal aneurysm height perpendicular to the aneurysmal neck distinguished well between recanalized and non-recanalized aneurysms (AUC=0.755, 95%CI: 0.521- 0.989, p=0.033).

Predictors of aneurysm recanalization can help choose best endovascular treatment strategies, which could reduce complication rates.