Comprehensive evaluation of management strategies and rupture status in partially thrombosed aneurysms: a systematic review and meta-analysis

This meta-analysis aims to evaluate and compare the clinical and angiographic outcomes of different management strategies for partially thrombosed intracranial aneurysms (PTIAs).

A systematic review was conducted using MEDLINE, Scopus, and Web of Science databases up to September 2024. Studies providing clinical and angiographic outcomes of PTIAs were included. Favorable outcomes were defined as those reported directly in the studies or, when the modified Rankin Scale (mRS) was available, as an mRS score of 0-2. Statistical analysis was conducted using R, with pooled estimates under a random-effects model.

Eighteen studies involving 362 patients with 363 PTIAs were analyzed. Favorable neurological outcomes were observed in 76% of patients, while 20% experienced procedure-related complications. Recurrence occurred in 36% of cases, and retreatment was required in 23%. Mortality was low at 0.8%. Subgroup analysis revealed that reconstructive approaches were associated with higher rates of favorable outcomes (72%) and lower complication rates (21%) compared with deconstructive methods (60% and 28%, respectively). Among the reconstructive techniques, flow diverter stenting showed the highest rate of favorable outcomes (82%), while simple coiling had the lowest (71%). Additionally, unruptured PTIAs had a significantly better prognosis, with 69% achieving favorable outcomes, fewer complications (22% vs 51% for ruptured), and lower mortality (0.8% vs 27%) compared with ruptured aneurysms. Among the reconstructive techniques, flow diverter stenting showed the best outcomes.

PTIAs treated with reconstructive approaches that are unruptured, non-giant, and located in the anterior circulation show higher rates of favorable neurological outcomes with acceptable complications. However, outcomes, complications, and occlusion rates are slightly worse compared with typical non-thrombotic saccular aneurysms, indicating that these aneurysms pose a greater challenge.