The importance of radiological follow-up and relevant interventions for aneurysmal recurrence after endovascular treatment

Background: Recurrence after cerebral aneurysm treatment is an important problem. Cerebrovascular endovascular treatment has a higher recurrence and retreatment rate than craniotomy, and how to deal with this problem will be discussed based on our own experience. Methods: Initially, 482 patients who underwent endovascular treatment for cerebral aneurysms performed at our facility from May 2014 to March 2022 were evaluated. Cases after treatment of saccular cerebral aneurysms were included, whereas treatment of dissecting cerebral aneurysms, initial treatment with flow diverter stents, retreatment cases after that, and cases having follow-up difficulty were excluded. Finally, 338 cases were recruited in the present study. Results: Retreatment was performed in 23 (18.1%) of 127 ruptured aneurysms and 18 (8.5%) of 211 unruptured aneurysms. Fifty-one retreatment procedures, including multiple retreatments, were performed during the study period (49 were endovascular procedures; on the other hand, the remaining were re-treated by craniotomy combined with bypass procedure). Two patients’ modified Rankin scale (mRS) decreased from 2 to 3, and one patient underwent retreatment by craniotomy 67.4 months later due to recurrent bleeding. The other 48 patients (94.1%) did not experience a decrease in mRS. The longest interval until retreatment was 62.1 months for ruptured aneurysms and 100.6 months for unruptured aneurysms. Conclusion: Timely retreatment could contribute to improving patient outcomes. To achieve this, it is important to conduct follow-up and appropriately intervene in retreatment before rebleeding occurs.