Open cerebrovascular management of failed endovascular treatments for intracranial aneurysms.

[OBJECTIVE] The authors aimed to evaluate the role of open cerebrovascular microsurgery for management of failed endovascular therapies for intracranial aneurysms in the modern neurointerventional surgery era.

[METHODS] To identify patients who underwent open cerebrovascular surgery on brain aneurysms previously treated with endovascular interventions, the medical records of 476 patients who underwent endovascular treatment of intracranial aneurysms at the Brigham and Women's Hospital between 2018 and 2025 were reviewed and analyzed. Clinical, demographic, radiological, and surgical data were collected. The main outcomes included radiographic occlusion rates, complications, neurological functioning at the latest follow-up, morbidity, and mortality.

[RESULTS] Twenty-one patients (mean age 54.6 years; 57.1% females) underwent microsurgical treatment following endovascular therapy for intracranial aneurysms. Seventeen aneurysms (81.0%) were initially ruptured. Most aneurysms were located at the anterior communicating artery (33.3%) and posterior communicating artery (19.0%). Prior endovascular modalities included coil embolization only (14 cases), stent-assisted coiling (2 cases), intrasaccular devices (3 cases), flow diversion (1 case), and flow diversion following stent-assisted coiling (1 case). The mean duration between endovascular treatment and open surgery was approximately 37.8 months. Indications for subsequent open surgery included aneurysm residual or recurrence (n = 14), incomplete (n = 2) or failed (n = 2) endovascular treatment, rerupture after endovascular treatment (n = 2), and progressive growth with edema and brainstem compression (n = 1). Microsurgical techniques included clip reconstruction, with the use of bypass techniques in 4 cases. Complete aneurysm occlusion was achieved in all cases based on postoperative imaging, except for 2 patients who required aneurysm clip repositioning directly after surgery. One patient needed coil embolization because of aneurysm recurrence after clip reconstruction. Complications occurred in 6 patients (29%), with death in 2 patients (9.5%). At the last follow-up (mean 21.0 months), 81.0% of patients had a modified Rankin Scale score less than or equal to 2.

[CONCLUSIONS] Brain aneurysms can be safely managed by endovascular therapy in many cases, but case selection should be tailored to the specific patient anatomy on a case-by-case basis. There remains a significant role for open surgical management of brain aneurysms after failed endovascular therapy, and these cases are increasingly complex and difficult to treat.