Background: Residual and recurrent intracranial aneurysms after endovascular treatment with Guglielmi detachable coils may necessitate a microsurgical occlusion.
Objective: To analyze the microsurgical technique and describe how the location, morphology, and appearance of the coiled aneurysm affect the technique.
Methods: We retrospectively analyzed 81 patients with 82 previously coiled aneurysms treated microsurgically at 2 Finnish neurosurgical university hospitals in Helsinki and Kuopio between July 1995 and August 2009. Seven videos were selected to demonstrate the microsurgical strategy in various locations.
Results: Fifty-eight aneurysms (71%) were located at anterior circulation and 24 (29%) at posterior circulation. Fifteen patients were operated on within the first month (early surgery) after coiling, whereas 66 were treated later (late surgery). Complete or partial removal of coils during surgery may facilitate clipping, but is significantly (P < .001) more difficult to accomplish in late surgery. Removal of coils may also increase the chance of poor outcome. Chance of poor outcome also increased with intraoperative aneurysm rupture, size of the aneurysm, and posterior circulation location. Good clinical outcome (same or better clinical condition 3 months after surgery) was achieved in 71 patients (88%). After microsurgery, 4 patients were severely disabled and 6 patients died, 3 of them because of poor clinical condition.
Conclusion: Complete microsurgical occlusion of the residual aneurysm is possible. However, in large or giant aneurysms direct microsurgery is a challenging high-risk procedure, and we recommend that these patients be referred to a dedicated neurovascular center to minimize surgical complications. Even in experienced hands, use of different bypass procedures may be the best option for demanding growing lesions, especially those in the posterior circulation.