gms | German Medical Science

Objective: Since the advancement of endovascular techniques, several large and giant aneurysms which arise in the location between the distal dural ring and the ICA bifurcation have been treated using these methods. However, several studies have reported that the angiographic recurrence rates and major recanalization rates after endovascular treatments were relatively high, despite the best efforts of neurointerventionists. Microsurgery is still one of effective treatment options to manage the large and giant ICA aneurysms. However, the mortality and morbidity rates related to microsurgery must be reduced to justify the surgical treatment of these aneurysms. To do that, the appropriate surgical techniques and equipment and a volume of experiences are essential. Therefore, we retrospectively reviewed our surgical experiences with large and giant ICA aneurysms. In addition, we also present our surgical strategies to treat these aneurysms based on our experiences.

Method: One hundred six patients underwent neurosurgical treatments for large (1.0-2.5cm) and giant (>2.5cm) aneurysms at the intradural ICA between January 2008 and December 2014 at our institution. Among them, we treated 68 patients (64%) with a total of 69 aneurysms using microsurgery. The aneurysms which were treated by only endovascular techniques were excluded. The medical records and radiologic images of the 68 patients with 69 aneurysms were retrospectively analyzed.

Results: Thirteen men and fifty-five women with a mean age of 57 ± 9.56 (range=34-78 years) were included in this study. The maximum diameter of the aneurysms raged between 10-37mm (mean=17 ± 6.85 mm). Fifty-five aneurysms (80%) are large, the remaining 14 (20%) are giant aneurysms. Seventeen patients (25%) presented with subarachnoid hemorrhage (SAH). In 51 patients with unruptured aneurysm, 17 patients (25%) had a cranial nerve deficit, 12 patients (17%) complained of chronic headache, 1 patient (1%) experience a transient ischemic attack. However, 21 patients (32%) were asymptomatic. Fifty-seven large and giant ICA aneurysms (83%) were directly clipped, including 6 aneurysms clipped using adenosine-induced transient asystoly and 10 aneurysms clipped using suction decompression technique. Extracranial-intracranial (EC-IC) bypass surgery and trapping of the aneurysm were performed for 12 unclippable aneurysms (17%). Sixty one (90%) patients showed good clinical outcomes (GOS 4-5) at discharge. However, 6 (9%) patients showed bad outcomes (GOS 3) at discharge. Among 6 patients with poor outcomes, 2 patients showed hemiparesis due to newly-developed cerebral infarction after surgery, 2 patients initially presented with Hunt-Hess grade IV SAH, 1 patient had nystagmus and cerebellar ataxia due to cerebellar ICH 1 day after surgery, and 1 patient has had a paraparesis after the patient had poliomyelitis in childhood. One patient (1%) died (GOS 1) due to ICA dissection. Recurrence of the aneurysm was identified in 2 patients (3%) during follow-up period, and these recurred aneurysms were treated by coil embolization.

Conclusions: Microsurgery for large and giant aneurysms at intradural ICA is an effective treatment modality, with a relatively low procedural complication rate and recurrence rate. In addition, suction decompression technique, adenosine-induced transient asystoly and EC-IC bypass are very useful methods supporting microsurgical treatment for these aneurysms.