Case studyEndovascular parent-artery occlusion of large or giant unruptured internal carotid artery aneurysms. A long-term single-center experience

- Parent-artery occlusion with selective use of low-flow bypass is proposed.
- Venous-phase delay >1 s is a predictor of perioperative ischemic events.
- Long-term outcomes of the strategy are excellent.

The development of stent-like devices has increased treatment options for complex internal carotid artery (ICA) aneurysms, but the optimal treatment remains unclear. The purpose of this study was to evaluate the safety and efficacy of endovascular parent-artery occlusion (PAO) for ICA aneurysms. We retrospectively reviewed 28 patients with unruptured ICA aneurysms ⩾10 mm treated with PAO between April 2002 and March 2015 at our institution. Patients who developed neurologic symptoms or with venous-phase delay >2 s during balloon test occlusion were not treated by PAO. Patients with venous-phase delays of 1-2 s underwent superficial temporal artery to middle cerebral artery (STA-MCA) bypass prior to PAO. The median patient age was 65 (range, 26-84) years. Nineteen aneurysms (68%) were located in the cavernous segment. The median aneurysm size was 25 (range 11-40) mm. Venous-phase delay of 1-2 s was observed in five patients. Perioperative ischemic complications (N = 9, 32%), which occurred within 30 days after treatment, were significantly associated with venous-phase delays of 1-2 s (p < 0.01) and history of hypertension (p < 0.01). Six-month morbidity was observed in one (3.6%) patient. Complete occlusion at final follow-up and delayed (i.e. ⩾31 days after treatment) ischemic events were observed in 100% and 0% of patients, respectively, over a median period of 63 (range, 6-147) months. Despite the high frequency of perioperative ischemic episodes, endovascular PAO with selective use of STA-MCA bypass showed excellent long-term outcomes in patients with unruptured ICA aneurysms ⩾10 mm.