Background Small and medium-sized aneurysms of the superior hypophyseal artery (SHA) comprise one-third of supraclinoid carotid lesions and are known for good results of endovascular treatment. Most of them are suitable for both flow diversion (FD) and coiling. The aim of this study was to compare the angiographic and clinical outcomes of both methods. The hypothesis was that FD provides better occlusion rates with similar procedural risks.

Materials and Methods Seventy-five SHA aneurysms sized between 4 and 12 mm were consecutively treated in a single center between 2014 and 2019. We retrospectively evaluated digital subtraction angiography (DSA) series and patient records, and recorded the demographics, aneurysm morphology, angiographic, and clinical outcomes. Total occlusion was defined as no filling at all. ‘Acceptable’ occlusion was defined as total OR subtotal occlusion, which remains stable during follow-up, with no signs of recanalization and no need for retreatment or further observation.

Results Twenty-six aneurysms were flow-diverted (36.4%); 49 aneurysms were coiled (65.4%). There was no difference between the groups in terms of aneurysm size (FD: median 7 mm, IQR 4; Coils: median 6 mm, IQR 3; p=0.51), neck size (FD: 4 mm, IQR 2; Coils: 5 mm, IQR 2, p=0.51), age (p=0.65), sex (p=0.57), and rate of symptomatic lesions (p=0.49). Follow-up DSA was available for all FD and 49/53 coiled lesions (92.4%).Definitive angiographic cure was achieved in 23/26 flow diverted cases (88.4%) and 28/49 coiled cases (57.1%); p=0.008. The rate of clinically acceptable occlusion was 24/26 in the FD group (92.3%) and 43/49 in the coil group (87.7%); p=0.7. There was one treatment-related hemorrhage in the FD group (3.8%) and one in the coil group (1.9%), both resulted in moderate morbidity (mRS 3 and 2, respectively), without mortality occurring.

Conclusion Flow diverters demonstrated a nearly twice higher rate of definitive angiographic cure vs coils, but the rate of clinically acceptable occlusion was similar. The complications and morbidity rates were equally very low. We suggest that the aneurysm and parent vessel anatomy should be the main factors when choosing the modality for treating SHA aneurysm.

Disclosures A. Gorbatykh: None. K. Orlov: None.