To evaluate the safety and effectiveness of Pipeline Flow Diverter (PED) in the treatment of unruptured small and medium-sized aneurysms of internal carotid artery.

From January 2018 to February 2022, the clinical data of 53 patients with unruptured internal carotid artery aneurysms treated by PED and stent-assisted coil embolization (SAC) in the neurointerventional therapy in the Department of Neurological Intervention in our hospital were collected. Retrospective analysis and comparison between groups were evaluated. O Kelly Marotta (OKM) scale and Raymond scale were used to evaluate the degree of aneurysm embolization immediately after operation and follow-up. The modified Rankin Scale (mRS) was used to evaluate the neurological function of the patients during perioperative period and follow-up. Digital subtraction angiography (DSA) or CT angiography (CTA) were used to evaluate the degree of aneurysm embolization and stent patency during the follow-up.

A total of 53 patients met the inclusion criteria, including 31 patients treated by PED and 22 patients treated by SAC. There is no significant statistical differences in gender, age and other baseline data between the two groups. The DSA of 34 aneurysms immediately after the operation of PED group showed that the cantrast agent was well filled in the aneurysms. The OKM grades were grade A in 9 (26.4%) cases, grade B in 7 (20.6%), grade C in 14 (41.2%), and grade D in 4 (11.8%).24 aneurysms immediately after the operation of SAC group showed that the Raymond grades were grade I in 16 (66.7%) cases, grade Ⅱ in 7 (29.1%), grade Ⅲ in 1 (4.2%). However there was a significant statistical difference in operation time between the PED group and SAC group (P = 0.003 < 0.05). There are 9 cases of perioperative complications, 4 cases in PED group and 5 cases in SAC group. There is no statistically significant difference between the two groups (P = 0.49). The mean follow-up time of PED group was (6.4 ± 1.8) months (range: 5~12 months) and SAC group was (10.4 ± 9.0) months (range: 2~30 months). The postoperative degree of aneurysm occlusion was observed, 28 cases (84.8%) in PED group and 17 cases (77.3%) in SAC group were completely occluded. But there are 4 postoperative recurrence cases in the SAC group and 0 in the PED group. In postoperative follow-up, all patients have a good prognosis, with mRS≤2, and no adverse events caused by bleeding or ischemia occurred.

The use of PED neuro-interventional therapy of small and medium-sized aneurysms of internal carotid artery shows less operation time and no less rate of complete aneurysm occlusion and safety than SAC therapy. It has obvious advantage in avoiding postoperative recurrence, but long-term efficacy still needs further follow-up observation.