Mid-term Results of Coil Embolization Alone and Stent-assisted Coil Embolization for Renal Artery Aneurysms

Coil embolization (CE) alone and stent-assisted coil embolization (SCE) are two major endovascular techniques to treat renal artery aneurysms (RAAs). This study aimed at providing safety and efficacy data of CE and SCE for RAAs.

Between August 2015 and June 2019, 40 RAA patients treated with CE or SCE were included in the retrospective study. Patients' demographics, clinical manifestations, aneurysm characteristics, treatment strategies, and follow-up results were collected and analyzed.

There were 26 and 14 patients in the CE and SCE group, respectively. The mean aneurysm diameter was 2.5 ± 1.5 cm and 2.2 ± 0.8 cm (CE versus SCE, P = 0.52). The neck width of the aneurysm was 0.63 ± 0.37 cm and 1.07 ± 0.42 cm (CE versus SCE, P = 0.021). Technical success was achieved in 97.5% patients. No death or aneurysm rupture occurred. During the perioperative period, 12% and 7.1% patients suffered partial renal infarction (CE versus SCE, P = 0.45). The mean duration of follow-up was 8.8 ± 9.4 months and 16.1 ± 16.3 months (CE versus SCE, P = 0.158) by imaging and 20.8 ± 11.3 and 22.7 ± 16.5 months by visit/telephone (CE versus SCE, P = 0.703). During the follow-up, 17.4% patients in the CE group and 30.8% patients in the SCE group suffered partial renal infarction, while their overall renal function remained normal. In addition, there was no aneurysm recurrence, sac enlargement, or death in both groups.

Both CE and SCE were safe and effective to treat RAAs. In addition, SCE may prevent coil migration in the wide neck aneurysm in selected patients.