Coil embolization of renal artery bifurcation and branch aneurysms with flow preservation

Coil embolization is one of the most common endovascular approaches to treatment of renal artery aneurysms (RAAs). The purpose of this retrospective study was to compare complications, mortality, and morbidity associated with sac packing, coil trapping, and inflow occlusion.

The records of all patients with RAAs treated with coil embolization at our center from June 2003 to May 2017 were retrospectively reviewed. Demographics of the patients, aneurysm characteristics, management strategies, perioperative and long-term outcomes, and complications were analyzed.

A total of 52 patient records were reviewed; 28 patients received sac packing and 24 patients underwent coil trapping/inflow occlusion. There was no significant difference in patients' demographics or RAA characteristics between the groups. The mean aneurysm diameter was 25.6 ± 8.4 mm in the sac packing group and 31.1 ± 16.8 mm in the coil trapping/inflow occlusion group (P = .130). Most aneurysms in the sac packing group originated from the main renal artery bifurcation (67.9%), whereas in the coil trapping/inflow occlusion group, most aneurysms originated from the renal segmental branch arteries (54.2%). The immediate technical success rate was 100%, and the in-hospital mortality rate was 0% in both groups. Sac packing was more likely to be associated with endoleak immediately after the procedure (28.6% vs 8.3%; P = .065). The overall perioperative complication rate was not statistically different between the groups (7.1% vs 16.7%; P = .284). The mean duration of follow-up was 37.67 ± 29.84 months and 49.35 ± 28.11 months in the sac packing and coil trapping/inflow occlusion groups, respectively (P = .192). No deaths related to RAAs or aneurysm rupture occurred in either group. The overall morbidity rate was similar between groups (12.5% vs 25%; P = .284). Partial renal infarction occurred in two and five patients in the sac packing and coil trapping/inflow occlusion groups, respectively (8.3% vs 25%; P = .132). Impaired renal function was more frequent after coil trapping/inflow occlusion (0% vs 15%; P = .049). A single patient in the sac packing group required further intervention for reperfusion of the aneurysmal sac at 4 months (4.2% vs 0%; P = .356).

Sac packing might be a safe and effective way to treat RAAs located at the main bifurcation or in branch arteries and may be preferable to coil trapping/inflow occlusion, considering the potential loss of functional renal mass.