Efficacy of the preloading coil-in-plug method for internal iliac artery embolization

During endovascular aneurysm repair (EVAR), embolization of the internal iliac artery (IIA) is sometimes necessary. The preloading coil-in-plug (P-CIP) technique allows high-density embolization within a confined area. This retrospective study at our institution evaluated the efficacy of the P-CIP technique and compared it with conventional coil embolization (CE). Between January 2015 and December 2023, 201 patients underwent EVAR. Seventy-three patients underwent IIA trunk embolization. Patients who underwent embolization using only an Amplatzer vascular plug or P-CIP using an Amplatzer vascular plug 2 were excluded. Fifty-six patients (mean age, 76.7 years; 11 female patients) were categorized into the P-CIP (25 patients) and CE (31 patients) groups. The embolization site vessel diameter (8.08±1.9 mm vs 8.01±2.2 mm; P=0.85), procedure time (36.4±3.1 minutes vs 34.0±3.1 minutes; P=0.45) and incidence of type 2 endoleaks (0 [0%] vs. 1 [3.2%]; P=0.27) of both groups were not significantly different. Compared to the CE group, the P-CIP group required fewer coils (3.36±0.26 vs 4.30±0.24; P=0.037) and had a significantly higher complete occlusion rate (19 [76.0%] vs 10 [32.3%]; P<0.002). Compared to the CE group, the P-CIP group had a significantly smaller embolization range (20.1±5.46 mm vs. 31.7±7.2 mm; P<0.001); however, the buttock claudication incidence was not significantly different (13 [52.0%] vs 13 [41.9%]; P=0.45). All patients experienced full recovery of buttock claudication within 1 year postoperatively. The P-CIP technique enabled effective and reliable embolization of the IIA trunk and demonstrated advantages over conventional CE.