Contralateral Snare Cannulation vs. Retrograde Gate Cannulation during Endovascular Aortic Repair in Difficult Iliac Artery Anatomy: A Single Center Experience

Objective: Endovascular aneurysm repair is well established as the gold standard in treating abdominal aortic aneurysms. Generally, endovascular repair is performed using a bi or trimodular stent graft, requiring placement of a contralateral iliac limb. Deployment of the contralateral iliac limb requires retrograde gate cannulation of the endograft main body contralateral limb. This step represents the crucial point of a standard endovascular repair procedure and can become challenging, especially in the case of high iliac tortuosity. This study compares the procedural times between the retrograde gate cannulation and the contralateral snare cannulation to demonstrate the possibility of directly performing the contralateral snare cannulation in the case of a complex iliac anatomy assessed by the iliac tortuosity index. Methods: One hundred and forty-eight patients with infrarenal abdominal aortic aneurysms who underwent endovascular aneurysm repair from 2017 to 2022 were analyzed retrospectively. Cannulation times between retrograde gate cannulation and contralateral snare cannulation were compared for each degree of iliac tortuosity. The degree of iliac tortuosity was assessed through the iliac tortuosity index. Cannulation times were detected from inserting the wire into the introducer to passing through the radio-opaque gate markers. Results: The cannulation times were 2.94 min for the retrograde gate cannulation group and 3.15 min for the contralateral snare cannulation group, respectively, with no statistically significant differences (p = 0.33). Overall cannulation times were 2.98 min. For the iliac tortuosity index grade 0, the cannulation times were 2.71 min for the retrograde gate cannulation group and 3.85 min for the contralateral snare cannulation group, respectively, with a significant difference in favor of the retrograde gate cannulation group (p < 0.0001). For the iliac tortuosity index grade 1, the cannulation times were 2.74 min for the retrograde gate cannulation group and 2.8 min for the contralateral snare cannulation group, respectively, with no statistically significant differences (p = 0.63). Regarding the iliac tortuosity index grades 2 and 3, the cannulation times were 3.01 and 4.93 min for the retrograde gate cannulation group and 2.71 and 3.28 min for the contralateral snare cannulation group, respectively. The first group’s times were significantly higher than the second group’s (p = 0.01 and p = 0.0001). Conclusions: In patients with infrarenal abdominal aortic aneurysms undergoing endovascular aortic repair, the gate cannulation times were significantly shorter for the contralateral snare cannulation method than the retrograde gate cannulation method in the iliac tortuosity index grades 2 and 3. Therefore, performing the contralateral snare cannulation method would be appropriate.