Outcomes Associated with Nonstandard Configuration of Renal Branches in Aortic Endografts

Endovascular repair of thoracoabdominal and pararenal aortic aneurysms involves the use of branched stent grafts to perfuse visceral arteries. Nonstandard renal branch configuration, such as "ballerina," may be required as a bailout technique in challenging anatomical or technical situations. This configuration may result in altered hemodynamic stress, increasing the risk of branch-related complications.

This single-center retrospective cohort study analyzed outcomes of renal branches in standard and nonstandard configurations (outside instructions for use) following endovascular repair of thoracoabdominal and pararenal aortic aneurysms. Renal branches were categorized as standard or ballerina (branch connected to the contralateral renal artery, ≥90° radial deviation from the cuff to the arterial orifice) based on postoperative imaging. Adverse outcomes, including branch occlusion, thrombus formation, and the need for reintervention, were recorded. Kaplan-Meier analysis was used to assess complication-free survival.

A total of 97 renal branches in 56 patients were analyzed and followed for a median of 25 months. Nonstandard configuration (11 branches) had significantly higher adverse event rates (45%) compared to standard configurations (16%, P = 0.04). Complications among the 11 ballerina branches included 2 occlusions, 1 thrombus, and 2 compressions requiring relining. In standard configurations, branch occlusions were the most common complication (14%). Kaplan-Meier analysis demonstrated significantly reduced complication-free survival in nonstandard configurations compared to standard configurations (median 54 vs. 594 days, P = 0.02).

Bailout nonstandard renal branch configurations are associated with a high rate of serious adverse events. Intensified postoperative imaging surveillance with readiness for reintervention and optimized antithrombotic therapy should be considered in these cases.