Perfusion techniques for renal protection during thoracoabdominal aortic surgery

Open thoracoabdominal aortic aneurysm (TAAA) repair includes aortic clamping that interrupts antegrade blood flow to distal organs. Ischemia involving the kidneys can lead to renal failure and poor outcomes. To this end, prevention of ischemic kidney damage has led to several perfusion strategies that protect the kidneys during TAAA surgery. Options for renal perfusion include the use of passive shunts or mechanical circulatory support to deliver oxygenated blood continuously to the kidneys until normal aortic flow is re-established. An alternative approach, renal perfusion with cold crystalloid, has emerged as the preferred option of renal protection at several centers. Although there is considerable variation, several studies have demonstrated that cold crystalloid renal perfusion provides excellent protection, particularly in high-risk patients such as those with renal artery occlusive disease, preoperative renal dysfunction, or a ruptured aneurysm. Notably, recent consensus practice guidelines recommend either cold crystalloid or blood perfusion be considered for renal protection during TAAA repair. In this article, we discuss these various strategies for renal protection during TAAA repair and highlight the related technical aspects.