Kidney protection in thoracoabdominal aortic aneurysm surgery

Acute kidney injury (AKI) is a common complication of both open and endovascular repair of thoracoabdominal aortic aneurysms (TAAA). Its definition varies across difference studies, some standardized definitions (RIFLE, AKIN, KDIGO) have been proposed but still not uniformly employed in published papers. Acute kidney injury is multifactorial and is associated with increased in-hospital mortality, long-term mortality and late renal function decline. In addition AKI is also associated with perioperative spinal cord ischemia. No specific pharmacological strategy has received a strong recommendation with high level of evidence as a protective measure. Fenoldopam, methylprednisolone or mannitol use to prevent AKI is commonly employed, but not supported by literature data. Avoiding nephrotoxic drugs and maintaining an adequate MAP, during and after the procedure plays a key role in preserving kidney function. During open TAAA surgery, renal arteries may be reimplanted using different techniques. The choice of the best option must be tailored to the patient, to reduce ischemic time and guarantee long-term patency. Current experience suggests that cold crystalloid solutions are the best substrates in preventing ischemia-reperfusion injury. Renal perfusion using Custodiol® 4°C, even if currently considered off-label, represents an encouraging organ protection tool. In endovascular TAAA repair, techniques such as fusion imaging, use of diluted contrast, and CO2 subtraction angiography have the potential to reduce postoperative AKI. Visceral vessels patency is closely related to the anatomy, therefore accurate endograft design according to these characteristics is crucial for long-term preservation of renal function.