 Acute kidney injury, A.K.I., is a serious complication after vascular surgery. Increased levels of quinolinate, a metabolite of tryptophan, have been found to be associated with an increased risk of A.K.I. in critically ill patients, patients hospitalized with COVID-19, and cardiac surgery patients. Additionally, higher levels of quinolinate are also linked to greater postoperative creatinine increases in vascular surgery patients. This suggests that impaired NAD plus synthesis may contribute to A.K.I. development in these patients. This article was authored by M. Maree Aimeed, Ginger L. Milne, Dewey Wei, and others.