[Case in which renal function improved following stent-graft placement in the aorta two months after the onset of stanford type B acute aortic dissection].
A 48-year-old man was admitted to the Department of Cardiovascular Surgery in our hospital after developing Stanford type B acute aortic dissection with a patent false lumen in July 2008. Conservative treatment involving rest and antihypertensive therapy was provided following admission. Urine volume decreased from day 9, and serum creatinine increased to 7.7 mg/dL. As it was suspected that the reduced renal blood flow was caused by progression of aortic dissection, contrast-enhanced computed tomography (CT)was performed. The left kidney showed reduced enhancement and the right kidney was heterogeneously enhanced. The dissection had extended to the left renal artery, and the reduced renal blood flow caused by narrowing of the left renal artery was thought to have caused the renal dysfunction. As elevated urea nitrogen and serum creatinine levels and hyperkalemia persisted, hemodialysis was performed a total of four times. Although the patient was subsequently withdrawn from dialysis, he continued to display severe renal dysfunction and was transferred to our department on day 28 for the treatment of renal failure. Conservative treatment was continued, but the maximum diameter of the thoracic aorta gradually increased, and stent placement at the entry of aortic dissection was indicated. On day 86, two stent-grafts were placed for entries at the distal site of the descending aorta and the distal site of the aortic arch. Postoperative abdominal contrast-enhanced CT showed expansion of the true lumen, and blood flow and contrast enhancement improved in both kidneys. Postoperatively, serum creatinine gradually decreased, improving to 1.16 mg/dL on day 96. Renography in the third month after stent-graft placement showed improved renal function in both kidneys. These findings suggest that even at approximately 2 months after the onset of acute renal failure associated with aortic dissection, renal function can be improved by restoring blood flow in the renal arteries.