Long-term follow-up results of acute renal embolism after anticoagulation therapy

Acute renal embolism (ARE) is a rare cause of acute abdominal pain. However, there are only a few studies on the clinical course of ARE. We attempted to investigate the clinical manifestations and long-term follow-up results of ARE.

From September 2006 to August 2012, 47 patients, who were diagnosed with ARE by computed tomography (CT), were enrolled. Patient demographic and clinical data were retrospectively reviewed. For the long-term outcomes, change in the serum creatinine (s-Cr) level, change in renal infarction on follow-up CT, recurrent embolism, and dialysis-free survival were investigated.

The mean age of patients was 61 years (range, 29-89 years), and 51% of the patients were men. All the patients presented with abdominal or flank pain. The sites of ARE were the right kidney in 57% of the patients, the left kidney in 36% of the patients, and both the kidneys in 6% of the patients. The infarction volume was less than 50% of renal volume in 54% of infarcted kidneys. Six patients had a concurrent infarction in other organs (3 cases of splenic infarction and 3 cases of cerebral infarction). Etiology of embolism was cardiogenic in 55% and idiopathic in 45%. Mean s-Cr level was 1.2 mg/dL (range, 0.6-3.7 mg/dL). s-Cr elevation >0.5 mg/dL was detected in 19% of patients during the follow-up (6 of 31 patients; mean duration, 31 months). Follow-up CT was performed in 23 patients (mean duration, 29 months). The infarcted lesions showed atrophic changes in all the cases except for 1 case. During the mean follow-up period of 41 months (1-118 months), recurrent embolism developed in 8 patients (6 cases of cerebral artery embolism, 1 case of superior mesenteric artery embolism, and 1 case of renal artery embolism). Dialysis was necessary in 1 patient, and dialysis-free survival rates were 91%, 82%, and 64% at 1 year, 3 years, and 5 years, respectively.

Although ARE causes irreversible loss of renal mass, it rarely leads to end-stage renal disease or long-term mortality. Therefore, the treatment should focus on the prevention of subsequent embolism to other vital organs.