Cause of renal infarction: a retrospective analysis of 186 consecutive cases

BACKGROUND: Renal infarction can cause abrupt and severe hypertension and less frequently renal failure. Renal infarction results from disruption of renal blood flow in the main ipsilateral renal artery or in a segmental branch. Underlying mechanism is either general, 'embolic' or 'thrombophilic', or local related to primary 'renal artery lesion'. It depends on various causes. In absence of an identified cause, renal infarction is classified as 'idiopathic'. Previous studies report a significant number of 'idiopathic' renal infarction. OBJECTIVE: The aim of this study was to analyze various renal infarction causes. METHODS: Between July 2000 and June 2015, 259 consecutive patients with renal infarction were admitted to our hospital center and retrospectively identified from weekly multidisciplinary round. Main clinical and biological characteristics were extracted from clinical data warehouse. Renal imaging was reviewed by two readers unaware of the diagnosis. RESULTS: Of 259 initially identified patients, 30 were excluded owing to a lack of imaging or clinical data and 43 because iatrogenic renal infarction. In the 186 studied patients, dissection was observed in 76 patients (40.8%) and occlusion in 75 (40.3%). Renal infarction mechanisms were 'renal artery lesion' (n = 151; 81.2%), 'embolic' (n = 17; 9.1%), 'thrombophilic' (n = 11; 5.9%) and 'idiopathic' (n = 7; 3.8%). Predominant renal artery lesions were atherosclerosis disease (n = 52; 34.4%) followed by dissecting hematoma (n = 35; 23.2%) and fibromuscular dysplasia (n = 29; 19.2%). Right and left kidneys were equally involved. CONCLUSION: Renal artery lesion is the most frequent cause of renal infarction. This result underlines the need for extensive arterial exploration to identify the renal infarction mechanism and, in case of renal artery lesion, the underlying vascular disease.