The higher injury risk of abnormal kidneys in blunt renal trauma

Objective: To investigate the vulnerability of abnormal kidneys in blunt tr auma, and to determine clinical features which enable identification of pat ients at risk of renal abnormality, hence modifying their management. Material and Methods: The medical records of 120 patients with blunt renal trauma were reviewed. Presence of pre-existing renal abnormalities, clinica l symptoms, contrast study findings, associated injuries and the estimated impact velocity were recorded. Results: Pre-existing renal abnormalities were found in 23 patients (19%). Patients with renal abnormalities had a lower rate of associated trauma to other abdominal organs, a lower Injury Severity Score (ISS) and their kidne ys were more frequently injured by low velocity impacts. Of the patients wi th normal kidneys requiring surgery, hemodynamics and/or severity of the re nal lesions triggered the operative indications in all cases, whereas most (57%) of the abnormal kidneys were operated because of their underlying ren al pathology. Conclusion: Patients at risk for harbouring renal pathology are characteriz ed by the association of monotrauma, macroscopic hematuria and low impact v elocity. In this clinical setting, contrast studies should be generously in dicated, since the management of abnormal kidneys unmasked by trauma is, to a large extent, dependent on the type of pathology.