Efficacy of radiographic imaging in pediatric blunt renal trauma

Purpose: We sought to determine whether radiographic imaging can effectively detect significant renal injuries in children with blunt trauma who do not have significant hematuria. Materials and Methods: We reviewed the records of 180 children who presented to our hospital for suspected renal trauma between 1977 and 1995. Results of excretory urography or abdominal computerized tomography were correlated with urinalysis findings and clinical outcome. Results: Of 147 patients with microscopic hematuria after blunt trauma 77 underwent imaging. Only 1 patient had a significant renal injury (grade 2 or greater) and 76 had normal findings or renal contusions only, including 11 with microscopic hematuria and shock. Of the 74 patients who did not undergo imaging a clinical diagnosis of renal contusion was made and followup was available for 57 (77%). All patients healed without adverse sequelae. Of 33 patients with gross hematuria significant renal injuries were found in 9, including 3 who required immediate surgical repair of a major renal laceration or vascular injury. Combining our results with those of other reported series revealed significant renal injuries in only 11 of 548 children (2%) with less than 50 red blood cells per high power field on presenting urinalysis after blunt abdominal trauma. These patients were likely to have multiple associated injuries. Conclusions: Significant renal injuries are unlikely in pediatric patients with blunt renal trauma but no gross or substantial microscopic hematuria. Shock does not appear to be a clinically useful indicator.