Most children with grade IV renal injury are treated using a conservative approach with a high success rate. However, a small minority of patients with grade IV renal injury require urological intervention because of symptomatic urinomas. The challenge lies in predicting which of the patients receiving initial conservative treatment may require delayed interventional management because of urological complications.To identify clinical factors and radiological features associated with the need for urological intervention in grade IV pediatric, blunt renal trauma patients who were initially treated with a conservative approach.The medical records of consecutive 26 children presenting to our center between 1996 and 2014 with grade IV renal injury, were retrospectively reviewed. Clinical factors, radiological features on computed tomography (CT), use of urological intervention, and patient outcomes were analyzed.The population algorithm of this study is shown in the figure. The patients who required urological intervention had a higher transfusion rate and larger perinephric hematomas (>2.2 cm) than those who did not require intervention. The main laceration was located in the antero-medial portion of the kidney, and intravascular contrast extravasation was observed more often in patients who underwent urological intervention compared with patients with successful conservative management.The authors recommend the use of cautious observation and timely imaging studies for unresolved or expanding urinomas in children with grade IV renal trauma with predictive factors. Moreover, most patients received urological intervention 4-8 days after the trauma. Therefore, it is suggested that a follow-up image study for early detection of urological complications should be conducted 4-5 days after trauma in grade IV renal trauma children with predictive factors. If none of these factors are observed on the initial CT or during the clinical course, follow-up imaging study may be avoided during hospitalization.The need for transfusion, and the presence of specific image features on initial CT, such as the main laceration location in the antero-medial portion of kidney, intravascular contrast extravasation, and a large perinephric hematoma, served as useful predictive factors for urological intervention in grade IV pediatric blunt renal trauma patients who were initially treated with a conservative approach. The findings indicate that early detection and appropriate intervention should be considered a priority in the conservative treatment of grade IV pediatric renal trauma with predictive factors.

作者：Jun Nyung, Lee；Jae Kwang, Lim；Myeong Jin, Woo；Se Yun, Kwon；Bum Soo, Kim；Hyun Tae, Kim；Tae-Hwan, Kim；Eun Sang, Yoo；Sung Kwang, Chung

来源：Journal of pediatric urology 2016 年 12卷 2期