A retrospective study of pediatric renal trauma: A single-center experience in Japan

Objectives: To report pediatric renal trauma experiences at the National Center for Child Health and Development in Japan according to the Japanese Association for the Surgery of Trauma (JAST) classification 2008.Methods: Medical records were retrospectively reviewed for 45 children younger than 18 years old diagnosed with renal trauma from February 2004 to December 2021, regarding details of external causes, treatments, complications, and injury scales according to the JAST classification 2008. The cases who cannot be classified into the JAST classification 2008 will be categorized into our original type 0.Results:There were 24 males and 21 females with a mean age of 8.5 years. Left kidneys were the predominantly affected side. Blunt injury was involved in every case (mainly falls and traffic accidents). Concomitant organ injuries were found in 13 cases. The injury scales were type I-a (13.3%), II (11.1%), IIIa (13.3%), IIIb (24.4%). Type 0 accounted for 37.8%, which were type 0(c) (congenital anomalies of the kidney and urinary tract without hematoma and/or laceration of kidney parenchyma) at 11.1% and type 0(h) (only hematuria and normal radiologic finding) at 26.7%. Treatments were blood transfusion, ureteral stenting, nephrostomy, and no nephrectomy. Complications were pseudoaneurysm, hypertension, and infection.Conclusions: Nearly 38% of cases cannot be classified into the JAST classification 2008, comprising at least two irrelevant types (type 0(c) and type 0(h)). Accordingly, a pediatric renal injury scale should be established to achieve the precise diagnosis and treatments. However, further studies are still needed.