BERKELEY, CA (UroToday Inc.) - Blunt trauma accounts for the majority of pediatric renal injuries. It is often minor and no long-term sequelae are seen. A small percentage of children, however, sustain significant renal injuries that demand immediate evaluation and a decision regarding renal exploration. Challenges in the pediatric population include the accurate diagnosis of major renal trauma, when present, and determining when renal exploration is necessary.

Records were retrospectively reviewed from the trauma database at San Francisco General Hospital to further define the mechanisms and presentation of pediatric renal trauma and to develop guidelines for management. J. C. Buckley and J. W. McAninch reported their review and published it in the August, 2004 issue of the Journal of Urology. Over a period of 25 years, 374 renal injuries were seen in patients 18 years and younger. Each patient underwent selective management based on initial presentation, mechanism of injury, associated non-urological injuries and radiographic imaging.

Of the 374 pediatric renal injuries, 333 resulted from blunt trauma and 41 from penetrating trauma (89% and 11%, respectively). Most injuries were caused by motor vehicle accidents or falls (94%) and most (320 of 374, or 86%) resulted in grade I injuries. Only 4% of blunt renal injuries (12 of 333) were grade IV or V and the resultant exploration rate in blunt trauma was less than 2% (6 of 333). Penetrating renal trauma was the result of stab wounds in 39% and gunshot wounds in 61% with more than 70% sustaining a significant renal injury (grade II or above). Ten of the 41 penetrating injuries (24%) were managed non-operatively, 5 (12%) required intraoperative renal exploration without repair and for the remaining 26 (63%) renal exploration was done with reconstruction. Overall renal salvage rate was greater than 99%.

Of the 37 kidneys explored, a majority (30 of 37 or 81%) sustained a concurrent severe nonurologic injury that mandated immediate abdominal exploration. Isolated renal injuries accounted for less than 20% of renal explorations (7 of 37). Hematuria was evaluated immediately with dipstick analysis or formal urinalysis during the initial assessment. Only 26% of patients presented with gross hematuria. Additionally, microhematuria was demonstrated in only 28% of grade II injuries or higher (15 of 53), invalidating hematuria as a sensitive screening tool for significant renal injuries. Of grade IV injuries, 41% were successfully managed nonoperatively based on computerized tomography (CT) and staging in hemodynamically stable children. Follow-up in this patient population is classically poor, but no patient who underwent post-operative functional imaging (39% of the group) showed a decrease in renal function from that seen on initial imaging.

In summary, pediatric renal trauma is often minor and can be managed conservatively. In serious pediatric injuries, early detection and staging based on clinical presentation and imaging are critical for determining operative versus nonoperative management. Regardless of the type of management, renal preservation is the standard of care.

J Urol. 2004; 172(2):687-90.