Introduction: Current renal trauma guidelines include repeat imaging after 48 hours for high grade (grade 4-5; HG) injuries. Recent studies propose that re-imaging should be based on clinical findings as opposed to routine use. In many cases, re-imaging does not change management and exposes patients to unnecessary radiation. The purpose of this study is to better determine which pediatric renal trauma patients benefit from a follow up CT scan and which patients may be spared unnecessary radiation.

Methods: 31 patients with Renal trauma ages 2-21 from year 2020-2022 were identified using the Puerto Rico Trauma Center Database. Data was recovered retrospectively from medical records and included imaging, laboratories, vital signs, management and outcomes. This study was approved by our local IRB committee. Statistical analysis were ran with the software GraphPad by Dotmatics.

Results: Of the 31 patients with renal trauma, blunt injury was the mechanism in 77%. The AAST grade distribution was 16% grade 1, 19% grade 2, 13% grade 3, 45% grade 4, and 6% grade 5. There was a total of 16 HG injuries. The average Cr at presentation was 0.79 for low grade (LG) and 1.08 for HG. 100% of LG injuries were managed conservatively versus 75% of HG injuries. A total of 14 patients were re-imaged, 9 of which were HG. Only in 3 patients, there was a change in management after re-imaging. Of the 14 patients that were re-imaged, the avg Cr was 1.01 and only 3 patients had an increasing Cr trend. These were the same patients that had a change in management after re-imaging.  The average Cr of the non re-imaged patients was 0.90.

Conclusion: Most renal injuries can be managed conservatively without a 48 hr follow up CT scan regardless of grade.  In our study, HG renal injuries with medial urine leak and/or increasing Cr benefited from follow up CT scan. Most HG injuries with stable Cr and no medial urine leak on initial imaging may not require follow up CT scan.  If our results are replicated in other studies, changes in the current renal trauma guidelines would be warranted.