The kidney is the most commonly injured solid organ in the pediatric population, with a frequency estimated at 10%–20% of all blunt abdominal injuries.¹ Compared to the adult population, the prevalence of pediatric renal trauma is relatively low, which makes robust data collection and guideline development challenging.² The EAST (Eastern Association for the Surgery of Trauma) recently established pediatric-specific renal trauma guidelines, which, unlike the AUA Urotrauma guidelines, are derived from review of literature focused on pediatric patients only rather than adult studies.^3,4 Both guidelines recommend nonoperative management for most patients, and angioembolization is preferred to operative management for hemodynamically stable patients with ongoing bleeding.^5–7 The EAST guidelines add that routine blood pressure checks should be performed at followup for children with a history of renal trauma. Due to limitations of existing pediatric evidence, detailed management recommendations concerning use and timing of drainage interventions, bedrest, antibiotic prophylaxis, followup imaging etc cannot be based on the existing pediatric literature alone. As a result, the management of pediatric renal trauma continues to be primarily derived from adult renal injury data.

There are several aspects unique to pediatric care that make direct extrapolation from adult care challenging. Perhaps the starkest example is the use of cross-sectional imaging. The AUA guidelines recommend that all patients with suspicion for renal injury should have an initial contrast-enhanced computerized tomography (CECT) with delayed phase, and that those with high-grade injury or clinical signs of complications should undergo followup imaging. The goal of minimizing radiation exposure and following the principle of ALARA (for As Low As Reasonably Achievable) in children calls into question the utility of such routine reimaging practices. Previously proposed protocols involving the use of ultrasonography as the preferred followup imaging modality, or repeat computerized tomography imaging only for those patients who become symptomatic after the acute injury, have not yet gained traction at this time.^8,9 Other opportunities for deviation specific to pediatric care include avoiding urological interventions for urinary drainage including urethral catheters and ureteral stents, or minimizing the use of bedrest and antibiotics. The absence of pediatric-specific data leads to substantial variation in the management of children with renal trauma and prohibits detailed pediatric-specific guideline development.

Figure. Survey questions and their responses.

With these considerations in mind, we are excited to announce the Mi-PARTS (Multi-institutional Pediatric Acute Renal Trauma Study), sponsored by the American Association for the Surgery of Trauma. This is a collaboration of 13 institutions located across the United States. The principal investigators are evenly distributed between urologists, pediatric urologists, general surgeons and pediatric surgeons. All institutions have a Level I trauma center designation and/or Level I pediatric trauma center designation.

Understanding the practice patterns of institutions was felt to be critical in identifying variation of care. We surveyed the 13 principal investigators participating in the study on their management preferences of pediatric renal trauma with attention to utilization of cross-sectional imaging, drainage procedures and aspects of nonoperative management. The survey questions and results are presented in the figure.

As expected, there is substantial variability in practice patterns, with some providers taking a “minimalist approach” as far as reimaging and use of interventions. From an imaging standpoint, 77% reported a preference to obtain completion imaging—that is, imaging protocolized to allow for delineation of a collecting system injury—only if a CECT without a delayed phase had a radiographic concern for a deep laceration or there was some other concerning aspect of the clinical presentation. The other 33% obtained completion imaging for any patient with a CECT without a delayed phase to assure full staging of the injury. Concerning followup imaging, one institution reported obtaining followup imaging for all renal trauma cases. The other institutions either reserved followup imaging for only high-grade injuries or reported use of followup imaging only for patients with a clinical concern for ongoing bleeding or symptomatic urinoma. The majority (77%) of institutions reserve urinary drainage procedures for patients who are symptomatic from, or who have complications related to, their injury. Routine urinary drainage for imaging findings alone is less practiced. The use of antibiotic prophylaxis for patients with urinary extravasation or patients undergoing drainage procedures varies by specialty. Twelve (92%) institutions use bedrest, 3 of which (25%) place all patients on bedrest regardless of injury severity.

Our survey is not intended to represent national practices; however, it confirms that there is considerable heterogeneity in the management of pediatric renal trauma. There is also deviation from the AUA guidelines with respect to cross-sectional imaging practices. The findings here further affirm a need for more comprehensive, pediatric specific, evidence-based renal trauma management guidelines. We anticipate that for most patients a “minimalist approach” is feasible and safe and that more rigorous monitoring and prophylactic interventions can often be omitted; however, some patients are at high risk for severe complication from their renal trauma and would likely benefit from close monitoring and reimaging, or perhaps require preemptive drainage procedures.

Our multi-institutional study aims to provide granular data on management and outcomes of over a thousand pediatric patients with renal trauma. All 13 institutions have completed phase 1 of the study, an in-depth review of all their pediatric renal trauma patients, including readmissions and complications over a 10-year study period. We are in the data analysis stage and hope to provide study results within the next few months. Phase 2 of Mi-PARTS has been initiated and consists of imaging review. We are grateful for our team of radiologists who are performing overreads of imaging studies, which will allow us to link outcomes data with objective, uniformly read imaging findings.

The questions posed in the above-mentioned survey are amongst many that will be addressed through our collaborative efforts. The heterogeneity of practice patterns allows us to assess different management strategies and evaluate their impact on outcomes. We expect that this study will be instrumental in guiding the future management of pediatric renal trauma.

Acknowledgments

The authors recognize the following individuals who contributed to this article:

1. Catalina K. Hwang, MD, Department of Urology, University of Washington, Seattle, Washington (ckhwang@uw.edu)
2. Emma Gause, MS, MA, Harborview Injury Prevention & Research Center, Seattle, Washington (egause@uw.edu)
3. Rano Matta, MD, MSc, University of Utah, Department of Surgery, Division of Urology, Salt Lake City, Utah (rano.matta@hsc.utah.edu)
4. Jonathan Woolstenhulme, Medical Student, University of Utah, School of Medicine, Salt Lake City, Utah (Jonathan.Woolstenhulme@hsc.utah.edu)
5. Anthony J. Schaeffer, MD, MPH, Intermountain Primary Children’s Hospital and University of Utah, Department of Surgery, Division of Urology, Salt Lake City, Utah (anthony.schaeffer@hsc.utah.edu)
6. Scott A. Zakaluzny, MD, Department of Surgery, University of California Davis, Sacramento, California (szakaluzny@ucdavis.edu)
7. Kara Teresa Kleber, MA, MD, Department of Surgery, University of California Davis, Sacramento, California (ktkleber@ucdavis.edu)
8. Adam Sheikali, BA, Medical College of Wisconsin, Milwaukee, Wisconsin (asheikali@mcw.edu)
9. Katherine T. Flynn-O’Brien, MD, MPH, Department of Surgery, Medical College of Wisconsin & Children’s Wisconsin, Milwaukee, Wisconsin (KFlynn-O’Brien@chw.org)
10. Georgianna Sandilos, MD, Department of General Surgery, Division of Trauma, Cooper University Health Care, Camden, New Jersey (sandilos-georgianna@cooperhealth.edu)
11. Shachar Shimonovich, MD, Department of General Surgery, Division of Trauma, Cooper University Health Care, Camden, New Jersey (shachar.shimonovich@gmail.com)
12. Nicole Fox, MD, MPH, Department of General Surgery, Division of Trauma, Cooper University Health Care, Camden, New Jersey (fox-nicole@cooperhealth.edu)
13. Alexis B Hess, MD, Department of Surgery, University of Tennessee Health Science Center, Memphis, Tennessee (ahess@wakehealth.edu)
14. Kristen A. Zeller, MD, Department of General Surgery, Section of Pediatric Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina (kzeller@wakehealth.edu)
15. George C. Koberlein, MD, Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina (gkoberle@wakehealth.edu)
16. Brittany E. Levy, MD, Department of Surgery, Division of Pediatric Surgery, University of Kentucky, Lexington, Kentucky (Brittany.Levy@uky.edu)
17. John M. Draus, Jr., MD, Department of Surgery, Division of Pediatric Surgery, University of Kentucky, Lexington, Kentucky (john.draus@uky.edu)
18. Marla Sacks, MD, Department of Surgery, Loma Linda University Medical Center and Children’s Hospital, Loma Linda, California (msacks@llu.edu)
19. Catherine Chen, MD, Department of Urology, Loma Linda University Medical Center and Children’s Hospital, Loma Linda, California (cachen@llu.edu)
20. Xian Luo-Owen, PhD, Department of Surgery, Loma Linda University Medical Center and Children’s Hospital, Loma Linda, California (xluoowen@llu.edu)
21. Jacob Robert Stephens, MD, Department of Urology, Beaumont Health–Royal Oak, Royal Oak, Michigan (Jacob.Stephens@beaumont.org)
22. Mit Shah, MD, Department of Urology, Beaumont Health–Royal Oak, Royal Oak, Michigan (mit.shah@beaumont.org)
23. Frank Burks, MD, Department of Urology, Beaumont Health–Royal Oak, Royal Oak, Michigan (fburks@urologist.org)
24. Rachel A. Moses, MD, MPH, Department of Surgery, Section of Urology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Rachel.A.Moses@hitchcock.org)
25. Michael E. Rezaee, MD, MPH, Department of Surgery, Section of Urology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Michael.E.Rezaee@hitchcock.org)
26. Vijaya M. Vemulakonda, JD, MD, Pediatric Urology Research Enterprise, Department of Pediatric Urology, Children’s Hospital Colorado; Division of Urology, Department of Surgery, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado (Vijaya.Vemulakonda@childrenscolorado.org)
27. N. Valeska Halstead, MD, MPH, Pediatric Urology Research Enterprise, Department of Pediatric Urology, Children’s Hospital Colorado; Division of Urology, Department of Surgery, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado (nadia.halstead@cuanschutz.edu)
28. Hunter M. LaCouture, Pediatric Urology Research Enterprise, Department of Pediatric Urology, Children’s Hospital Colorado; Division of Urology, Department of Surgery, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado (hunter.lacouture@cuanschutz.edu)
29. Behnam Nabavizadeh, Department of Urology, University of California San Francisco, San Francisco, California (behnam.nabavizadeh@ucsf.edu)
30. Hillary Copp, MD, MS Department of Urology, University of California San Francisco, San Francisco, California (Hillary.Copp@ucsf.edu)
31. Benjamin Breyer, MD, MAS, Department of Urology, University of California San Francisco, San Francisco, California (Benjamin.Breyer@ucsf.edu)
32. Ian Schwartz MD, Division of Urology, Hennepin Healthcare, Minneapolis, Minnesota (ian.schwartz@hcmed.org)
33. Kendall Feia, MD, Division of Urology, Hennepin Healthcare, Minneapolis, Minnesota (kendall.feia@hcmed.org)
34. Travis Pagliara, MD, Division of Urology, Hennepin Healthcare, Minneapolis, Minnesota (travis.pagliara@hcmed.org)
35. Judith C. Hagedorn, MD, MHS, Department of Urology, University of Washington, Seattle, Washington (judithch@uw.edu)