Assessing the usefulness of delayed imaging in routine followup for renal trauma

Renal trauma is often managed conservatively. Repeat imaging within 48 hours of injury is recommended but to our knowledge the value of further delayed imaging is unknown. We determined the usefulness of routine followup imaging beyond 48 hours in cases of conservatively managed renal trauma.

Of 377 patients who presented to our institution with renal injury in the last 8 years we identified 138 who underwent a trial of conservative treatment and repeat imaging more than 48 hours after injury. Followup imaging was categorized as routine in 108 patients (group 1) and indicated in 30 (group 2), and assessed for complications and the need for subsequent intervention.

Of the patients 121 (76%) were male. Mean age was 36 years. All except 4 injuries were the result of blunt trauma, predominantly due to road traffic accidents. Injury was grade 1 to 5 in 26, 24, 44, 33 and 11 cases, respectively. We identified 108 patients with routine followup imaging (group 1) while 30 were re-imaged due to a clinical indication. The rate of progression was 0.93% in group 1 with only 1 complication requiring a management change. In contrast, 20% of group 2 patients had progression requiring a treatment change (p = 0.0004).

Routine re-imaging in patients with renal trauma outside the initial 48-hour window in the absence of a clear clinical indication had little benefit and changed treatment in less than 1%.