Non-operatively managed blunt and penetrating renal trauma: Does early follow up CT scan change management? A systematic review

•Literature determining the indications and rate of intervention following early CT re-imaging of adult patients, with non-operatively managed, renal trauma is rare.•This systematic narrative review examined the characteristics of patients with non-operatively managed, renal trauma which required subsequent intervention with endoscopic, radiological or surgical procedures, following early re-imaging.•All NOM renal injuries, requiring subsequent intervention, were for injuries grade 3 or higher.•All injuries requiring intervention presented with a clinical deterioration and/ or had a collecting system injury identified on initial CT imaging.•There was significant heterogeneity between included studies and three of the five studies included in this review were deemed to be of low quality. Renal injury accounts for 1–5% of all traumatic injuries. Non-operative management (NOM) of renal trauma has demonstrated higher renal salvage rates and reduced morbidity. The aim of this review is to clarify the indications of early follow up CT scan for adult patients, with NOM, renal trauma, with a view to avoiding unnecessary CT scanning and radiation exposure in this cohort of patients. A systematic search was conducted using PubMed (MEDLINE), Web of Science, Embase, and Cochrane library, with references from relevant articles also evaluated. Inclusion criteria were defined as studies reporting outcomes of patients ≥12 years of age, with NOM, renal trauma and early CT re-imaging. The outcomes of interest were renal complications requiring intervention, specifically collecting system and vascular complications. Five studies met the inclusion criteria. In total, 542 patients were included in this analysis; study sizes ranged from 48 to 207 patients. Early re-imaging was performed for 510 patients, including 489 CTs and 31 Ultrasounds (US). Mean time to re-imaging ranged from 1 - 35.9 days. Twenty three patients required intervention following re-imaging, all of which were for injuries grade ≥ 3 and presented with clinical deterioration prior to re-imaging, had a collecting system injury identified on initial CT scan or both. The number needed to re-image, in order to change the management of one patient, was 22. Although the findings of this review are based on retrospective data, they suggest routine early re-imaging can be safely omitted for all NOM, renal injuries which remain asymptomatic, with no collecting system injury diagnosed on initial CT, provided appropriate