Abstract: PD63-05
Sources of Funding: none

Introduction

AUA guidelines suggest that follow-up imaging post-renal trauma is not routinely required for American Association for the Surgery of Trauma (AAST) grade I-III renal injuries but early CT imaging is prudent for grade IV-V renal injuries. Our aim was to determine the yield of follow-up imaging in patients sustaining renal trauma at our major trauma unit and prospectively validate a new conservative follow-up imaging strategy.

Methods

All patients who attended Cork University Hospital with a diagnosis of blunt renal injury from 2000-2016 were identified. Review of all charts and imaging was undertaken with relevant patient demographics recorded. Operative records, complications, date and results of follow-up imaging were also reviewed. Injuries were graded by a staff radiologist using the AAST Organ Injury Scale and were grouped as low-grade (I, II, III) or high-grade injuries (IV, V). We correlated clinical outcomes with repeat imaging results. A new conservative follow-up imaging strategy was introduced in 2012.

Results

One hundred and fifty patients (155 renal units) were identified with a median age 23 years (IQR 18-38 years), 86% were male. Low-grade injuries accounted for 69% of cases, all were managed conservatively with a complication rate of 3% (n=3 pain). Forty-six patients (31%) had high-grade injuries; 3 cases required nephrectomy and 1 case required angio-embolisation, 87% were managed conservatively with a complication rate of 17% (n=2 urinoma; n=2 hypertension; n=2 pain; n=1 febrile episode; n=1 secondary haemorrhage). All patients with complications were symptomatic, prompting repeat imaging. Results of routine repeat imaging did not independently predict any complication or prompt urologic intervention. Following the introduction of a conservative follow-up imaging strategy in 2012 (validation cohort n=48, high grade injuries n=22), we have safely reduced repeat CT imaging in high grade injuries by 41% (p=0.018).

Conclusions

Selective reimaging of renal injuries based on clinical and laboratory criteria would have detected all complications in our series. Routine follow-up imaging for renal injuries grades I-III is unnecessary in the absence of clinical deterioration. Follow-up imaging of high grade renal injuries (IV,V) should be guided by the presence of urine extravasation in addition to clinical and laboratory criteria. AUA guidelines are clinically appropriate in a major tertiary trauma unit in Ireland but can be tailored further to reduce repeat CT imaging of Grade IV renal injuries.

Funding

none