Grade 4 renal injury: current trend of management and future directions.

The management of blunt renal trauma has been evolving. The past management largely based on American Association for Surgery of Trauma (AAST) grading system, i.e. necessitated a computed tomography (CT) scan. Although the CT scan use is increasing and becomes the standardized mode of investigation, AAST grading no longer plays the sole role in the decision of surgical interventions. Two case reports of blunt renal trauma managed successfully by conservative methods are presented. Case one was an 18 year-old boy who had a fall when riding a motorbike at 20 km/h with a helmet and full protective equipments. He was landed by his left flank onto a rock. Contrast abdominal CT revealed a 4 cm, grade III splenic tear and a grade IV left kidney injury with large perirenal haematoma. His international severity score (ISS) was 34. He was managed conservatively with bed rest and frequent serum haemoglobin monitoring. Subsequent CT with delayed contrast revealed stable perirenal haematoma with urine extravasation which was consistent with a grade IV renal injury. Case two was a 40 year-old male who had a motor bike accident on a racetrack when he was driving at 80 to 100 km/h, wearing a helmet. He lost control and hit onto the sidewall of the racetrack. Contrast abdominal CT revealed a grade IV left renal injury with a large urine extravasation. His renal injury was managed conservatively with interval delayed phase CT of the abdomen. A repeat CT on abdomen was performed five months after the initial injury which revealed no residual urinoma. In this study, moreover, a review of the literature to the management of blunt renal trauma was conducted to demonstrate the trend of increasing conservative management of such traumas. Extra radiological parameters may guide future decision making. However, the applicability of data may be limited until randomized trials are available.