Introduction: The AAST renal injury grading scale is currently the most important variable predicting the need for kidney repair or removal, morbidity and mortality after blunt or penetrating kidney injuries. The 2011 revised version included renal pelvis, uretero-pelvic junction and segmental vascular injuries as grade IV, limiting grade V to severe hilar injuries. However, patients requiring surgery cannot be properly identified because of hemodynamic instability due to grade IV renal injuries. This study proposes an add-on for the AAST grade IV renal injury scale to improve the management of these patients.
Method: We searched the Medline and Scopus databases up to September 2014. Searches were not restricted by date, language or publication status. Pediatric studies were excluded.
Results: 71 articles were found, 57 were pertinent, including 6 directly related to the topic. 3 risk factors were identified to be associated with surgery for hemodynamic instability: perirenal hematoma >3.5 cm, intravascular contrast extravasation and medial renal laceration. Presence of two or more of these criteria has been validated in two other studies to predict the need for intervention. Patients with >25 % devascularized fragments also have poor prognosis and should be treated more aggressively.
Conclusion: These elements should be included in future classification reassessment to efficiently determine the time for surgery in grade IV renal traumas, generally leading to nephrectomy.
Keywords: AAST classification; Grade IV; Renal trauma; Revision.