11 - THE AMERICAN ASSOCIATION FOR THE SURGERY OF TRAUMA ORGAN INJURY SCALE IS ASSOCIATED WITH CYSTOSCOPIC AND PERCUTANEOUS UROLOGIC PROCEDURES IN RENAL INJURIES

Objectives: The American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) for the kidney (and other organs) was created in 1989. It has been validated to predict mortality, need for operation, length of stay (LOS), and intensive care unit (ICU) LOS. It was updated in 2018 to better predict endourologic interventions, but this change has not been validated. In addition, the AAST-OIS does not consider mechanism of trauma in its interpretation.

Methods: We analyzed the Trauma Quality Improvement Program (TQIP) database from 2017-2019, including all patients with a kidney injury. We recorded rates of mortality, operation, renal-operation, nephrectomy, renal embolization, cystoscopic intervention, and percutaneous urologic procedures. Odds ratios and 95% Confidence Intervals (OR, CI) were calculated for each grade as compared to the immediately lower grade.

Results: 26294 patients had a kidney injury with an OIS grade. In penetrating trauma, mortality (p < 0.05), operation (p < 0.02), renal-specific operation (p < 0.02), and nephrectomy rates (p < 0.05) increased at every grade. Renal embolization and cystoscopy rates increased up to grade IV, then decreased in Grade V. Percutaneous interventions were rare across all grades.

In blunt trauma, mortality and nephrectomy rates increased only in grades IV and V (p < 0.03). Operation, renal operation, and renal embolization rates increased at every grade level (p < 0.001). Cystoscopy rates increased up to grade IV (p < 0.04), then decreased in grade V (p < 0.001). Percutaneous procedure rates were similar in grades I-III, increased in Grade IV (OR 7.9, 4.2-14.8), and were similar in grade V (vs IV).

When comparing mechanism, penetrating injuries are more likely to require nephrectomy in grades III (OR 10.2, CI 3.8-27), IV (OR 8.0, CI 4.7-13.8), and V (OR 3.2, CI 2.1-4.9). Cystoscopy is used more frequently in Grade III penetrating injuries (OR 4.5, CI 2.8-7.2). Percutaneous procedures are utilized more in Grades I-II (OR 4.9, CI 1.8-12.8) and III (OR 9.0, CI 4.4-18.3).

Conclusion: AAST-OIS is strongly associated with cystoscopic procedures in both blunt and penetrating trauma. These procedures are most utilized in Grade IV injuries. This is pertinent as Grade IV injuries include those with central collecting system injuries. Despite penetrating injuries more frequently requiring nephrectomy, they also more frequently require nonsurgical procedures. Mechanism of trauma should be considered when interpreting the AAST-OIS for kidney injuries.