AJR:189, December 2007 1421 AJR 2007; 189:1421–1427 0361–803X/07/1896–1421 © American Roentgen Ray Society Marmery et al. MDCT Grading of Splenic Injury Abdominal Imaging • Original Research Optimization of Selection for Nonoperative Management of Blunt Splenic Injury: Comparison of MDCT Grading Systems Helen Marmery 1,2 Kathirkamanthan Shanmuganathan 1 Melvin T. Alexander 3 Stuart E. Mirvis 1 Marmery H, Shanmuganathan K, Alexander MT, Mirvis SE Keywords: CT, grading system, splenic injury, trauma DOI:10.2214/AJR.07.2152 Received February 28, 2007; accepted after revision June 24, 2007. 1 Department of Diagnostic Radiology, University of Maryland School of Medicine, 22 S Greene St., Baltimore, MD 21201. Address correspondence to K. Shanmuganathan (kshanmuganathan@umm.edu). 2 Present address: Department of Radiology, Nuffield Orthopaedic Hospital, Oxford, UK. 3 National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD. OBJECTIVE. The purpose of this study was to compare the usefulness of two CT grading systems of blunt splenic trauma in predicting which patients need surgery or angioembolization. MATERIALS AND METHODS. Four hundred patients in hemodynamically stable condition admitted with blunt splenic injury were included in the study. All patients underwent contrast-enhanced MDCT. Grade of splenic injury was prospectively assigned according to the American Association for the Surgery of Trauma (AAST) splenic injury scale. Patients were treated with surgical intervention, splenic arteriography with or without embolization, or ob- servation alone. All MDCT images were retrospectively reviewed and regraded according to a novel grading system that specifically incorporates the findings of active bleeding or splenic vascular injury, including pseudoaneurysm and arteriovenous fistula. Receiver operating char- acteristics curves were generated with both grading systems for all splenic interventions, and statistical analyses were performed. RESULTS. The area under the ROC curves for the new splenic grading system for splenic arteriography, surgery, and both interventions exceeded 80%. The area under the curve for the new splenic grading system was greater than that for the AAST injury scale for all interven- tions. Differences were found to be statistically significant for splenic arteriography (p = 0.0036) and the combination of arteriography and surgery (p = 0.0006). CONCLUSION. The proposed CT grading system is better than the AAST system for predicting which patients with blunt splenic trauma need arteriography or splenic intervention. onoperative management of blunt splenic injury is now commonly practiced [1–8]. The decision to at- tempt nonoperative management is largely determined by the splenic CT injury grade among other clinical factors, including patient age, presence of concurrent injuries, and the ability to perform reliable serial clini- cal assessments. The most widely used grading system for blunt splenic injury in trauma cen- ters across the United States is the American Association for the Surgery of Trauma (AAST) splenic injury scale [1, 2]. This organ injury scale is based on the appearance of the spleen at surgery (Table 1). Similar CT-based grading systems, derived from the AAST scale, are based on the extent of anatomic dis- ruption of the spleen. Previous studies [3–5] have shown that the traditional AAST injury grade and the CT-based injury grading system derived from it are poor predictors of which pa- tients can best be treated with observation and which need angiographic or surgical interven- tion. The use of nonoperative management with splenic arteriography and embolization has substantial support [6–8]. Aggressive management of active splenic bleeding and vascular injuries, including pseudoaneurysm and arteriovenous fistula, with splenic artery embolization has helped to prevent failure of nonoperative management [6–9]. We have had extensive experience in the use of CT combined with arteriographic find- ings to identify patients most likely to need intervention for splenic injury as opposed to observation alone. We conducted a retrospec- tive review of our experience with 400 pa- tients to describe and compare the efficacy of two CT grading systems to optimize selection of patients for nonoperative management of blunt splenic injury to achieve a high salvage rate with minimal complications. Materials and Methods This study was compliant with the requirements of the HIPAA and was approved by our institutional review board. Written informed consent was ob- tained from 76 patients. The institutional review N Downloaded from www.ajronline.org by 52.73.204.196 on 05/16/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved