Proposed revision of the American Association for Surgery of Trauma Renal Organ Injury Scale: Secondary analysis of the Multi-institutional Genitourinary Trauma Study.

BACKGROUND: This study updates the American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) for renal trauma using evidence-based criteria for bleeding control intervention. METHODS: This was a secondary analysis of a multicenter retrospective study including patients with high-grade renal trauma from seven level 1 trauma centers from 2013 to 2018. All eligible patients were assigned new renal trauma grades based on revised criteria. The primary outcome used to measure injury severity was intervention for renal bleeding. Secondary outcomes included intervention for urinary extravasation, units of packed red blood cells transfused within 24 hours, and mortality. To test the revised grading system, we performed mixed-effect logistic regression adjusted for multiple baseline demographic and trauma covariates. We determined the area under the curve (AUC) to assess accuracy of predicting bleeding interventions from the revised grading system and compared this to 2018 AAST OIS. RESULTS: Based on the 2018 OIS grading system, we included 549 patients with AAST grades III to V injuries and computed tomography scans (III, 52% [n = 284]; IV, 45% [n = 249]; and V, 3% [n = 16]). Among these patients, 89% experienced blunt injury (n = 491), and 12% (n = 64) underwent intervention for bleeding. After applying the revised grading criteria, 60% (n = 329) of patients were downgraded, and 4% (n = 23) were upgraded; 2.8% (n = 7) downgraded from grade V to IV, and 69.5% (n = 173) downgraded from grade IV to III. The revised renal trauma grading system demonstrated improved predictive ability for bleeding interventions (2018 AUC, 0.805; revised AUC, 0.883; p = 0.001) and number of units of packed red blood cells transfused. When we removed urinary injury from the revised system, there was no difference in its predictive ability for renal hemorrhage intervention. CONCLUSION: A revised renal trauma grading system better delineates the need for hemostatic interventions than the current AAST OIS renal trauma grading system. LEVEL OF EVIDENCE: Diagnostic Test/Criteria; Level III.

Improved chest wall trauma taxonomy: an interdisciplinary CWIS and ASER collaboration.

PURPOSE: Chest wall injury taxonomy and nomenclature are important components of chest wall injury classification and can be helpful in communicating between providers for treatment planning. Despite the common nature of these injuries, there remains a lack of consensus regarding injury description. The Chest Wall Injury Society (CWIS) developed a taxonomy among surgeons in the field; however, it lacked consensus and clarity in critical areas and collaboration with multidisciplinary partners. We believe an interdisciplinary collaboration between CWIS and American Society of Emergency Radiology (ASER) will improve existing chest wall injury nomenclature and help further research on this topic. METHODS: A collaboration between CWIS and ASER gathered feedback on the consensus recommendations. The workgroup held a series of meetings reviewing each consensus statement, refining the terminology, and contributing additional clarifications from a multidisciplinary lens. RESULTS: After identifying incomplete definitions in the CWIS survey, the workgroup expanded on and clarified the language proposed by the survey. More precise definitions related to rib and costal cartilage fracture quality and location were developed. Proposed changes include more accurate characterization of rib fracture displacement and consistent description of costal cartilage fractures. CONCLUSIONS: The 2019 consensus survey from CWIS provides a framework to discuss chest wall injuries, but several concepts remained unclear. Creating a universally accepted taxonomy and nomenclature, utilizing the CWIS survey and this article as a scaffolding, may help providers communicate the severity of chest wall injury accurately, allow for better operative planning, and provide a common language for researchers in the future.

Shattered Kidney After Renal Trauma: Should It Be Classified As an American Association for the Surgery of Trauma Grade V Injury?

OBJECTIVE: To study the prevalence and management of shattered kidney and to evaluate if the new description of "loss of identifiable renal anatomy" in the 2018 American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) would improve the ability to predict bleeding control interventions. METHODS: We used high-grade renal trauma data from 21 Level-1 trauma centers from 2013 to 2018. Initial CT scans were reviewed to identify shattered kidneys, defined as a kidney having ≥3 parenchymal fragments displaced by blood or fluid on cross-sectional imaging. We further categorized patients with shattered kidney in two models based on loss of identifiable renal parenchymal anatomy and presence or absence of vascular contrast extravasation (VCE). Bleeding interventions were compared between the groups. RESULTS: From 861 high-grade renal trauma patients, 41 (4.8%) had shattered kidney injury. 25 (61%) underwent a bleeding control intervention including 18 (43.9%) nephrectomies and 11 (26.8%) angioembolizations. 18 (41%) had shattered kidney with "loss of identifiable parenchymal renal anatomy" per 2018 AAST OIS (model-1). 28 (68.3%) had concurrent VCE (model-2). Model-2 had a statistically significant improvement in area under the curve over model-1 in predicting bleeding interventions (0.75 vs 0.72; P = .01). CONCLUSION: Shattered kidney is associated with high rates of active bleeding, urinary extravasation, and interventions including nephrectomy. The definition of shattered kidney is vague and subjective and our definition might be simpler and more reproducible. Loss of identifiable renal anatomy per the 2018 AAST OIS did not provide better distinction for bleeding control interventions over presence of VCE.

Grade V renal trauma management: results from the multi-institutional genito-urinary trauma study.

PURPOSE: To investigate management trends for American Association for the Surgery of Trauma (AAST) grade V renal trauma with focus on non-operative management. METHODS: We used prospectively collected data as part of the Multi-institutional Genito-Urinary Trauma Study (MiGUTS). We included patients with grade V renal trauma according to the AAST Injury Scoring Scale 2018 update. All cases submitted by participating centers with radiology images available were independently reviewed to confirm renal trauma grade. Management was classified as expectant, conservative (minimally invasive, endoscopic or percutaneous procedures), or operative (renal-related surgery). RESULTS: Eighty patients were included, 25 of whom had complete imaging and had independent confirmation of AAST grade V renal trauma. Median age was 35 years (Interquartile range (IQR) 25-50) and 23 (92%) had blunt trauma. Ten patients (40%) were managed operatively with nephrectomy. Conservative management was used in nine patients (36%) of which six received angioembolization and three had a stent or drainage tube placed. Expectant management was followed in six (24%) patients. Transfusion requirements were progressively higher with groups requiring more aggressive treatment, and injury characteristics differed significantly across management groups in terms of hematoma size and laceration size. Vascular contrast extravasation was more likely in operatively managed patients though a statistically significant association was not found. CONCLUSION: Successful use of nonoperative management for grade V injuries is used for a substantial subset of patients. Lower transfusion requirement and less severe injury radiologic phenotype appear to be important characteristics delineating this group.

Nonoperative Management in Blunt Splenic Trauma: Can Shock Index Predict Failure?

INTRODUCTION: Predicting failure of nonoperative management (NOM) in splenic trauma remains elusive. Shock index (SI) is an indicator of physiologic burden in an injury but is not used as a prediction tool. The purpose of this study was to determine if elevated SI would be predictive of failure of NOM in patients with a blunt splenic injury. METHODS: Adult patients admitted to a level-1 trauma center from January 2011 to April 2017 for NOM of splenic injury were reviewed. Patients were excluded if they underwent a procedure (angiography or surgery) prior to admission. The primary outcome was requiring intervention after an initial trial of noninterventional management (NIM). An SI > 0.9 at admission was considered a high risk. Univariate and multivariate analyses were used to identify predicators of the failure of NOM. Findings were subsequently verified on a validation cohort of patients. RESULTS: Five hundred and eighty-five patients met inclusion criteria; 7.4% failed NIM. On an univariate analysis, findings of pseudoaneurysm or extra-arterial contrast on computed tomography did not differentiate successful NIM versus failure (8.1% versus 14.0%, P = 0.18). Age, the American Association for the Surgery of Trauma injury grade, and elevated SI were included in multivariate modeling. Grade of injury (OR 3.49, P = 0.001), age (OR 1.02, P = 0.009), and high SI (OR 3.49, P = 0.001) were each independently significant for NIM failure. The risk-adjusted odds of failure were significantly higher in patients with a high risk SI (OR 2.35, P < 0.001). Validation of these findings was confirmed for high SI on a subsequent 406 patients with a c-statistic of 0.71 (95% CI 0.62-0.80). CONCLUSIONS: Elevated SI is an independent risk factor for failure of NIM in those with splenic injury. SI along with age and computed tomography findings may aid in predicting the failure of NIM. Trauma providers should incorporate SI into decision-making tools for splenic injury management.

Computed tomography-based volume calculations of renal ischemia predicts post-traumatic renal function after renal infarction injury.

OBJECTIVES: To describe a systematic method to quantify the severity of renal infarction injury and assess its association with post-traumatic renal function after blunt trauma. METHODS: We retrospectively reviewed all patients who suffered an AAST grade IV renal infarction injury without active bleeding secondary to blunt trauma between 1/2010 and 10/2020. Only patients with a pre-traumatic eGFR within 12 months of injury and post-traumatic eGFR within 3-12 months were included. Percentage of renal ischemia was defined as: (ischemic volume/total volume) × 100%. Two radiologists reviewed computed tomography images to determine ischemic and overall cross-sectional areas using the polygon region of interest tool. These areas were multiplied by slice thickness to obtain ischemic and total volumes. Intraclass correlation coefficient was used to assess consistency between radiologists. Linear regression analyses were used to assess the association between percentage of renal ischemia and post-traumatic renal function. RESULTS: Thirty-five of 140 (25.0%) patients met inclusion criteria. The median (IQR) pre-trauma eGFR was 107.7 ml/min/1.73m2 (90.6-121.8), percentage of renal ischemia was 8.4% (2.9-30.1), and decrease in eGFR after trauma was 12.9 ml/min/1.73m2 (0.4-32.6). There was excellent reliability in calculating ischemic volume (ICC = 0.987) and total kidney volume (ICC = 0.995) between two radiologists. When adjusting for pre-traumatic eGFR, patient age, and injury severity score, a 10% increase in ischemic volume was associated with a post-injury eGFR value that was 8.0 ml/min/1.73 m2 (95% CI - 11.2, - 4.7) lower. CONCLUSIONS: CT-based volume calculation of renal ischemia may be utilized to quantify kidney injury and be associated with post-traumatic renal function loss.

A Piercing Diagnosis - Occult Foreign Body as the Cause of Acute Inguinal Pain.

CASE PRESENTATION: A 35-year-old woman presented to the emergency department with severe right inguinal pain. Her medical history was non-contributory and there was no known trauma or injury to the region. Amid concern for an incarcerated inguinal hernia, a computed tomography was obtained revealing a linear foreign body (FB) lateral to the femoral vessels. The FB was removed without complication at bedside and found to be a beading needle likely occultly lodged three days prior. DISCUSSION: Occult inguinal FBs are rare but can lead to deep venous thrombosis or pulmonary embolism if in or near vessels. By nature of being occult, an absence of ingestion, insertion, or penetrative history should not preclude consideration of a FB etiology. Computed tomography imaging is crucial in determining the urgency of, and approach to, inguinal foreign body removal.

External validation of a nomogram predicting risk of bleeding control interventions after high-grade renal trauma: The Multi-institutional Genito-Urinary Trauma Study.

BACKGROUND: Renal trauma grading has a limited ability to distinguish patients who will need intervention after high-grade renal trauma (HGRT). A nomogram incorporating both clinical and radiologic factors has been previously developed to predict bleeding control interventions after HGRT. We aimed to externally validate this nomogram using multicenter data from level 1 trauma centers. METHODS: We gathered data from seven level 1 trauma centers. Patients with available initial computed tomography (CT) scans were included. Each CT scan was reviewed by two radiologists blinded to the intervention data. Nomogram variables included trauma mechanism, hypotension/shock, concomitant injuries, vascular contrast extravasation (VCE), pararenal hematoma extension, and hematoma rim distance (HRD). Mixed-effect logistic regression was used to assess the associations between the predictors and bleeding intervention. The prediction accuracy of the nomogram was assessed using the area under the receiver operating characteristic curve and its 95% confidence interval (CI). RESULTS: Overall, 569 HGRT patients were included for external validation. Injury mechanism was blunt in 89%. Using initial CT scans, 14% had VCE and median HRD was 1.7 (0.9-2.6) cm. Overall, 12% underwent bleeding control interventions including 34 angioembolizations and 24 nephrectomies. In the multivariable analysis, presence of VCE was associated with a threefold increase in the odds of bleeding interventions (odds ratio, 3.06; 95% CI, 1.44-6.50). Every centimeter increase in HRD was associated with 66% increase in odds of bleeding interventions. External validation of the model provided excellent discrimination in predicting bleeding interventions with an area under the curve of 0.88 (95% CI, 0.84-0.92). CONCLUSION: Our results reinforce the importance of radiologic findings such as VCE and hematoma characteristics in predicting bleeding control interventions after renal trauma. The prediction accuracy of the proposed nomogram remains high using external data. These variables can help to better risk stratify high-grade renal injuries. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level III.

The American Association for the Surgery of Trauma Renal Grading System-Should Segmental Kidney Infarction be Classified as a Grade IV Injury?

PURPOSE: In 2018 the American Association for the Surgery of Trauma revised renal injury grading. One change was inclusion of segmental kidney infarction under grade IV injuries. We aimed to assess how segmental kidney infarction will change the scope of grade IV injuries and compare bleeding control interventions in those with and without isolated segmental kidney infarction. METHODS: We used high grade renal trauma data from 7 level 1 trauma centers from 2013 to 2018 as part of the Multi-institutional Genito-Urinary Trauma Study. Initial computerized tomography scans were reviewed to regrade the injuries. Injuries were categorized as isolated segmental kidney infarction if segmental parenchymal infarction was the only reason for inclusion under grade IV injury. All other grade IV injuries (including combined injury patterns) were categorized as without isolated segmental kidney infarction. Bleeding interventions were compared between those with and without isolated segmental kidney infarction. RESULTS: From 550 patients with high grade renal trauma and available computerized tomography, 250 (45%) were grade IV according to the 2018 American Association for the Surgery of Trauma grading system. Of these, 121 (48%) had isolated segmental kidney infarction. The majority of patients with isolated segmental kidney infarction (88%) would have been assigned a lower grade using the original 1989 grading system. Rate of bleeding control interventions was lower in isolated segmental kidney infarction compared to other grade IV injuries (7% vs 21%, p=0.002). Downgrading all patients with isolated segmental kidney infarction to grade III did not change the grading system's associations with bleeding interventions. CONCLUSIONS: Approximately half of the 2018 American Association for the Surgery of Trauma grade IV injuries have isolated segmental kidney infarction. Including isolated segmental kidney infarction in grade IV injuries increases the heterogeneity of these injuries without increasing the grading system's ability to predict bleeding interventions. In future iterations of the American Association for the Surgery of Trauma renal trauma grading isolated segmental kidney infarction could be reclassified as grade III injury.

Clinical and Radiographic Factors Associated With Failed Renal Angioembolization: Results From the Multi-institutional Genitourinary Trauma Study (Mi-GUTS).

OBJECTIVE: To find clinical or radiographic factors that are associated with angioembolization failure after high-grade renal trauma. MATERIAL AND METHODS: Patients were selected from the Multi-institutional Genito-Urinary Trauma Study. Included were patients who initially received renal angioembolization after high-grade renal trauma (AAST grades III-V). This cohort was dichotomized into successful or failed angioembolization. Angioembolization was considered a failure if angioembolization was followed by repeat angiography and/or an exploratory laparotomy. RESULTS: A total of 67 patients underwent management initially with angioembolization, with failure in 18 (27%) patients. Those with failed angioembolization had a larger proportion ofgrade IV (72% vs 53%) and grade V (22% vs 12%) renal injuries. A total of 53 patients underwent renal angioembolization and had initial radiographic data for review, with failure in 13 cases. The failed renal angioembolization group had larger perirenal hematoma sizes on the initial trauma scan. CONCLUSION: Angioembolization after high-grade renal trauma failed in 27% of patients. Failed angioembolization was associated with higher injury grade and a larger perirenal hematoma. Likely these characteristics are associated with high-grade renal trauma that may be less amenable to successful treatment after a single renal angioembolization.

CT volumetric measurements correlate with split renal function in renal trauma.

PURPOSE: To evaluate whether volumetric measurements of segmental vascular injuries (SVIs) based on computed tomography (CT) imaging obtained during an initial trauma survey correlate with future nuclear medicine (NM) split renal function. METHODS: A retrospective review was performed of renal trauma patients treated at a level 1 trauma center between 2008 and 2015. Patients with unilateral SVIs on initial CT imaging with follow-up NM renal scans were evaluated. CT-based split renal function was calculated by assessing the ratio of ipsilateral uninjured kidney volume to bilateral total uninjured kidney volume by two separate radiologists. RESULTS: Eight patients with unilateral SVIs on initial CT trauma evaluation underwent follow-up NM renal scans at a mean of 4 months (range 2-6) after injury. Mean NM split renal function of the injured kidney was 43% (range 22-57). Based on the CT volumetric measurements of the affected kidney, mean percent injured was 23% (range 7-62) with a calculated mean split renal function of 44% (range 23-60). Calculated mean CT split function correlated with NM split function (R = 0.89). Intraclass correlation measuring inter-rater reliability for CT volumetric measurements was 0.94 (95% confidence interval 0.72-0.99). CONCLUSION: Volumetric measurements based on CT imaging obtained during the initial trauma evaluation correlated with future NM split renal function after SVIs with high inter-rater reliability. This method utilizes pre-existing imaging and avoids additional radiation exposure, work burden, and financial cost from a NM scan. Further evaluation is required to assess feasibility with more complex injuries.

Core curriculum illustration: abdominal wood impalement injury from motor vehicle collision.

This is the 42nd installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.erad.org/page/CCIP_TOC.

The American Association for the Surgery of Trauma renal injury grading scale: Implications of the 2018 revisions for injury reclassification and predicting bleeding interventions.

BACKGROUND: In 2018, the American Association for the Surgery of Trauma (AAST) published revisions to the renal injury grading system to reflect the increased reliance on computed tomography scans and non-operative management of high-grade renal trauma (HGRT). We aimed to evaluate how these revisions will change the grading of HGRT and if it outperforms the original 1989 grading in predicting bleeding control interventions. METHODS: Data on HGRT were collected from 14 Level-1 trauma centers from 2014 to 2017. Patients with initial computed tomography scans were included. Two radiologists reviewed the scans to regrade the injuries according to the 1989 and 2018 AAST grading systems. Descriptive statistics were used to assess grade reclassifications. Mixed-effect multivariable logistic regression was used to measure the predictive ability of each grading system. The areas under the curves were compared. RESULTS: Of the 322 injuries included, 27.0% were upgraded, 3.4% were downgraded, and 69.5% remained unchanged. Of the injuries graded as III or lower using the 1989 AAST, 33.5% were upgraded to grade IV using the 2018 AAST. Of the grade V injuries, 58.8% were downgraded using the 2018 AAST. There was no statistically significant difference in the overall areas under the curves between the 2018 and 1989 AAST grading system for predicting bleeding interventions (0.72 vs. 0.68, p = 0.34). CONCLUSION: About one third of the injuries previously classified as grade III will be upgraded to grade IV using the 2018 AAST, which adds to the heterogeneity of grade IV injuries. Although the 2018 AAST grading provides more anatomic details on injury patterns and includes important radiologic findings, it did not outperform the 1989 AAST grading in predicting bleeding interventions. LEVEL OF EVIDENCE: Prognostic and Epidemiological Study, level III.