The associations between initial radiographic findings and interventions for renal hemorrhage after high-grade renal trauma: Results from the Multi-Institutional Genitourinary Trauma Study

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.

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.

Is routine re-imaging for high-grade renal injury needed? Retrospective analysis of 1500 abdominal trauma patients from a tertiary care trauma center over 11 years

INTRODUCTION AND AIM

The AUA and EAU guidelines recommend re-imaging in high-grade renal trauma, regardless of the clinical findings. The aim of this study was to assess the impact of re-imaging on the overall management and outcomes in these patients.

METHODS

The trauma registry of our tertiary care Level-1 trauma center was reviewed from January 2007 till October 2018. Out of 1536 patients with abdominal trauma, 174 patients with isolated renal injury were identified. Renal injuries were classified based on the AAST classification. Variables retrieved were demographics, renal injury grade, presence of urinoma, repeated imaging findings, and intervention after initial and repeated imaging.

RESULTS

Low-grade injury was found in 78.7% (137/174) compared to 21.3% (37/174) with high-grade injury. The majority (n = 136) of low-grade patients were managed conservatively except one patient with Grade III injury required angioembolization after initial imaging. Of the high-grade patients, 31/37 were treated conservatively except 6/37 patients required surgical intervention after initial imaging. Following re-imaging, only one patient required surgical intervention in the form of insertion of a drainage tube for a hematoma, which was possibly infected. The existence of urinoma (5 patients) or hematoma (47 patients) was not associated with significantly higher rate of intervention (p values: 0.717 and 0.138, respectively). No significant association was noted between hematoma size and rate of intervention (p value = 0.055).

CONCLUSION

Re-imaging for high-grade renal injuries could be limited to the presence of urinary extravasation in initial imaging or the presence of clinical deterioration such as pain, fever or decrease in hemoglobin level.

Initial radiological findings associated with active bleeding control necessity and long term functional outcomes after isolated high grade blunt renal trauma

INTRODUCTION

To assess the predictors for conservative management failure and long term outcomes after isolated blunt high grade renal trauma (HGRT).

METHODS

 A retrospective analysis of patients with isolated blunt HGRT (renal trauma grade ≥ IV) was conducted. Patients' demographics, clinical presentation, laboratory and radiological investigations, and different lines of treatment were retrieved. The primary outcome was to assess the predictors of conservative treatment failure (need for active bleeding control e.g.: transarterial angioembolization (TAE) and/or surgical exploration). The secondary outcome was to assess the renal parenchymal volume (RPV) changes post HGRT in correlation with the different lines of management using CT-measured RPV. The difference in RPV ≥ 5% at follow up was considered significant.

RESULTS

The study included 63 patients, mean (SD) age was 35.1 (16.6) years. Conservative management was successful in 39 patients (62%), while the need for active bleeding control was required in 16 and 8 patients who underwent TAE and surgical exploration, respectively. Increased hematoma rim distance (HRD), laceration numbers > 3, parenchymal devascularization ≥ 25%, and presence of vascular contrast extravasation (VCE) were predictors for conservative treatment failure (P= 0.006, 0.02, 0.045 and 0.002, respectively). After a mean of 19 months follow up, patients were subclassified into 2 groups: patients with preserved RPV (28 patients) and patients with decreased RPV (29 patients). Renal parenchymal devascularization ≥ 25% was found a predictor for ipsilateral RPV decrease (P = 0.02).

CONCLUSION

Increased HRD, laceration numbers > 3, parenchymal devascularization ≥ 25%, and presence of VCE are findings that reflect the necessity for active bleeding interventions after isolated blunt HGRT. Parenchymal devascularization ≥ 25% is an independent factor for RPV deterioration. Neither the grade of renal trauma nor the type of treatment is a predictor for such deterioration.

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.

Factors Predictive of Selective Angioembolization Failure for Moderate- to High-grade Renal Trauma: A French Multi-institutional Study

BACKGROUND

Angiography with selective angioembolization (SAE) is safe and effective in addressing bleeding in patients with renal trauma. However, there are no validated criteria to predict SAE efficacy.

OBJECTIVE

To evaluate factors predictive of SAE failure after moderate- to high-grade renal trauma.

DESIGN, SETTING, AND PARTICIPANTS

TRAUMAFUF was a retrospective multi-institutional study including all patients who underwent upfront SAE for renal trauma in 17 French hospitals between 2005 and 2015.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was SAE efficacy, defined as the absence of repeat SAE, salvage nephrectomy, and/or death for each patient.

RESULTS AND LIMITATIONS

Out of 1770 consecutive patients with renal trauma, 170 (9.6%) with moderate- to high-grade renal trauma underwent SAE. Overall upfront SAE was successful in 131 patients (77%) and failed in 39 patients: six patients died after the embolization, ten underwent repeat SAE, 22 underwent open nephrectomy, and one underwent open surgical exploration. In multivariate logistic regression analysis, gross hematuria (odds ratio [OR] 3.16, 95% confidence interval [CI] 1.29-8.49; p=0.015), hemodynamic instability (OR 3.29, 95% CI 1.37-8.22; p=0.009), grade V trauma (OR 2.86, 95% CI 1.06-7.72; p=0.036), and urinary extravasation (OR 3.49, 95% CI 1.42-8.83; p=0.007) were predictors of SAE failure. The success rate was 64.7% (22/34) for patients with grade V trauma and 59.6% (31/52) for those with hemodynamic instability. The study was limited by its retrospective design and the lack of a control group managed with either surgery or surveillance.

CONCLUSIONS

We found that gross hematuria, hemodynamic instability, grade V trauma, and urinary extravasation were significant predictors of SAE failure. However, success rates in these subgroups remained relatively high, suggesting that SAE might be appropriate for those patients as well.

PATIENT SUMMARY

Selective angioembolization (SAE) is a useful alternative to nephrectomy to address bleeding in patients with renal trauma. Currently, there are no validated criteria to predict SAE efficacy. We found that gross hematuria, hemodynamic instability, grade V trauma, and urinary extravasation were significant predictors of SAE failure.

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.

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.