Therapie und Nachsorge traumatischer Nierenverletzungen – 10 Jahre Erfahrung eines Schweizer Level‑1-Traumazentrums

External validation of the MiGUTS nomogram for the prediction of bleeding control intervention after renal trauma

INTRODUCTION

The American Association for the Surgery of Trauma (AAST) renal trauma grading leads to a variable management of patients with high-grade renal injuries. For a better prediction of the risk for bleeding interventions, Keihani et al. introduced the multi-institutional genito-urinary trauma study (MiGUTS) renal trauma nomogram in 2019. The aim of this study was to conduct an external validation and generalization for all kidney trauma cases of the nomogram with a European cohort of a Swiss level 1 trauma center.

METHODS

We collected data from the clinical information system of the Kantonsspital Graubünden, Chur, Switzerland. All patients ≥ 18 years of age from 01.01.2008 to 01.12.2020 with a renal trauma who underwent computed tomography imaging of the abdomen were included. The descriptive analysis was performed by a t-test/Wilcoxon signed-rank test and a Chi-square test. The predictions of the nomogram were analysed by the Pearson correlation coefficient. The threshold of prediction of a bleeding intervention was optimized by a ROC analysis.

RESULTS

Overall, 166 patients were included. Most patients were male (80.7%) with a median age of 44 years. Using the prediction from the MiGUTS nomogram developed by Keihani et al. we were able to identify a threshold with a sensitivity of 1.00, specificity of 0.87, positive predictive value of 0.44, negative predictive value of 1.00 and accuracy of 0.88.

CONCLUSION

The MiGUTS nomogram by Keihani et al. demonstrated to be reliable in the prediction of an intervention for bleeding control in our validation study in a European cohort.

The effect of percutaneous tract dilation technique on renal parenchymal trauma: An experimental in vivo study on a porcine model

Purpose

The purpose of this study was to evaluate renal parenchymal trauma of two-step dilation compared to the conventional Amplatz gradual dilation during percutaneous nephrolithotomy on a porcine model.

Materials and Methods

A nonpapillary percutaneous access tract was established under fluoroscopic guidance in both kidneys of four female pigs. On the right kidney of each pig, gradual dilation was performed using an Amplatz dilator set with a gradual dilation to 30 Fr, whereas on the left, a two-step dilation was utilized using only 16 Fr and 30 Fr dilators. Two of the animals were euthanized immediately after the procedure and the remaining two 1 month later. The pigs that were kept alive underwent a contrast-enhanced computed tomography immediately, 15, and 30 days postoperatively. A dimercaptosuccinic acid (DMSA) scintigraphy and single-photon emission computed tomography-computed tomography (CT) were also performed after the last CT and afterward, the pigs were sacrificed. All kidneys were harvested for pathohistological examination.

Results

The follow-up radiologic imaging showed similar parenchymal damage caused by the compared dilation techniques and an expected reduction in scar size in the later scans. No scar was identified by DMSA in any kidney. Gross and microscopic examinations conducted both on the kidneys that were harvested immediately after the procedure and the ones from the animals that were left to heal, revealed no significant differences in tissue damage, grade of fibrosis, or inflammation depending on the dilation method.

Conclusions

Our study showed no inferior outcomes caused by two-step dilation compared to gradual dilation regarding renal parenchymal damage following a nonpapillary puncture. In fact, postoperative imaging findings suggested a trend toward better healing and less scar tissue when the two-step method was used.

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.

Comparison of renal parenchymal trauma after standard, mini and ultra-mini percutaneous tract dilation in porcine models

OBJECTIVE

To evaluate whether reducing tract dilation diameter in PCNL (percutaneous nephrolithotomy) procedures results in minimizing of renal trauma of the percutaneous tract.

METHODS

A percutaneous renal access tract was established bilaterally to 11 pigs. Two pigs were euthanized immediately after the experiment, while nine pigs were sacrificed 1 month later. The percutaneous accesses were dilated up to 30Fr, 22Fr or 12Fr. The animals underwent a contrast-enhanced computer tomography immediately after the procedure and 30 days later. DMSA-scintigraphy with SPECT-CT was also performed. The kidneys of all animals were harvested for histological evaluation. The volume of scar tissue and the percentage of renal volume replaced by scar tissue were calculated.

RESULTS

Immediate post-procedural CT-scans revealed a significant difference in defect diameter among the three modalities. However, the scar volume calculated on CT-images and histopathology showed a significant difference only when 30Fr dilation was compared to 12Fr dilation. The percentage of scar volume was negligible in all cases, but there was still a statistical difference between 30 and 12Fr dilation. Dilation up to 22Fr revealed no statistical differences compared to the other two modalities. DMSA-scintigraphy showed no scar tissue in any case.

CONCLUSION

Dilation up to 30Fr may cause a significantly larger scar tissue on renal parenchyma compared to 12Fr dilation as it was shown on CT-images and microscopic evaluation, but based on the DMSA/SPECT-CT this difference seems to be insignificant to the renal function. The scar tissue caused by 22Fr dilation seemed to have no significant difference from the other modalities.

Non-operatively managed blunt and penetrating renal trauma: Does early follow up CT scan change management? A systematic review

BACKGROUND

Renal injury accounts for 1-5% of all traumatic injuries. Non-operative management (NOM) of renal trauma has demonstrated higher renal salvage rates and reduced morbidity.

AIMS

The aim of this review is to clarify the indications of early follow up CT scan for adult patients, with NOM, renal trauma, with a view to avoiding unnecessary CT scanning and radiation exposure in this cohort of patients.

METHODS

A systematic search was conducted using PubMed (MEDLINE), Web of Science, Embase, and Cochrane library, with references from relevant articles also evaluated. Inclusion criteria were defined as studies reporting outcomes of patients ≥12 years of age, with NOM, renal trauma and early CT re-imaging. The outcomes of interest were renal complications requiring intervention, specifically collecting system and vascular complications.

RESULTS

Five studies met the inclusion criteria. In total, 542 patients were included in this analysis; study sizes ranged from 48 to 207 patients. Early re-imaging was performed for 510 patients, including 489 CTs and 31 Ultrasounds (US). Mean time to re-imaging ranged from 1 - 35.9 days. Twenty three patients required intervention following re-imaging, all of which were for injuries grade ≥ 3 and presented with clinical deterioration prior to re-imaging, had a collecting system injury identified on initial CT scan or both. The number needed to re-image, in order to change the management of one patient, was 22.

CONCLUSIONS

Although the findings of this review are based on retrospective data, they suggest routine early re-imaging can be safely omitted for all NOM, renal injuries which remain asymptomatic, with no collecting system injury diagnosed on initial CT, provided appropriate delayed phase imaging is available. Future prospective studies are required to further clarify the indications of early re-imaging, specifically for NOM penetrating injuries, and the appropriate modality and timing of early re-imaging for all NOM renal trauma.