Editing Upper Urinary Tract Trauma (section)

=== Diagnosis and Evaluation ===

==== History and Physical Exam ====

===== History =====

* '''<span style="color:#ff0000">Extent of deceleration''' involved in high-velocity impact trauma
**'''<span style="color:#ff0000">Most important information in blunt renal injury'''
* '''<span style="color:#ff0000">Trauma anterior vs. posterior to the axillary line'''
**'''<span style="color:#ff0000">Trauma anterior to axially line is more likely to damage important renal structures such as the renal hilum and pedicle compared to the posterior axially line, which more commonly results in parenchymal injury'''

===== Physical Exam =====

* '''<span style="color:#ff0000">Findings indicating possible renal injury (5):'''

# '''<span style="color:#ff0000">Flank hematoma'''
# '''<span style="color:#ff0000">Abdominal or flank tenderness'''
# '''<span style="color:#ff0000">Rib fractures''' 
#* Ipsilateral rib fracture can increase the incidence of significant renal trauma by 3x
# '''<span style="color:#ff0000">Hematuria'''
#* '''<span style="color:#ff0000">The degree of hematuria and the severity of the renal injury do not consistently correlate'''; presence or absence of hematuria should not be the sole determinant in the assessment of a patient with suspected renal trauma
#'''<span style="color:#ff0000">Penetrating injuries to the low thorax or flank'''

==== Imaging ====

===== Indications =====
* '''<span style="color:#ff0000">[https://pubmed.ncbi.nlm.nih.gov/33053308/ 2020 AUA Urotrauma Guidelines]'''
**'''<span style="color:#ff0000">Indications for imaging (contrast enhanced CT with immediate and delayed films) in stable trauma patients (5):''' 
**# '''<span style="color:#ff0000">Gross hematuria''' 
**# '''<span style="color:#ff0000">Microscopic hematuria and systolic blood pressure < 90mmHG'''
**# '''<span style="color:#ff0000">Mechanism concerning for renal injury (e.g., rapid deceleration, significant blow to flank)'''
**# '''<span style="color:#ff0000">Physical exam findings concerning for renal injury (e.g. rib fracture, significant flank ecchymosis)''' 
**# '''<span style="color:#ff0000">Penetrating injury of abdomen, flank, or lower chest''' 
*** '''<span style="color:#ff0000">Generally, children can be imaged using the same criteria as adults. Children, however, often do not exhibit hypotension as adults do.'''

===== Modality =====
* '''<span style="color:#ff0000">CT abdomen/pelvis with IV contrast (with immediate and delayed images) should be performed when there is suspicion of renal injury''' (AUA)
** In children, ultrasound may be used, although CT is preferred
** In rare cases where the patient is taken to the operating room without preliminary CT scan and surgeons are considering renal exploration or nephrectomy, an intraoperative one-shot IVP (2 mL/kg IV bolus of contrast with a single image obtained 10-15 minutes later) may be used to confirm that a contralateral functioning kidney is present
** '''<span style="color:#ff0000">Major limitation of CT scan in renal trauma: inability to adequately define a renal venous injury adequately.''' 
*** '''<span style="color:#ff0000">A medial hematoma strongly suggests a venous injury, however, there is no imaging modality which can accurately diagnose a venous injury'''

===== Findings =====
*'''<span style="color:#ff0000">CT findings suspicious for significant renal injury include (6):''' 
*# '''<span style="color:#ff0000">Medial laceration'''
*# '''<span style="color:#ff0000">Medial hematoma (vascular pedicle injury)'''
*# '''<span style="color:#ff0000">Medial urinary extravasation (renal pelvis or ureteropelvic junction injury)'''
*# '''<span style="color:#ff0000">Hematoma > 3.5cm'''
*# '''<span style="color:#ff0000">Lack of contrast enhancement of the parenchyma (main renal arterial injury)'''
*# '''<span style="color:#ff0000">Active intravascular contrast extravasation (arterial injury with brisk bleeding)'''
[[File:Leftrenalarteryinjury.png|center|thumb|600x600px|Axial CT scan with contrast, red arrow showing left renal artery injury with extravasation. [[commons:File:Leftrenalarteryinjury.png|Source]]]] 

* '''<span style="color:#ff0000">Differential diagnosis of fluid collections seen on serial imaging for renal trauma (3):'''

# '''<span style="color:#ff0000">Hematoma''' - density is almost always > 30 HU
# '''<span style="color:#ff0000">Urinoma''' - density ranges from 0-20 Hounsfield units (HU)
# '''<span style="color:#ff0000">Abscess''' - associated with rim enhancement; perinephric abscess rarely occurs after renal injury

==== Grading ====

==== [https://www.aast.org/resources-detail/injury-scoring-scale#kidney AAST Grading] ====
 {| class="wikitable"
|'''<span style="color:#ff0000">Grade'''
|'''<span style="color:#ff0000">Imaging criteria (CT findings)'''
|-
|'''<span style="color:#ff0000">I'''
|
* '''Subcapsular hematoma and/or parenchymal <span style="color:#ff0000">contusion</span> without laceration'''
|-
|'''<span style="color:#ff0000">II'''
|
* '''Perirenal hematoma confined to Gerota fascia'''
* '''Parenchymal <span style="color:#ff0000">laceration ≤1 cm depth without urinary extravasation'''
|-
|'''<span style="color:#ff0000">III'''
|
* '''Parenchymal <span style="color:#ff0000">laceration >1 cm depth without collecting system rupture or urinary extravasation'''
* '''<span style="color:#ff0000">Any injury in the presence of a kidney vascular injury (pseudoaneurysm or AV fistula) or active bleeding contained within Gerota fascia'''
|-
|'''<span style="color:#ff0000">IV'''
|
* '''Parenchymal <span style="color:#ff0000">laceration extending into urinary collecting system with urinary extravasation'''
* '''<span style="color:#ff0000">Active bleeding beyond Gerota fascia</span> into the retroperitoneum or peritoneum'''
* '''<span style="color:#ff0000">Renal pelvis laceration and/or complete ureteropelvic disruption'''
* '''<span style="color:#ff0000">Segmental renal vein or artery injury'''
* '''<span style="color:#ff0000">Segmental or complete kidney infarction(s) due to vessel thrombosis without active bleeding'''
|-
|'''<span style="color:#ff0000">V'''
|
* '''<span style="color:#ff0000">Main renal artery or vein laceration or avulsion of hilum'''
* '''<span style="color:#ff0000">Devascularized kidney</span> with active bleeding'''
* '''<span style="color:#ff0000">Shattered kidney</span> with loss of identifiable parenchymal renal anatomy'''
|}
<nowiki>*</nowiki>Advance one grade for bilateral injury up to grade III
[[File:Abdotrauma.png|center|thumb|600x600px|What Grade of injury is this based on the AAST classification? [[commons:File:Abdotrauma.PNG|Source]]]]