Renal trauma can occur from blunt or penetrating injuries. Evaluation involves stabilizing the patient, assessing for life-threatening injuries using ATLS protocols, and obtaining imaging. CT is the preferred imaging method and allows grading of injuries according to the AAST scale. Most grade I-III injuries can be managed conservatively with observation. Higher grade injuries may require angioembolization or surgery to control bleeding. Goals of management are to control hemorrhage and salvage renal tissue when possible. Patients require follow-up imaging and monitoring for early or delayed complications.

1. RENALTRAUMA
Presenter :- Dr. Resen Rajan
Junior Resident
Department of General Surgery
Regional Institute of Medical Sciences
Imphal, Manipur, India

2. Trauma
Trauma is defined as a physical injury or a wound to
living tissue caused by an extrinsic agent.

3. Initial evaluation and treatment
• The first priority is stabilization of the patient and
treatment of associated life-threatening injuries
• ATLS Protocol
• Securing the airway with C-spine immobilisation
• Breathing
• controlling external bleeding and resuscitation of shock.

4. Renal Trauma (Epidemiology)
• Kidney is the most commonly injured organ in
the genito-urinary system.
• Seen in up to 5% of all trauma cases, and in
10% of all abdominal trauma cases.
• Associated with young age and male gender
with incidence of about 4.9 per 100,000.

5. Renal Trauma
• Blunt injury
• Penetrating injury

6. Renal Trauma (Mode of injury)
Blunt injuries
• motor vehicle collision,
• falls,
• vehicle-associated pedestrian accidents
• Assault
• Sports injury

7. Renal Trauma (Mode of injury)
Blunt injuries
• Sudden deceleration or a crush injury
• Parenchymal injury (Contusion or laceration)
• Renal hilum (Renal vascular injuries)
• <5% of blunt abdominal trauma,
• isolated renal artery injury (0.05-0.08%)
• Renal artery occlusion is associated with rapid
deceleration injuries.

8. Renal Trauma (Mode of injury)
Penetrating injuries
• Gunshot and stab wounds
• Tend to be more severe and less predictable than
blunt trauma.
• In urban settings, the percentage of penetrating
injuries can be as high as 20% or higher

9. Renal Trauma (Mode of injury)
Penetrating injuries
• Bullets have the potential for
• greater parenchymal destruction
• Disruption of vascular pedicles, or collecting
system
• multiple-organ injuries.

10. AAST renal injury grading scale
• This validated system has clinical relevance
• Helps to predict the need for intervention.
• Predicts morbidity after blunt or penetrating
injury and mortality after blunt injury.

11. AAST renal injury grading scale
Contusion Hematoma Laceration Vascular
1 + Subcapsular
(non expanding)
2 Peri-renal
(non expanding)
Cortical (< 1 cm deep;
without extravasation)
3 Cortical (> 1 cm deep;
without urine
extravasation)
4 through
corticomedullary
junction into collecting
system
• segmental renal artery or vein
injury with contained hematoma,
partial vessel laceration,
vessel thrombosis
•
•
5 shattered kidney renal pedicle or avulsion
*Advance one grade for bilateral injuries up to grade III.

12. AAST renal injury grading scale

13. Mechanism of injury
• Lacerations from blunt trauma usually occur in the
transverse plane of the kidney.
• The mechanism of injury is thought to be force transmitted
from the center of the impact to the renal parenchyma.
• In injuries from rapid deceleration- the kidney moves
upward or downward, causing sudden stretch on the renal
pedicle and sometimes complete or partial avulsion
• Acute thrombosis of the renal artery may be caused by an
intimal tear from rapid deceleration injuries owing to the
sudden stretch.

14. Indications for renal imaging
Blunt injuries Penetrating injuries
• macroscopic hematuria
• imaging is indicated
regardless of hematuria• microscopic hematuria and
hypotension (systolic blood pressure
< 90 mmHg)
• rapid deceleration injury,
• direct flank trauma,
• flank contusions,
• fracture of the lower ribs and
• fracture of the thoracolumbar
spine, (regardless of presence or
absence of haematuria)

15. Imaging
Objectives:
• To grade the renal injury,
• To document pre-existing renal pathology,
• To demonstrate presence of the contralateral kidney
• To identify injuries to other organs.

16. USG
• First imaging modality
• FAST (hemoperitoneum).
• poor specificity
• it does not provide information about renal function or
urine leak.
• Ultrasonography is useful in follow-up of stable renal
injury patients
• Can confirm the presence of two kidneys
• Can detect a retroperitoneal hematoma

17. USG
Advantages :
• Noninvasive
• May be performed in real time in concert with resuscitation
• May help define the anatomy of the injury
Disadvantages
• Optimal study results related to anatomy require an
experienced sonographer
• The focused abdominal sonography for trauma (FAST)
examination does not define anatomy and, in fact, looks only
for free fluid
• Bladder injuries may be missed.

18. CECT Abdomen
• Imaging modality of choice in hemodynamically
stable patients following blunt or penetrating
trauma.
Merits:
• widely available,
• can quickly and accurately identify and
grade renal injury,
• establish the presence of the contralateral
kidney and demonstrate concurrent injuries
to other organs.

19. • Absence of enhancement on contrast administration or
presence of parahilar hematoma suggests renal pedicle
injury.
• WBCT in the initial management of polytrauma patients
significantly increases the probability of survival.
• Although the AAST system of grading renal injuries is
primarily based on surgical findings, there is a good
correlation with CT appearances.
• Difficult to directly visualize renal vein injury
CECT

20. CECT
Isolated Renal trauma
Multiphase CT with IV contrast
Pre contrast phase identify subcapsular haematomas
Post contrast Arterial phase
Nephrographic
phase
Delayed phase
(Pyelographic)
Assessment of vascular injury and presence of
active extravasation of contrast.
parenchymal contusions and lacerations
Collecting system/ureteric injury

21. CECT
• CT imaging is both sensitive and specific for demonstrating
parenchymal lacerations and urinary extravasations
• delineating segmental parenchymal infarcts
• determining the size and location of the surrounding
retroperitoneal hematoma and/or associated intra-abdominal
injury (spleen, liver, pancreas, and bowel)
• Renal artery occlusion and global renal infarct are noted on CT
scans by lack of parenchymal enhancement or a persistent
cortical rim sign

28. Intravenous pyelography (IVP)
• superseded by cross-sectional imaging
• should only be performed when CT is not
available.
• can be used to confirm function of the injured
kidney and presence of the contralateral
kidney

29. Intraoperative pyelography
• One-shot, intraoperative IVP remains a useful
technique to confirm the presence of a
functioning contralateral kidney in patients too
unstable to undergo preoperative imaging.
• A bolus IV injection of radiographic contrast
(2ml/kg) followed by a single plain film taken
after minutes.
10

30. Disease management
• Non-operative management
• Conservative
• Interventional radiology
• Operative management

31. Conservative management
• In stable patients, this include supportive care with bed-rest,
hydration, continuous monitoring of vital signs until
hematuria resolves.
• Merit:
lower rate of nephrectomies, without any increase in the
immediate or long-term morbidity

32. Conservative management
Normal CT + clinical correlation Hospitalization or prolonged
observation for evaluation of possible
injury unnecessary in most cases
All grade 1 and 2 (Blunt + can be managed non-operatively
Penetrating)
Grade 3 most studies support expectant treatment
Grade 4 and 5 • Often undergo exploration and
nephrectomy
• many of them can be managed safely
with an expectant approach (next slide)

33. Conservative management
(Blunt renal trauma)
Grade 4 and 5:
• stable patients with devitalised fragments
• urinary extravasation from solitary injuries (>90%
resolution)
• unilateral main arterial injuries are normally managed
non-operatively in a hemodynamically stable patient
with surgical repair reserved for
• bilateral artery injuries or
• injuries involving a solitary functional
kidney
• unilateral complete blunt arterial thrombosis

34. Conservative management
(Penetrating renal trauma)
• Traditionally (surgically)
• Systematic approach based on clinical,
laboratory and radiological evaluation
• Can minimize the incidence of negative exploration
without increasing morbidity from a missed injury.

35. Conservative management
(Penetrating renal trauma)
Stab wounds
• Site of penetration: posterior to the anterioraxillary
line 88% of such injuries can be managed non-
operatively
• major renal injuries (grade 3 or higher) are more
unpredictable and are associated with a higher rate
of delayed complications if treated expectantly

36. Gunshot injuries
Indication for exploration
• involve the hilum or
• accompanied by signs of ongoing bleeding, ureteral
injuries or renal pelvis lacerations

37. Conservative management
(Penetrating renal trauma)
Gunshot injuries
• Minor low-velocity gunshot and stab wounds may be
managed conservatively with an acceptably good
outcome.
• High-velocity gunshot injuries can be more
extensive and nephrectomy may be required.

38. Interventional radiology
(Angioembolisation)
Indication:
• Hemodynamically stable blunt renal trauma
• CT findings
• active extravasation of of contrast (± a large
hematoma i.e. > 25 mm depth)
• arteriovenous fistula
• pseudo aneurysm

39. Interventional radiology
(Angioembolisation)
Outcome:
• most beneficial in the setting of high grade renal
trauma (AAST > 3)
• successful in up to
• 94.9% of grade 3
• 89% of grade 4 and
• 52% of grade 5 injuries

40. Interventional radiology
(Angioembolisation)
• In severe polytrauma or high operative risk, the
main artery may be embolised, either as a
definitive treatment or to be followed by interval
nephrectomy.
• Available evidence regarding angioembolisation
in penetrating renal trauma is sparse.

41. Surgical management
Indications for renal exploration
• Continuing hemodynamic instability and
unresponsive to aggressive resuscitation due to renal
haemorrhage (irrespective of the mode of injury)
• Expanding or pulsatile peri-renal hematoma
identified at exploratory laparotomy performed for
associated injuries.

42. Surgical management
Indications for renal exploration
• Inconclusive imaging and a pre-existing abnormality or an
incidentally diagnosed tumour may require surgery even
after minor renal injury
• Grade 5 vascular injuries (absolute indication for
exploration)

43. Surgical management
Operative findings and reconstruction
• The overall exploration rate for blunt trauma is less
than 10%
• Goal:
• Control of hemorrhage and
• renal salvage.
• Approach is trans-peritoneal
• early control of renal pedicle
• Temporary occlusion of the pedicle during the exploration
of kidney reduces blood loss without increasing post-
operative morbidity

44. Surgical management
• Stable haematomas (Zone 2)
• should not be opened.
• Central (Zone 1) or expanding haematomas
indicate injuries of the renal pedicle, aorta, or vena
cava and are potentially life-threatening
• Unilateral arterial intimal disruption,
repair can be delayed, especially in the presence of
normal contralateral kidney.

45. Surgical management
• Entering the retroperitoneum and leaving the
confined haematoma undisturbed within the
perinephric fascia is recommended unless it is
violated and cortical bleeding is noted;
• Packing the fossa tightly with laparotomy pads
temporarily can salvage the kidney

46. Surgical management
Renal reconstruction:
• Renorrhaphy (most common reconstructive
technique)
• Partial nephrectomy ( in case of non-viable
tissue)

47. Surgical management
Renal reconstruction:
• Watertight closure of the opened collecting
system (desirable),
• closing the parenchyma over the injured collecting
system.
• If the capsule is not preserved, an omental pedicle
flap or perirenal fat bolster may be used for
coverage
• use of hemostatic agents and sealants

48. Surgical management
• Nephrectomy for main artery injury has outcomes similar
to those of vascular repair and does not worsen post-
treatment renal function in the short-term.
• Repair of Grade 5 renal injury is rarely successful, and
nephrectomy is usually the best option, except in case of
a solitary kidney.
• Retroperitoneum should be drained following renal
exploration.

49. Management (Summary)

50. Follow up
• Repeat imaging two-four days after trauma minimizes
the risk of missed complications, especially in grade
3-5 blunt injuries.
• Do CT scan if fever, unexplained decreased
haematocrit or significant flank pain

51. Follow up
• Repeat imaging can be safely omitted for patients
with grade 1-4 injuries as long as they remain
clinically well.
• Nuclear scans are useful for documenting and
tracking functional recovery following renal
reconstruction

52. Follow up
• Follow-up should involve
• physical examination,
• urinalysis,
• individualised radiological investigation,
• serial blood pressure measurement and
• serum determination of renal function

53. Follow up
• Follow-up examinations should continue until
• healing is documented and
• laboratory findings have stabilised,
• although checking for latent renovascular
hypertension may need to continue for years.

54. Follow up (Summary)

55. Complications
Early complications (< 1 month ) Delayed Complications
Bleeding Bleeding
Infection Hydronephrosis
Perinephric abscess Calculus formation
Sepsis Chronic pyelonephritis
Urinary fistula Hypertension
Hypertension ( < 5 %) AVF
Urinary extravasation Hydronephrosis
Urinoma Pseudo anuerysm

56. Post Renal trauma hypertension
Investigation: Arteriography
Treatment (if hypertension persists)
• medical management,
• excision of the ischemic parenchymal segment, vascular
reconstruction, or total nephrectomy
Acute As a result of external compression from peri-renal hematoma
(Page kidney).
Chronic Due to compressive scar formation
Renin-mediated hypertension
•Renal artery thrombosis,
•segmental arterial thrombosis,
•renal artery stenosis (Goldblatt kidney),
•devitalised fragments and
•arteriovenous fistulae (AVF).

57. Paediatric renal trauma:
• Children are more prone to renal trauma as the kidneys
are lower in the abdomen.
• Less well-protected by the lower ribs and muscles of the
flank and abdomen.
• Kidney is more mobile, have less protective peri-renal fat
and are proportionately larger in the abdomen than in
adults.
• Hypotension is a less reliable sign and significant injury
can be present despite stable blood pressure.