2. Renal Trauma
The incidence of genitourinary tract injury
following abdominal trauma is approximately
10%
Renal trauma occurs in approximately 1-5% of
all trauma cases
Kidney - MC injured genitourinary organ in all
ages with M:F ratio 3:1
3. Mode of injury
Classified by their mechanism as blunt or penetrating
Blunt renal trauma: 90-95% in rural settings
Motor vehicle accidents
Falls from heights
Assault
Direct blow to the flank or abdomen during sports
Penetrating renal injuries: 40% in urban settings
Gunshot
Stab wounds
4. Major reno vascular injuries occur at
retroperitoneal points of fixation such as the renal
hilum or UVJ, resulting in renal artery thrombosis,
renal vein disruption, and renal pedicle avulsion
Trauma to the anterior axillary line is more prone to
damage renal hilum and pedicle, compared with
the posterior axillary line more often resulting in
parenchymal injury
5. Suspect renal injury after trauma in case of :
Flank hematoma
Abdominal or flank tenderness
Rib fractures
Penetrating injuries to the low thorax or flank
7. The best indicators of significant urinary system
injury include microscopic (>5 RBCs/HPF or positive
dipstick finding) or gross hematuria and
hypotension (systolic BP <90 mm Hg)
Degree of hematuria and severity of the renal
injury do not consistently correlate
Although critical to the initial evaluation of
traumatic urinary tract injury, the presence or
absence of hematuria should not be the sole
determinant in the assessment of a patient with
suspected renal trauma
8. Urinalysis, haematocrit and baseline creatinine are
the most important tests for evaluating renal
trauma
Haematuria that is out of proportion to the history
of trauma may suggest pre-existing renal pathology
Serial haematocrit determination together with
vital signs, is used for continuous evaluation of the
trauma patient
9. American Association for the Surgery of Trauma
(AAST) renal injury grading scale
Grade* Description of injury
1 Contusion (Microscopic or gross hematuria, urologic studies normal)
Non-expanding subcapsular haematoma
No laceration
2 Non-expanding peri-renal haematoma
Cortical laceration < 1 cm deep without urinary extravasation
3 Cortical laceration > 1 cm without urinary extravasation
4 Parenchymal laceration extending through renal cortex, medulla,
and collecting system
Segmental renal artery or vein injury with contained haematoma, or
partial vessel laceration, or vessel thrombosis
5 Completely shattered kidney
Avulsion of renal hilum, devascularizing the kidney
*Advance one grade for bilateral injuries up to grade III
Abdominal CT or direct exploration is used to classify injuries
10.
11. Indication of renal imaging
The criteria for radiologic imaging include
Gross hematuria, microscopic hematuria with hypotension or
presence of major associated injuries
All penetrating trauma patients with a likelihood of renal injury
(abdomen, flank, or low chest) who are hemodynamically stable
All blunt trauma with significant mechanism of injury, specifically
rapid deceleration as would occur in a motor vehicle accident or a fall
from heights
All blunt trauma with gross hematuria
All blunt trauma with hypotension defined as a systolic pressure of <
90 mm Hg at any time during evaluation and resuscitation
All pediatric patients with > 5 RBCs/HPF
Patients who are hemodynamically unstable after initial resuscitation
require surgical intervention
12. CECT - gold standard for genitourinary imaging in
renal trauma
Arteriovenous scanning (typically 80 seconds after
contrast administration) provides visualization of
the kidneys in the nephrogenic phase of contrast
excretion and is necessary to detect arterial
extravasation
Delayed scanning of kidneys 10 minutes after
injection of contrast identifies parenchymal
lacerations, injury to collecting system and urinary
extravasation accurately and reliably
13. Findings on CT that raise suspicion for major injury:
Medial hematoma, suggesting vascular injury
Medial urinary extravasation, suggesting renal
pelvis or UVJ avulsion injury
Lack of contrast enhancement (uptake of contrast)
of the parenchyma, suggesting arterial injury
14. Major limitation of CT - inability to define a
renal venous injury adequately
Renal vein injury remains difficult to diagnose
with any type of radiographic study, but the
presence on CT of a large haematoma, medial
to the kidney and displacing the vasculature,
should raise the suspicion of venous injury
15. Excretory urography, largely replaced by CT
Limited role - intraoperative “single-shot” IVP only
a single film is taken 10 minutes after iv injection
of 2 mL/kg of contrast material
Indications - an unexpected retroperitoneal
hematoma surrounding a kidney during abdominal
exploration
To assess the presence of a functioning C/L kidney
and to radiographically stage the injured side
16. Sonography used in immediate evaluation of
injuries and can facilitate the rapid diagnosis of
intraabdominal injuries (i.e., hemoperitoneum)
Focused assessment with sonography for trauma
(FAST)
Can confirm the presence of two kidneys and can
define a retroperitoneal hematoma
Cannot clearly delineate parenchymal lacerations,
vascular disruptions, collecting system injuries,
and urinary extravasation in the acute setting
17. Angiography is largely used to define arterial injuries
suspected on CT or to localize and control arterial
bleeding
Renal embolization has proved useful in primary
setting with persistent bleeding in a hemodynamically
stable patient
Pseudoaneurysms and A-V fistula are treated by
angiographic embolization to stop secondary
hemorrhage.
Test of choice for evaluating venous injuries
18. Nonoperative Management
Nonoperative management has become standard
of care in hemodynamically stable, well-staged
patients with AAST grade I to III renal injuries,
regardless of mechanism
Most experts agree that patients with grade IV and
V injuries more often require surgical exploration,
but even these high-grade injuries can be
managed without renal operation if carefully
staged and selected
19. Contrary to past experience, obligatory exploration is
no longer mandated for renal gunshot wounds
Gunshot injuries should be explored only if they
involve the hilum or are accompanied by signs of
continued bleeding, ureteral injuries, or renal pelvis
lacerations
Strict bedrest is mandatory until gross hematuria
resolves
Although most grades II to IV injuries resolve
uneventfully, delayed renal bleeding can occur in up
to 25%
20. All patients with high-grade injuries (grades III to
V) selected for nonoperative management should
be closely observed with serial hematocrit
readings
Periodic imaging in the absence of worrisome
symptoms (fever, flank pain, dropping
hematocrit) no helpful in patients presenting
with urinary extravasation or nonviable
parenchyma
21. Presence of concomitant injuries often
influences management of renal trauma;
approximately 80% to 90% of renal injuries have
major associated organ injury requiring surgical
exploration
If site of penetration by stab wound is posterior
to the anterior axillary line, 88% of such renal
injuries can be managed non-operatively
22.
23. Indications for angiography with embolization therapy:
Bleeding from a renal segmental artery with or
without parenchymal laceration
Unstable condition with grade III to IV injury,
A-V fistula or pseudoaneurysm
Persistent gross hematuria, and/or blood loss
exceeding 2 units in 24 hours
24. Operative Management
Indications for renal exploration after trauma
Absolute indications:
Hemodynamic instability with shock
Expanding/pulsatile renal hematoma identified during
laparotomy (usually indicating renal artery avulsion)
Suspected renal pedicle avulsion (grade 5 vascular injury)
PUJ disruption
Relative indications: rare
Urinary extravasation together with nonviable tissue
Renal injury together with colon/pancreatic injury
A delayed diagnosis of arterial injury (which most likely
will need delayed nephrectomy)
25. Urinary extravasation alone from a grade IV
parenchymal laceration or forniceal rupture can
be managed nonoperatively with an expectation
of spontaneous resolution of > 90%
Should nonviable tissue constitute > 25% in
association with a parenchymal laceration or
urinary extravasation or both, the potential for
complications greatly increases and operative
management is recommended
26. Renal Exploration
The overall exploration rate for blunt trauma is < 10%
Goal of exploration following renal trauma - control of
haemorrhage and renal salvage
Transperitoneal approach for surgery
Obtaining early vascular control before opening
Gerota fascia can decrease renal loss
Access to the pedicle is obtained either through the
posterior parietal peritoneum, which is incised over
the aorta, just medial to the inferior mesenteric vein,
or by bluntly dissecting along the plane of the psoas
muscle fascia adjacent to the great vessels and
directly placing a vascular clamp on the hilum
27. Renal Reconstruction
Principles of renal reconstruction after trauma:
Complete renal exposure
Measures for temporary vascular control
Debridement of nonviable tissue
Hemostasis by individual suture ligation of bleeding
vessels
Watertight closure of the collecting system if possible
coverage or reapproximation of the parenchymal
defect
Judicious use of drains
28. Renovascular injuries
Main renal artery thrombosis from blunt trauma occurs secondary
to deceleration injuries
Mobility of the kidney - stretch on renal artery- disrupt arterial
intima- thrombus occludes the vessel, rendering kidney ischemic
Prompt diagnosis by CT or angiography may lead to immediate
renal exploration in the appropriate candidate in an attempt to
salvage the kidney, but outcomes for salvage remain dismally low
and nephrectomy is almost always required.
Successful renal revascularization through use of endovascular
stents during angiography (Disadvantage- inability to effect
anticoagulation in polytrauma patient)
With delayed diagnosis (>8 hours), the kidney typically cannot be
salvaged
When repair is attempted in renal artery thrombosis, the area of
injury (noted by a visible contusion on the vessel) should be
excised and a replacement graft done, preferably with hypogastric
or splenic artery
29. Indications for nephrectomy
The unstable patient, with low body temperature
and poor coagulation, cannot risk an attempt at
renal repair if a normal contralateral kidney is
present
Total nephrectomy would be indicated
immediately in extensive renal injuries when the
patient’s life would be threatened by attempted
renal repair
30. Complications
Persistent urinary extravasation- urinoma,
perinephric infection- systemic antibiotics, if
persist, placement of an internal ureteral stent
Delayed renal bleeding can occur up to several
weeks after injury but usually occurs within 21
days- bed rest and hydration, if persist,
angiography and embolization
Perinephric abscess-rare, persistent urinary
extravasation and urinoma are typical precursors.
Percutaneous drainage /surgical drainage if
necessary
31. Hypertension is seldom noted in the early postinjury
period
Basic mechanisms for arterial hypertension:
(1) renal vascular injury, leading to stenosis or occlusion of
the main renal artery or one of its branches (Goldblatt
kidney)
(2) compression of the renal parenchyma with
extravasated blood or urine (Page kidney)
(3) post-trauma A-V fistula
In these instances, the reninangiotensin axis is stimulated
by partial renal ischemia, resulting in hypertension
32. Post-operative care and follow-up
Repeat imaging 2-4 days after trauma minimizes the
risk of missed complications, especially in grade 3-5
blunt injuries
Repeat imaging / CT scan is recommended in cases of
fever, flank pain or falling haematocrit
Nuclear scans are useful for documenting and
tracking functional recovery in patients following
renal reconstruction .
First follow up should be at approximately 3 months
after major renal injury with hospitalisation.
Each follow up should involve physical examination,
urinalysis, individualized radiological investigation,
serial BP measurement and RFT
34. Iatrogenic ureteral trauma - commonest cause of
ureteral injury
External ureteral trauma- more common in upper
ureter
Gynaecological operations are the commonest
cause of iatrogenic trauma to the ureters and
usually involve damage to the lower ureter
The incidence of ureteral injury during
laparoscopic colectomy is higher than in open
surgery
35. External Trauma
Overall, ureteral trauma accounts for 1-2.5% of
urinary tract trauma, <4% of all penetrating and
<1% of all cases of blunt trauma
Associated visceral injury is common
Small bowel perforation (39% to 65%)
Large bowel perforation (28% to 33%)
Renal injuries (10% to 28%)
Bladder injuries (5%)
36. American Association for the Surgery of Trauma
Organ Injury Severity Scale for the Ureter
Grade Type Description
1 Hematoma Contusion or hematoma without devascularization
2 Laceration <50% transection
3 Laceration ≥50% transection
4 Laceration Complete transection with <2 cm devascularization
5 Laceration Avulsion with >2 cm devascularization
Advance one grade for bilateral upto grade 3
37. Mechanism by which bullets injure the ureter -
not only by direct transection but by disruption of
the delicate intramural blood supply and
subsequent necrosis
In experimental models, such microvascular
damage has been found as far away as 2 cm from
the point of transection
38. Surgical injury
Overall incidence of ureteral injury - 0.5% - 10%
Total incidence of ureteral injury after gynecologic surgery
is 0.5% and 1.5% and after abdominoperineal colon
resection 0.3% to 5.7%
Following procedures contribute to iatrogenic ureteral
injuries:
Hysterectomy (54%)
Colorectal surgery (14%)
Other pelvic procedures like ovarian tumor removal (8%)
Transabdominal urethropexy (8%)
Abdominal vascular surgery (6%)
39. A large percentage of ureteral injuries after
gynecologic laparoscopy occur during electrosurgical
or laser-assisted lysis of endometriosis
There are probably three reasons
(1) endometrioma can involve the ureter either
extrinsically or intrinsically
(2) long-standing endometriosis can cause
intraperitoneal adhesion, making ureteral visualization
difficult
(3) the disease can deviate the ureters medially away
from their normal anatomic position
40. In contradistinction to open operation, where at
least one third of ureteral injuries are recognized
immediately, fewer injuries to the ureter are
immediately identified after laparoscopy.
Therefore during laparoscopy, a high index of
suspicion for ureteral injury is required.
41. Avoidance of ureteral injury is predicated on
intimate knowledge of its location, especially its
relation to the uterine and ovarian arteries, if those
structures are going to be ligated, as in a
hysterectomy. Visualization of the ureter in the area
of the ureterosacral ligaments is thought to be
especially difficult, and special care must be taken
in this area.
Intra-operative hydration or diuretic
Preoperative ureteral stenting
5-10 ml of IV indigo carmine followed by cystoscopy
after lap hysterectomy
42. Ureteroscopic injury
In fact, ureteroscopic injury is mc cause of iatrogenic
ureteral trauma in modern series
One factor cited as a cause of ureteral injury during
ureteroscopy was the persistence of stone basket
attempts after recognition of a ureteral tear. Current
recommendations are to stop the procedure and
place a ureteral stent when ureteral perforations are
identified
Prevention of ureteroscopic injury
(1)Use of the Ho:YAG laser to fragment larger stones
before basket manipulation
(2)Perform ureteroscopy alongside or over a wire
placed up into the renal pelvis
43. The safest approach is to avoid injury by performing
ureteroscopy over a ureteral guidewire. The next
safest approach is to use a second ureteral “safety
wire” that is always in place during ureteroscopy and
assists ureteral stent placement in the presence of
problems
Safe ureteroscopy practices should be followed
including using sound technique, limiting
ureteroscopy times, using safety wires, scoping over
guidewires, and halting ureteroscopy immediately in
the face of any ureteral injury
44. During stone fragmentation attempts,
electrohydraulic lithotripsy (EHL) is associated
with the highest risk of ureteral injury ,followed
by the Nd:YAG laser and finally by the Ho:YAG
laser
Factors that are thought to protect against
ureteral injury are smaller ureteroscopes and
flexible ureteroscopes
45. Clinical Diagnosis
Hematuria is a nonspecific indicator of urologic injury. Absence of
hematuria in ureteral injury may result from an adynamic,
partially transected ureter or a complete ureteral transection
Haematuria is unreliable and a poor indicator of ureteral injury, as
it is present in only 50-75% of patients
Fever, leukocytosis, and local peritoneal irritation are mc signs
and symptoms of missed ureteral injury and should always
prompt CT examination
In contrast to acute injuries, “missed” injuries that are discovered
> 48 hours after injury are best delineated with retrograde
ureterography
Unrecognized or mismanaged ureteral injury can lead to
significant complications including urinoma, abscess, ureteral
stricture, urinary fistula, and potential loss of an I/L renal unit.
Methylene Blue- If a ureteral or renal pelvis injury is suspected
intraoperatively, 1 to 2 mL of methylene blue dye can be directly
injected into the renal pelvis with a 27-gauge needle to confirm
the diagnosis.
46. Radiological diagnosis
Extravasation of contrast medium in CT or in IVP
is the hallmark sign of ureteral trauma
All patients with significant ureteropelvic
laceration, for instance, had either medial
extravasation of contrast material or
nonopacification of the ipsilateral ureter on CT.
Such findings should always raise suspicion for
ureteral injury
In unclear cases, a retrograde or antegrade
urography is the gold standard for confirmation
47. Retrograde Ureterography
Most sensitive radiographic test for ureteral injury
Used to delineate the extent of ureteral injury
seen on CT scan or IVP if further clinical
information is necessary
MC used to diagnose missed ureteral injuries
because it allows the simultaneous placement of a
ureteral stent if possible
48. Prevention of iatrogenic trauma
Prevention depends upon the visual identification
of the ureters and careful intraoperative dissection
in their proximity
Use of prophylactic preoperative ureteral stent
(it does not decrease the rate of injury)
Intraoperative cystoscopy after intravenous dye
injection, which can provide confirmation of
ureteral patency (secondary prevention)
49. Management
Depend on nature, severity and location of injury
Immediate diagnosis of a ligation injury during an
operation can be managed by de-ligation and stent
placement, if viability is in question, ureteroureterostomy
or ureteral reimplantation should be performed
Immediate repair of ureteral injury is usually advisable.
However, in unstable trauma patients, a ‘damage control’
approach is preferred
4 options for damage control in ureteral injuries:
(1) do nothing but plan a reoperation when the patient is
more stable, usually within 24 hours
(2) place a ureteral stent and do nothing else
(3) exteriorize the ureter
(4) ligation of the ureter, diversion of the urine (e.g. by a
nephrostomy), and a delayed definitive repair
50. Injuries that are diagnosed late are usually
treated first by a nephrostomy tube with or
without antegrade stent. Retrograde stenting is
often unsuccessful in this setting. If the ureter
ultimately cannot be stented, safest approach is
to allow at least 6 weeks for complete healing of
the wounds and then attempt open repair
Major ureteral injury requires ureteral
reconstruction following temporary urinary
diversion
51. Principles of surgical repair of
ureteral injury
Mobilize injured ureter carefully, sparing adventitia widely,
so as not to devascularize ureter
Debride ureter liberally until edges bleed, especially in high-
velocity gunshot wounds
Repair ureters with spatulated, tension-free, stented
watertight mucosa to mucosa anastomosis; using fine
absorbable monofilament and retroperitoneal drainage
afterward
Retroperitonealize the ureteral repair by closing peritoneum
over it
With severely injured ureters, blast effect, concomitant
vascular surgery, and other complex cases, consider omental
interposition to isolate the repair when possible
52. Proximal and mid-ureteral injuries can often be
managed by primary uretero-ureterostomy, while
a distal injury is often treated with ureteral
reimplantation.
Wide debridement is highly recommended for
gunshot wound injuries due to ‘blast effect’ of
injury
53. Reconstruction option by site of injury
Site of injury Reconstruction options
Upper ureter Uretero-ureterostomy
Transuretero-ureterostomy
Uretero-calycostomy
Mid ureter Uretero-ureterostomy
Transuretero-ureterostomy
Ureteral reimplantation and a Boari flap
Lower ureter Ureteral reimplantation
Ureteral reimplantation with a psoas hitch
Complete Ileal interposition graft
Autotransplantation
54. Uretero-ureterostomy
most common repair performed, usually in
upper and mid-ureter
Bridge 2-3 cm ureteral defect
Uretero-calycostomy
In profound damage to renal pelvis and PUJ
Ureter stump anastomosed ETS to a lower pole
calyx of I/L kidney
55. Transuretero-ureterostomy
Distal end of injured ureter is ligated and proximal end
anastomosed to ETS with C/L ureter
Most often performed as delayed procedure
In extensive ureteral loss or when pelvic injuries
preclude ureteral reimplantation
In middle or distal ureteral injury, in which
ureteroureterostomy or bladder flap/hitch repair is
impossible (usually because of severe bladder
scarring, a congenitally small bladder, or a long
segment of missing ureter)
C/I in history of urothelial carcinoma or calculi
56. Ureteral reimplantation with a psoas hitch
Distal ureteral injuries are best managed by ureteral
reimplantation because the primary trauma usually
jeopardises blood supply to the distal ureter
A psoas hitch with non-absorbable sutures between
the bladder and the I/L psoas tendon is usually
needed to bridge the gap and to protect
anastomosis from tension
It is important to avoid the genitofemoral nerve
C/L superior vesical pedicle may be divided to
improve bladder mobility
Psoas hitch bridge 6-10 cm ureteral defect
57. Ureteral reimplantation with a Boari flap
Injuries to the lower two thirds of the ureter
with long ureteral defects
It is a time-consuming operation and not usually
suitable in the acute setting
Boari flap bridge 12-15 cm ureteral defect
58. Ileal interposition graft
In delayed ureteral repairs, especially when entire ureter
or a long ureteral segment defect
Not suggested for acute repair
This should be avoided in patients with impaired renal
function or known intestinal disease
Ileal segment is placed in the isoperistaltic orientation
between renal pelvis and bladder
Follow-up should include serum chemistry to diagnose
hyperchloremic metabolic acidosis
Long-term complications - 3% anastomotic stricture and
6% fistulae
59. Autotransplantation
Used after extensive ureteral loss or after
multiple attempts at ureteral repair have failed
Final option before nephrectomy
Kidney can be relocated to pelvis
Renal vessels are anastomosed to iliac vessels
and a ureteral reimplantation is performed
60. Delayed nephrectomy
Poor renal function (seen after delayed
recognition of an obstructing ureteral injury)
Severe panureteral injury when ileal ureter or
other reconstruction is impossible
Persistent ureteral fistula (especially vascular
fistula) despite previous intervention