Renal Trauma
Introduction
• The kidneys are cushioned by perinephric fat inside Gerota’s fascia
and have a vertical mobility .
• The lower rib cage (ribs 10 to 12) covers and protects the kidneys.
• the kidneys should be considered intrathoracic as well as
retroperitoneal organs.
• Trauma to the back, flank, lower thorax or upper abdomen may
result in renal injury
Incidence and Etiology
❖ Renal trauma is present in approximately 10% of all abdominal
injuries.
❖ 80% of renal trauma is due to blunt injury.
❖ 20% of renal trauma is due to penetrating injury
❖ Injuries to the kidney from external trauma are the most common.
❖ Blunt renal injuries are most often caused by motor vehicle
accidents, falls from heights, and assaults.
❖ Rapid deceleration can cause vascular damage to the renal vessels,
resulting in renal artery thrombosis, renal vein disruption, or renal
pedicle avulsion.
Etiology and clinical picture
Penetrating renal injuries most often come from:
o Stab wounds.
The abdomen, chest, and back must be examined:
fractures of the lower ribs and upper lumbar and lower thoracic
vertebrae are associated with renal
injuries.
Hematuria
▪ Is the best indicator of urinary system
injury.
▪ The degree of hematuria does not correlate with severity of renal
injury.
▪ Hematuria is absent in up to 36% of renal vascular injuries resulting
from blunt trauma.
Imaging
▪ Methods of Radiographic assessment
IVP
CT
Angiography
• Indications for imaging:
– All blunt trauma with gross hematuria or microscopic hematuria
in shock patient should undergo renal imaging, usually CT with
intravenous contrast.
– Penetrating injuries with any degree of hematuria should be
imaged.
– Pediatric patients (younger than 16 years) sustaining blunt renal
trauma must be carefully evaluated for hematuria.
– Deceleration injury as falling from height
– Children have a high catecholamine output after trauma, which
maintains blood pressure until approximately 50% of blood
volume has been lost.
– Shock is not a useful parameter in children to determine if
imaging studies should be performed or not.
Imaging CT
❖ Use of contrast-enhanced computed tomography (CT) has provided
anatomic detail and facilitates accurate grading of renal injuries
❖ In contrast, excretory urography is less sensitive and much less
specific.
❖ The preferred imaging study for renal trauma is contrast-enhanced
CT.
❖ Spiral CT is used in many centers to evaluate renal injuries. Although
the rapidity of the study 2 to 3 minutes is a major disadvantage in
renal injuries.
Findings on CT that suggest major injury are:
o medial hematoma, suggesting vascular injury.
o medial extravasation, suggesting renal pelvis or ureteropelvic
junction avulsion.
o lack of contrast enhancement of the parenchyma, suggesting
arterial injury.
Imaging IVU
▪ "Single-shot" intraoperative excretory urography.
▪ When the surgeon encounters an unexpected retroperitoneal
hematoma surrounding a kidney during abdominal exploration, the
study can provide essential information.
▪ Only a single film is taken 10 minutes after intravenous injection of 2
mL/kg of contrast material.
▪ If findings are not normal or near normal, the kidney should be
explored to complete the staging of the injury and reconstruct any
abnormality found.
Imaging – angiography
❖ Arteriography is largely used to define arterial injuries suspected
on CT or to localize arterial bleeding that can be controlled by
embolization
Imaging – sonography
• Sonography: used in immediate evaluation of injuries.
• It confirms the presence of two kidneys and can easily define any
retroperitoneal hematoma.
Management of renal trauma
Non-operative Management:
– 98% of renal injuries can be managed nonoperatively.
– Significant injuries (grades II through V) are found in only 5.4%
of renal trauma cases .
Surgical exploration:
– Grade IV and V injuries more often require surgical exploration.
– Penetrating trauma usually need exploration but can be
managed non-operatively if carefully staged with CT.
Indications for renal exploration
Absolute indications:
o Evidence of persistent renal bleeding,
o Expanding perirenal hematoma,
o Pulsatile perirenal hematoma.
Relative:
o Urinary extravasation,
o Nonviable tissue,
o Delayed diagnosis of arterial injury, segmental arterial injury, and
incomplete staging.
Management of renal trauma
• Via a transabdominal approach allows complete inspection of intra-
abdominal organs and bowel.
• Complete renal exposure, debridement, hemostasis, watertight
closure of the collecting system, and coverage or approximation of
the parenchymal defect
• Total nephrectomy is immediately indicated in extensive renal
injuries when the patient's life would be threatened by attempted
renal repair.
Complications
▪ Persistent urinary extravasation can result in urinoma, perinephric
infection, and renal loss.
▪ Delayed renal bleeding can occur several weeks after injury
▪ Perinephric abscess rarely occurs after renal injury
▪ Hypertension is seldom noted in the early postinjury period
▪ Post-trauma arteriovenous fistula.
Ureteric injury
Mechnism of injury
▪ 95% caused by penetrating trauma and 5% caused by blunt trauma
as rapid deceleration injury
▪ surgical trauma As anorectal surgery, vascular surgery and
gynecological surgery or laparoscopic surgery
Diagnosis
▪ Haematuria is not reliable sign and may absent in 50 % of ureteric
injury
▪ Early sign of missed ureteric injury are prolonged ileus , elevated
blood urea, palpable abdominal mass and protinitis
Imaging
▪ IVU To see incomplete visualization of the ureter, deviation of ureter
, dilatation or extravasation
Intra-operative diagnosis By direct exploration , intravenous indigo
carmine or cystoscopy with retrograde injection of indigo carmine
Treatment
Stable patient
Repair of ureter according the size and side of injury by
▪ Ureteroureterostomy
▪ Ileal loop interpostion
▪ Ureteral reimplantation, Psoas Hitch
Unstable patient
o By nephrostomy tube and definitive reconstruction is delayed after 2
weeks
ETIOLOGY
• Blunt Trauma
• Penetrating Injury
• Iatrogenic Injury
• 95% of patients with bladder associated with pelvic fracture.
DIAGNOSIS
• Hematuria:
– Any degree of hematuria must alert to injuries to the kidney,
ureter, bladder or urethra.
– Gross hematuria in (95% to 100%)
– Microscopic hematuria in (5%)
• Lower abdominal pain, tenderness, and bruising.
• Inability to void and urethral catheter does not return urine.
• Pelvic fracture
• Should undergo formal cystography.
Types of bladder injury
• Extraperitoneal rupture (60%)
• Intraperitoneal rupture (30%)
• Combined rupture (10%)
Intraperitoneal rupture caused by severe blunt trauma to the lower
abdomen or pelvic trauma to a distended bladder , elevated vesical
pressure by trauma lead to rupture at the weak point at the dome of the
bladder
DIAGNOSIS
Cystography:
– Retrograde cystography: with plain abdominal x-ray imaging
(including drainage films) has proved 100% accurate in
diagnosing significant bladder injuries
– The technique involves two important steps: filling the bladder
completely and obtaining a post-drainage film.
Cystography (technique):
– 350 ml of 30% contrast material is infused by gravity into U.B
CLASSIFICATION AND MANAGEMENT
1- Contusions:
– Constitutes (67%) of bladder injuries). Diagnosis: trauma
patients with hematuria who ultimately have no evidence of
urethral or renal injury and in whom results of cystography are
normal.
– Treatment: require no specific therapy
2- Extraperitoneal ruptures: Extraperitoneal bladder rupture can be
managed with catheter drainage only.
Indications for exploration in extraperitoneal ruptures:
– Bone fragment projecting into the bladder (which is unlikely to
heal).
– Open pelvic fracture.
– Rectal perforation.
– Laparotomy for other reasons.
Management:
Intraperitoneal ruptures require open operative repair, with two-
layer closure with absorbable suture and peri vesical drain
placement.
• Reasons for early operative repair:
– To avoid persistent urinary leakage into the peritoneum
resulting to peritonitis.
URETHRAL INJURIES
Etiology:
• It divided into anterior and posterior urethral injury , posterior
urethral injury due to fracture pelvis and anterior urethral injury due
to fall astride
Mechanism of injury
• Shearing force between fixed prostate and mobile bladder and
shearing force between fixed membranous urethra and mobile
bulbous urethra
URETHRAL INJURIES
Type I: Urethral stretch injury
Type II: Urethral disruption proximal to the genitourinary diaphragm
Type III: Urethral disruption both proximal and distal to the
genitourinary diaphragm
Diagnosis :
• Triad of blood at the urethral meatus,
inability to urinate, and full bladder
• Perineal hematoma or swelling from
extravasated urine and blood.
• Non palpable prostate or high riding up
by PR examination due to presence of
pelvic haematoma
• Retrograde urethrogram
Anterior urethral injury
Caused by direct trauma to perineum or urethra due to fall astride
The urethra and corps spongiosum are surrounded by a tunica
albuginea which further enveloped by buck’s fascia which inserted in
urogenital diaphragm. When urethral injury occur and buck’s fascia
intact , the extravasation of blood and urine remain within the penis
lead to swelling and ecchymosis around the penis only but if the
buck’s fascia injured the extravasation extended to anterior
abdominal wall , scrotum, perineum and upper part of the thigh give
picture of butterfly distribution of extravasation
posterior urethral injury
o Injury to posterior urethra carry
many complication as impotence,
incontinence, and late stricture
urethra this complication occur
more frequently with primary
exploration and repair so the
primary repair not done and patients managed by suprapubic tube
only and after 3 months do urethrography and if stricture occurred
treated according site and size of stricture
Urethrography:
• A small-bore urethral catheter (14 F).
• Knudson clamp can be used.
• 30 mL of contrast injected gently in
the urethra Static films in lateral
decubitus position or fluorography.
• In case of partial injury , see
extravasation of contrast at the site of injury and contrast passed
into the bladder but in complete disrupture no contrast pass into the
bladder
Retrograde urethrogram:
– If findings are normal:
• A urethral catheter is placed.
– If a urethral injury is demonstrated:
• Formal suprapubic urinary catheter, bladder exploration,
and repair of bladder injuries if present
POSTERIOR URETHRAL INJURIES
• Delayed Reconstruction (Treatment of stricture):
– Timing: When?
• Until the associated injuries have healed
• Until patient can be positioned for the reconstructive
procedure (3 to 12 months).
• At 3 months: scar tissue at the urethral disruption site is
stable and mature
Complications:
1-Impotence
2-Incontinence
3-Stricture urethra
