1) The retroperitoneum is the potential space behind the abdominal cavity containing major blood vessels and organs. Injury can occur via blunt or penetrating trauma. 2) Evaluation involves history, physical exam looking for signs of internal bleeding, radiologic imaging like CT scans, and exploratory surgery for unstable patients. Injuries are graded based on their severity. 3) For stable patients, non-operative management with monitoring or angioembolization is usually sufficient. Unstable patients may require surgery or techniques like REBOA to control bleeding while prepping for surgery. Mortality depends on injury severity and presence of other injuries.

1. Traumatic retroperitoneal
injury
Uptodate

2. Overview
• The retroperitoneum represents a potential anatomic space that is
immediately posterior to the abdominal cavity.
• Hemodynamically unstable patients with retroperitoneal hematoma
represent an intraoperative diagnostic challenge.
• Traumatic injury to retroperitoneal structures often accompanies
abdominal trauma.
• The initial resuscitation, diagnostic evaluation, and management of the
patient with blunt or penetrating injury, including suspected retroperitoneal
injury, are based upon protocols from the Advanced Trauma Life
Support (ATLS) program.

3. Zones of retroperitoneum
1. Zone 1 (central retroperitoneum) :- It extends from the
diaphragm superiorly to the bifurcation of the aorta inferiorly.
• contains the aorta, the inferior vena cava, the origins of the renal
and major visceral vessels, a portion of the duodenum, and the
pancreas.
2. Zone 2 includes both of the lateral perinephric areas of the upper
retroperitoneum. It extends :-
• from the renal vessels medially to the white line of Toldt laterally
• from the diaphragm superiorly to the level of the aortic bifurcation inferiorly.
• contains the adrenal glands, the kidneys, the renal vessels, the
ureters, and the ascending and descending colon.

4. 3. Zone 3 :- inferior to the
aortic bifurcation.
• includes the right and
left internal and external
iliac arteries and veins,
the distal ureter, the
distal sigmoid colon, and
the rectum
Zones of retroperitoneum
contd.

5. Trauma evaluation
Patient history :- should include detail about the mechanism of
injury.
• AMPLE (allergies, medications, previous medical/surgical history, last
meal, events)
• For retroperitoneal injury, a history of anticoagulant use is particularly
important.
• In acute trauma, patients cannot relate their symptoms or medical
history due to altered mental status (eg, neurologic injury, intoxication)
or because they are intubated and sedated  contact the patient's
primary care physician or family members.

6. Initial radiologic studies
• Chest & Pelvis radiographs :- Pelvis radiograph is most likely to raise
the possibility of retroperitoneal injury with the identification of pelvic
fracture, which may be associated with zone 3 bleeding
• Focused assessment with sonography for trauma (FAST) :- FAST
does not evaluate the retroperitoneum and may be less reliable in
patients with pelvic fracture. Approximately one-third of patients with
retroperitoneal injuries, including injuries of the duodenum and
pancreas, will have normal FAST examinations . Nevertheless, a
negative FAST in a hypotensive patient with negative chest findings
should increase suspicion for retroperitoneal bleeding.
Trauma evaluation

7. Mechanism of injury
• Blunt trauma is less likely to injure contiguous tissue planes, thus
allowing containment of hematomas such as falls or motor vehicle
crashes. Its mechanisms of injury are as follows.
• Direct transfer of energy causing organ compression – especially
kidney
• Shear stress from deceleration:- all retroperitoneal organs.
• Crush injury :- duodenum, pancreas, and great vessels lie over the
spine (it serving as anvil)
• organ puncture from an adjacent rib fracture
Trauma evaluation

8. • Penetrating injuries violate tissue planes and can lead to hemorrhage
from the retroperitoneum freely into the chest or abdomen.
• Stab wounds are generally confined to the area contacted by the object. The
size and shape of a stab injury will correspond to the implement, although there
can be increased damage from twisting of the object.
• Projectile injuries show wide variation in the amount of tissue damage.
Primary injury results from the projectile passing through the tissue, but
secondary injury also occurs due to the cavitation wave of gas and fluid of
surrounding tissue or from fragmentation of adjacent bone. Velocity &
characteristics of missile influence the damage.
Trauma evaluation

9. Associated injuries :-
• Injuries to abdominal organs or bony structures adjacent each
retroperitoneal zone should raise suspicion for potential retroperitoneal
injury.
• Zone 1 :- injury to the liver, spleen, stomach or spine
• Zone 2 :- injury to the spleen, intestines, mesentery, or lower ribs
• Zone 3 :- injury to the bladder, vagina, pelvis, and spine.
Trauma evaluation

10. Clinical evaluation
• A true "seatbelt" sign with bruising over the abdomen above the iliac crests
may indicate a crush mechanism to the retroperitoneum.
• Large ecchymosis may be suggestive but are unreliable. Eg :- flank
ecchymosis [Grey-Turner sign], periumbilical ecchymosis [Cullen's sign],
proximal thigh ecchymosis [Fox's sign], scrotal ecchymosis [Bryant's sign]
• Examination of the pelvis may indicate instability and if accompanied by
hypotension, should raise suspicion for zone 3 hemorrhage.
• This exam should be performed only once, preferably by a senior
examiner.

11. Clinical evaluation
Laboratory evaluation :- guided by clinical suspicion for injury and
patient physiology.
• For severe trauma, complete blood count, serum electrolytes, liver function
tests, amylase or lipase, and coagulation studies are done
• Urinalysis investigating the presence of microscopic hematuria should be
obtained to screen for urinary tract injury.
• For patients with hemodynamic abnormalities or suspected hemorrhage, a
sample for blood type and crossmatch should be sent immediately.
Triggering a massive transfusion protocol may be indicated based upon
the anticipated need for transfusion (eg, severe pelvic fracture).

12. Diagnosis
1. Cross-sectional imaging studies in hemodynamically stable
patients
• Computed tomography (CT) scan with intravenous contrast :-
imaging study of choice to evaluate the retroperitoneum d/t its ready
availability and speed of image acquisition,
• CT with delayed venous phases :- for evaluation of the collecting
system if there is suspicion for renal trauma.
• Cystography (CT or radiograph imaging) should be considered in
those with a pelvic fracture and/or hematuria.
2. Exploratory laparotomy of hemodynamically unstable patients in
the operating room  direct identification of retroperitoneal
hematoma

13. Grading of injuries
According to the American Association for the Surgery of Trauma
(AAST) Injury Scoring Scale
• Vascular injury – Aortoiliac vascular injury is graded as type I through
type IV
• Duodenum/pancreas – Duodenal and pancreatic injuries are graded I
through V
• Stomach, small intestine, colon, and rectum
• Kidney, ureter, adrenal gland

14. Grading of duodenal injury
Grade Injury type Description of injury
I
Hematoma Involving single portion of duodenum
Laceration Partial thickness, no perforation
II
Hematoma Involving more than one portion
Laceration Disruption <50% of circumference
III Laceration
Disruption 50 to 75% of circumference of D2
Disruption 50 to 100% of circumference of D1, D3, D4
IV Laceration
Disruption >75% of circumference of D2
Involving ampulla or distal common bile duct
V
Laceration Massive disruption of duodenopancreatic complex
Vascular Devascularization of duodenum

15. Grading of pancreatic injury
Grade* Injury type Description of injury¶
I
Hematoma Minor contusion without duct injury
Laceration Superficial laceration without duct injury
II
Hematoma Major contusion without duct injury or tissue loss
Laceration Major laceration without duct injury or tissue loss
III Laceration
Distal transection or parenchymal injury with duct
injury
IV Laceration
Proximal
Δ
transection or parenchymal injury
involving ampulla
V Laceration Massive disruption of pancreatic head

17. Approach to management
• The initial approach to management of the trauma patient
depends on the clinical status of the patient with management of
retroperitoneal injury occurring simultaneously with management
of injuries sustained to the abdomen or chest.
• Resuscitative endovascular balloon occlusion of the aorta
(REBOA) :- To control noncompressible hemorrhage in
hemodynamically unstable patients, , particularly in the abdomen
or pelvis.
• REBOA is a temporizing maneuver and needs to be followed
urgently by surgical or angiographic control of hemorrhage.

18. Operative exploration
• Considered in cases of :-
 persistent hemodynamic instability (damage control laparotomy)
 bleeding that is not responsive to minimally invasive control measures
(ie, angiography)
 development of abdominal compartment syndrome due to a large
retroperitoneal hematoma.

19. Exploration of retroperitoneal hematoma
Penetrating injury
• Zone 1 – Explore; likely a major vascular
injury. Zone 1 contains the visceral
segment, which in emergency settings is
generally not amenable to less invasive
vascular options such as endovascular
repair with fenestrated grafts
• Zone 2 – Selectively explore the kidney for
active hemorrhage or an expanding
hematoma. Mobilize the colon to rule out
retroperitoneal colon injury, and explore the
ureters if in proximity to the wound.
• Zone 3 – Explore; likely a major vascular
injury.
Blunt injury
• Zone 1 – Explore; likely a major vascular
injury.
• Zone 2 – Explore for an expanding
hematoma or one that has failed alternative
methods of hemorrhage control
(angioembolization). Do not explore a
contained, nonexpanding hematoma.
• Zone 3 – Do not explore; use an alternative
method for hemorrhage control including
intraoperative preperitoneal packing or
angioembolization

20. • Surgical access to the retroperitoneum involves the systematic
retraction of the abdominal contents and mobilization from the
left or right.
• The choice of direction depends on anatomic need for access.
• Surgical access above the mesocolon is best achieved with a left
medial visceral rotation.
• Access below the mesocolon and to the inferior vena cava can be
achieved with a right medial visceral rotation.

21. Nonoperative management
• For retroperitoneal injuries in hemodynamically stable patients who
do not have other indications for surgical exploration
• Nonoperative management may be appropriate for the following
injuries:
1) Minimal vascular injury (ie, intimal disruption without dissection)
2) Grade I through IV renal injuries
3) All adrenal injuries
4) Minor duodenal and pancreatic injuries

22. • Management includes
• pain control
• serial abdominal examination
• serial laboratory studies (tailored to the specific injuries identified),
• follow-up imaging as indicated.
• Angioembolization is performed :-
• if active extravasation or pseudoaneurysm is identified on computed
tomography (CT; pelvic, renal, other vessels); particularly true with
blunt renal trauma
• in selected patients with pelvic fractures despite initial hemodynamic
instability, with no other indication of immediate surgical exploration
• For patients who have been managed nonoperatively, failure of
observation (eg, expanding hematoma) can occur.

23. Mortality
• Mortality rates for retroperitoneal injury depend upon the
patient's clinical condition, the zone of injury, injury severity
score, and associated injuries.
• Mortality is greater for blunt compared with stab injury.
• Causes of death are multiorgan failure, hypovolemic shock &
sepsis
• The presence of major vascular injury significantly increases
mortality rates.