Traumatic Retroperitoneal

Hematoma Spreads Through the

Interfascial Planes

Volume 59(3), September 2005, pp 595-608

BACKGROUND

• In the early 1980s, Sheldon introduced a treatment principle founded on a location-based classification of traumatic RH as 1. Central-medial (zone I) RH

2. Flank or perirenal (zone II) RH

3. Pelvic (zone III) RH

• Feliciano established management strategies for various kinds of traumatic RH by sub-dividing the zones and by focusing on vascular injuries

1. Central-medial (zone I) RH

2. Flank or perirenal (zone II) RH

3. Pelvic (zone III) RH

• Traditionally, the retroperitoneal

space was believed to comprise

only 3 compartments:

1. Anterior pararenal space (APS)

2. Perirenal space (PRS)

3. Posterior pararenal space (PPS)

which are demarcated by 3 well-

defined fascias:

1. Anterior renal fascia

2. Posterior renal fascia

3. Lateroconal fascia

Traditional tricompartmental theory New concept of interfascial planes

anterior renal fascia

posterior renal fascia

lateroconal fasciaretromesenteric plane

retrorenal plane

lateroconal plane

1. anterior pararenal space (APS)

2. perirenal space (PRS)

3. posterior pararenal space (PPS)

retrorenal plane

retromesenteric plane

combined

interfascial

plane

Traditional tricompartmental theory New concept of interfascial planes

Spread of renal lesion by means of

perinephric bridging septa and

interfascial planes

Track of Perinephric Hematoma

An 80-year-old man suffered renal injury from a motorcycle

crash. Midlevel of a left renal CT scan shows extension

of the perinephric hematoma along the perinephric

bridging septa (dotted arrow), RMP (open arrow), and

RRP (open arrowhead).

Note that RH within the RMP

traverses the midline, anterior to

the aorta and inferior vena cava,

and that RH extends into the

LCP (closed arrowhead) by

means of the fascial trifurcation

(FT) (thin arrow). Perinephric

bridging septa provide the

conduit between the kidney and

interfascial planes.

This is considered Zone I +

Zone II RH and Type II-a RH.

PATIENTS AND METHODS

• Between January 1997 and December

2003, 594 trauma patients required

abdominal or pelvic CT scans for

evaluation of abdominal or pelvic

injury within 24 hours after admission

to Osaka Prefectural Senshu Critical

Care Medical Center, a Level I trauma

center in Japan.

• RH was diagnosed when a high-

attenuation (>30 hounsfield units)

retroperitoneal lesion was identified

on two or more consecutive CT

images. According to this criterion,

169 (28.5%) of the 594 patients had

traumatic RH.

Assessment of RH on CT Images

10 component parts of the

retroperitoneal space were identified:

• 3 compartments (APS, PRS, and PPS),

• 4 interfascial planes comprise

1. Retromesenteric plane (RMP)

2. Retrorenal plane (RRP)

3. Lateroconal plane (LCP)

4. Combined interfascial plane (CIP),

providing a route for the spread of

disease from the abdominal

retroperitoneum into the pelvis.

• 3 other extraperitoneal spaces are

1. Retrohepatic space (rhe)

2. Prevesical space (PV)

3. Presacral space (PS)

Massive RH Resulting from Renal Injury

A 53-year-old man suffered renal injury from an

industrial accident. (A) Midlevel of the left renal CT

scan reveals an enormous perinephric hematoma

displacing the left kidney, spreading into the RRP

(open arrowhead) and RMP (open arrow) by means

of the bridging septa (dotted arrows).

RH within the RMP spread

across the midline. RH with

a total volume of 2,248 mL

can be clearly subdivided in

to the PRS RMP, RRP, and

LCP (closed arrowhead)

components with

intermediate adipose

tissues. K, kidney.

CT scan at the level of the upper pole of the left kidney

shows RH extension into the RRP (open arrowhead) by

means of bridging septa (dotted arrow) behind the left

kidney. Sp, spleen. (C) Below the promontory, RH

extended into the retroperitoneum of the lesser pelvis and

presacral space (PS) by means of the CIP (hatched

arrowhead). Note that RH in the presacral space is clearly

distinguished from hemoperitoneum (HP) in the Douglas

pouch.

Delayed scans at the level of the lower pole of the left

kidney and at a slightly lower level reveal thickened

perinephric bridging septa (dotted arrow) and the

expanded RMP (open arrow) and RRP (open

arrowhead) stained with contrast medium. Note that

RRP lies apposed to the psoas muscle. This is

considered Zone I + Zone II + Zone III RH and Type

II-b RH.

RESULTS

• The study population included

169 patients with traumatic RH:

• One or more injuries of

retroperitoneal organs or major

vessels were immediately

identified in 70 patients (38.7%):

renal injury (n = 52), adrenal

injury (n = 12), pancreatic or

duodenal injury (n = 7), liver

injury in the bare area (n = 5),

and vascular injury (n = 9). In 86

patients (50.9%), RH was

attributed to pelvic fracture.

• There was a high incidence of

intraperitoneal organ injury to the

liver (n = 42), spleen (n = 20), or

intestine (n = 12). Head or facial injury

(n = 80), chest injury (n = 88), and

fracture of the extremities (n = 101)

were common associated injuries.

• Shock was present in 112 (66.3%)

patients at admission. Because of

multiple injuries, the mean Injury

Severity Score was 29.8 ± 14.5, much

higher than the score (18.6 ± 15.6) of

all trauma patients admitted to our

institute during the same period.

• 51 patients (30.2%) were treated

nonoperatively, most of whom

underwent transfusion.

• 61 patients (36.1%) were treated by

emergent laparotomy, and 26 (15.4%)

of these underwent retroperitoneal

exploration.

• 51 patients (30.2%) underwent TAE,

C-clamp, or external fixation of the

pelvic ring without laparotomy.

• 6 patients died before aggressive

treatment could be undertaken.

• There were 39 deaths among the 169

patients, yielding an overall mortality

rate of 23.1%; the overall mortality rate

of contemporary traumatic patients was

only 10.9% in our institute.

• In 27 study patients (16.0%),

uncontrolled hemorrhage from multiple

locations, including RH, was the major

cause of death.

• 4 died as a result of exsanguination

apart from RH and 5 died as a result of

severe head injury. The remaining 3

patients died as a result of complicated

multiple organ dysfunction 40.0 ± 16.5

days after admission.

Distribution of total volume of RH

and mortality rate by volume

• RH volume, need for surgical exploration,

and patient mortality were significantly

higher in the broadly defined Zone I RH

patients (patients with RH in Zone I, in

Zone I + Zone II , and Zone I + Zone II +

Zone III than in any other group of

patients, reconfirming the importance of

the conventional Zone I RH classification.

• However, of the 73 patients with broadly

defined Zone I RH, 40 (54.8%) did not

undergo laparotomy and 17 (23.3%)

survived with only conservative

treatment.

• Major vascular injuries were identified in

only 6 of the 73 patients.

Our interpretation of the relation between the PPS and

the RRP it is neither the PPS nor the PRS but the RRP

that lies immediately adjacent to the psoas muscle or

QLM.

Extent of RRP identified with CT scanning.

(A) A 41-year-old woman was shot in the

abdomen. CT scan shows that the RRP

(open arrowhead) seems to terminate at

the lateral edge of the QLM and divides

the PPS from the PRS. Note gases in the

PRS caused by the gunshot injury. This is

considered Zone II RH and Type II-a RH.

Open arrow, RMP; closed arrowhead, LCP;

thin arrow, fascial trifurcation.

(B) A 35-year-old

man suffered renal

injury from a motor

vehicle crash. CT

scan shows that

the RRP seems to

terminate at the

lateral face of the

psoas muscle.

This is considered

Zone I + Zone II

RH and Type II-a

RH.

Percentage distribution

of RH and partial volume

of RH by component.

• The largest volume

(61 ± 96 mL) and

percentage

distribution (66.1%)

occurred in the CIP.

• RH in interfascial

planes accounted for

78.1% of the total RH

volume.

Extension of RH from

pancreatic injury. A 45-year-

old man was kicked in the

abdomen. (A) CT scan

obtained at level of the

pancreatic uncinate process

shows a large hematoma

with extravasation from the

pancreaticoduodenal artery

(hatched arrow) pressing on

the inferior vena cava. Du,

duodenum; P, pancreas. (B)

CT scan obtained below the

kidney shows RH spreading

along either side of the RMP

(open arrow). This is

considered Zone I + Zone II

RH and Type I-a RH.

Extension of RH from pelvic fracture.

A 63-year-old man was hit by a

dump truck. (A) CT scan at level of

the anterior superior iliac spine

shows pelvic fracture and RH in the

PV and CIP (hatched arrowhead).

(B and C) RH ascended within the CIP

(hatched arrowhead) near the left kidney.

This is considered Zone II + Zone III RH and

Type III-b RH.

• In patients with great vessel

injuries, because the artery or

inferior vena cava is located in

the RRP or CIP, bleeding in the

planes spread uninhibitedly

upward and downward within

interfascial planes.

Extension of RH from aortic injury. A 68-year-old man

was involved in a motor vehicle collision. (A) CT

scan at level of the fourth lumbar vertebra shows

aortic injury with an enormous RH and massive

extravasation of contrast medium (short arrows).

RH within the CIP (hatched arrowhead) extends

into the LCP (closed arrowhead) and contralateral

CIP. (B) CT scan at the level of the right renal hilus

shows ascending extension of RH into the RRP

(open arrowhead), RMP (open arrow), and PRS by

means of bridging septa in retrograde fashion. (C)

CT scan at the level of the acetabulum shows RH

extension into the presacral space. HP,

hemoperitoneum. Note that this 1,508-mL RH is

confined to interfascial planes and the PRS. The

abdominal aorta was repaired, but the patient died

as a result of multiple hemorrahages complicated

with coagulopathy. This is considered Zone I +

Zone II + Zone III RH and Type IV-b RH.

Extension of RH from lumbar artery injury. A

62-year-old man fell from a height of 8 m.

(A) Midlevel right renal CT scan shows

massive RH in the RMP (open arrow), LCP

(closed arrowhead), and RRP (open

arrowhead) surrounding the right kidney.

There is neither perirenal hematoma nor

thickened perirenal bridging septa. (B) CT

scan at the level of the third lumbar

vertebra shows continuity of the massive

RH (1,356 mL). Note extravasations from

both sides of the lumbar arteries (short

arrows) that were misidentified as fractures

in the transverse process of the lumbar

vertebra. Emergent laparotomy with

retroperitoneal exploration revealed that

bleeding was derived from a psoas injury.

Despite bilateral TAE for the third and

fourth lumbar arteries, he died as a result

of uncontrollable hemorrhage from multiple

areas complicated with coagulopathy. Note

hematoma escaping from the lateral edge

of the QLM. (checkmark sign, curved

dotted arrows). This is considered Zone I +

Zone II + Zone III RH and Type IV-b RH with

checkmark sign. (C) Schematic diagrams of

the checkmark sign. Hematoma intrudes

into another potential space among the

PPS, QLM, and transversalis fascia,

forming the checkmark sign (curved dotted

arrow).

Extension of RH from inferior vena cava

injury. A 14-year-old boy was

involved in a motorcycle crash. CT

scan at the midlevel of the left

kidney shows an enormous RH

(1,484 mL) with massive

extravasation from the inferior vena

cava (short arrows) and right renal

laceration. Extravasion from the

inferior vena cava intruded directly

into the RMP (open arrow) and RRP

(open arrowhead) and spreading

into the LCP (closed arrowhead),

whereas RH in the PRS seemed to

derive from the renal laceration. The

checkmark sign is also visible

(curved dotted arrow). He died as a

result of massive hemorrhage

complicated with coagulopathy

during retroperitoneal exploration.

This is also considered Zone I +

Zone II + Zone III RH and Type IV-b

RH with the checkmark sign.

New Classification of RH

• Each RH was first classified by the

component where bleeding originated:

– Type I derived from the APS or RMP

– Type II from the PRS, LCP, Rhe, or PPS

above the pelvis

– Type III from the pelvis

– Type IV from the RRP or CIP

• Each type was subdivided according to

the degree of extension into subtype

– “a” if the RH never exceeded the

promontory or

– “b” if the RH spread beyond the

promontory.

• Ten of 13 patients with Type I RH

underwent surgical repair of an

injured organ or vessels.

• Renal or adrenal injury consisted

mostly of Type II RH, which occurred

in 43 of 51 patients. Most of these 43

patients were treated conservatively.

It is noteworthy that 4 of these

patients underwent TAE into the

adrenal artery or capsular artery and 7

underwent nephrectomy, which in

retrospect was considered

unnecessary in 3 patients, and was

ineffective in 3 other patients with

renal vein injury.

• No patient with Type III RH underwent laparotomy

with retroperitoneal exploration for hemostasis,

but TAE, C-clamp, or external fixation was often

applied.

• Unfortunately, we could not save many patients

with Type IV RH. This type of RH, which resulted

not only from great vessel injuries but also from

psoas injury, had an unexpectedly high mortality

rate (62.1%) despite aggressive therapy, including

retroperitoneal exploration in 8 patients and TAE

in 12. In particular, the checkmark sign, indicated

an extremely poor prognosis. Patients with Type

IV-b had the highest mortality rate; 13 of the 15

patients with the checkmark sign and and only 2 of

the 12 without the checkmark sign died as a result

of uncontrollable hemorrhage. Of the 12 patients

with other types of RH who died as a result of

uncontrollable hemorrhage, 6 manifested a clear

checkmark sign.

DISCUSSION

• RH was identified in interfascial

planes in most cases in this study

(88.8%) and the partial volume of RH

in interfascial planes accounted for

78.1% of the total volume. It is no

exaggeration to say that interfascial

planes are the base and center of RH.

• We suspected that the tri-

compartmental theory was

inappropriate for classification of

traumatic RH because it was

impossible to assign the major part of

the RH located within interfascial

planes, as shown in this study, to any

of the three compartments.

This Classification Also Indicated

The Appropriate Treatment Policy

1. Type I RH requires emergent

retroperitoneal exploration, which

also affords a good prognosis.

2. Type II RH is treatable with

conservative therapy unless renal

vein injury is complicated.

3. Type III RH requires TAE, C-clamp,

or external fixation but no

laparotomy for RH hemostasis.

4. Treatment of Type IV RH is still

challenging and requires further

investigation.

• Traditional RH management

strategies have recommended that all

Zone I hematomas discovered at

laparotomy should be explored

because of the high possibility of

major vascular or visceral injury.

• In this study, RH involving the Zone I

area required retroperitoneal

exploration more frequently (30.1%)

and had a higher rate (27.4%) of

mortality caused by uncontrollable

hemorrhage in comparison with RH

that did not invade Zone I, reaffirming

the value of conventional strategies.

• Exploration of all Zone I RH is not

always necessary, and indication for

exploration is assessed by

determining the bleeding source and

extension by means of interfascial

planes, as we did.

• Type I RH, derived from the APS or

the RMP, should always be explored

because of the high possibility of

major vascular or visceral injury.

• We detected 113 RHs intruding into

the broadly defined Zone II area. The

original bleeding derived from renal or

adrenal injury in only 43 (38.1%) of

113 cases and from flank injury in 3

cases (1.8%) because RH in the PRS;

LCP; PPS; or the lateral part of the

RMP, PPR, or CIP was considered

Zone II RH. Hemorrhage from the PRS,

LCP, Rhe, or suprapelvic PPS should

be considered Type II RH.

• Among the 43 cases of RH derived

from the PRS, only 4 required

effective retroperitoneal exploration

for hemostasis. 3 patients died

because of renal vein injury, with

extravasation clearly apparent on CT

scans. This low mortality rate

supports use of the conservative

treatment advocated in conventional

strategies.

• Type III RH corresponds to

conventional broadly defined Zone III

RH, usually requiring no

retroperitoneal exploration.

• The fact that the source of pelvic

bleeding has been identified as

predominantly a bone or vein in the

PPS serves as the basis for a recent

strategy for initial management of

unstable pelvic fracture, prioritizing

pelvic bony stability with a C-clamp or

external fixation over TAE.

• Type III-b RH ascended beyond the

promontory by means of the CIP and

sometimes spread all the way up to the

diaphragm. In such patients, the

bleeding source could be located in the

CIP in the pelvis; thus, angiography and

TAE should be performed along with

pelvic stabilization with a C-clamp or

external fixation because external

fixation cannot generate enough

pressure to stop arterial bleeding.

Gauze packing is often performed in the

PS or PV, a part of interfascial planes,

suggesting that pelvic packing can

serve to tampon interfascial planes.

• Because of the high mortality rate, we

have distinguished Type IV RH,

bleeding from the RRP or CIP, from

broadly defined Zone I RH. The RRP and

CIP contain great vessels and lie just

above the psoas muscles.

• Vessel injuries or psoas disruption

could induce direct bleeding into

interfascial planes without interference

from the compartments, which are

expected to have a tamponade effect in

other types of RH, and the hemorrhage

could spread rapidly throughout the

expansile interfascial planes, leading to

a high likelihood of mortality.

• If extravasations from great vessels

are detected in contrast-enhanced CT

scanning, the patient must undergo

emergent laparotomy and

retroperitoneal exploration.

• Angiography and TAE have recently

been shown to be safe and effective

modalities for evaluating and

controlling lumbar artery hemorrhage.

• In our study, many patients with

psoas injury died as a result of

exsanguination after apparent

coagulopathy despite aggressive

application of TAE.

• The checkmark sign was

frequently detected among

nonsurvivors.

• The checkmark sign must be

considered a predictor of

uncontrollable massive RH.

CONCLUSION

• The major portion of RH exists within

the interfascial planes, not in the three

compartments, and that RH extends

by means of interfascial planes and

bridging.

• We formulated an RH management

strategy by classifying RH into four

types according to the original

location and the extension.

• Type IV-b RH with the checkmark sign

have the worst prognosis.

DISCUSSION

Dr. Felix D. Battistella:

Do your findings,

which are based on

CT scan

appearance of

retroperitoneal

hematoma, alter

current treatment

recommendations

for retroperitoneal

hematomas

discovered during

laparotomy?

Dr. Kazuo Ishikawa

Our findings do not

change the treatment

strategies of Dr.

Sheldon and Dr.

Feliciano. In fact, we

treat patients with

retroperitoneal

hematoma according

to their principles.

We must determine

the real bleeding

source, by means of

the concept of

interfascial planes,

to exactly apply their

strategies.