SLIDE 1:
Biomechanics and Medical Diagnosis of HVI in Adults and Children  An Illustration of the CIREN Model
Dorraine Watts, RN, PhD
Honda Inova Fairfax CIREN
Chris Sherwood, MS
University of Virginia
for Childrens National Medical Center CIREN
SLIDE 2:
Introduction
HVI  Hollow Viscous Injury
Complicated diagnosis and treatment
Common injury in automobile crashes
Children at risk due to smaller anatomy
SLIDE 3:
Abdominal Anatomy
[photos]
	* Diaphragm
	* Liver
	* Stomach
	* Spleen
	* kidney
[CT scan]
	* Kidney
	* Spleen
SLIDE 4:
Abdominal Solid Organs
	Liver - 27% of total blood flow
	Spleen- 5% of total blood flow
	Kidneys - 22% of total blood flow
	Pancreas
	Adrenal Glands
SLIDE 5:
Abdominal Solid Organs
 * Primary Injury Concern - Hemorrhage
 * Diagnosis - Accurate
SLIDE 6:
Abdominal Hollow Organs
Stomach
	Small Intestine
	Duodenum, Jejunum, Ileum
	Large Intestine
	Ascending, Transverse,
	Descending, Sigmoid
	Gall Bladder
	Urinary Bladder
SLIDE 7:
Abdominal Hollow Organs
Primary Injury Concern:
 * Spillage of Contents - Sepsis
 * Diagnosis - Inaccurate
SLIDE 8:
HVI Issues
* Trauma surgeons are increasingly managing blunt
abdominal trauma non-operatively
* Intestinal injuries that were previously discovered at laparotomy for solid organ injuries may be missed with non-operative management
* In older reports, delays in diagnosis of less than 12-24 hours were associated with limited morbidity and no mortality
* Longer delays result in significantly increased morbidity and mortality
SLIDE 9:
Surgeons Dilemma
* There is no well-publicized consensus among trauma surgeons as to the optimal way to diagnose occult intestinal injury
* Debate over using exploratory surgery as a diagnostic tool focuses on whether or not the risks associated with a non-therapeutic laparotomy outweigh the morbidity and mortality associated with a delay in the diagnosis of small bowel injury
=================
SLIDE 10:
Diagnosis and Management of Blunt Small Bowel Injury: A Survey of the Membership of the American Association for the Surgery of Trauma
Brownstein, Bunting, Meyer, Fakhry
University of North Carolina, Chapel Hill, NC
and
the Inova Regional Trauma Center,
Falls Church, VA
The purpose of this study was to survey the membership of the AAST regarding current diagnostic approaches in the management of patients with suspected small bowel injury, and evaluate their perceptions of the morbidity and mortality associated with a delay in diagnosis
SLIDE 11:
Conclusions
Significant variation exists in the diagnostic approach
*  Surgeons underestimated the morbidity of non-therapeutic laparotomy and the mortality associated with a delay in diagnosis
*  The lack of consensus regarding the diagnostic approach may have undesirable effects on injured patients
SLIDE 12:
Hollow Viscous Injury and Small Bowel Injury in Blunt Trauma: An analysis of 275,557 trauma admissions from the EAST Multi-Institutional Trial
EAST Multi-Institutional HVI Research Group
Watts DD, Fakhry SM et al. J of Trauma, 54:289-294, 2003
SLIDE 13:
Conclusions
* Motor Vehicle Crashes (MVC) was the most frequent mechanism of injury in patients with perforating SBI
* Logistic regression models of CT data yielded no useful discriminators in predicting SBI
* Patients from MVCs had a relative risk (RR) of SBI of 1.7
* The non driver position increased the risk of perforating SBI (RR = 1.9,  95% CI 1.6-2.3)
* Use of a seat belt increased the risk of perforating SBI (RR = 2.4 ,  95% CI 2.0-2.8)
* Delay in treatment of SBI injuries increased treatment complications
SLIDE 14:
Risk
The presence of an abdominal seatbelt mark was the most significant risk factor, carrying a 4.7 increase in relative risk (95% CI 3.7 - 5.9)
So 2 ways CIREN data can assist this field
1  Prevention  by learning more about the injury mechanisms to reduce risk of these injuries
2  Diagnosis is very important in this injury.  If factors can be determined which indicate high risk of this type of injury, can help medical personnel in treatment course
SLIDE 15:
Biomechanics Research
Hollow Viscous Organs
SLIDE 16:
Frontal Crashes
Seatbelt, Steering Wheel
SLIDE 17:
[diagram]
position of lap belt relative to pelvis
belt across anterior superior iliac spines
SLIDE 18:
[diagrams]
SUBMARINING
SLIDE 19:
Reasons for Booster Seats
Practical concerns
 - Prevent slouching due to leg length
 - Slouching degrades fit for both lap and shoulder belt
 - Reduces misuse of shoulder belt
SLIDE 20:
Lap Belt Only  Seat Belt Syndrome
 - HVI
 - Lumbar Spine
< Gumler et al., 1982 >
SLIDE 21:
SIDE IMPACT
SLIDE 22:
INJURIES
 * Contusion, perforations, transections, lesions
 * Mechanisms of Injury
	- Increased intraluminal pressure
	- Perforation from rib and pelvic fractures
	- Shearing or crushing against spine
	- Deceleration (relative motion from fixed attachments - mesentery)
SLIDE 23:
[diagram]
Blowout of Intestines caused by high intraluminal pressures
Steering Wheel or Lap Belt Loading
SLIDE 24:
[bar chart]
BELT USE/ PERCENTAGE OF VEHICLES WITH DRIVER AIRBAG
There is another phase here in late 80s and early 90s of a 2 point belt.  It was shown to have higher rates of liver injuries, when lap belt not used.  This will not be included in data we present.
SLIDE 25:
AIS = 2 Hollow Viscous  Injury Sources - Frontal Impact 1977-1979
	Front:
	-Steering Assembly
	-Instrument Panel
	(52%)
	Side Interior:
	-Surface
	-Armrests
	(9%)
	Belt Restraint
	(4%)
<Bondy, 1977-1979>
SLIDE 26:
AIS = 3 Abdominal Injury Distribution - Frontal Impact
 - Liver (30%)
 - Kidney (22%)
 - Spleen (22%)
 - Digestive 	(12%)
<Bondy, 1980>
SLIDE 27:
Early Research Focused on Steering Wheel Contact
SLIDE 28:
Abdominal Injury Corridors
<Trollope, 1972>
Squirrel Monkeys, Rhesus Monkeys, Baboons, Pigs
This parameter is sort of a stress term combined with a duration term.  Higher stress (higher force, lower area) and higher duration result in higher injury values.
HVI, or lower abdomen, have higher values because they have lower mass, and are more distensible.  This allows them to move out of the way, more so than liver, spleen, etc.
SLIDE 29:
Porcine Test
* Test frame mounted on Hyge sled (Delta V=32 km/h)
* Anesthetized subject supported by suspension suit attached to trolley
* Lower steering wheel rim impacted torso at liver
SLIDE 30:
Abdominal Impact Tests
[diagram]
SLIDE 31:
There is another phase here in late 80s and early 90s of a 2 point belt.  It was shown to have higher rates of liver injuries, when lap belt not used.  This will not be included in data we present.
SLIDE 32:
AIS = 3 Hollow Viscous Injury Sources - Frontal Impact 1988 - 1994
 * Belt Restraint (56%)
 * Front:  -Steering Assembly (39%)
 * Side Interior:
	-Surface
	-Armrests
		(5%)
Importance of normalizing injury to restraint type
SLIDE 33:
AIS = 3 Abdominal Injury Distribution - Frontal Impact
	- Liver (38%)
	- Spleen (23%)
	- Digestive (17%)
	- Kidney (4%)
<Elhagediab & Rouhana 1988-1994>
SLIDE 34:
Seatbelt Loading of Abdomen
Injuries
	Mesentery
	Duodenum
	Small bowel
	Large bowel
	Cecum
<Miller (1988)>
SLIDE 35:
There is another phase here in late 80s and early 90s of a 2 point belt.  It was shown to have higher rates of liver injuries, when lap belt not used.  This will not be included in data we present.
SLIDE 36:
AIS = 2 Hollow Viscous Injury Sources - Frontal Impact 1993-1997
 * Belt Restraint (59%)
 * Front:
	-Steering Assembly
	-Instrument Panel
	(27%)
 * Side Interior:
	-Surface
	-Armrests
	(15%)
SLIDE 37:
AIS = 3 Abdominal Injury Distribution - Frontal Impact
	Liver (35%)
	Spleen (31%)
	Digestive (15%)
	Kidney (7%)
	Urogenital (N/A)
SLIDE 38:
[diagram]
Unbelted occupant with airbags
SLIDE 39:
[post-crast photos from dummy test - airbag deployed]
	Steering Wheel Contact Despite Airbag
SLIDE 40:
Airbag Loading of Abdomen
[point-of-contact photos from dummy test - airbag deploying]
 - Injuries
	Colon, Mesentery, Peritoneum
< Cadaveric tests with loading to abdomen Hardy et al. (2001)>
SLIDE 41:
Recent Advances
Force Limiter
	Improve torso pitch
Lap belt pretensioners
	Reduce slack and submarining risk
	Trosseille et al. (2002)
	Steffan et al. (2002)
SLIDE 42:
Steering wheel impacts to abdomen
Dummy and cadaver
< Shaw et al. (2004) >
SLIDE 43:
Hollow Viscous Injury
 Analysis of CIREN Data
SLIDE 44:
CIREN Query
 * Hollow Viscous Injury
 * No rollovers
 * No ejections
 * 16 years and older
 * Driver and Front Right Passenger
SLIDE 45:
61% of HVI in Frontal Crash with PDOF 330-30
33% in Right (30-150) or Left (210-330)
SLIDE 46:
Demographics of CIREN HVI Cases - FRONTAL CRASHES
Incidence
39 / 856 drivers had HVI (4.6%)
12 / 224 pass had HVI (5.4%)
Injuries
62 injuries - 39 drivers
25 injuries - 12 passengers
39 drivers  50% Belted, 50% Unbelted
12 pass  All Belted
SLIDE 47:
Demographics of CIREN HVI Cases - SIDE CRASHES
Incidence
18/348 NEAR Side had HVI (4.6%)
9 / 132 FAR Side had HVI (6.8%)
Injuries
24 injuries - 18 NEAR Side
 23 injuries - 9 FAR Side
18 NEAR Side  72% Belted, 18% Unbelted
9 FAR Side  55% Belted, 45 % Unbelted
SLIDE 48:
Frontal Crashes
Colon
Driver
	N 	% all HVI
	13	21
Passenger
	N 	% all HVI
	7	28
Mesentery
Driver
	N 	% all HVI
	27	44
Passenger
	N 	% all HVI
	5	20
Small Bowel
Driver
	N 	% all HVI
	12	19
Passenger
	N 	% all HVI
	6	24
Bladder
Driver
	N 	% all HVI
	4	6
Passenger
	N 	% all HVI
	0	0
Duodenum
Driver
	N 	% all HVI
	1	2
Passenger
	N 	% all HVI
	3	12
Gallbladder
Driver
	N 	% all HVI
	3	5
Passenger
	N 	% all HVI
	0	0
Stomach
Driver
	N 	% all HVI
	1	2
Passenger
	N 	% all HVI
	4	16
Omentum
Driver
	N 	% all HVI
	1	2
Passenger
	N 	% all HVI
	0	0
For Drivers, colon, mesentery, small bowel made up 84% of the HVI
In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum
The Driver had twice as many SW injuries with unbelted drivers, even though all drivers split evenly btw belted and unbelted
SLIDE 49:
SIDE CRASHES
NEAR SIDE
Colon
	N 	% all HVI
	5	21
Mesentery
	N 	% all HVI
	8	33
Small Bowel
	N 	% all HVI
	1	4
Bladder
	N 	% all HVI
	8	33
Duodenum
	N 	% all HVI
	0	0
Gallbladder
	N 	% all HVI
	0	0
Stomach
	N 	% all HVI
	1	4
Omentum
	N 	% all HVI
	1	4
FAR SIDE
Colon
	N 	% all HVI
	7	30
Mesentery
	N 	% all HVI
	8	35
Small Bowel
	N 	% all HVI
	6	26
Bladder
	N 	% all HVI
	1	4
Duodenum
	N 	% all HVI
	0	0
Gallbladder
	N 	% all HVI
	0	0
Stomach
	N 	% all HVI
	0	0
Omentum
	N 	% all HVI
	1	4
For Drivers, colon, mesentery, small bowel made up 84% of the HVI
In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum
SLIDE 50:
All Crash Types, AIS 2+ HVI
Bondy 1977-79  7% belted
CIREN 1996-2003  64% belted
CRASH TYPE:
Bondy
	Frontal 63%
	Side	24.4%
CIREN
	Frontal	35%
	Side	34.6%
INJURY SOURCE:
Bondy
	SW	46%
	Belt	 4%
	Side	18%
	Unknown	33%
CIREN
	SW	25%
	Belt	50%
	Side	11%
	Unknown	13%
For Drivers, colon, mesentery, small bowel made up 84% of the HVI
In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum
SLIDE 51:
Frontal Crashes
Elhagediab & Rouhana 1988-94  AIS 3+
CIREN 1996-2003  AIS 2+
Unbelted / no airbag
	Elhagediab	40%
	CIREN		15%
Belted / no airbag
	Elhagediab	60%
	CIREN		14%
Unbelted / airbag
	Elhagediab	0%
	CIREN		21%
Belted / airbag
	Elhagediab	0%
	CIREN		51%
SLIDE 52:
HVI Injury Source
Changes Over Time
[bar chart]
SLIDE 53:
CIREN Case Examples
For Drivers, colon, mesentery, small bowel made up 84% of the HVI
In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum
SLIDE 54:
Case # 1  Frontal Crash
Belted Adult in Rear Seat
[post-crash frontal exterior photo of vehicle]
1997 Honda Accord
CDC: 12FYEW3
PDOF: 10 degrees
Delta V: 33 km/h/21 mph
SLIDE 55:
Scene Diagram Showing Point of Impact
SLIDE 56:
Clavicle fx
Jejunal perforation
Age:53
Gender:	Female
Position: Right Rear
Weight:	120 lbs.
Height:	54
Safety Device:	3-point restraint
SLIDE 57:
INJURIES (ICD)
Jejunal Perforation 	(863.20)
	AIS Severity	541424.3
	Info source  	Surgery
	Aspect		Right
	Contact Area	SB
Flank Contusion		(922.8)
	AIS		590402.1
	Info source	exam
	Aspect		Left
	Contact Area	SB
SLIDE 58:
Case # 2  Frontal Crash
[overhead photo post-crash vehicle]
Belted Adult Driver
	1999 Kia Sportage SUV
	CDC: 12FDEW4
	PDOF: 350
	Delta V: 37 kmph/23 mph
SLIDE 59:
Scene Diagram Showing Point of Impact
SLIDE 60:
	Age: 32
	Gender:	Male
	Position:  Driver
	Weight:	340 lbs.
	Height:	62
Safety Devices:
	3-point restraint
	Pretensioner
	Airbag
	Knee Airbag
SLIDE 61:
Steering Wheel Contact
340 pound driver
	Liver contusion
	Mesentery, Duodenum Lacerations
	Bilateral Femur fractures
	Metatarsal, navicular, cuboid fxs
SLIDE 62:
Case # 3  Frontal Crash
Misuse of Shoulder Belt, Child
2001 Toyota 4Runner SUV
CDC: 11LYEW44
PDOF: 330
Delta V: 34 kmph/21 mph
SLIDE 63:
Scene Diagram Showing Point of Impact
SLIDE 64:
[photo] Lap Belt
	Age: 6
	Gender:	Male
	Position: Right Rear
	Weight:	42 lbs.
	Height:	42
Safety Device:3-point restraint with shoulder belt worn behind back
* Jejunum serosal laceration
* Mesentery contusion
* Colon contusion
* Retroperitoneal hematoma
SLIDE 65:
[post-crash exterior vehicle photo - right front quarterpanel]
Case # 4  Side Crash
Belted Far Side Adult
	1998 Toyota Camry
	CDC: 02RYAW3
	PDOF:  50
	deltaV: 44 kmph/27 mph
SLIDE 66:
[line drawing]
Scene Diagram Showing Point of Impact
SLIDE 67:
Colon laceration / Pelvic fracture
	Age:  56
	Gender:	Female
	Position: Driver
	Weight:	146 lbs.
	Height:	54
	Safety Device:	3-point restraint
	[xrays] Belt Load on Abdomen
SLIDE 68:
Questions?