Nature and etiology of hollow-organ abdominal injuries in frontal crashes.
Injuries to the hollow organs of the lower digestive system carry substantial risk of complication due to infection and blood loss, and commonly require invasive abdominal surgery to diagnose and treat. The causes of, and risk factors for, lower abdomen injury in automobile collisions are poorly understood. The goal of this study was to investigate the risk factors and potential mechanisms of hollow-organ, lower abdomen injury in belted automobile occupants in frontal collisions. A field survey data analysis was performed to examine the relationship between various occupant and collision factors and the risk of moderate or greater severity injury (i.e., Abbreviated Injury Scale, AIS 2+) to the small intestine, large intestine, or mesentery among belted occupants involved in frontal collisions. Descriptive and comparative risk factor analyses were performed with data originating from that National Automotive Sampling System Crashworthiness Data System (NASS-CDS) over the years 2000-2011. Multivariable logistic regression models were developed to describe the effects of these factors on hollow-organ injury risk. Potential injury mechanisms were further investigated through in-depth examination of select cases exhibiting hollow-organ injuries from the Crash Investigation Research and Engineering Network (CIREN). The inclusion criteria yielded 25,407 individual cases from NASS-CDS, representing a weighted population of 11,373,358 exposed automobile occupants. Within this dataset, 143 cases (weighted frequency: 7962 occupants) exhibited AIS 2+ injury to hollow abdominal organs. Multivariable regression analysis indicated a statistically significant increased risk of moderate or greater severity injuries to the hollow organs of the abdomen with increased in ΔV (odds ratio (OR) 1.07, 95% confidence interval: 1.06-1.09) and age (OR: 1.03, 1.01-1.06). Albeit non-statistically significant, a positive association between BMI and injury risk was observed, especially among obese individuals (OR: 3.55, 0.82-15.2). No association was observed for gender or seated location within the vehicle.


RESULTS
from this study indicate that hollow abdominal organ injury is a universal problem in frontal collisions, not confined to a specific gender or seating location. Examination of CIREN cases suggests these types of injuries are associated with direct loading of the lower abdomen by the lap belt, either through poor initial belt positioning or through a "submarining" type of kinematic where the lap belt slips off of the pelvis and loads into the abdomen. Potential countermeasures against hollow-organ abdominal injury should include measures to improve initial lap belt fit, and to retain engagement of the lap belt on the pelvis throughout the collision event.
Center for Applied Biomechanics, University of Virginia, United States. Electronic address: poplin@virginia.edu.
Gerald S
GS
Poplin
Public Health Sciences, School of Medicine, University of Virginia, United States.
Timothy L
TL
McMurry
Center for Applied Biomechanics, University of Virginia, United States.
Jason L
JL
Forman
Emergency Medicine, School of Medicine, University of Virginia, United States.
Thomas
T
Hartka
Center for Applied Biomechanics, University of Virginia, United States.
Gwansik
G
Park
Center for Applied Biomechanics, University of Virginia, United States.
Greg
G
Shaw
Research & Development Division, Hyundai Motor Group, South Korea.
Jangho
J
Shin
Research & Development Division, Hyundai Motor Group, South Korea.
Hyung Joo
HJ
Kim
Center for Applied Biomechanics, University of Virginia, United States.
Jeff
J
Crandall
D000007:Abdominal Injuries / Q000453:epidemiology* / Q000209:etiology; D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D015984:Causality; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012622:Seat Belts / Q000009:adverse effects / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
Abdominal injury risk; Lap belt; Submarining; Survey data