A non-invasive method to produce pressure ulcers of varying severity in a spinal cord-injured rat model.
METHODS
Experimental study.


OBJECTIVE
The objective of this study was to establish a non-invasive model to produce pressure ulcers of varying severity in animals with spinal cord injury (SCI).


METHODS
The study was conducted at the Johns Hopkins Hospital in Baltimore, Maryland, USA.


METHODS
A mid-thoracic (T7-T9) left hemisection was performed on Sprague-Dawley rats. At 7 days post SCI, rats received varying degrees of pressure on the left posterior thigh region. Laser Doppler Flowmetry was used to record blood flow. Animals were killed 12 days after SCI. A cardiac puncture was performed for blood chemistry, and full-thickness tissue was harvested for histology.


RESULTS
Doppler blood flow after SCI prior to pressure application was 237.808±16.175 PFUs at day 7. Following pressure application, there was a statistically significant decrease in blood flow in all pressure-applied groups in comparison with controls with a mean perfusion of 118.361±18.223 (P<0.001). White blood cell counts and creatine kinase for each group were statistically significant from the control group (P=0.0107 and P=0.0028, respectively).


CONCLUSIONS
We have created a novel animal model of pressure ulcer formation in the setting of a SCI. Histological analysis revealed different stages of injury corresponding to the amount of pressure the animals were exposed to with decreased blood flow immediately after the insult along with a subsequent marked increase in blood flow the next day, conducive to an ischemia-reperfusion injury (IRI) and a possible inflammatory response following tissue injury. Following ischemia and hypoxia secondary to microcirculation impairment, free radicals generate lipid peroxidation, leading to ischemic tissue damage. Future studies should be aimed at measuring free radicals during this period of increased blood flow, following tissue ischemia.
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
A K
AK
Ahmed
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
C R
CR
Goodwin
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
R
R
Sarabia-Estrada
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
F
F
Lay
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
A M
AM
Ansari
Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
C
C
Steenbergen
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
C
C
Pang
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
R
R
Cohen
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
L J
LJ
Born
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
A E
AE
Matsangos
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
C
C
Ng
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
G P
GP
Marti
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
N
N
Abu-Bonsrah
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
N A
NA
Phillips
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
I
I
Suk
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
D M
DM
Sciubba
Department of Surgery and Hendrix Burn/Wound Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
J W
JW
Harmon
D000818:Animals; D001774:Blood Chemical Analysis; D003402:Creatine Kinase / Q000097:blood; D004195:Disease Models, Animal; D005260:Female; D017078:Laser-Doppler Flowmetry; D007958:Leukocyte Count; D011312:Pressure; D003668:Pressure Ulcer / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D013119:Spinal Cord Injuries / Q000150:complications* / Q000503:physiopathology; D013904:Thoracic Vertebrae
D003402:Creatine Kinase