Skin perfusion responses under normal and combined loadings: Comparisons between legs with venous stasis ulcers and healthy legs.
BACKGROUND
Venous ulcers, also known as stasis ulcers, are skin wounds often found at the medial surface of the lower leg. These wounds are related to chronic venous insufficiencies and affect almost 2.5 million patients every year in the United States.


METHODS
Eighteen participants with venous stasis ulcers on at least one leg and twenty healthy participants were tested. Normal and combined normal and shear loadings were applied to each lower leg and local blood perfusion was monitored. Basal perfusion, post-occlusive reactive hyperemia as well as changes in perfusion due to different loadings were compared.


RESULTS
Legs with existing venous stasis ulcers ("wounded legs") had the highest reactive hyperemia and basal perfusion values. Legs without ulcers but from participants with venous stasis ulcers ("non-wounded legs") had intermediate reactive hyperemia, and healthy legs exhibited the lowest values. Wounded legs also exhibited the largest decrease in blood perfusion under both normal and combined loadings. Non-wounded legs decreased perfusion similarly to healthy legs under normal loadings; however, non-wounded legs exhibited larger decreases in blood flow than healthy legs in response to shear and normal loading together.


CONCLUSIONS
These results suggest that patients with venous stasis disease have abnormal responses to tissue loading and raise the possibility that this technique may have the potential to identify patients at risk for developing a venous stasis ulcer. Moreover, they emphasize the importance of studying shear loading in addition to normal loading in attempting to understand the pathophysiology of this disease.
Department of Mechanical Engineering, MI State University, East Lansing, USA.
Wu
W
Pan
Department of Mechanical Engineering, MI State University, East Lansing, USA.
Josh P
JP
Drost
Department of Surgery, MI State University, East Lansing, USA.
Marc D
MD
Basson
Department of Mechanical Engineering, MI State University, East Lansing, USA. Electronic address: reidtama@msu.edu.
Tamara Reid
TR
Bush
D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000098:blood supply*; D013314:Stress, Mechanical; D014647:Varicose Ulcer / Q000503:physiopathology*; D014689:Venous Insufficiency / Q000503:physiopathology*; D016474:Weight-Bearing / Q000502:physiology
Blood perfusion; Hyperemia; Shear loading; Stasis ulcers