[libribook.com] Traumatic Scar Tissue Management 1st Edition

alterations in the mechanical environment, including alterations seen during
wound healing (Ingber 1997, Wynn 2004, Ogawa 2011, Garg et al. 2012).
It is well established that undue mechanical forces on a wound impairs healing
and is considered by many the most significant factor in pathophysiological scar
formation (Krammer et al. 1999, Yu & Stamenkovic 2000, Yano et al. 2004,
Distler et al. 2006, Reichelt 2007, Akaishi et al. 2008, Ogawa 2008, 2011, Chin
et al. 2009, Cheng et al. 2011, Wong et al. 2011, Garg et al. 2012, Widgerow
2013).
As noted in Chapter 2, MFBs play an important role in; inflammation,
remodeling, excess scarring and fibrosis. MFBs mediate wound
closure/contraction – covered in greater detail in Chapter 5. During wound
healing the differentiation of fibroblasts into MFBs occurs in the wound by day
5. If the wound contraction cycle is repeated intermittently and sufficient times,
subsequent consequences can include excess scarring and fibrotic conditions
(Akaishi et al. 2008; Garg et al. 2012).
Ravi et al. (2012) found that when traction (mechanical tension) was applied
along the edges of an incision in a mouse model, the wound recapitulated nearly
all the features of human hypertrophic scars. Conversely, stress-shielding of high
tension wounds resulted in a decrease in pro-fibrotic TGFβ1 signaling,
diminished cellular and vascular density, reduced scarring and restoration of near
normal skin architecture. This supports that wounds under elevated stress
develop increased fibrosis and mechanical forces alone could significantly alter
wound characteristics (Gurtner et al. 2011; Garg et al. 2012).
The common view is that keloids and hypertrophic scars arise from the dermis
and therefore it is theorized that modulating mechanical forces on the dermis
could reduce the risk of pathophysiological scar formation after surgery (Akaishi
et al. 2010; Ogawa et al. 2012). The work of Guimberteau supports that aberrant
scar presentations occur below the skin as well, implying that mechanical force
tension in deeper tissues should also be considered.
An improved understanding of how mechano sensory pathways influence
remodeling and how manual methods can influence mechanosensory pathways
will likely yield improved wound healing outcomes.