Abstract
Background. Clinical experience suggests that granulation tissue may be inhibited by coverage
with a musculocutaneous flap. We hypothesized that coverage of an open wound with
a musculocutaneous flap would result in regression and apoptosis of the wound's granulation
tissue. Methods. In the first experiment, 32 rats underwent excisional wounding; 16 underwent musculocutaneous
flap coverage of their granulation tissue on postwounding day 8, and then 16 rats
(8 controls + 8 flaps) were killed on both postwounding days 10 and 12 (2 and 4 days
after the flap procedure, respectively). In the second experiment, 18 rats were wounded,
and on postwounding day 5 the rats underwent flap coverage (n = 6), wound edge release/mobilization
(the first step of the flap procedure) without flap coverage (n = 6), or dressing
change only (n = 6); all rats were killed on postwounding day 6 (24 hours after the
secondary intervention). Apoptosis was quantified with the terminal deoxynucleotidyl
transferase-mediated nick-end labeling assay. Results. Placement of a musculocutaneous flap over an 8-day-old excisional wound in the first
experiment increased the apoptotic rate in the granulation tissue from 0% to 1% (controls)
to 5% to 10% at both 2 and 4 days after flap coverage (P <.05). Cell population density decreased 50% in the flap-covered granulation tissue
compared with the controls (P <.05). In the second experiment, circumferential release of the granulation tissue
resulted in an equivalent increase in granulation tissue apoptosis over controls compared
to that induced by the full flap procedure. Conclusions. Coverage of established granulation tissue with a musculocutaneous flap resulted
in histologic regression of the wound's granulation tissue after 2 to 4 days of flap
coverage and induced at least a 5-fold increase in the apoptotic rate of the granulation
tissue. Releasing the wound edge increased granulation tissue apoptosis to a level
equivalent to that produced by the musculocutaneous flap procedure, suggesting that
alteration of the wound's mechanical environment is responsible for the acute induction
of apoptosis in this model. (Surgery 2002;131:332-7.)
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Article info
Publication history
Accepted:
September 24,
2001
Footnotes
*These studies were initiated and many of the techniques developed when M.A.C. was a research fellow in the Department of Surgery at the University of Texas Southwestern Medical School and supported by NIH grants R01-GM31321 and T32-GM08593. M.A.C. currently is a recipient of a K Award from the NIH (K08 GM00703).
**Reprint requests: Mark A. Carlson, MD, Surgery 112, VA Medical Center, 4101 Woolworth Ave, Omaha, NE 68105.
Identification
Copyright
© 2002 Mosby, Inc. Published by Elsevier Inc. All rights reserved.
