Compromised Skin Grafts and Flaps
Skin grafts and compromised skin flaps represent a classical problem
involving insufficient oxygen supply to tissue. Plastic surgeons
use the grafts and flaps to repair serious damage, and to close
or cover wounds. Skin is taken from one part of the patients, body
and used to cover a break in the skin on another part. There are
several types of skin grafts. They include Full-thickness grafts,
in which all of the skin layers are used, and split-thickness grafts,
in which only the top layers and several of the deeper layers are
used. There are also pedicle grafts, in which part of the skin remains
attached to the donor site. This allows the old blood supply to
remain intact while a new blood supply develops.
The problem is what to do when skin grafts appear not to be taking.
A freshly applied split-thickness graft receives no oxygen until
tiny blood vessels called capillaries can penetrate into it. Such
capillary ingrowth normally takes place over a two to three day
period. If this does not happen, it's not likely that the graft
will survive. HBOT improves the chances that a graft will take,
both by supplying oxygen and by encouraging quick capillary growth.
Providing hyperoxygenation increases the oxygen tension in the
graft bed and wound margins up to 1500 percent. In turn, the hyperoxygenation
causes a marked increase in the effectiveness of the blood or plasma
that reaches the graft through compromised blood vessels. The volume
of tissue that derives sufficient oxygen from a single damaged blood
vessel increases 16 fold, and marked tissue salvage results.
Lack of oxygen tends to be less of a problem with full-thickness
and pedicle grafts, since these grafts have their own supply of
capillaries, Even so, it still takes time for good blood flow to
become established through these typed of grafts, Therefore, full-thickness
and pedicle grafts also respond to HBOT. I the case of pedicle graft,
it is important that HBOT be employed before what little circulation
this is present develops blood clots.
In many instances, HBOT is used only after a skin graft starts
to fail. While HBOT can help save failing grafts, it can be even
more effective when used before surgery to keep grafts from failing
in the first place.
Hyperbarics also offer strategies for reducing edema. The edema
reduction effect, induced by the relative spasm of a precapillary
arteriolar sphincter, helps to limit the swelling of the graft or
flap. The high oxygen tension achievable with HBOT induce large
oxygen neovascularization. Among other things, oxygen dissolved
in plasma is readily available to tissues and organs limiting damage
from reperfusion injury.
HBOT's effectiveness in aiding skin graft survival us supported
by research. The effectiveness of HBOT is shown in grafting and
in reimplantation of limbs, with a salvage rate of 75% for the HBOT
group compared to 46% for the controls, with 100% HBOT salvage when
the patient is treated within 72 hours post-operatively.
The use of HBOT for the preparation of a base for skin grafting
and the preservation of compromised skin grafts has been well documented
as effective.