Preface - Ous-research.no

Plastic and reconstructive surgery
ence, our group is performing investigations to optimize
the reconstruction technique and to minimize the donor
morbidity.
Until now little attention has been paid to reinnervation of
the flap. We have investigated the spontaneous reinnervation
of the DIEAP flap after breast reconstruction and at the
donor site at the abdomen. Pressure thresholds have been
analysed on the skin using Semmes-Weinstein monofilaments.
Histological studies to evaluate the reinnervation in
skin are planned both for the perforator flaps and for the
donor site.
Through better understanding of flap anatomy, physiology
and better surgical technique the complication rate has decreased
and the cosmetic outcome has improved. However,
partial flap necrosis is still a recurrent complication that can
affect the final cosmetic result and the patient satisfaction.
In most cases this can be avoided by discarding parts with
unreliable capillary refilling after transferring the flap to the
recipient site. The abdominal flap is divided into four equal
vertical perfusion zones based on clinical observations. The
zone with the best perfusion was designated zone I represented
by the quarter part of the flap where the vascular
pedicle entered. Zone II was represented by the kontralaterale
neighbor zone and zone III the ipsilaterale neighbor
zone. Zone IV was the remaining part most distant from
zone I. Since the introduction of this perfusion model it has
been widely accepted. Today it is common clinical practice
to discard zone IV to avoid partial flap necrosis using the
DIEAP flap for unilateral breast reconstruction. Occasionally
further trimming is necessary to obtain an optimal cosmetic
result because the flap is still too full. In order to preserve
tissue with better vascularity the next zone to be sacrificed
would be zone III. However, we have little scientific data that
prove the validity of these perfusion zones. In other words
trimming zone III before zone II could be wrong. We are
performing quantitative evaluation of the perfusion zones
with laser Doppler perfusion imaging (LDPI) in order to get
a more exact picture of the microcirculatory differences in
the DIEAP flap (fig 5). Our results showed that the perfusion
of zone II was significantly lower than zone III in the period
between 2 hours and 3 days after surgery. This suggest
that it may be right to convert zone II to III and zone III to II,
which will have major clinical impact on all surgical procedures
involving DIEAP-flaps.
Figure 5.
Colour map of blood flow for the DIEAP flap processed by laser
Doppler perfusion imaging. The flap has been divided into
perfusion zones. The colour scale red-yellow-green-blue-black
represents perfusion values where red is the highest and black the
lowest value
Measurements of microcirculation with laser Doppler
perfusion imaging (LDPI)
Measurements of microcirculation are a central part of all
our animal and human experiments. It is performed with
a PIM 3.0 LDPI from Perimed, Stocholm, Sweden. The LDPI
generates, processes and displays colour-coded images of
tissue perfusion. An optical scanner guides a low power laser
beam stepwise to the tissue surface. The LDPI measures
microcirculation to a depth of a few hundred micrometers.
When the laser beam hit moving erytrocytes in the subepidermal
plexus the light is backscattered and detected by a
photodetector, this convert the light intensity to electrical
signals and colour-coded images.
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