Discussion
Median sternotomy is the most frequently used incision for pediatric
cardiac operation. However,DSWI after cardiac surgery is a severe
complication that not only increases mortality and morbidity[9,10],
but also prolongs hospital stays and increases treatment
costs[11,12]. Risk factors for sternal wound infection in infant
include low gestational age,prolonged ICU stay and open chest, cyanotic
congenital heart diseases, high complexity of the surgical treatment,
quality of the operative field treatment and surgical team
experience[13-16].
The principles of treatment for DSWI are adequate debridement,removal of
all infected tissue and foreign materials, a well-vascularized tissue
transfer to promote wound healing, anterior mediastinal protection, and
chest wall stability[3]. If the wound infection is suspected, early
wound exploration and drainage are necessary, empirical broad spectrum
intravenous antibiotics should be initiated. when culture results are
available, targeted antibiotics should be used. once deep sternal
infection is definite, surgical debridement should be performed as soon
as possible. During debridement, the presence of residual foreign
materials and infection involving implants should be carefully
examined.In our study, 4 patients were found to have residual pacemaker
wires and one patient was found to have infection involving the
extracardiac conduit.we removed residual pacemaker wires,replaced the
extracardiac conduit.
There is no consensus as to the best specific treatment for close the
sternum after thorough surgical debridement.At present,the main
treatment methods include sternal rewiring after debridement,
Vacuum-assisted closure(VAC) therapy and flap reconstruction. For deep
sternal wound infections, part of the sternum is often resected,
resulting in unsatisfactory outcomes with the method of sternal
rewiring. VAC can improve wound healing by increasing parasternal blood
flow, reducing bacterial loads, enhancing formation of granulation
tissue [17,18].But, using a vacuum system over an open sternum has
raised concerns that the strong negative pressure could cause right
ventricle rupture and other bleeding complications[19],and for
sternum necrosis and severe infection, the failure rate of VAC is still
high[20,21].
Currently, flap reconstruction is regarded as the gold standard in DSWI
where there is inadequate sternum following debridement or uncertainty
whether the infectious process has been controlled[22]. There has
been a variety of flap choices for reconstructing sternal wounds, such
as the pectoralis major flap,
rectus abdominis flap and omental flap. The pectoralis major is a broad
flat muscle that lies close to the sternum, allowing for easy dissection
and providing adequate coverage. It has rich blood supply from
thoracoacromial artery, segmental pedicles from the internal thoracic
artery and some branches of the lateral thoracic and intercostals
arteries. Based on the above advantages, pectoralis major muscle flap is
the most commonly used flap and has achieved good results in adult
patients [23].However, there are only a few reports about these
techniques in pediatric patients.In this study, we used the pectoralis
major muscle turnover flap technique. This technique preserves the
lateral one third of the muscle with its dominant vascular pedicle and
motor nerves, and preserves the contour of the chest wall, producing a
better cosmetic result[24]. We consider the technique is easy and
unilateral flap can completely
fill stermal defect in most patients.It may be related to the relatively
short sternum in infants. If unilateral flap does not completely close
the defect, the residual sternal defect can be filled by splitting the
opposite pectoralis major muscle turnover flap. Zahiri demonstrated the
turnover flap to be associated with less postoperative complications
when compared to the advanced pectoralis major flap[25]. Many
studies suggest the use of VAC therapy to bridge definitive primary
closure or flap reconstruction. However, we consider that immediate flap
reconstruction after debridement may improve outcomes and shorter
treatment time. In our study,all patients underwent one-stage
debridement and flap reconstruction,and all of the sternal wounds healed
successfully.
In pediatric patients, long-term development and limb function should be
of special concern. During the follow-up,we found no evidence of any
upper limb or upper trunk movements disorder,and chest walls were stable
in all patients.Erez and colleagues [3] reported similar results in
5 neonates who were treated with unilateral PMMTF reconstruction. In
female patients, the use of
pectoralis major flap may have
potential impact on breast development, should be long-term follow-up.
The study is subject to the usual limitations of a retrospective,
uncontrolled study design. Our experience with
pectoralis major turnover flap
reconstruction over the past 10 years and have achieved good therapeutic
results. Therefore, pectoralis major turnover flap reconstruction is our
first choice for the treatment of DSWI. This is one of the reasons we
did not have a control group. Another limitation of this study is the
number of cases is small, so further large-scale controlled studies are
needed.