Discussion
Osteomyelitis is a rare, low-virulent chronic infection
of the sternum which usually occurs following
trauma or surgery, with no systemic symptoms.[
4]
Patients typically have a purulent sternocutaneous
fistula that usually appears weeks, months, or even
years after discharge.[
5] Sternocutaneous fistula is
a complication characterized by high recurrence
rates and which lasts for months or even years,
usually requiring repeated surgical intervention
and prolonged antibiotic therapy.[
6] The persistent
presence of sternocutaneous fistula causes chronic
discharge from the wound, resulting in increased
treatment costs and reduced quality of life.[
4] Surgical
treatment with median sternotomy was carried out
in three of our cases, and complaints of frequent
discharge from the incision site were reported
to occur within 1-2 months. Despite repeated
debridement and various surgical interventions, the
discharge persisted months later at the incision site
of sternum.
Although the proportion of patients recovering with
antimicrobial therapy and simple wound care without
surgical intervention is not well known, the recurrence
rate of chronic osteomyelitis is approximately 30%
per year, despite surgical debridement and long-term
antibiotic treatment, a rate which is even higher in
cultured Pseudomonas aeruginosa cases to a level of
about 50%.[7] There is currently no general consensus
on appropriate postoperative surgical treatment for
mediastinitis/sternal osteomyelitis.[6,8] The duration of
optimal antibiotherapy is uncertain, and prolonged oral
prophylactic antibiotherapy for 3-30 months has been
reported in case-based studies.[5,9] The delay between
the surgical approach and the appearance of the
sternocutaneous fistula and the order may be the cause
of persistent and chronic progression of the condition
in some patients.
Revision and prolonged mechanical ventilation
due to postoperative bleeding has been reported to
be directly related to sternal infections.[10] Two of
our patients were subjected to more than one median
sternotomy, and in one patient six days of intensive care
followed by at least 60 hours of extended ventilatory
support was required.
The most commonly encountered microorganisms
are Staphylococcus strains and Enterobacter,
Escherichia coli, Klebsiella, Serratia and
Pseudomonas are other responsible microorganisms.[11]
Gram (+) bacteria such as Staphylococcus aureus and
Enterococcus faecalis may cause rhabdomyolysis.
Rhabdomyolysis also causes muscle ischemia and
cytokine-dependent muscle toxicity. However, in the
microbiology, mycobacteriology and mycological
examinations of our patients, no microorganism
culture-growth was reported. The main reason for
the lack of culture-growth of microorganism was the
fact that broad-spectrum antibiotics were initiated
during the outpatient clinic follow-ups or during
follow-up at external clinical centers. In all our three
patients, cefazolin, cefuroxime, ampicillin - sulbactam,
clindamycin and ceftriaxone group antibacterial drugs
were used during the posoperative period.
Todays commonly used and accepted treatment
methods include, conventional wound dressing,
antibiotic administration, early debridement, closed
mediastinal irrigation and drainage, sternal refixation,
partial sternal resection, delayed sternal closure, well
vascularized muscle flaps and omental flap applications
such as pectoralis major, bilateral or unilateral rectus
abdominis, latissimus dorsi.[11,12] In addition, the
vacuum assisted closure system, a noninvasive active
treatment based on controlled and continuous negative suction pressure, which is used to help and speed
up wound healing, can be used in chronic deep
osteomyelitis.[13] Different results can be obtained
with oral antibiotic treatments. Although fusidic
acid and rifampicin give good results, regular use is
difficult due to gastrointestinal side effects.[5] In this
light, TMP-SMX has been reported to have provided
good results in long-term antibiotherapy studies.[5]
All these treatment modalities in the literature have
been experimented in our patients; however, complete
wound healing was not achieved until initiation of
the long-term oral TMP-SMX antibiotic therapy for
low virulent chronic sternal osteomyelitis. Surgeons
generally prefer antibiotic therapy and recurrent
debridement because, aside from high mortality
and morbidity, aggressive surgical interventions
result in treatment failures. Unfortunately, surgical
debridement alone has a high rate of failure, except
for cases of presternal tissue infection. Sternal
osteomyelitis requires a multidisciplinary approach
due to the inadequacy in pathological diagnosis.
Tocco et al.[5] reported that oral antibiotics were tried
in these patients without aggressive debridement
or sternal resection, and that the fistula could still
be treated despite the presence of steel wires at the
wound site. An important issue with regards antibiotic
treatment is the frequent preferences of antibiotic
use, which do not include or partially include gram
positive strains and which have a relatively low soft
tissue/bone penetration during the early postoperative
and postoperative periods. As a result, the treatment
process of the rarely encountered cases of lowvirulent
and often gram-positive sternal osteomyelitis
is unnecessarily prolonged.
Long-term treatment patterns for chronic
osteomyelitis have been demonstrated in many
studies.[5,9] The duration of treatment is the basic
determinant for treatment success. As a result,
successful treatment protocols, which usually last
for about one year and even longer in some cases,
can be provided.[5] In our cases, introduction of
debridement and long antibiotherapy of up to two
years, particularly in serious cases of osteomyelitis
complication and decrease in quality of life, can be
prevented. Although 1-2 years may appear to be a
long course of treatment, it should be emphasized that
these patients are susceptible to prolonged exposure to
different repeated antibiotics at different times and to
the development of possible resistance to antibiotics.
In light of this, we suggest that antibiotherapy should
be continued during the period of 1-3 months when
postoperative recurrence is most frequent, particularly
with wound healing.
Incisional site wound infection after discharge
is reported to occur especially in patients with no
congenital or acquired immunocompromised
conditions, those who undergo open heart surgery with
median sternotomy, and in particular patients who
are subjected to multiple median sternotomies, and
patients who require long-term mechanical ventilation
and intensive care conditions. Effective and prolonged
antibiotherapy should be considered in these patients
who experience a significant decrease in the quality
of life and who require a large number of surgical
interventions.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect to
the authorship and/or publication of this article.
Funding
The authors received no financial support for the research
and/or authorship of this article.
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