الفهرس 
Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
One of the greatest worries for patients following cardiac
surgery is a condition known as post-sternotomy mediastinitis, or deep
sternal wound infection. The CDC in the United States has officially
approved the definition of mediastinitis.
Preoperative risk factors for mediastinitis include obesity (BMI
>40), diabetes mellitis (elevated hemoglobin A1C [HbA1c]), smoking,
and chronic obstructive pulmonary disease [COPD].
HF, renal dysfunction, PVD, advanced age, and inadequate
nutritional status (low serum albumin) are all risk factors for death.
Other significant risk factors for mediastinitis include preoperative
colonization with methicillin-resistant staph aureus and steroid usage.
Emergency operations, previous operations, and the (debatable)
use of both internal thoracic arteries (ITAs) in patients with diabetes
are all surgical risk factors for mediastinitis. Instances when CPB or
surgery go on for too long, where intra-aortic balloon pressure (IABP)
is required, and where excessive bone wax is used.
Mediastinitis is more likely to occur in patients who have
experienced postoperative complications such as excessive bleeding,
reexploration for bleeding, multiple transfusions, prolonged
ventilatory support, low cardiac output states (cardiogenic shock) with
use of an IABP, refractory hyperglycemia in the ICU, regardless of
whether the patient has a history of diabetes, or acute kidney injury.
At first surgical revision, staphylococcus aureus and coagulasenegative staphylococcus are the most prevalent pathogens isolated
from wound cultures. Klebsiella, Escherichia coli, and
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Propionibacterium are some of the other bacteria that can cause
illness.
Many different wound-healing procedures have been developed
for the treatment of post-sternotomy mediastinitis in the modern era of
cardiac surgery, and there is currently no consensus regarding the best
surgical approach to mediastinitis after open-heart surgery.
Surgery, either open or closed irrigation, or reconstruction using
vascularized soft tissue flaps such omentum or pectoral muscle, is the
gold standard for treatment. Unfortunately, standard treatments often
result in procedure-related morbidity, and their long-term clinical
prognosis has been unsatisfactory.
Closure with the help of a vacuum is a cutting-edge technique
that uses a clever mechanism. Local negative pressure is the basis of
this method of wound healing. Several benefits of traditional surgical
treatment are integrated during the process of applying negative
pressure to a sternal incision. Recent articles show promising clinical
findings, although observations are still limited and the underlying
mechanisms are mainly unclear.
The purpose of this research was to evaluate the efficacy of
early surgical debridement followed by vacuum-assisted closure in the
treatment of mediastinitis following heart surgery.
At the hospital affiliated with Menoufia University, a
prospective study was conducted. Thirty-two patients who developed
an infection in their deep sternal wounds following cardiac surgery
were included in our study.
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The main results of the study revealed that:
14 (43.8%) patients were females, while 18 (56.3%) patients
were males. The male to female ratio was 1.3: 1
the mean age at the time of the study was 52.3 ± 8.5 years,
ranging between 38 and 70 years and patients were classified
into three age categories: less than 50 years (n = 13), between
50 and 60 (n = 13), and more than 60 years old (n = 6)and the
mean BMI was 33.4 ± 4.9 kg/m2, ranging between 25.9 and 42
kg/m2and patients were classified into four BMI categories:
Overweight (n = 10), class I (n = 8), class II (n = 11), and class
III (n = 3).
14 (43.8%) patients were hypertensive, 13 (40.6%) were known
to be diabetic, eight (25%) patients were diagnosed with chronic
obstructive pulmonary disease (COPD), and 11 (34.4%) patients
had peripheral vascular disease (PVD). Two (6.3%) patients
were on steroid therapy.
Regarding to the type of procedure, 14 (43.8%) patients
underwent coronary artery bypass graft (CABG) surgery, seven
(21.9%) patients underwent mitral valve replacement, five
(15.6%) patients underwent aortic valve replacement, and six
(18.8%) patients underwent double valve replacement.
Regarding classification of intervention according to NCEPOD,
28 (87.5%) interventions were elective, and four (12.5%) were
emergent. The mean operating time was 246.8 ± 40.4 minutes,
ranging from 157 to 300 minutes. 24 (75%) procedures were
primary, whereas eight (25%) procedures were re-do.
The mean interval between surgery and SWI was 13.4 ± 6.7
days, ranging from 5 to 25 days, the onset of SWI was on the
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5th day in three (9.4%) patients, on the 6th day in four (12.5%)
patients, between 1 and 2 weeks in 12 (37.5%) patients, and
more than 2 weeks in 13 (40.6%) patients. According to
microbiological testing, Staph aureus was the causative
organism in majority (53.1%) of patients. The causative
organism was MRSA in three (9.4%) patients, gram negative
organisms in nine (28.1%) patients. Combined multi-microbial
infection was reported in three (9.4%) patients.
In all, leukocytosis (WBC > 11 x109/L) was reported in 28
(87.5%) patients. All patients demonstrated high levels of CRP.
As demonstrated in Table 5, the mean WBC count at time of
diagnosis was 18.1 6.2 x109/L, ranging from 9 to 30 x109/L.
The mean CRP level was 39.7 9.1 mg/dl, ranging from 25.6 to
54.2 mg/dl. 10 (31.3%) did not demonstrate any CT findings.
However, air was found in eight (25%) patients, fluid collection
was found in nine (28.1%) patients, and both air and fluid
collection were found in five (15.6%) patients.
The average interval between the onset of DSWI and surgical
debridement was 8.2 ± 3.7 days, ranging from 3 to 14 days.
Following surgical debridement, VAC therapy was initiated for
all patients. The mean duration of VAC application was 5.9 ±
0.8 days, ranging from 5 to 7 days. The mean percentage of
wound size reduction was 16.7 ± 5.2%. The mean percentage of
granulation tissue formation was 32.6 ± 4.7%. The average
WBC count was 13.5 ± 3.1 x109/L, and the average CRP level
was 22.3 ± 4.8 mg/dl. Microbiological culture was negative in
23 (71.9%) patients.