Objectives This study evaluated the risks of sternal wound infections in pa
tients undergoing myocardial revascularization using bilateral skeletonized
internal mammary arteries (IMAs).
Background The skeletonized IMA is longer than the pedicled one, thus provi
ding the cardiac surgeon with increased versatility for arterial myocardial
revascularization without the use of vein grafts. It is isolated from the
chest wall gently with scissors and silver clips, and no cauterization is e
mployed. Presentation of collateral blood supply to the sternum and avoidan
ce of thermal injury enable more rapid healing and decrease the risk of ste
rnal wound infection.
Methods From April 1996 to August 1997, 545 patients underwent arterial myo
cardial revascularization using bilateral skeletonized IMAs. The right gast
roepiploic artery was used in 100 patients (18%). The average age of the pa
tients was 65 years; 431 (79%) were men and 114 (21%) were women; 179 (33%)
were older than 70 years of age; 166 (30%) were diabetics. The average num
ber of grafts was 3.2 per patient.
Results The 30-day operative mortality rate was 2% (n = 11). There were six
perioperative infarcts (1.1%) and six strokes (1.1%); 9 patients had stern
al infection (1.7%) and 15(2.8%) had superficial infection. Risk factors fo
r sternal infection were chronic obstructive pulmonary disease and emergenc
y operation. Superficial sternal wound infections were more common in women
and in patients with chronic obstructive pulmonary disease, renal failure,
or peripheral vascular disease. The 1-year actuarial survival rate was 97%
. Two of the six late deaths were not cardiac-related. Late dehiscence occu
rred in three patients (0.6%). The death rate (early and late) of patients
with any sternal complication was higher than that of patients without thos
e complications (33% vs. 2.7%).
Conclusions Routine arterial myocardial revascularization using bilateral s
keletonized IMAs is safe, and postoperative morbidity and mortality rates a
re low, even in elderly patients and those with diabetes. Chronic obstructi
ve pulmonary disease and emergency operations were found to be associated w
ith an increased risk of sternal infections, and the authors recommend avoi
ding the use of bilateral skeletonized IMAs in patients with these preopera
tive risk factors.