Discussion
GSV remains the most common conduit for CABG, which is the most common
operation in cardiac surgery. Multiple studies in the literature have
examined surgical site infection (SSI) after GSV harvested, and these
show advantage of EVH (3%-13%) vs. OVH (12%-43%)[7] .The incidence of infection is (20%) in OVH group
without any recorded infection in EVH group in our study.
Preoperative risk factors normally associated with leg wound
complications include female gender, DM, obesity, hypoalbuminemia,
anemia, PVD, chronic ischemia and steroid use. OVH technique has more
severe infections involving larger areas of the wound. However, tissue
trauma and wound closure methods likely play a role. EVH may minimize
the effect of both diabetes and obesity on the incidence of wound
complications. The fact that only thigh veins are harvested in EVH group
might reduce the wound complications as diabetic vasculopathy being
largely a small vessel disease would affect wound healing more below the
knees. OVH technique in the thigh was found to be the only risk[3] .The risk factors are similar in both groups of our
study. In Our study, EVH is mainly from thigh, however, 10% from leg
and 30% extended from the whole lower limb. The site of harvesting did
not affect rate of infection. Also, there is high rate of infection in
diabetic patients 22% more than non-diabetic 9%.
Compared with OVH, EVH using the back-approach technique was associated
with satisfactory short-term results. EVH was associated with lower
rates of leg wound complications and a shorter length of hospitalization[8] . Total hospital stay for EVH group was (5.5 ± 2.4 days)
vs. OVH group was (9.5 ± 2.7 days).
Extended EVH offers significant advantages over OVH and with experience
a surgeon can safely perform EVH in shorter time. The results using this
technique are superior to OVH or combined (EVH in thigh and OVH in leg)
techniques. By avoiding wound complications minimally invasive
techniques for vein harvest may reduce postoperative morbidity, and
hospital stay [4] . Learning curve of EVH is growing; we
started with 70min. until reached 40min. In cases of combined technique
or conversion of EVH to OVH, we exclude cases from study. We harvested
by extended technique in thigh and leg within reasonable time, and
provided long vein graft for multiple conduits in (15) cases.
Traditional OVH may increase post operation wound complications. These
wounds and their complications can influence the patient’s physical
activity and may make limitations of mobility, so it is very harmful in
post CABG rehabilitation therapy [9] . As, we know that
physiotherapy and early mobilization after CABG is very important for
convalescence, EVH has significant early mobilization over OVH (P
value 0.02)
EVH has been shown to be safe and reproducible with low incidence of leg
complications. Patients are satisfied by small incision and absence of
leg wound discomfort. As the experience grows, learning curve is
required to become familiar with EVH [2] . Postoperative leg
pain, mobilization, and overall patient satisfaction were also
significantly improved in study EVH group.
There is widespread general acceptance of EVH doubts about its impact on
the integrity, quality of the conduit and longterm graft patency[3] . EVH has emerged as minimally invasive technique that
reduces wound pain and infection in CABG surgery. In a histological and
immunohistochemical evaluation of SVG, EVH showed superiority in
endothelial layer preservation when compared to OVH [10] .
We take EVH as a step for MIDCAB. We did not perform vein endoscopy
after EVH or coronary angiography during follow up period, however,
coronary Flowmeter was done in all cases without any difference between
both groups.
CABG is a commonly performed open heart surgery worldwide, and GSV is
used as a conduit for bypass in over 95% cases. The OVH technique has
remained unchanged over the years. However, leg wound complications can
be a major source of postoperative morbidity [11] . The best
indication for EVH is the patients with increased risk for wound
infection and in whom cosmetics is a major concern. EVH should be the
standard in all cases of GSV harvesting.
Cost may be an important consideration when choosing an endoscopic
approach to harvesting GSV. Each endoscopic procedure has a definite
added cost due to the expense of the disposable equipment required along
with an initial investment in the non-disposable equipment (monitor,
camera, light source, and CO2 insufflator). However, overall savings
based on improved wound healing and, therefore, fewer additional
treatments may counter balance the added cost of the equipment[12] .The cost of EVH is already more than OVH, however,
cost of long time hospital stay, readmissions, needed other surgical
procedure and antibiotics have a cost loaded on health system. We needed
large number of patients to compare cost effect of both techniques.
Another consideration is the time it takes to learn and master this
technique. The time it takes to become fully adept at this technique
varies and is operator dependent. By logistic regression analysis, the
only significant of impaired wound healing was open vein harvesting[12] . We finished training course until reaching reasonable
time of EVH to start the study, so EVH has significant less leg wound
complications vs. OVH (P value 0.03)
EVH reduces the incidence of postoperative leg wound complications,
especially leg wound infections. Moreover, there are significant
differences in the patients’ postoperative mobility, leg pain, and
satisfaction, favoring EVH. Therefore, the recommendation is routine use
of EVH in CABG [13] . During the last decade, surgery has
been moved towards less invasive access and to minimizing length of
incision [14]. In EVH group, patients were very satisfied
with leg wound (99%), and had significant less pain and more cosmesis
(P value 0.02) vs. OVH group.