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Elsayed et al. Vessel Plus 2018;2:39 I http://dx.doi.org/10.20517/2574-1209.2018.65 Page 3 of 11

and the plaque was removed under direct vision using the fine dissecting spatula. This method allowed
complete extraction of the plaque from the LAD as well as from septal and diagonal branches if present
under vision. Passage of 1 mm probe was done distally to ensure the distal bed was free from plaques.The
proximal end of the arteriotomy was not extended beyond the proximal occlusion for fear of competitive
flow between the native coronary artery and the graft. The atherosclerotic plaque was sharply divided
proximally. This was followed by reconstruction using the left internal mammary artery (LIMA) or on-lay
saphenous patch. LIMA was always the first choice for reconstruction. Saphenous vein patch was used in
very lengthy reconstructions needing a generous patch or when harvested LIMA appeared short to avoid
having a LIMA-LAD anastomosis under tension.

In cases of reconstruction using the saphenous vein, a small part of the vein graft was completely opened
longitudinally using scissors to convert it to a vein patch and fashioned to match the length of the
arteriotomy. The vein was then sewn to the endarterectomized LAD using prolene 7-0. A small opening was
then created in the proximal or mid part of the vein patch using a scalpel and LIMA was anastomosed to the
vein graft using prolene 8-0.

In cases where LIMA was used to reconstruct the LAD the LIMA was incised to match the length of the
arteriotomy and it was anastomosed directly to the LAD using prolene 7-0 or 8-0 in an onlay fashion.
Sometimes the surgeons prefer to start this anastomosis at the toe of the anastomosis unlike the usual where
anastomosis is started at the heel. This approach makes it easier to adjust the length of the LIMA patch in case
of discrepancy between the length of LIMA patch and the arteriotomy. Bulldog was removed from LIMA to
allow flow in the coronary anastomosis and check if there was any leak that can be repaired before removing
the cross clamp. After completion of distal anastomoses, the cross clamp was removed. Vein grafts were cut
to appropriate length and proximal anastomoses to the aorta were done with partial side biting clamp.

In our study, 2 different anticoagulation protocols were used. In both regimens intravenous unfractionated
heparin was started in ICU on day 0 typically after 6 h or as soon as chest tube output dictated with target
partial thromboplastin time of 60-90 s. In the dual antiplatelet therapy (DAPT) protocol, 75 mg clopidogrel
and low dose aspirin were given on day 1. Clopidogrel was discontinued after 1 year and aspirin given for
life. The second regimen was triple therapy with warfarin for 3 months with target international normalized
ratio (INR) of 2 in addition to 75 mg clopidogrel (1 year) and low dose aspirin for life.

Echocardiography was done to all patients routinely prior to discharge. Following discharge, patients were
followed up in outpatient clinic one week following discharge, then one month after discharge.

Patients enrolled in this study were contacted by phone following discharge to ask about their status
regarding dyspnea and chest pain. They were asked to perform CT coronary angiography for assessment
of LAD patency. CT coronary angiography was chosen for this study due to its sensitivity in assessment of
bypass patency, as well as being less invasive than conventional coronary angiography.

Definitions: operative mortality was defined as death occurring during the hospitalization in which the
surgery was performed or death occurring after hospital discharge, but within 30 days, unless clearly
unrelated to the operation.

Stroke was defined as neurologic deficit of abrupt onset caused by disturbance in blood supply to the brain
persisting > 24 h.

Renal failure: acute or worsening renal function resulting in one or both more of the following. Increase of
serum creatinine to > 2 mg/dL and to 2 × the most recent preoperative creatinine or requirement for dialysis.