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Page 8 of 11 Elsayed et al. Vessel Plus 2018;2:39 I http://dx.doi.org/10.20517/2574-1209.2018.65

components (LIMA, SVG, and native coronary) caused turbulence of flow due to difference in compliance of
[9]
the the three components . Enlarging the lumen of the reconstructed LAD was accused of decreasing flow
[9]
velocity . In addition long term patency was questioned due to the known predilection of veins to more
rapid intimal hyperplasia.

As studies continued to support the use of arterial grafting, and showing arterial grafts to show better
late patency rates than SVG, the use of onlay LIMA patching to endarterectomized LAD gained wider
[10]
popularity . In this method the LIMA itself was used as a patch after adjusting its opening to the length of
the LAD arteriotomy. Using the LIMA directly as a patch took advantage of the superior anti-atherosclerotic
property of LIMA compared to SVG, besides the known vasomotor functions of the LIMA and its ability to
adjust the flow rate to the distal runoff of the LAD by virtue of its release of endothelium derived relaxing
[10]
factors . Neverthelesss the verdict on the optimal method of LAD reconstruction is not yet clear.
[3]
Soylu et al. in a best evidence series published in 2014 included 150 articles in their search and stated in
conclusion that open coronary endarterectomy appeared to be safer, carried a lower rate of mortality than
closed endarterectomy, and that the use of LIMA may improve mortality.

With this large study in mind and with the theoretical advantages of open over closed endarterectomy stated
previously the surgeons in our study were disinclined to use the closed traction method of endarterectomy in
a vessel as precious as LAD and all patients operated on in this study had open endarterectomy of the LAD.

It is worth mentioning that Barra and his colleagues from France advocated a different method of using the
[11]
LIMA in reconstruction of the LAD without endarterectomy . In this method LIMA onlay graft is sutured
inside the coronary in such a fashion as to exclude atheromatous plaques from the lumen of the coronary
artery. LIMA wall makes up 75% of the reconstructed vessel, and the newly reconstructed artery retains
25% of the native coronary artery. However this method was reserved mainly for non calcified plaques,
since heavily calcific plaques can preclude suturing. They explained that by using this method they limit the
use of endarterectomy and hence decrease the postoperative cascade of myofibrointimal hyperplasia and
thrombosis since no area of the coronary is denuded of its covering endothelium.

Bridge or jump graft was also used for LAD reconstruction. This method was used in patients with multiple
lesions in their LAD. Arteriotomies were performed proximal and distal to the site of coronary stenosis and
[12]
a valveless saphenous segment was used as a bridge between the lesion to which LIMA was anastomosed .

LIMA itself was used to perform jump grafts by performing a side to side anastomosis to the LAD proximal
[13]
to the site of stenosis then another end to side anastomosis after jumping over the site of stenosis . Again
the merits of both of these methods were mainly to avoid endareterectomy of the LAD. All of the above
methods were considered by the surgeons in our study for the sake of avoiding endarterectomy and its
histopathological consequences and endarterectomy was saved as the last option when other methods
appeared to be futile.

In our study the use of the SVG (26.7%) was reserved for patients who needed a much lengthier
reconstruction of the LAD and in cases where there was fear that the LIMA was too short or would be
under tension if used in the reconstruction. This was reflected in our results showing a greater mean of
reconstruction length in the saphenous vein group.

The cross clamp time was shorter in the LIMA patch group however did not reach statistical significance.
[15]
[14]
Owais et al. and Myers et al. showed a statistically significant shorter cross clamp time in the LIMA
patch group compared to the saphenous vein patch group.