Comparison of clipping versus ligation of side-branches during saphenous vein graft harvesting: which method is superior?

Background: The greater saphenous vein remains the most common conduit used in coronary artery bypass grafting procedures. Surgical trauma during vein harvesting can cause endothelial and smooth muscle injury that has important implications for vein graft longevity. This study was designed to investigate the effect of clipping and ligation of the side-branches during saphenous vein graft harvesting on histologic structures of the saphenous vein.

Material And Methods: A total of 50 coronary artery bypass grafting patients (37 men and 13 women, mean age of 59 ± 6 years) were investigated in two groups according to side-branch closing method. In each patient, two side-branches were studied; one of them was ligated using 3/0 silk suture, and the other one was clipped next to the saphenous vein. Each venous sample was studied using hematoxylin and eosin, Masson's trichrome, and elastic tissue fibers-Verhoeff's Van Gieson staining. Histopathologic examination using light microscope was performed to assess intimal, elastic tissue, muscular layer, and adventitial changes. The pathologic alterations were graded on the basis of a scoring system (normal [0], minimal changes [+], mild changes [++], or severe changes [+++]) to assess the degree of damage inflicted by these two different types of branch closing methods.

Results: Histologic examination of venous tissue samples with ligated side-branches demonstrated vascular injury in most sections, including denudation and loss of the integrity of the endothelial layer of the vein. An evident disorganization of the subintimal collagen and elastic fibers was also reported. By contrast, histopathologic structure of most sections obtained from the specimens with clipped side-branches remained intact. Intimal, elastic tissue, muscular layer, and adventitial changes were significantly different between the two methods (p = 0.001).

Conclusions: Clipping, rather than ligation, of the side-branches of the saphenous vein conduit during its harvesting for coronary bypass grafting is associated with decreased vein damage. These findings suggest that clipping of the side-branches can be used without major detrimental effects on vascular integrity.