An innovative panel to assess endothelial integrity of pedicled and skeletonized internal thoracic artery used as aortocoronary bypass graft: a randomized comparative histologic and immunohistochemical study.

Background: Optimal preservation of endothelial integrity of the vessels used as aortocoronary grafts is a crucial determinant of long-term clinical success of coronary artery bypass grafting (CABG). The purpose of this study was to evaluate an impact of two common techniques to harvest left internal thoracic artery (LITA) on endothelial integrity.

Methods: One hundred twenty consecutive patients (84 males and 36 females) with a mean age of 64.9±8.8 years undergoing CABG were randomized to receive pedicled (group P; n=60) or skeletonized (group S; n=60) LITA grafts. During surgery LITA was harvested by the same experienced cardiac surgeon. The most peripheral surplus segments of LITA were obtained and then analysed histologically under light microscope. Additionally, endothelial expression of CD31, CD34, CD133 and nitric oxide synthase (eNOS) were evaluated by means of immunohistochemistry.

Results: In both groups, no cases of major arterial wall damage such as disruption, dissection, thrombosis or subadventitial hematoma were noted on LITA cross sections. Immunohistochemical assessment of protein expression revealed no differences in endothelial expression of CD133, CD34 antigens (markers of regeneration potential) and eNOS (indicating preserved functional integrity) between studied groups. Contrary to them, endothelial immunoreactivity of CD31, a marker of the morphological integrity of the endothelium, was revealed to be stronger in group P.

Conclusions: The skeletonized method of LITA harvesting may be associated with worse preservation of morphological integrity of endothelium but without compromising functional integrity and potential for tissue regeneration.