LAUSR

To the Editor, In the June 2020 issue of the Journal of Cardiac Surgery, Guida et al have presented a review on the pathology of saphenous veins (SVs) used as conduits for coronary artery bypass grafting (CABG), discussing the pathophysiology, prevention, and treatment of this disease. In recent years there has been an increasing trend to favor total arterial revascularization especially in young patients; this is generally done by routinely using both internal mammary arteries, at times with sequential or Y‐shaped anastomoses, supplemented by employing a segment of radial artery when indicated. Nevertheless, the SV still remains an important conduit, particularly because it is readily available and with sufficient length to obtain more than a single graft; therefore, especially in elderly subjects, the use of the left internal mammary artery associated to SV grafts is still a valid option. However, the major drawback of SV is represented by its limited durability, in terms of graft patency, when compared with arterial grafts. Almost 40 years ago, our group was among the first to perform a histologic study on autologous SVs, before their use for CABG in a consecutive series of 150 patients. Our results demonstrated that in almost all specimen various degrees of thickening and fibrosis were present in the intima and longitudinal medial layers, which, however, were not severe enough to cause critical narrowing of the SV lumen; in addition, such changes were not statistically related to aging. The conclusions of the study were that such pre‐implant structural changes could be a trigger for subsequent progression and eventual graft occlusion; indeed, such findings justify the subsequent development of SV atherosclerosis favored by inherent wall fragility and inability to withstand a higher pressure, once inserted in the arterial system. Such hypothesis should have been validated by subsequent angiographic findings, which unfortunately were not performed. Guida et al have correctly underlined the role of atherosclerosis, inflammation, harvesting techniques and pretreatments, in SV grafts disease, but the importance and possible impact on SV failure of pre‐ existing histological wall changes has been unfortunately overlooked.