Preserved Vasoconstriction and Relaxation of Saphenous Vein Grafts Obtained by a No-Touch Technique for Coronary Artery Bypass Grafting

Abstract

SVGs from the procedures has been suspected. 6 A no-touch (NT) technique preserving PVAT to minimize the damage of SVGs at the time of collection was reported years ago. 7 Clinical and histological data have been accumulated until now. 8-11 A study of the longest observation showed that patency of SVGs using the NT technique was comparable with that of thoracic artery grafts after 16 years. 12 However, the physiological function of SVGs before use for CABG has not been fully investigated so far. The study was sought to compare SVGs collected by using either the CON or NT techniques and a myograph. We hypnotized that the technique for harvesting SVGs could affect the functions of grafts associated with durability. C oronary artery bypass grafting (CABG) for ischemic heart disease is a major surgical procedure, and approximately 50 years have passed since CABG using a saphenous vein graft (SVG) was first reported. 1 Nevertheless, these grafts are still widely used because of their several advantages, including ease of access, ease of operation, sufficiency of length for transplantation, and short harvest time. In the conventional (CON) technique, SVG is harvested by removing perivascular adipose tissue (PVAT), and subsequently expanding it by saline and high pressure. These processes are intended to secure graft flow. Nonetheless, the CON SVGs have low patency rates and poor clinical outcomes relative to arterial grafts. 2-5 Damage of

Towards Endoscopic No-Touch Saphenous Vein Graft Harvesting in Coronary Bypass Surgery

“…Densitometric analysis was used to determine the response to VEGF where the NT group was significantly better than the conventional OVH group at five and 60 minutes. Interestingly, as reported by others, by exchanging organ bath medium, the authors provide evidence for a transferable anti-contractile effect of PVAT [ 29 ] . Based on their data, this group concluded that “the NT technique is suggested to be advantageous for preserving the functions of vasoconstriction and relaxation”.…”

“…More recently, the role of perivascular adipose tissue (PVAT) on graft performance has attracted considerable attention, particularly via the so-called adipocyte-derived relaxing factor(s) [ 26 , 27 ] . While quite dramatic relaxant or anti-contractile effects of PVAT have been demonstrated in SVs harvested by NT vs. OVH SVs [ 28 ] , we believe that the recent study by Yamada et al [ 29 ] is the first to describe a comparison between OVH and EVH SVs.…”

“…In the last 30 years, a number of in vitro studies examining the vasoreactivity of conduits used in CABG have been published [ 36 - 38 ] with many recently focusing on the potential role of perivascular fat [ 28 , 29 , 39 ] . While these studies have shown varied effects of perivascular fat on OVH vs. NT SV segments in vitro , as far as we are aware, only one recent study has used segments of SVs removed by EVH [ 40 ] .…”

“…Conflicting data from PVAT/SV organ bath studies have been reported with some suggesting PVAT to possess anti-contractile actions and with others suggesting that PVAT-derived factor(s) are contractile [ 29 ] . This study was on small patient numbers, using myography, showing that contractions to phenylephrine were greater in NT SVs than in OVH SVs, and that this effect was “eliminated” when SVs were harvested using electrocautery.…”

Early and Midterm Outcomes of “No-Touch” Saphenous Vein Grafts in Japanese Institutions

“…NT-SVGs could be associated with better endothelial function than conventionally harvested SVGs [ 15 ] . The vasodilatation and vasoconstriction responses are better preserved in NT-SVGs [ 16 ] , which could be beneficial in preventing graft occlusion. NT-SVGs could keep more vasa vasorum [ 17 ] , which supply nutrients and oxygen to the vein wall, rather than conventionally harvested SVGs.…”