The effect of distension pressure on endothelial injury and vasodilatation response in saphenous vein grafts: conversion of a bypass graft to a dead pipe

Abstract

IntroductionEndothelial damage caused by high pressure applied for spasm relaxation during graft preparation is one of the most plausible theories explaining early graft failure.Aim of the studyWe aimed to demonstrate the extent of endothelial damage in saphenous vein grafts distended to different pressure levels by using immunohistochemical methods and in vitro tissue baths.Material and methodsSaphenous vein grafts (SVGs) of 25 patients who underwent isolated elective CABG surgery were used in this study. By using a specific mechanism, SVGs were distended to five different pressure levels for two minutes: 0 mmHg, 50 mmHg, 100 mmHg, 200 mmHg, 300 mmHg. In vitro tissue baths and immunohistochemical examinations were performed.ResultsNone of the grafts distended to 300 mmHg pressure were functional in the tissue bath system. The relaxation response to carbachol of SVGs distended to 0, 50, 100 and 200 mmHg was 97.87 ± 4.47%, 98.52 ± 3.95%, 93.78 ± 3.64%, and 30.87 ± 4.11%, respectively. There were no statistically significant differences in terms of relaxation responses between samples distended to 0, 50, and 100 mmHg (p = 0.490). The relaxation response of samples distended to 200 mmHg was significantly decreased (p = 0.021). The endothelia of samples distended to 0 mmHg were almost intact in CD31 staining. Endothelial cell loss occurred at all tested distension pressures at different degrees.Conclusion In vitro and immunohistochemical studies revealed that distending an SVG used for coronary artery bypass grafting with pressures of 100 mmHg or less results in less endothelial damage and increases graft patency.

The saphenous vein harvest procedure affects the arteriovenous system and postoperative wound healing in patients following coronary aortic bypass surgery

“…Contrarily, in EVH, sidings were clipped using an endoscopic clipper when visibility was poorer and access was more challenging, which may have contributed to the vascular clip occasionally rolling off the siding and bleeding from the distal region. To avoid injuring the GSV tissue, the tightness of the GSV was tested intraoperatively by injecting a fluid (NaCl 0.9% + heparin) at a pressure of 50-100 mm Hg [14]. Similarly to EVH, the harvested GSV needed additional surgical care and a vascular suture.…”

Saphenous Vein Graft

“…Gurkan et al reported that a pressure of 300 mmHg abolished both contraction and relaxation due to endothelial and medial damage. The authors stated, "Pressures of 300 mmHg or more turn the SVG into a dead pipe" 20) . The upregulation of inflammatory biomarkers is related to the pressure value and degree of distention 21) .…”

Endoscopic and classic comparison for the great saphenous vein used as a material for the coronary artery for patients with the risk of post-operative infection

“…Wszyscy operowani pacjenci zaliczali się do grupy średniego lub wysokiego ryzyka operacyjnego SSI na podstawie oceny skali BHIS (Broptom & Harefield Infection Score) [6]. U każdego z chorych występowały wybrane czynniki ryzyka SSI, do których należały to the great saphenous vein nor a problem with its patency during syringe administration of 0.9% NaCl with heparin through the cannula at a pressure between 50-100 mmHg (so as not to damage the tissue of the blood vessel taken) were found [7]. Because of the positive assessment of vein quality, all the blood vessels were used during CABG or OPCAB procedures as a coronary artery bypass.…”

“…U chorych z obydwu grup po pobraniu materiału żylnego nie stwierdzono istotnych makroskopowych uszkodzeń żyły odpiszczelowej ani problemu z jej drożnością. Materiał sprawdzono, podając strzykawką przez kaniulę 0,9% NaCl z heparyną pod ciśnieniem między 50--100 mmHg, tak by nie uszkodzić tkanki pobranego naczynia [7]. W związku z pozytywną oceną jakości żyły, wszystkie naczynia zostały wykorzystane do zabiegów CABG lub OPCAB jako pomost aortalno--wieńcowy.…”