No-touch Saphenous Vein Research Articles

Vasa vasorum of the no-touch saphenous vein graft observed using frequency-domain optical coherence tomography.

One possible reason for the long-term patency of no-touch saphenous vein grafts is the preservation of the vasa vasorum in the adventitia/perivascular adipose tissue. In this study, we investigated the vasa vasorum of the no-touch saphenous vein graft in vivo using frequency-domain optical coherence tomography, performed qualitative and quantitative analyses, and compared them with the conventional saphenous vein graft. A frequency-domain optical coherence tomography study was performed on 14 saphenous vein grafts at the postoperative coronary angiography 1-2 weeks after surgery (no-touch group, n = 9; conventional group, n = 5). Many signal-poor tubular lumen structures that can be recognised in the cross-sectional and longitudinal profiles, which indicates the vasa vasorum, were observed in the adventitial/perivascular adipose tissue layer in the no-touch saphenous vein grafts. In contrast, the vasa vasorum was less abundant in the conventional saphenous vein grafts. The vasa vasorum volume per millimetre of graft in the no- touch group was significantly higher than in the conventional group (0.0020 [0.0017, 0.0043] mm3 and 0.0003 [0.0000, 0.0006] mm3, P = 0.023). Frequency-domain optical coherence tomography showed abundant vasa vasorum in the thick adventitia/perivascular adipose tissue layer of no-touch saphenous veins in vivo. In contrast, few vasa vasorum was observed in the conventional saphenous vein grafts.

Rationale and design of a single-center randomized trial to compare the graft patency between the radial artery and the no-touch saphenous vein in coronary artery bypass grafting surgery (GRAFT-CAB Study)

Previous studies suggested only the radial artery and the No-touch (NT) technique were effective in reducing graft occlusion after coronary artery bypass grafting (CABG) surgery. However, there is no randomized trial comparing these 2 graft conduits. The optimum second conduit for CABG remains undetermined. This study is a prospective, single-center randomized clinical trial, aiming to compare the graft patency between the radial artery and the NT vein graft. All patients undergoing isolated CABG with left internal mammary artery (LIMA) plus at least 2 additional grafts will be considered eligible. About 774 cases (516 in the radial artery group and 258 in the NT vein group) will be enrolled in over 1 to 2 years. Participants will be randomized and allocated to two bypass strategies: the LIMA plus 1 radial artery and 1 conventional vein graft, or the LIMA plus 2 NT vein grafts. The primary outcome is graft occlusion at 1 year after CABG evaluated by CT angiography. The secondary outcomes include graft occlusion at 3 and 5 years and major adverse cardiac or cerebrovascular events at 1, 3, and 5 years follow-ups. This study will define whether or not the NT vein has a lower graft occlusion rate than the radial artery in short and mid-term follow-ups, and provide new evidence for the second conduit choice in CABG surgery. ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Endoscopic Pedicle Saphenous Vein Graft Harvesting.

The excellent long-term patency of no-touch (NT) saphenous vein grafts (SVGs) makes the grafts very attractive for coronary artery bypass grafting; however, NT-SVG harvesting has a greater incidence of wound complications than conventional methods. Since 2009, we have performed endoscopic vein harvesting (EVH) in our department with very few major wound complications. Because NT-SVG harvesting is expected to provide long-term patency, if performed with EVH, the incidence of wound complications will be reduced. Thus, we began performing endoscopic pedicle SVG harvesting (Pedicle-EVH) in March 2019. Herein, we report the early results obtained using our current Pedicle-EVH procedure. No major wound complications were reported, and the early results, including patency, were satisfactory. To harvest the pedicle SVG, however, we used a different method than the NT-SVG procedure, so careful monitoring will be needed to assess long-term outcomes.

A Novel Technique of No-Touch Endoscopic Saphenous Vein Harvesting.

No-touch saphenous vein harvesting is considered an ideal procedure for harvesting good-quality veins, whereas endoscopic vein harvesting (EVH) is considered ideal for decreasing wound complications. The no-touch EVH (NT-EVH) technique, which was developed in 2018, is one of the best vein-harvesting procedures. We have improved this method in several aspects since our initial experience. Herein, we present the details of this technique.

No-Touch Saphenous Vein as Y-Composite vs Aortocoronary Graft: Early Outcome Analysis

BackgroundA randomized controlled trial was designed to compare 1-year morphologic changes of the no-touch saphenous vein (SV) as a Y-composite graft (composite group) vs an aortocoronary graft (aorta group) in coronary artery bypass grafting. This study evaluated early clinical and angiographic outcomes as a preliminary analysis. MethodsThe primary end point of the trial was the intima-media thickness measured by intravascular ultrasound at 1-year angiographic follow-up. Patients were screened to enroll 25 patients in each group based on a superiority design. Early postoperative clinical and angiographic outcomes were compared between the 2 groups. ResultsThe numbers of distal anastomoses per SV graft were 2.7 ± 1.1 and 2.6 ± 0.8 in the composite and aorta groups, respectively. There was no operative death, and postoperative complications in the 2 groups did not significantly differ. All patients underwent early postoperative graft angiography at a median of 1 (interquartile range, 1-1) day after operation. Early angiographic patency rates were 98.9% (93/94 anastomoses) and 100% (90/90 anastomoses) in the composite and aorta groups, respectively. There was no distal anastomosis showing competitive flow in the aorta group, whereas 3 anastomoses with competitive flow were found in the composite group. All 3 anastomoses with competitive flow were SV grafts that were anastomosed to the right coronary artery territory with moderate stenosis. ConclusionsEarly clinical outcomes and angiographic graft patency rates were not significantly different with use of no-touch SV as a Y-composite graft or an aortocoronary graft.

Reply from authors: The perivascular adipose tissue is a versatile "jacket" that the saphenous vein wears inherently.

We thank Dashwood and colleagues1 for their constructive comments on our recent article. There is a growing body of research illuminating the efficacy and mechanism of no-touch (NT) saphenous vein (SV) grafts. Many researchers are focusing on the perivascular adipose tissue (PVAT) surrounding the NT SV grafts, which is believed to have 2 crucial roles in the improved patency of NT SV grafts. First, PVAT releases a variety of beneficial humoral factors, such as nitric oxide2 and leptin. Second, it functions as a natural external stent.

Impact of saphenous vein harvesting on graft diameter: Supporting the no-touch technique.

In a recent study published in the Journal, Kurazumi and colleagues1 compare the effect of conventional (CV) versus no-touch (NT) saphenous vein (SV) harvesting on graft diameter pre- and postimplantation. Here, ultrasound imaging and electrocardiogram-gated enhanced computed tomography showed that preoperative versus postoperative SV graft diameter was significantly distended in the CV group (P < .0001) but not changed in the NT group (P = .33). Also, the diameter mismatch was significantly smaller in the NT versus the CV group (P < .0001).

Thirty Years of No-Touch Saphenous Vein Harvesting: A Timely Jubilee Gift

Thirty Years of No-Touch Saphenous Vein Harvesting: A Timely Jubilee Gift

Angiographic Patency of Coronary Artery Bypass Conduits: An Updated Network Meta-Analysis of Randomized Trials

IntroductionThe second best conduit for coronary artery bypass grafting is uncertain. The objective of this study is to determine the second best conduit according to graft patency results from randomized controlled trials using a network meta-analysis.MethodsA systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the no-touch saphenous vein (NT-SV), the radial artery (RA), the right internal thoracic artery (RITA), and the gastroepiploic artery (GEA) in reference to the conventionally harvested saphenous vein (CON-SV). The primary outcome was graft occlusion, and the secondary outcome was all-cause mortality.ResultsA total of 859 studies were retrieved, of which 18 were included. A total of 6,543 patients and 8,272 grafts were analyzed. The weighted mean angiographic follow-up time was 3.5 years. Compared with CON-SV, RA (incidence rate ratio [IRR] 0.56; 95% confidence interval [CI], 0.43-0.74) and NT-SV (IRR 0.56; 95% CI, 0.44-0.70) demonstrated lower graft occlusion. NT-SV and RA were ranked as the best conduits (rank score for NT-SV 0.88 vs. 0.87 for RA, 0.29 for GEA, 0.27 for CON-SV, and 0.20 for RITA). There was no significant difference in late mortality between different conduit types.ConclusionRA and NT-SV are associated with significantly lower graft occlusion rates and are comparably ranked as the best conduit for patency.

No-Touch Saphenous Vein - Vascular Damage and the London Connection.

In this review, I summarise the circumstances leading to the collaboration between London and Örebro on the basic research performed to study potential mechanisms underlying the improved patency of saphenous veins harvested by the no-touch technique. Histological studies reveal various forms of vascular damage to saphenous vein grafts harvested in conventional coronary artery bypass grafting (CABG) whereas no-touch grafts retain a normal architecture. The perivascular fat that remains intact on no-touch saphenous vein grafts seems to play a particularly important role as the “protector” of all layers of the graft. In addition, the perivascular fat is a source of adipose cell-derived factors that may contribute to the success of the no-touch technique. While a number of trials have compared no-touch with conventional grafts following CABG, these have generally been limited to short follow-up periods, low patient numbers, and inadequate histological data. When handling no-touch saphenous vein at harvesting, there is no direct contact of the vein by surgical instruments, spasm does not occur, and high-pressure intraluminal distension is not required. While damage to both endothelial and vascular smooth muscle cells are evident at the microscopic and ultrastructural level in conventional saphenous vein grafts, their structure in no-touch grafts is preserved. Also, in no-touch veins, the vasa vasorum remains intact and transmural blood supply is maintained. This microvascular network is disrupted during conventional harvesting, a situation likely to stimulate processes involved in graft occlusion. The use of excess graft material for histology is to be encouraged for the assessment of vascular damage and even surgeon competence. If you don’t look, you don’t find.

The No-Touch Saphenous Vein Harvesting Improves Graft Patency After Off-Pump Coronary Artery Bypass Surgery: A Propensity-Matched Analysis.

IntroductionThis single-center study of propensity-matched data was performed to assess the effect of the no-touch saphenous vein (NTSV) harvesting technique on early- and long-term outcomes of patients after off-pump coronary artery bypass grafting (OPCABG) in China.MethodsA retrospective analysis of 767 patients who underwent OPCABG in the Beijing Anzhen Hospital (June 2017 to October 2021) was performed, and their data entered the conventional saphenous vein (CSV) harvesting technique group or the NTSV group. In-hospital and follow-up outcomes were evaluated by adjusting baseline characteristics using propensity score matching (1:1). Clinical outcomes and postoperative angiographic results were compared.ResultsThe saphenous vein graft patency rates at postoperative three months and one year for the NTSV group vs. CSV group were 99.6% vs. 96.2% (P<0.001) and 97.3% vs. 93.1% (P<0.001), respectively. The two matched groups received a significantly different cumulative incidence function of saphenous vein graft occlusion for the longer follow-up period in Kaplan-Meier curves (χ2=4.330, log-rank P=0.037). No difference in early- and long-term mortality or major adverse cardiac and cerebrovascular events (MACCE) were observed between the groups. The rate of MACCE was not statistically significant different between the groups, but there was a tendency favoring the no-touch technique (9.8% CSV vs. 4.8% NTSV; P=0.067). More patients in the NTSV group developed postoperative leg wound exudation (5.4% vs. 1.2%; P=0.032) and skin numbness (22.2% vs. 8.9%; P=0.001) than in the CSV group.ConclusionThe NTSV is an excellent conduit to be used in OPCABG. There remains a need to reduce leg wound complications.

Skin Closure After No-Touch Saphenous Vein Harvest: Strategies to Minimize Wound Complications.

The no-touch saphenous vein with surrounding pedicle tissue harvesting technique preserved endothelium and vessel wall integrity and demonstrated improved long-term saphenous vein conduit patency that was comparable to internal thoracic artery conduit patency. Despite improved saphenous vein conduit patency rates, there is a possibility that no-touch saphenous vein harvest may increase wound complication rates by increased tissue disruption, including venous and lymphatic channels. Comprehensive strategies to minimize leg wound complications after no-touch saphenous vein harvest are discussed.

Morphological Changes in Endothelial Cell Organelles in a No-Touch Saphenous Vein Graft.

IntroductionImproved long-term patency of the no-touch (NT) saphenous vein graft has been reported to result from the preservation of a healthy vascular microstructure, especially endothelial cells. However, the precise morphology of endothelial cells and their organelles in NT saphenous vein graft has not been fully investigated. In this study, we assessed the ultrastructure of preserved endothelial cells in saphenous vein graft using transmission electron microscopy.MethodsIntact control (IC) vein, NT saphenous vein graft, and conventional (CT) saphenous vein graft were harvested from a patient. After observation by light microscopy, the nuclei and mitochondria in the preserved endothelial cells were compared among IC, NT, and CT using transmission electron microscopy, and the endothelial organelles were assessed quantitatively.ResultsLight microscopy showed that the preservation of endothelial cells was comparable in IC, NT, and CT. Subsequent transmission electron microscopy observation showed that the nuclei in preserved endothelial cells appeared more swollen in CT than that in NT. Quantitative analysis revealed that nuclear size and circularity of preserved endothelial cells in NT and IC were similar, but those in CT were larger and higher, respectively, than those in IC and NT. In addition, the mitochondrial size in preserved endothelial cells in CT was larger than that in IC and NT.ConclusionNecrotic changes in endothelial organelles characterized by swelling of nuclei and mitochondria were prominent in CT saphenous vein graft. The normally maintained ultrastructure of preserved endothelial cells in NT saphenous vein graft could contribute to long-term patency.

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

The saphenous vein is the most used conduit for coronary artery bypass surgery. However, the patency rate of this graft is inferior to the internal thoracic artery patency rate, which is the gold standard. Using the conventional technique, the saphenous vein is harvested via a large open incision and excised in such a way that causes both vascular damage and wound healing complications. Consequently, vein graft patency and surgical site infection may be compromised. Graft patency is markedly improved when the saphenous vein is harvested atraumatically with minimal damage and with surrounding cushion of perivascular fat intact. However, despite the improved graft performance, wound healing complications and infection remain a problem. Although wound healing complication is reduced when using endoscopic vein harvesting, there may be a negative impact on graft performance. This is due to vascular damage associated with application of forces to the vein that are usually avoided in open vein harvesting, including traction, adventitial stripping, and venous compression. There is evidence to suggest that improved patency of endoscopically harvested saphenous veins is associated with the surgeon’s experience of the technique. Recently, endoscopic methods of harvesting have been described where the saphenous vein is removed intact and with minimal vascular damage caused. In addition, wound healing complications, infection, and scarring are reduced. While the effect of these techniques on vein graft patency have yet to be reported, the ability to obtain a superior graft with reduced wound complications will be of great benefit to patients undergoing coronary revascularization procedures.

Quality of Life After Percutaneous Coronary Intervention in No-Touch Saphenous Vein Grafts is Significantly Better Than in Conventional Vein Grafts.

ObjectiveTo compare health-related quality of life (HRQoL) of patients primarily treated with a no-touch saphenous vein graft with that of patients who received a conventional graft.MethodsThe study included all individuals treated with a percutaneous coronary intervention (PCI) on a saphenous vein graft (SVG) between January 2006 and June 2020. The RAND-36 health survey was used to assess HRQoL. The Mann-Whitney U test was used to test differences in HRQoL between the two groups. Effect size was estimated via Cohen’s d. The average treatment effect between the groups was tested by propensity score matching (PSM).ResultsOf the 346 patients treated with a PCI in a stenosed or occluded SVG, 165 responded to RAND-36 (no-touch: n=48; conventional: n=117). Patients with a no-touch graft reported better mean values on seven of the eight health survey domains. Statistically significant differences were observed for four of the domains, all in favour of the no-touch group. The effect size estimates indicated a small difference for five domains, with the highest values (>0.40) seen for the general health and energy/fatigue domains. PSM confirmed a statistically significant difference for the physical functioning and general health domains.ConclusionAt a mean follow-up of 5.4 years, patients who received a PCI in no-touch vein grafts showed significantly better HRQoL than those who received a PCI in conventional vein grafts.

Graft Patency of a Second Conduit for Coronary Artery Bypass Surgery: A Network Meta-Analysis of Randomized Controlled Trials

It has been well documented that the use of the left internal thoracic artery (LITA) to graft the left anterior descending (LAD) artery has a significant benefit in coronary artery bypass graft (CABG) surgery. However, what graft is the best as a second conduit to complement LITA-LAD anastomosis remains uncertain. We thus conducted a network meta-analysis of RCTs to compare graft patency of the radial artery (RA), the right internal thoracic artery (RITA), the right gastroepiploic artery (RGEA), conventional saphenous vein (C-SVG), and no-touch saphenous vein (NT-SVG) as a second conduit in CABG. MEDLINE and EMBASE were searched through August 31, 2020 to identify randomized controlled trials (RCTs) that investigated graft patency of a second conduit in CABG. From each study, we extracted the incidence rate ratios of the outcome. A total of 13 RCTs were identified, including 3728 patients and 2773 angiographic results. The graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA. There was no significant difference among the other comparisons. A sensitivity analysis restricting trials with ≥3 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA, and a sensitivity analysis restricting trials with ≥5 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG. In a network meta-analysis of the updated outcomes from RCTs, NT-SVG and RA have better graft patency compared to C-SVG and RGEA.

Saphenous veins in coronary artery bypass grafting need external support

The saphenous vein is the most commonly used conduit for coronary artery bypass grafting. Arterial grafts are harvested with the outer pedicle intact whereas saphenous veins are harvested with the pedicle removed in the conventional graft harvesting technique. This conventional procedure causes considerable vascular damage. One strategy to improve vein graft patency has been to provide external support. Ongoing studies show that fitting a metal external support improves conventionally harvested saphenous vein graft patency. On the other hand, the no-touch technique of harvesting the saphenous vein provides an improved graft with long-term patency comparable to that of the internal mammary artery. This improvement is suggested to be due to preservation of vessel structures. Interestingly, many of the mechanisms proposed to be associated with the beneficial actions of an artificial external support on saphenous vein graft patency are similar to those underlying the beneficial effect of no-touch saphenous vein grafts where the intact outer layer acts as a natural support. Additional actions of external supports have been advocated, including promotion of angiogenesis, increased production of vascular-protective factors, and protection of endothelial cells. Using no-touch harvesting, normal vascular architecture is maintained, tissue and cell damage is minimized, and factors beneficial for graft patency are preserved. In this review, the significance of external support of saphenous vein grafts in coronary artery bypass grafting is discussed.

A Novel Technique of Endoscopic Vein Harvesting With Preserved Perivascular Tissue.

The no-touch saphenous vein harvesting technique is considered to be the ideal procedure to achieve the best quality of vein, whereas the endoscopic vein harvesting (EVH) technique is considered to be ideal for decreasing wound complications. We developed a new technique of EVH with perivascular tissue preservation. This procedure was performed by dissecting the immediate anterior and posterior perivascular connective tissues of the saphenous vein followed by cutting approximately 1 cm laterally from the saphenous vein with the use of a harvester (MAQUET Getinge Group, Getinge AB, Göteborg, Sweden). Histopathological examination revealed preserved perivascular tissue and intimal folding.

No-touch saphenous vein grafts in coronary artery surgery (SWEDEGRAFT): Rationale and design of a multicenter, prospective, registry-based randomized clinical trial

The SWEDEGRAFT study (ClinicalTrials.gov Identifier: NCT03501303) tests the hypothesis that saphenous vein grafts (SVGs) harvested with the "no-touch" technique improves patency of coronary artery bypass grafts compared with the conventional open skeletonized technique. This article describes the rationale and design of the randomized trial and baseline characteristics of the population enrolled during the first 9 months of enrollment. The SWEDEGRAFT study is a prospective, binational multicenter, open-label, registry-based trial in patients undergoing first isolated nonemergent coronary artery bypass grafting (CABG), randomized 1:1 to no-touch or conventional open skeletonized vein harvesting technique, with a planned enrollment of 900 patients. The primary end point is the proportion of patients with graft failure defined as SVGs occluded or stenosed >50% on coronary computed tomography angiography at 2 years after CABG, earlier clinically driven coronary angiography demonstrating an occluded or stenosed >50% vein graft, or death within 2 years. High-quality health registries and coronary computed tomography angiography are used to assess the primary end point. The secondary end points include wound healing in the vein graft sites and the composite outcome of major adverse cardiac events during the first 2 years based on registry data. Demographics of the first 200 patients enrolled in the trial and other CABG patients operated in Sweden during the same time period are comparable when the exclusion criteria are taken into consideration. RCT# NCT03501303.

Twenty-Five Years of No-Touch Saphenous Vein Harvesting for Coronary Artery Bypass Grafting: Structural Observations and Impact on Graft Performance.

The saphenous vein is the most common conduit used in coronary artery bypass grafting (CABG) yet its failure rate is higher compared to arterial grafts. An improvement in saphenous vein graft performance is therefore a major priority in CABG. No-touch harvesting of the saphenous vein is one of the few interventions that has shown improved patency rates, comparable to that of the left internal thoracic artery. After more than two decades of no-touch research, this technique is now recognized as a Class IIa recommendation in the 2018 European Society of Cardiology and the European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization. In this review, we describe the structural alterations that occur in conventional versus no-touch saphenous vein grafts and how these changes affect graft patency. In addition, we discuss various strategies aimed at repairing saphenous vein grafts prepared at conventional CABG.