Novel no touch technique of saphenous vein harvesting: Is great graft patency rate provided?

Long Saphenous Vein Harvesting: Reviewing Various Techniques

Ischemic heart disease is the leading cause of mortality and morbidity in the Western world. Thus, coronary artery bypass graft is the most common cardiac procedure performed as it remains the gold standard for multiple vessel disease and left main disease. Long saphenous vein is the conduit of choice for coronary artery bypass graft as it is accessible and easy to harvest. Over the previous 4 decades, several techniques have emerged to optimize harvesting and reducing adverse clinical outcomes. The most cited techniques are open vein harvesting, no-touch technique, endoscopic vein harvesting, and standard bridging technique. In this literature review, we aim to summarize current literature for each of the 4 techniques in terms of: (A) graft patency and attrition, (B) myocardial infarction and revascularization, (C) wound infections, (D) postoperative pain, and (E) patient satisfaction.

Percutaneous coronary intervention versus coronary artery by-pass grafting in premature coronary artery disease: What is the evidence? -A narrative review

Coronary artery disease (CAD) remains one of the leading causes of death globally. In the United States of America, in 2016, 19% of all patients under the age of 65 died of cardiovascular disease despite improvements in primary prevention. The premature clinical onset of symptoms in the young population (<60 years) is much more aggressive than in the older population, and the overall long-term prognosis is poor. CAD appears to have a rapidly progressive form in those under the age of 60 due to genetic predisposition, smoking, and substance abuse, however, the ideal management strategy is still yet to be established. The two primary methods of establishing coronary revascularization are percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). Despite the increasing prevalence of CAD in the young population, they are consistently underrepresented in major randomized clinical trials of each revascularization strategy. Both CABG and PCI are known to have similar survival rates, but PCI is associated with higher repeat revascularization rate. Many argue this may be due to the progressive nature of CAD combined with the vessel patency time required in a patient under 60 with potentially another 20-30 years of life. There is little in literature regarding the outcomes of these various revascularization strategies in populations under 60 years with CAD. This review summarises the current evidence for each revascularisation strategy in patients under the age of 60 and suggests future avenues of research for this unique age group.

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)

BACKGROUND

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.

MATERIALS AND METHODS

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.

DISCUSSION

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.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Comparison between radiofrequency ablation and CHIVA procedure in patients with varicose veins

OBJECTIVE

Conservatrice et Hémodynamique de l'Insuffisance Veineuse en Ambulatoire, the French acronym for CHIVA, is a strategy aimed to convert a venous reflux into a physiological drainage. We compared CHIVA with radiofrequency ablation and determined its possible advantages.

METHODS

We retrospectively analyzed the clinical recurrence, ultrasound recurrence, quality of life scores, and complications. They were compared after propensity score matching.

RESULTS

212 limbs of 166 patients were included: 42 limbs underwent radiofrequency ablation and 170 limbs underwent CHIVA. The hospital stay was shorter in the CHIVA group. There was no difference in clinical, ultrasound recurrence, quality of life scores and complications between the two groups. The preoperative saphenous vein diameter was larger in the recurrence cases.

CONCLUSIONS

CHIVA showed comparable results to radiofrequency ablation. There was more ultrasound recurrence with larger vein diameters. The CHIVA appears to be a simple and more efficient treatment method when performed on select patients.

Acute shear stress and vein graft disease

The long saphenous vein is commonly used in cardiac surgery to bypass occluded coronary arteries. Its use is complicated by late stenosis and occlusion due to the development of intimal hyperplasia. It is accepted that intimal hyperplasia is a multifactorial inflammatory process that starts immediately after surgery. The role of acute changes in haemodynamic conditions when the vein is implanted into arterial circulation, especially shear stress, is not fully appreciated. This review provides an overview of intimal hyperplasia and the effect of acute shear stress changes on the activation of pro-inflammatory mediators.

No-Touch Sequential Saphenous Venous Harvesting Technique in Off-Pump Bypass Surgery: A Retrospective Study

Background

In the mid-1990s, the Swedish expert team proposed saphenous vein graft (SVG) harvesting with pedicle tissue. The short-term and long-term patency rates of the great saphenous vein obtained by the no-touch (NT) were higher than those obtained by the conventional (CON). In the past, NT harvesting was mainly used in on-pump coronary artery bypass grafting (CABG), and vein grafts were mostly single vein grafts. In this study, we retrospectively analyzed the safety and effectiveness of sequential vein grafts using NT harvesting in off-pump CABG.

Methods

From 2017 to 2019, a total of 505 patients were included in the study. There were 150 patients in the NT group and 355 patients in the CON group. After applying propensity score matching (1:1 matching), 148 patients were included in each group. Baseline data, graft patency, post-operative complications, leg wound complications and 1-year major adverse cardiac and cerebrovascular events (MACCEs) were compared between the two groups.

Results

There was no significant difference in the patency rate of sequential venous grafts between the two groups 1 year after the operation either before [NT: 7.1% (10/141) vs. CON: 11.5% (38/331), p = 0.149) or after matching (NT: 7.1% (10/140) vs. CON: 7.3% (9/124), p = 0.971]. There was no significant difference in the composite clinical endpoint between the two groups either before [NT: 3 (2.3%) vs. CON: 9 (2.8%), p = 1.000] or after matching [NT: 3 (2.3%) vs. CON: 3 (2.5%), p = 1.000]. There were differences in leg wound complications between the two groups both before [NT: 9 (6.9%) vs. CON: 6 (1.9%), p = 0.007] and after matching [NT: 9 (6.9%) vs. CON: 2 (1.7%), p = 0.043].

Conclusions

The application of the NT harvesting in off-pump CABG with sequential vein grafts is safe and effective. NT method has disadvantages in leg wound.

Peripheral nerve regeneration: A comparative study of the effects of autologous bone marrow-derived mesenchymal stem cells, platelet-rich plasma, and lateral saphenous vein graft as a conduit in a dog model

BACKGROUND

The quality of healing of peripheral nerve injuries remains a common challenge causing pain and poor quality of life for millions of people and animals annually.

AIMS

The objectives of this study were to evaluate the healing quality of facial nerve injury in a dog model following local treatment using an autologous injection of platelet-rich plasma (PRP) or bone marrow-derived mesenchymal stem cells (BM-MSCs) at the injury site in combination with the application of an autologous saphenous vein graft as a conduit.

METHODS

20 apparently healthy adult Mongrel dogs were randomly divided into 4 equal groups. Dogs in groups 1, 2, and 3 were subjected to facial nerve neurectomy and saphenous vein conduit graft implantation at the site of facial nerve injury. Dogs in groups 2 and 3 received 1 ml of autologous PRP and BM-MSCs, respectively. Injections were administered directly in the vein conduit immediately after nerve injury. Dogs in group 1 (grafted but not treated; control) received only an autologous vein graft, and those in group 4 (normal control) received no graft and no PRP or BM-MSCs treatment. The dogs were monitored daily for 8 weeks after surgery. Clinical evaluation of the facial nerve, including lower eyelid, ear drooping, upper lip, and tongue functions, was carried out once per week using a numerical scoring system of 0-3. At the end of the study period (week 8), the facial nerve injury site was evaluated grossly for the presence of adhesions using a numerical scoring system of 0-3. The facial nerve injury site was histopathologically assessed for the existence of perivascular mononuclear cell infiltration, fibrous tissue deposition, and axonal injury using H&E-stained tissue sections.

RESULTS

Clinically, BM-MSCs treated dogs experienced significant (p < 0.05) improvement in the lower eyelid, ear, lip, and tongue functions 4 weeks postoperatively compared to other groups. Grossly, the facial nerve graft site in the BM-MSCs treated group showed significantly (p < 0.05) lesser adhesion scores than the other groups. Histopathologically, there was significantly (p < 0.05) less perivascular mononuclear cell infiltration, less collagen deposition, and more normal axons at the facial nerve injury site in the BM-MSCs treated group compared to the other groups.

CONCLUSION

This study showed clinically significant enhancement of nerve regeneration by applying autologous BM-MSCs and autologous vein grafting at the site of facial nerve injury. However, further clinical trials are warranted before this application can be recommended to treat traumatic nerve injuries in the field.

Antiatherosclerotic Phenotype of Perivascular Adipose Tissue Surrounding the Saphenous Vein in Coronary Artery Bypass Grafting

Background

Perivascular adipose tissue (PVAT) is associated with metabolically driven chronic inflammation called metaflammation, which contributes to vascular function and the pathogenesis of vascular disease. The saphenous vein (SV) is commonly used as an essential conduit in coronary artery bypass grafting, but the long‐term patency of SV grafts is a crucial issue. The use of the novel “no‐touch” technique of SV harvesting together with its surrounding tissue has been reported to result in good long‑term graft patency of SV grafts. Herein, we investigated whether PVAT surrounding the SV (SV‐PVAT) has distinct phenotypes compared with other PVATs of vessels.

Methods and Results

Fat pads were sampled from 48 patients (male/female, 32/16; age, 72±8 years) with coronary artery disease who underwent elective coronary artery bypass grafting. Adipocyte size in SV‐PVAT was significantly larger than the sizes in PVATs surrounding the internal thoracic artery, coronary artery, and aorta. SV‐PVAT and PVAT surrounding the internal thoracic artery had smaller extents of fibrosis, decreased gene expression levels of fibrosis‐related markers, and less metaflammation, as indicated by a significantly smaller extent of cluster of differentiation 11c–positive M1 macrophage infiltration, higher gene expression level of adiponectin, and lower gene expression levels of inflammatory cytokines, than did PVATs surrounding the coronary artery and aorta. Expression patterns of adipocyte developmental and pattern‐forming genes were totally different among the PVATs of the vessels.

Conclusions

The phenotype of SV‐PVAT, which may result from inherent differences in adipocytes, is closer to that of PVAT surrounding the internal thoracic artery than that of PVAT surrounding the coronary artery or that of PVAT surrounding the aorta. SV‐PVAT has less metaflammation and consecutive adipose tissue remodeling, which may contribute to high long‐term patency of grafting when the no‐touch technique of SV harvesting is used.

Tam D, Hare DL, Girardi LN, Biondi‐Zoccai G, E. Fremes S. Angiographic Patency of Coronary Artery Bypass Conduits: A Network Meta-Analysis of Randomized Trials

Background Several randomized trials have compared the patency of coronary artery bypass conduits. All of the published studies, however, have performed pairwise comparisons and a comprehensive evaluation of the patency rates of all conduits has yet to be published. We set out to investigate the angiographic patency rates of all conduits used in coronary bypass surgery by performing a network meta-analysis of the current available randomized evidence. Methods and Results A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the conventionally harvested saphenous vein, the no-touch saphenous vein, the radial artery (RA), the right internal thoracic artery, or the gastroepiploic artery. The primary outcome was graft occlusion. A total of 4160 studies were retrieved of which 14 were included with 3651 grafts analyzed. The weighted mean angiographic follow-up was 5.1 years. Compared with the conventionally harvested saphenous vein, both the RA (incidence rate ratio [IRR] 0.54; 95% CI, 0.35-0.82) and the no-touch saphenous vein (IRR 0.55; 95% CI, 0.39-0.78) were associated with lower graft occlusion. The RA ranked as the best conduit (rank score for RA 0.87 versus 0.85 for no-touch saphenous vein, 0.23 for right internal thoracic artery, 0.29 for gastroepiploic artery, and 0.25 for the conventionally harvested saphenous vein). Conclusions Compared with the conventionally harvested saphenous vein, only the RA and no-touch saphenous vein grafts are associated with significantly lower graft occlusion rates. The RA ranks as the best conduit. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020164492.

Saphenous vein graft disease, pathophysiology, prevention, and treatment. A review of the literature

BACKGROUND

The saphenous vein remains the most frequently used conduit for coronary artery bypass grafting, despite reported unsatisfactory long-term patency rates. Understanding the pathophysiology of vein graft failure and attempting to improve its longevity has been a significant area of research for more than three decades. This article aims to review the current understanding of the pathophysiology and potential new intervention strategies.

METHODS

A search of three databases: MEDLINE, Web of Science, and Cochrane Library, was undertaken for the terms "pathophysiology," "prevention," and "treatment" plus the term "vein graft failure."

RESULTS

Saphenous graft failure is commonly the consequence of four different pathophysiological mechanisms, early acute thrombosis, vascular inflammation, intimal hyperplasia, and late accelerated atherosclerosis. Different methods have been proposed to inhibit or attenuate these pathological processes including modified surgical technique, topical pretreatment, external graft support, and postoperative pharmacological interventions. Once graft failure occurs, the available treatments are either surgical reintervention, angioplasty, or conservative medical management reserved for patients not eligible for either procedure.

CONCLUSION

Despite the extensive amount of research performed, the pathophysiology of saphenous vein graft is still not completely understood. Surgical and pharmacological interventions have improved early patency and different strategies for prevention seem to offer some hope in improving long-term patency.

Antiplatelet therapy and coronary artery bypass grafting: Protocol for a systematic review and network meta-analysis

INTRODUCTION

Saphenous vein graft (SVG) is the most common conduit used for coronary artery bypass grafting (CABG) surgery. Unfortunately, SVG are associated with poor long-term patency rates; a significant predictor of re-operation rates and survival. As such, medical therapy to prevent SVG narrowing or occlusion is of paramount importance. Aspirin (ASA) monotherapy is the standard of care after CABG, to improve long-term major adverse cardiovascular events (MACE) and graft patency. Benefits of dual antiplatelet therapy (DAPT) have not been well established in all CABG patients. We present a protocol for a network meta-analysis (NMA) comparing the effects of various antiplatelet therapy regimens on SVG patency, mortality, and bleeding among adult patients following CABG.

METHODS

We will search CENTRAL, MEDLINE, EMBASE, CINAHL ACPJC, and grey literature sources (AHA, ACC, ESC, and CCC conference proceedings, ISRCTN Register, and WHO ICTRP) for randomized controlled trials (RCTs) which fit our criteria. RCTs that evaluate different antiplatelet regimens at least 3-months after CABG and have any of SVG patency, mortality, MACE, and major bleeding as outcomes will be selected. We will perform title and abstract screening, full-text screening, and data extraction independently and in duplicate. Two independent reviewers will also assess risk of bias (ROB) for each study, as well as evaluate quality of evidence using the GRADE framework. We will use R to perform the NMA and use low-dose ASA as reference within our network. We will report results as odds ratios with confidence intervals for direct comparisons, and credible intervals for indirect or mixed comparisons. We will use the surface under the cumulative ranking curve (SUCRA) to estimate the ranking of interventions.

DISCUSSION

Given the limited direct comparison of various antiplatelet regimens, a network approach is ideal to clarify the optimum antiplatelet therapy after CABG. We hope that our NMA will be the largest quantitative synthesis evaluating antiplatelet regimens among patients requiring CABG. It should inform clinicians and guideline developers in selecting the most effective and safest antiplatelet regimen.Systematic Review registration: International Prospective Register for Systematic Reviews (PROSPERO)-CRD42019127695.

Rationale and design of a multicenter randomized trial to compare the graft patency between no-touch vein harvesting technique and conventional approach in coronary artery bypass graft surgery

BACKGROUND

Vein graft failure is a crucial challenge in coronary artery bypass graft (CABG) surgery. Previous studies have suggested a patency benefit of the No-Touch vein harvesting technique, but only with small sample sizes.

MATERIALS AND METHODS

This study is a prospective, multicenter randomized clinical trial with a large sample size, aiming to investigate the efficacy of the No-Touch technique compared with the conventional approach. All patients requiring isolated CABG with left internal mammary artery plus at least one saphenous vein graft will be considered for entry into the study. Two thousand cases (1000 in each arm) will be enrolled over 1 to 2 years in 7 hospitals in China. Participants will be randomized in equal proportions between two surgical strategies: the No-Touch or conventional technique. The primary endpoint is graft vessel occlusion at 3 months after CABG surgery by CT coronary angiography. Secondary outcomes are major adverse cardiac or cerebrovascular events at 3 and 12 months post-operation and graft vessel occlusion at 1 year.

DISCUSSION

This study will define the role of the No-Touch vein harvesting technique in CABG surgery and provide strong evidence to answer whether this technique could reduce vein graft occlusion.