Vein NT vs C.pptx

1. Saphenous vein Harvest, No- Touch vs Conventional Abeer Alfadhli, cardiac surgery resident Feb 01,2023
2. Saphenous Vein Graft: • Remains the most common graft used for CABG • Vein graft failure associated with recurrent angina and possibly need for reoperation • 10% fail within the first month, 30-50% first year. By 10 years > 50% of vein grafts fail • During dissection and vein harvest, high pressure is needed to overcome spasm. • Vein manipulation, distention and dissection induces intima and media damage which affect graft function
3. No-Touch Vein Harvest Technique: • A tissue layer is left immediately superficial and 1.5cm on both sides of the vein • The vein is exposed without having to cut its perivascular tissue • After exposure branches are dissected, ligated and divided • vein is removed with cushion protecting it from direct contact
4. Endothelial Integrity:
5. Summary of the reasons why NT Superior: • 1- operative Technique and avoiding distension pressure as it was reported that it can cause endothelial injury • 2- Lack of intimal hyperplasia, NT associated with decrease VSMC activation • 3- preservation of endothelial integrity, NT associated higher rates of NOS • 4- NT vein able to resist higher aortic pressure due to surrounding tissue
6. Summary: • Though short-term patency was higher with NT, it wasn’t clinically significant • NT associated with higher rate of leg wound infections postop (flap, learning curve) • Long term data needed

Editor's Notes

This is the first study to show that the surrounding tissue of the SV contributes to high early patency rate of SV grafts compared with preparation of SV grafts with conventional technique.

156 patients who underwent coronary artery bypass grafting were randomized to three saphenous vein harvesting groups: group C (conventional) 56— the vein was stripped, distended, and stored in saline; group I (intermediate) 41—the vein was stripped, local application of papaverine was used instead of distention, and the vessel was then stored in heparinized blood; and group NT (no-touch) 45—the vein was harvested with surrounding tissue, not distended, and stored in heparinized blood.

127 vein grafts in group C, 116 in group I, and 124 in group NT, as well as 118 left internal mammary artery grafts, were angiographically assessed at 18 months mean follow-up time.

Results. The vein graft patency was 88.9% in group C,
86.2% in group I, and 95.4% in group NT.

The higher the flow, the better the patency irrespective of the technique used.
A higher attrition rate was found in vein segments taken from the knee area in group I.

Poor vein quality affected patency in all groups.

47 of all 51 sequential grafts (92.2%) were
patent.

The patency of left internal mammary artery
grafts was 108 of 118 (91.5%).

Conclusions: We conclude that preservation of the
surrounding tissue of the saphenous vein using this
no-touch technique abolishes venospasm intraoperatively
and plays an important role in maintaining vein
graft function and patency.

No major wound complication occurred, and we attribute
this to our exclusion criteria, which did not
include older patients or patients with peripheral vascular
disease or insulin-dependent diabetes mellitus who
are at a higher risk of wound complications.
Method: This randomized longitudinal trial compares graft patency of two patient
groups undergoing coronary artery bypass surgery. Conventional: 52 patients had
their veins stripped, distended, and stored in saline solution. No-touch: 52 patients
had veins removed with surrounding tissue, not distended, and stored in heparinized
blood.

Angiographic assessment was performed at mean time 18 months after the
operation in 46 patients in the conventional group and 45 patients in the no-touch
group and repeated at mean time 8.5 years in 37 patients from both groups.

Results: The distribution of the grafts to the recipient coronary arteries regarding
their size and quality was similar in both groups.
The angiographic assessment at 18 months postoperatively showed 89% conventional versus 95% no-touch grafts were
patent.

Repeated angiography at 8.5 years showed a patency rate for the conventional
group of 76% and 90% for the no-touch group (P .01).

The multivariate analysis showed that the most important surgical factors for graft patency were the
technique of harvesting (odds ratio 3.7, P .007) for the no-touch versus the
conventional technique and the vein quality before implantation (odds ratio 3.2,
P .007) for veins that were of good quality.

By comparison the patency of the thoracic artery grafts was 90%.

Conclusion: Harvesting the saphenous vein with surrounding tissue provides high
short- and long-term patency rates comparable to the left internal thoracic artery.

The site for the anastomoses is also an important factor for the fate of the graft, irrespective of the harvesting technique used, as we found that 28% of the vein grafts that
were anastomosed to the RCA above the crux region were occluded compared with 7% for those anastomosed distally to this site.
Seven patients were excluded for medical reasons (4
for strokes and dementia; 3 because of renal failure); and
3 were lost to follow-up. Six cardiac-related deaths (12%)
occurred in group C, and 4 (8%) with the NT technique
(myocardial infarctions and heart failure). The noncardiac
deaths in group C were: 4 cancer, 1 renal failure, 1 pneumonia,
1 lung fibrosis, and 1 drowning. In the NT group,
the noncardiac causes were cancer (6), ruptured abdominal
aortic aneurysm (1), stroke (1), and septicemia (1).

Despite the fact that the patency rate of the LITA in our
study was higher than that of the NT vein (88% vs 83%,
respectively), after a mean time of 16 years, they still
were comparable (Figure 3).
poor vein quality was noted with NT 89%, 38%C
This study is an CT angiographic follow-up of the C and NT groups, at a mean time of 16 years postoperatively.

54 patients were included (C group . 27; NT group . 27). In all,
72 and 75 vein grafts were completed in groups C and NT, respectively.

Crude SVgraft patency was 64% in the C group versus 83% in the NT group (P . .03),
which was similar to the patency of the LITA (88%). The harvesting technique
had a major impact on the patency with a hazard ratio for occlusion of 1.83 for
the C group (P .04).

Harvesting the SV with the NT technique conferred, at a mean time
of 16 years, a significantly higher patency than the conventional technique that
was still comparable to that of the LITA.

First 2 studies follow up by angiogram 3rd by CTA
A total of 45 patients (118 grafts) in the NT group and 46 patients (112 grafts) in the C group had patent
grafts at short-term follow-up after 18 months.
37 patients (91 grafts) in the NT group and 37 patients (77 grafts) in the C group had patent grafts at long-term follow-up after 8.5 years, and were evaluated on a scale from 0 (normal) to 2 (significant stenosis) by cineangiogram.

IVUS was performed in 15 NT grafts and 14 C grafts in the short-term follow-up, and 27 NT grafts and 26 C grafts in the long-term follow-up, in
grafts considered normal by the cineangiogram. The grafts were evaluated with respect to lumen volume, intimal thickness, incidence of plaque
and plaque components.

In the short-term follow-up, the cineangiogram showed more normal grafts (89.0% in the NT group compared
with 75.0% in the C group), and the number of grafts with stenosis was 11.0% in the NT group compared with 25.0% in the C group ( p = 0.006).

IVUS showed less mean intimal thickness (0.43 (0.07) mmvs 0.52 (0.08) mm; p = 0.03), less grafts with considerable intimal hyperplasia ( 0.9 mm; 20%
vs 78.6%; p = 0.011) and fewer patients with considerable hyperplasia ( 0.9 mm; 25% vs 100%; p = 0.007).

In the long-term follow-up, the cineangiogram showed more normal grafts, with 91.2% in the NT group compared with 83.1% in the C group; there were fewer grafts with
significant stenosis, with 7.7% in the NT group compared with 15.6% in the C group ( p = 0.14). IVUS showed fewer grafts containing multiple
plaques (14.8% vs 50%; p = 0.008), less advanced plaque with lipid (11.8% vs 63.9%; p = 0.0004) and less maximal plaque thickness (1.04 (0.23) mm
vs 1.32 (0.25) mm; p = 0.02) in the NT group compared with the C group.

The superior long-term patency rate using the NT vein-graft
technique at CABG could be explained by a significantly slower progression of atherosclerosis.

Therefore, it is very interesting to note that 63.9% of the
plaque in the C group contained lipid compared with 11.8% in
the NT group. There were no differences between the entire
C and NT groups with respect to basic characteristics
including blood lipids and other risk factors [12]. However,
in the subgroups included in the present IVUS study, the
patients from the C group compared with those from the NT
group had a more unfavourable lipid profile, although not
significant, with higher values of low-density lipoprotein
(LDL) and total cholesterol and fewer patients treated with
Simvastatin
8.5:
The clinical follow-up was performed by two
cardiologists blinded to which study group the
patient belonged to. The follow-up included all
living patients, 49 patients in group NT and
44 patients in group C. The patients were assessed
with respect to re-angina with CCS-classification IIV,
functional class; NYHA I-IV, myocardial infarction
during follow-up and new revascularization.
Investigation of cardiovascular risk factors included
recording of history of smoking, complete lipid
status, B-glucose and blood pressure. Hypertension
was defined as blood pressure 140/90 mm Hg.

Patients free from angina and in NYHA class I (67.3) in NT group compared
to (43.2%) in group CON (p = 0.02). No cardiac death in group NT versus
three in group C.

NT technique is encouraging with no cardiac deaths, and a
trend towards impact on hard clinical endpoints compared
to the conventional technique

They attribute the need for revascularization to progression of disease in native artery
16: Left ventricle ejection fraction was seen in the NT group compared to the
CON group (57.9% vs 49.4%; p = 0.011). No patients in NT had atrial
fibrillation compared to five patients in CON (p = 0.021). Patients with a
brain natriuretic peptide value (BNP) ≥ 150 were 30% in NT compared to
38% in CON. Total mortality was 25% in NT vs 27% in CON.

NT vein graft preserves the left ventricular ejection fraction
after 16 years. A smaller left atrium, a lower BNP, and no
atrial fibrillation indicate an improved diastolic left
ventricular function in the NT group.
Methods: 20 patients were randomly divided into two groups with the objective of evaluating the vascular endothelium. The No Touch (NT) technique consists in removing the saphenous vein with perivascular tissue. The conventional technique consists in harvesting with "in situ" removal of the perivascular tissue. The standard saphenous vein harvesting procedure used bridged incisions. Characteristics of the vein were considered. Evaluation of the endothelium was achieved by electron microscopy and histologic analysis using hematoxylin eosin staining. The Picrosirius and Masson Trichrome methods were used to analyze subendothelial collagen.
Results: Electron microscopy demonstrated that the NT Group had larger non-denudated endothelial areas as well as a smaller number of degraded cells. Histological analysis showed the form and integrity of the saphenous vein layers. A larger amount of collagen fibers were identified in the NT Group.
Conclusions: The NT technique better preserves the saphenous vein endothelium suggesting a more viable graft in the long term.

Methods: A prospective, randomized study with 156 patients who underwent artery bypass grafting was performed comparing three saphenous vein harvesting techniques: conventional, intermediate, and no-touch. A morphological study of the endothelium was carried out using scanning microscopy. An angiographic assessment of the vein graft patency was performed at a mean follow-up time of 18 months. Also, an immunohistochemical assessment was carried out to identify the endothelial enzyme nitric oxide synthase (eNOS) in the vein wall
Results: The preservation of the endothelial cell integrity was greater in the no-touch technique than in the other procedures. At angiographic follow-up, the patency for the no-touch group was 95.4%, 88.9% for the grafts of the conventional technique group, and 86.2% for the grafts performed in the intermediate technique group. The immunohistochemical assessment revealed eNOS in all three layers of the vein wall in the no-touch group and reduction of this enzyme in the conventional group.
Conclusion: The endothelial integrity and eNOS activity were better preserved when using the no-touch technique for vein graft harvesting. The mechanical protection provided by the cushion of surrounding tissue in the no-touch group, the vasorelaxation and thromboresistant activities of nitric oxide may be responsible for the reduction of vasospasms and improved patency rate.

Methods: We performed a prospective, randomized study that compared 2 techniques for harvesting saphenous vein-conventional and no-touchin 40 patients undergoing coronary artery bypass grafting. We carried out a morphologic study of the endothelium with the aid of light and transmission electron microscopy and an immunohistochemical assessment to identify adenosine, inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) in the vein wall.
Results: The integrity of endothelial cell and all vascular layers was maintained better with the no-touch technique than with the conventional procedure. The immunohistochemical assessment revealed that adenosine receptor, iNOS, and VEGF immunoexpression levels were normal or lower in the no-touch group than in the conventional-harvest group, as shown by the staining densities in all layers of the vein wall.
Conclusion: Endothelial integrity and adenosine, iNOS, and VEGF immunoreactivities were better preserved when the no-touch technique was used for vein graft harvesting. The mechanical protection provided by the cushion of surrounding tissue in the no-touch group and the vasorelaxation and thromboresistant activities of nitric oxide may be responsible for the reduction in vasospasms and the improved patency rate.
17 Patients undergoing coronary artery bypass surgery were enrolled in the PATENT SVG trial, Patients were randomly allocated to have SVGs harvested with the NT technique from one leg and the CON method from the other.

NT technique exhibits an early molecular and morphological pattern consistent with decreased VSMC activation compared with CON harvesting.
Leg assessment scores were worse in the NT legs at 3 months, but similar to CON scores at 12 months.
A large retrospective observational study they looked at 1349 patients from 2005-2015

Main determinants of vein graft failure has been proposed to be a small vessel diameter, reduced wall motion of the vessel-dependent myocardial region and the right coronary as target vessel [10]. This indicates that it often are grafts supplying less important myocardial regions that fail and perhaps why they generally do so without any symptoms and seemingly without increasing the mortality or risk of myocardial infarction [8]. An improvement in overall patency does therefore not necessarily confer a better clinical result and may explain the lack of improvements in outcome with multiple arterial grafts

An improvement in the risk for new angiography for the NT group compared to the group with conventional vein harvesting could be observed, however no difference could be observed for mortality and need for reintervention. Earlier reported improvements in patency of NT veins are thereby possibly reflected in an improved clinical outcome during the first 10 years after surgery

In the first randomized angiographic study of the NT vein, the patency in the group with conventional harvesting technique was high and the difference in patency between groups was initially small [12]. This difference later increased gradually but was not significant and clinically relevant until the 8.5 and 16 years follow-up
Adults undergoing isolated CABG with at least 1 SVG were eligible. CT angiography was performed 1-year
post CABG. Leg adverse events were assessed with a questionnaire. A systematic review was performed for published
NT graft patency studies and results aggregated including the SUPERIOR study results.

Results: 250 patients were randomized across 12-centres (NT 127 versus CON 123 patients). The
primary outcome (study SVG occlusion or cardiovascular (CV) death) was not significantly different in NT versus CON
(NT: 7/127 (5.5%), CON 13/123 (10.6%), p = 0.15). Similarly, the proportion of study SVGs with significant stenosis or total
occlusion was not significantly different between groups (NT: 8/102 (7.8%), CON: 16/107 (15.0%), p = 0.11). Vein harvest
site infection was more common in the NT patients 1 month postoperatively (23.3% vs 9.5%, p < 0.01).

meta-analysis, NT was associated with a significant reduction in SVG occlusion, Odds Ratio 0.49, 95%
Confidence Interval 0.29–0.82, p = 0.007 in 3 randomized and 1 observational study at 1 year postoperatively.

Conclusions: The NT technique was not associated with improved patency of SVGs at 1-year following CABG while
early vein harvest infection was increased. The aggregated data is supportive of an important reduction of SVG
occlusion at 1 year with NT harvesting.

The primary outcome was the proportion of study SVGs
(NT vs CON) which were completely (100%) occluded
on 64-slice CCTA at 1-year following CABG or death
due to cardiovascular or unknown causes.

The secondary outcomes were angiographic (the number
of study SVGs with a significant (50–99%) stenosis,
and a composite of significant stenosis or complete occlusion
of the study SVG), and clinical (major adverse
cardiac and cerebrovascular events (MACCE: defined as
all-cause mortality, non-fatal myocardial infarction (MI)
including perioperative MI [17], stroke, and repeat revascularization
at 1 year). Leg adverse events (infection,
necrosis, dehiscence, drainage, fluid collection) and leg
quality of life were assessed with a questionnaire
METHODS: From April 2017 to June 2019, we randomly assigned 2655 patients undergoing coronary artery bypass
grafting at 7 hospitals in a 1:1 ratio to receive no-touch technique or conventional approach for vein harvesting.
The primary outcome was vein graft occlusion on computed tomography angiography at 3 months and the
secondary outcomes included 12-month vein graft occlusion, recurrence of angina, and major adverse cardiac and
cerebrovascular events. The generalized estimate equation model was used to account for the cluster effect of grafts
from the same patient.

RESULTS: During the follow-up, 2533 (96.0%) participants received computed tomography angiography at 3 months after
coronary artery bypass grafting and 2434 (92.2%) received it at 12 months. The no-touch group had significantly lower
rates of vein graft occlusion than the conventional group both at 3 months (2.8% versus 4.8%; odds ratio, 0.57 [95% CI,
0.41–0.80]; P<0.001) and 12 months (3.7% versus 6.5%; odds ratio, 0.56 [95% CI, 0.41–0.76]; P<0.001). Recurrence of
angina was also less common in the no-touch group at 12 months (2.3% versus 4.1%; odds ratio, 0.55 [95% CI, 0.35–0.85];
P<0.01). Rates of major adverse cardiac and cerebrovascular events were of no significant difference between the 2 groups.
The no-touch technique was associated with higher rates of leg wound surgical interventions at 3-month follow-up (10.3%
versus 4.3%; odds ratio, 2.55 [95% CI, 1.85–3.52]; P<0.001). But 12 months follow up wasn’t different

CONCLUSIONS: Compared with the conventional vein harvesting approach in coronary artery bypass grafting, the no-touch
technique significantly reduced the risk of vein graft occlusion and improved patient prognosis.

The primary outcome
was graft-level vein graft occlusion at 3 months after
CABG. Graft occlusion was detected by multislice computed
tomography (CT) angiography or earlier clinically driven coronary
angiography. According to the FitzGibbon criteria,26 graft
occlusion was considered when a conduit did not fill with contrast
at all or string sign was found in any segment. For sequential
anastomosis, 1 occlusion of any of the distal anastomoses
was judged as occlusion of the whole graft vessel. Two radiologists
independently reviewed the results of CT angiography in
a central core laboratory.

The secondary outcomes included 12-month vein graft
occlusion, recurrence of angina, composite and individual major
adverse cardiac or cerebrovascular events (ie, cardiovascular
death, nonfatal myocardial infarction, stroke, or target vessel
revascularization) at 3 months and 12 months after CABG.
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.

At network meta-analysis, compared with the CON-SV,
only the RA (incidence rate ratio [IRR], 0.54; 95% CI, 0.35–0.82)
and the NT-SV (IRR, 0.55; 95% CI, 0.39–0.78) were associated with significantly lower rate of graft occlusion,

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Editor's Notes