Abbreviations, Acronyms & Symbols
CABG	= Coronary artery bypass grafting
LITA	= Left internal thoracic artery
NT	= No-touch
RA	= Radial artery
RITA	= Right internal thoracic artery
RCTs	= Randomized controlled trials
SV	= Saphenous vein

The saphenous vein (SV) remains the most commonly used conduit for revascularization in patients undergoing coronary artery bypass grafting (CABG). However, the optimal choice of conduit for CABG remains a matter of debate. Studies have shown that vein graft occlusion rates range from 5% to 13% in one month and from 10% to 15% within the first year^[1].

To address the issue of vein graft occlusion, the no-touch (NT) vein harvesting technique was introduced in 1996, providing a reproducible, safe, and promising alternative. However, the "Achilles' heel" of the NT technique lies in its higher rate of local complications. In a prospective randomized trial, Meice Tian et al.^[1] reported a 10.3% incidence of leg complications using the NT technique compared to 4.3% with conventional harvesting.

Given these findings, our aim is to describe our particular approach to SV harvesting using the NT method with LigaSure™ and small incisions. This technique represents a hybrid option between conventional and endoscopic vein harvesting, aiming to balance safety, efficacy, and complication rates (Video 1).

Video 1 Link: https://youtu.be/wLiFvZm4XTw

Arterial conduits are widely regarded as the gold standard for graft quality and long-term outcomes in CABG, particularly in terms of patency and survival. However, randomized controlled trials (RCTs) have struggled to conclusively demonstrate the superiority of arterial conduits over the SV. The Arterial Revascularization Trial (or ART), one of the most prominent RCTs, revealed a 14% crossover rate from bilateral internal thoracic artery to single internal thoracic artery, which has been suggested as a potential explanation for its neutral results^[2].

While the patency and quality of the left internal thoracic artery (LITA) are undisputed, the right internal thoracic artery (RITA) has shown more heterogeneous results. A likely explanation is that RITA harvesting is technically demanding and not "surgeon-friendly", requiring a high degree of expertise. Importantly, RITA patency has been shown to depend significantly on the surgeon’s experience and proficiency^[3,4].

The Radial Artery Patency and Clinical Outcomes (or RAPCO) trial demonstrated the superiority of the radial artery (RA) over the RITA as a second conduit. The estimated 10-year graft patency was 89% for the RA vs. 80% for the free RITA, with patient survival at 10 years reaching 90.9% in the RA group compared to 83.7% in the RITA group^[5]. Similarly, Gaudino et al.^[6], in a meta-analysis evaluating the patency of second conduits, reported that only the RA and NT vein grafts were associated with significantly lower graft occlusion rates. This analysis, encompassing 14 RCTs, challenges the conventional assumption that RITA should be the natural second conduit of choice.

Given the infrequent use of more than one arterial conduit for CABG (< 10% in North America), the NT technique for SV harvesting is emerging not as a novel option, but as a compelling second graft choice. This is supported by its reproducibility, patency rates, and long-term results^[5].

In a landmark trial, Meice Tian et al.^[1] randomized 2,655 patients undergoing CABG into two groups - NT vs. conventional vein harvesting. At both three and 12 months, the NT group demonstrated significantly lower vein graft occlusion rates (three months: 2.8% vs. 4.8%; 12 months: 3.7% vs. 6.5%). Furthermore, recurrence of angina at 12 months was lower in the NT group (2.3% vs. 4.1%). However, the NT technique was associated with a higher incidence of leg wound surgical interventions at three months (10.3% vs. 4.3%).

Ninos Samanos et al.^[7] conducted a randomized study involving 156 patients divided into three groups: conventional, intermediate, and NT vein harvesting. In the conventional group, the SV was stripped and distended; in the intermediate group, it was stripped but not distended; and in the NT group, the SV was harvested intact with a surrounding fat pedicle. The patency rate in the NT group (83%) was significantly higher than in the conventional group (64%) and was comparable to the LITA (88%).

We strongly advocate for the NT technique based on its multiple benefits. This approach preserves the adventitia and endothelial integrity of the SV, thereby slowing the processes of intimal hyperplasia and atherosclerosis^[8]. The vasa vasorum plays a crucial role in supplying oxygen and nutrients to the vessel wall, a function that is particularly relevant in the SV due to its more prolific and deeper microvascular network compared to arterial grafts. Conventional SV harvesting disrupts this network, compromising transmural blood flow and promoting neointimal hyperplasia and atheroma formation. Additionally, the preservation of nitric oxide synthetase within the endothelium and the adipose pedicle may provide further protective effects against graft failure.

Our described technique offers a reproducible, cost-effective approach for NT SV harvesting that can be adopted by well-trained surgical teams. The hybrid NT technique, incorporating LigaSure™, small incisions, and pressurized closure, achieves excellent results with minimal major and local complications. Given the robust evidence supporting improved patency and outcomes, the NT approach should be considered a reliable and superior option for the second conduit in CABG procedures.