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Updated: May 21, 2026
A Rabbit Venous Interposition Model Mimicking Revascularization Surgery using Vein Grafts to Assess Intimal Hyperplasia under Arterial Blood Pressure
Published on: May 15, 2020
Inducible nitric oxide synthase and vein graft performance in patients undergoing coronary artery bypass surgery:
Michael R Dashwood, Andrzej Loesch1
1Department of Clinical Biochemistry, Royal Free and University College Medical School, Pond Street, London NW3 2QG, UK. m.dashwood@ucl.ac.uk.
Insights
Inducible nitric oxide synthase (iNOS) plays a key role in maintaining vein graft patency after coronary artery bypass grafting (CABG). Minimally invasive saphenous vein harvesting enhances this beneficial effect.
Area of Science:
- Cardiovascular Surgery
- Vascular Biology
- Nitric Oxide Research
Background:
- Coronary artery disease (CAD) is a leading cause of mortality, with coronary artery bypass grafting (CABG) as a primary treatment.
- The long saphenous vein (LSV) is a common CABG conduit, but its long-term patency is inferior to the internal thoracic artery.
- Conventional LSV harvesting causes significant vascular trauma, affecting endothelium, nerves, and smooth muscle, all sources of nitric oxide (NO).
Purpose of the Study:
- To review the role of nitric oxide synthases (NOS) in vein graft performance following CABG.
- To investigate the specific contribution of inducible nitric oxide synthase (iNOS) to saphenous vein graft patency.
- To explore the impact of surgical trauma during vein harvesting on iNOS activity and graft outcomes.
Main Methods:
- Literature review focusing on studies examining nitric oxide synthase isoforms (eNOS and iNOS) in vein grafts.
- Analysis of research investigating the effects of surgical trauma on vascular cells and nitric oxide production.
- Synthesis of findings related to iNOS expression and function in the context of saphenous vein graft patency.
Main Results:
- Endothelial nitric oxide synthase (eNOS) is well-studied, but less is known about inducible nitric oxide synthase (iNOS).
- While iNOS is often linked to pathology, emerging evidence suggests a protective role in maintaining vein graft patency.
- Minimally traumatic saphenous vein harvesting is associated with improved graft patency, potentially mediated by iNOS activity.
Conclusions:
- iNOS may play a crucial, beneficial role in preserving saphenous vein graft patency after CABG.
- Surgical technique, specifically minimizing trauma during vein harvesting, can positively influence iNOS function and graft survival.
- Further research into iNOS modulation could offer novel strategies to improve CABG outcomes.
Abstract:
Coronary artery disease is the major cause of mortalilty in the West with coronary artery bypass surgery (CABG) being a means of restoring blood supply to ischaemic myocardium. The long saphenous vein is the most commonly used bypass conduit but its patency is inferior to the internal thoracic artery, the 'gold standard' graft. In conventional procedures the saphenous vein is harvested in such a manner that considerable vascular damage is inflicted. The structures mainly affected by this vascular trauma are the endothelium, autonomic nerves and vascular smooth muscle all containing cells with the potential to release nitric oxide (NO). While the majority of studies into the potential role of NO in vein graft performance have focussed on the involvement of endothelial nitric oxide synthase (eNOS) less information is available regarding the role of the inducible isoform of nitric oxide synthase (iNOS). While the effects of eNOS-derived NO are principally beneficial, iNOS is generally associated with pathological conditions. While potential pathophysiological roles of iNOS are discussed in this review we also outline many studies suggesting that this isoenzyme plays an important role in maintaing vein graft patency in patients undergoing CABG, particularly when the saphenous vein is harvested with minimal surgical trauma.
