The Link between Ex Vivo
Storage Interval and Subsequent
Failure of Vein Grafts
Robert Poston, MD
Chairman, Department of Cardiothoracic Surgery
St Francis Medical Center, Trenton, NJ

Choice of
conduit
• Arterial vs. venous: OR 10
Harvesting
conduit
• “No touch” vs. conventional: OR 3.1
• Open vs. endoscopic: OR 2
Storage of
conduit
Anastomotic
technique
• Interrupted vs. continuous: OR 1.4
• On-pump vs. off-pump: OR 1.3
Postoperative
management
• Aggressive vs. standard statin therapy: OR 1.3
• Aspirin vs. no aspirin: OR 2.2
Factors that influence
graft patency post-CABG
?

Mechanism of early graft failure
Endothelial dysfunction
Arterial conduits
Meticulous harvest
Statin therapy
Hypercoagulability
Anti-platelet therapy
Abnormal flow
Perfect anastomotic
technique
THROMBOSIS

Status of bypass graft endothelium
In situ
(baseline)
Ex vivo storage
(after explant)
After
grafting onto
the heart
?
Normal endothelium Disrupted endothelium

Recovery of venous endothelium after grafting
• Large animal studies
• Venous vs. prosthetic grafts

HANDLE WITH CARE

The Vascular Conduit as a Transplant Organ
• Veins/arteries are organs:
• differentiated structures comprised of two or more tissues working together to provide a specific
function
• Respond to a variety of complex signals including hormones, other molecules and nerve impulses to
adjust blood flow
• Correct functioning is dependent upon proper integrated functioning of vessel’s constituent tissues
• Majority of vascular grafts are transplanted autologous vein or artery derived grafts-
• Vascular grafts and heterologous organ transplants are subject to many of the same
graft failure mechanisms:
• Oxidative damage
• Storage lesions
• Ischemia Reperfusion Injury

Subanalysis of preservation solutions from the
PREVENT IV Trial1
• Multicenter, randomized, placebo-controlled trial of edifoligide during
CABG
• Enrolled 3014 patients at 107 US sites from 8/1/02 – 10/22/03
• Analyzed the impact of preservation solution on graft patency
Saline
Blood
Buffered
saline
1. Harskamp et al. JAMA Surg. 2014;149(8):798-805

Choice of
conduit
• Arterial vs. venous: OR 10
Harvesting
conduit
• “No touch” vs. conventional: OR 3.1
• Open vs. endoscopic: OR 2
Storage of
conduit
Anastomotic
technique
• Interrupted vs. continuous: OR 1.4
• On-pump vs. off-pump: OR 1.3
Postoperative
management
• Aggressive vs. standard statin therapy: OR 1.3
• Aspirin vs. no aspirin: OR 2.2
Factors that influence
graft patency post-CABG
Buffered solution vs. other
alternatives: OR 1.7

Ischemic damage
is “invisible”
• Bypass graft failure often asymptomatic
• Whole organ failure never asymptomatic
Saline/blood
standard of care
• Informational cascade
Saline/blood used
when training
• Reputational cascade
Selective
emphasis of risk
factors
• Easy to see the influence of technical/anatomic factors
• Difficult to see the analogy to organ transplant
Factors that influenced
choice of vein solution