The Link between Ex Vivo Storage Interval and Subsequent
Failure of Vein GraftsRobert Poston, MD
Chairman, Department of Cardiothoracic SurgerySt 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 influencegraft patency post-CABG
?
Mechanism of early graft failure
Endothelial dysfunction
Arterial conduitsMeticulous harvestStatin therapy
Hypercoagulability
Anti-platelet therapyAbnormal 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
Bufferedsaline
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 influencegraft 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