These are open questions to liver and renal transplanters around the world. What are your current practices with respect to both the utilization and storage of deceased donor vessels (to assist with the implantation of liver and renal allografts)? Would you ever cryopreserve these vessels for future use and do you consider cryopreserved vessels as effective as non-cryopreserved relatively "fresh" vessels in the transplantation setting?
Donor iliac vessels can be stored safely for at least 10 days. The University of Wisconsin group reported (Annals of Surgery/January 2003):
At our center, we retain leftover cadaveric iliac vessels for up to 10 days, preserved in University of Wisconsin solution at 4°C. We have not had to delay surgical revascularization beyond 2 weeks because of lack of availability of donor vessels of the correct blood type. Most often, blood vessels are immediately available to allow surgical repair within several days. However, if there is an inadequate supply of vessels at any one transplant center, vessels could be shared between centers within a single organ procurement organization, or possibly between organ procurement organizations.
Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513976/
Cryopreservation remains problematic. Suggest Muller-Schweinitzer's excellent review "Cryopreservation of Vascular Tissues" from Organogenesis July-Sept 2009 full text at:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781088/
It is funny that the use of deceased donor iliac vessel allografts are mostly perceived as the use of arteries for liver allograft arterial conduits in the Western World. However, in countries where deceased donor organs are scarce and living donor liver transplantation dominates (Japan, Korea, Turkey), iliac vein allografts rather that the arterial grafts are of greater value. LDLT practices depend mostly on the portal inflow and venous outflow reconstructions and cryopreserved iliac vein grafts are the most valuable players in this arena. Unfortunately, deceased donor iliac vessels are as scarce as the deceased donor organs. So, we try our best to cryopreserve as much of the donor iliac vein grafts as possible. Another underestimated source for the vein grafts is the saphenous veins which are harvested for CABG surgery. Because of the high demand and poor supply for the iliac vein grafts, we developed new reconstruction techniques with the use of saphenous vein grafts instead of the traditional methods using iliac veins. Now, we collect all the unused saphenous vein grafts harvested by the vascular surgeons and cryopreserve them to be used for (future) back table reconstructions of the hepatic and portal veins. Naturally, we always use the fresh saphenous veins for hepatic arterial reconstructions and we find them more reliable even for the venous reconstructions. But the fact that we don't have that many available fresh saphenous veins strengthens our reliance on the cryopreserved material. In addition, the fact that the cryopreserved vessels are not used immediately gives us the opportunity to obtain cultures from every single graft which minimizes the risk of infection.
Thanks for this information as it clearly outlines the challenges that are faced in countries where deceased donors are scarce and hence other sources of vascular conduits need to be relied upon.
My purely anecdotal response: In the mid-90s, eschewing our longstanding practice of using fresh donor arteries and veins (preserved up to 2 weeks in tissue culture media (Eagle's), a newly arrived colleague insisted on using cryopreserved donor vessel and his incidence of both thrombosis and rupture was alarming.
Useful as this fits with some of the published literature from the 90
's. The important knowledge that resides within peoples minds as well as within organizations around the world is invaluable.
Since we used to have our own cryo-bank we used iliac grafts from other donors. With the new european regulation regarding the handling of tissue, the use of vessels is only allowed for the same recipient. In older days we always had grafts to use. nowadays we dont. We are not used to keep the iliacs for 10 days wthich is indeed possible. We use in the rare cases for the arterie a biosynthttic prothesis calles omniflow. For the venous vessels we use pericard patches preparde as a tube to get the rigt diameter.
I have worked for 3 transplant centers with 3 different situations regading deceased donor availability; a center in Egypt where no deceased organ donation is available, even for vessels, a center in Taiwan which is a predominantly living donor program, and an Italian center which is deceased organ-based program.
For the Egyptian center, only ePTFE grafts are used for vascular reconstruction in LDLT. In the Taiwanese center, all vessels are cryopreserved, whether arteries or veins, not only restricted to iliac vessels but also aorta, SMA and carotid arteries. In the Italian center, cold stored iliac vessels are available and can be used for reconstruction, and if not available, cryopreserved vessels may be used.
Cropreserved arteries and veins have good patency when used for anterior section drainage in RL LDLT. Atherosclerosis of cryopreserved arteries may have no impact on patency. Storage time also appear to have no impact on patency.
http://www.ncbi.nlm.nih.gov/pubmed/25783415
http://www.ncbi.nlm.nih.gov/pubmed/24382821
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