Postmortem Retrieval of Arterial Allografts: Preliminary Results.

BACKGROUND: Cryopreserved arterial allografts are vascular substitutes used for arterial reconstructions in a septic field. Their use remains however limited by the shortage of donors. One of the possibilities to address this lack of grafts is to multiply the sources of retrieval. The objective of this preliminary study was the evaluation of the early clinical results and the microbiological safety of arterial grafts retrieved after death.

METHODS: In addition to the standard conditions of arterial sampling, the criteria of inclusion for postmortem retrieval comprised the refrigeration of the body of the donor within 4 hr following the death, a 24-hr time limit from the death, and the availability of an adapted place for retrieval (surgical unit or death chamber respecting the required aseptic conditions). We only retrieved the femoral axes (FAs) and the aortoiliac bifurcation. The conditions of retrieval, transportation, preparation, and conservation were identical to those of cryopreserved arterial allografts harvested during standard multiple organs retrieval. We evaluated the bacteriological risk of contamination and the patency of the grafts in the short and medium term.

RESULTS: In 2015 and 2016, 6 donors were included. Eleven FAs and 2 aortic bifurcations were harvested. The bacteriological samples done on arrival in bank and after thawing were negative in the 6 donors, but one of the 6 donors presented a bacterial contamination of other removed tissues, and the arterial grafts obtained from this donor were destroyed as a precaution (3 grafts). The quality of the grafts evaluated by the surgeon during harvesting was good in all the cases. The indications of allografts were arterial reconstruction in a septic field (n = 8) and aorto-hepatic bypass during hepatic transplantation (n = 1). One graft was unhopefully thawed without being used. At the end of the follow-up, 8 out of 9 grafts were patent. Two ruptures occurred in a context of locally persistent sepsis (crural abscess due to Salmonella typhi and persistent groin wound disunion with a polymicrobial flora). One allograft thrombosis was observed (aorto-hepatic bypass for transplantation). These complications were unrelated to the mode of graft harvesting. No aneurysmal evolution was observed.

CONCLUSIONS: The preliminary results of this protocol are encouraging because the immediate quality of the grafts was good with a risk of microbiological contamination identical with that of the usual harvesting mode. This mode of harvesting looks promising to reduce the shortage in arterial allografts and could be extended to harvest thoracic aortic allografts. However, results at a larger scale are necessary to confirm these data.