Glycerol preservation is an effective method for long-term preservation of skin allografts and has a potential use in preserving arterial allografts. We evaluated the effect of glycerol concentration and incubation period on vessel-wall integrity of rat aortic allografts. No significant differences were measured in breaking strength (2.3 ± 0.3 N) and bursting pressure (223 ± 32 kPa) between standard glycerolized and control segments (1.7 ± 0.3 N, 226 ± 17 kPa). Isometric tension measurements showed complete lack of functional contraction and relaxation capacity in allograft segments prepared according to all preservation protocols. Morphologically, thickness of the vessel-wall media diminished after preservation using low (30/50/75 %) or high (70/85/98%) concentrations of glycerol, as compared to control segments (i.e. 81 ± 2.4 μm, 95 ± 5.6 μm and 125 ± 3.5 μm, respectively). Confocal microscopy and Fourier analysis demonstrated that vascular collagen and elastin bundle orientation had remained unaltered. Electron microscopy showed defragmentation of luminal endothelial cells. In conclusion, glycerol preservation of rat aorta resulted in an acellular tissue matrix, which maintained biomechanical integrity and extracellular matrix characteristics. The next step in the investigation will be to test the concept of glycerol preservation of arterial allografts in a vascular transplantation model.

A firm conclusion could not be made because there were no studies available in which direct comparison was performed between different preservation methods of vascular allografts. In addition, heterogeneity of the individual studies hampered direct comparison of different types of vascular allografts. However, the overall graft performance of glutaraldehyde-preserved human umbilical vein allografts may be superior to that of other vascular allografts.

Background: Prosthetic grafts have poor patency rates in peripheral arterial reconstructions. Glycerol (GL)-preserved grafts are an alternative. The aim of this study was to examine patency, graft morphology and function of GL-preserved allografts in a goat carotid artery animal model. Methods: The first group (n = 7) underwent bilateral replacement of the carotid artery by a carotid allograft that was preserved in GL for 1 week. In the second group (n = 5), a carotid artery allograft that was preserved in University of Wisconsin solution (UW) for 48 h was used. In the third group (n = 5), the jugular vein (autologous vein, AU) was used. The follow-up was 3 months. Results: One UW graft and 1 GL graft occluded in the first 24 h postoperatively. Three-month primary patency rates for GL, UW and AU grafts were 93, 100 and 80%, respectively (p = 0.39). Graft diameter was increased in UW allografts (p < 0.005), whereas GL allografts remained unchanged. After explantation, GL allografts demonstrated contraction and relaxation capacity and lower intimal thickness (p < 0.001). Conclusion: GL preservation has proven to be a feasible method for arterial allograft transplantation in a large animal model with decreased intimal hyperplasia and renewed functional capability.

Background: Vascular transplantation has become an alternative for prosthetic grafts. Suitable storage methods for vascular allografts are therefore necessary. For small caliber arterial allografts, cryopreservation and cold storage showed discouraging results. Since glycerol preservation proved effective for the storage of skin allografts, this preservation method was investigated for vascular allografts using a rat aortic transplantation model. Methods: Glycerol-preserved allografts (GA) were transplanted to the infrarenal aorta (n = 18) in Wistar rats. A control group (n = 18) underwent immediate autotransplantation (AU) of an equal length of aorta. Results: Cumulative graft patency at 90 days’ follow-up was 93% for AU and 78% for GA (ns). No aneurysm formation was detected in both groups. Intraluminal endothelial cell coverage, integrity of the media and smooth muscle cell repopulation were comparable in both groups. Intimal thickness was less in GA than in AU and inflammatory reaction in the adventitia was diminished in GA. Conclusion: GA were successfully grafted with acceptable patency rates compared to autografts, while intima hyperplasia and adventitial inflammatory reaction were less.