Comparing five simple vascular storage protocols

We aim to find a storage protocol for vessels that preserves their dimensional, histologic, and mechanical characteristics to facilitate reproducible anastomosis experiments and microsurgical training with constant quality.

We compared stored rabbit aortas, harvested in a slaughterhouse, using five different protocols with fresh controls. Aortas were preserved for 125 d in (1) NaCl 0.9% at -18°C, (2) Roswell Park Memorial Institute 1640 90% with 10% dimethyl sulfoxide (RPMI/DMSO) at -18°C, (3) RPMI/DMSO at -70°C, (4) glycerol 85% at 4°C, and (5) glycerol in stepwise increased concentrations until 85% at 4°C. After preservation, we measured vessel diameter, wall thickness, and Young's Modulus indicating stiffness. Neurosurgeons compared stored vessels with fresh vessels, blinded for preservation subgroup. We performed histologic assessment blinded for preservation subgroup.

Fresh rabbit aortas showed a mean diameter of 2.65 ± 0.14 mm, a mean wall thickness of 126 ± 22 μm, and a Young's Modulus of 11.4 ± 2.4 N/mm(2). NaCl 0.9%-preserved aortas showed a significantly increased vessel diameter and decreased stiffness. RPMI/DMSO-preserved aortas showed no significant differences from fresh aortas in dimensions and mechanical characteristics. Glycerol-preserved tissue showed a significant increase in wall thickness, a related significant decrease in diameter, and increase in stiffness. Neurosurgeons regarded RPMI/DMSO tissue as most comparable with fresh tissue. Histologic assessment revealed no differences between the different protocols and fresh control group.

Storage of rabbit aortas in RPMI/DMSO most adequately preserves their dimensional and mechanical properties.