Effects of hypothermic storage on the vascular endothelium: a scanning electron microscope study of morphological change in human vein.
OBJECTIVE
The aims of this study were: i) to identify morphological changes occurring in the endothelium of human umbilical veins subjected to the typical storage procedures used in transplantation and ii) to determine the relative efficacy of preservation solutions containing intra and extracellular levels of sodium and potassium.


METHODS
Prospective.


METHODS
Scanning electron micrographs were taken pre and post cold hypoxic storage of human umbilical veins for 3 or 16 hours.


RESULTS
Cold preservation resulted in severe cell detachment with subsequent loss of monolayer continuity and exposure of thrombogenic basal membrane components (highly significant after only 3 hours of cold storage, Kruskal-Wallis, p < 0.01). The morphological alterations culminated in EC with spherical shapes. Cytoplasmic membranes presented an increased number of microvilli and intercellular processes, followed by microvillous swelling and surface blebbing as damage increased. Bleb detachment was seen in severely damaged specimens. However, morphological preservation was not significantly affected by the duration of hypoxia or the ionic balance of the solution tested.


CONCLUSIONS
The present results demonstrate that even short periods (3 hours) of cold storage without revascularization cause significant morphological damage to the endothelium. The ionic composition of the preservation solution did not significantly affect the process. The morphological changes seen in this study could explain storage-related problems such as loss of normal vascular permeability and increased thrombogenicity, problems often associated with transplantation procedures.
Hidalgo
M A
MA
Department of Surgical Research, Northwick Park Institute for Medical Research, Harrow, Middlesex, UK.
Sarathchandra
P
P
Fryer
P R
PR
Fuller
B J
BJ
Green
C J
CJ
D015925:Cryopreservation; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009994:Osmolar Concentration; D011446:Prospective Studies; D012996:Solutions; D014021:Tissue Preservation; D014680:Veins / Q000648:ultrastructure*
D012996:Solutions