Ultrastructural investigations for reducing endothelial cell damage of vein grafts during CABG-operation and practical consequences.
BACKGROUND
In the present study the influence of different storage solutions on endothelial integrity or damage was investigated with direct methods particularly with transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunohistochemistry.


METHODS
Saphenous vein segments of 10 cm in length were taken surgically from 6 male CABG-patients (aged 60-70) under standardized conditions. Each vein segment was cut into rings, which were incubated at room temperature for 45 minutes in different storage solutions, particularly in 0.9% sodium chloride solution and in buffered solution (M 199) with 5% human serum albumin respectively. Then, the vein segments were fixed in 3.5% glutaraldehyde and prepared for scanning and transmission electron microscopy to evaluate the endothelial damage. In addition, immunohistochemical staining (CD34, PECAM and Factor VIII) was performed.


RESULTS
When using 0.9% sodium chloride solution, the SEM-examination revealed that 55% of the cell population was destroyed. In comparison to these findings only 26% of the endothelial cell population was damaged when the venous segment was stored in buffered solution with 5% albumin (p<0.01). In immunohistochemistry (CD34, PECAM, Factor VIII) these findings were supported.


CONCLUSIONS
This study demonstrates the importance of storage solutions in regard to endothelial integrity. For best preservation of endothelium it is necessary to modify conventional storage methods. So, storage in buffered solution with albumin has shown much better endothelial cell preservation compared with physiological saline which might reduce the obliteration rate of CABG in future.
Hickethier
T
T
Department of Cardiovascular and Thoracic Surgery, University of Wuerzburg, Germany.
Dämmrich
J
J
Silber
R E
RE
Finster
S
S
Elert
O
O
D000368:Aged; D000418:Albumins; D002021:Buffers; D001026:Coronary Artery Bypass; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D019188:Organ Preservation Solutions; D012501:Saphenous Vein / Q000473:pathology / Q000637:transplantation* / Q000648:ultrastructure; D012965:Sodium Chloride; D014021:Tissue Preservation
D000418:Albumins; D002021:Buffers; D019188:Organ Preservation Solutions; D012965:Sodium Chloride