Loss of blood platelet adhesion after heating native and cultured human subendothelium to 100 degrees Celcius.
OBJECTIVE
Balloon angioplasty produces mechanical vessel wall injury that leads to substantial blood platelet deposition at the angioplasty site. The aim of the study was to determine whether thermal angioplasty might, by contrast, reduce platelet adhesion by denaturation of subendothelial adhesive proteins.


METHODS
Native and cultured human subendothelium was briefly heated to greater than or equal to 100 degrees C by laser irradiation or to 50-100 degrees C by immersion in preheated phosphate buffered saline (PBS). Subsequently, the subendothelium was exposed for 5 min to flowing human blood at a shear rate of 1300 s-1. Blood platelet adhesion to the subendothelium was determined quantitatively.


METHODS
Human umbilical arteries were used and the subendothelial matrix derived from cultured umbilical vein endothelial cells.


RESULTS
After heating arterial subendothelium by laser irradiation to greater than or equal to 100 degrees C, zero platelet adhesion was found v 36(SD 2)% adhesion to the non-heated surface (p less than 0.001). After laser heating of the subendothelial matrix to greater than or equal to 100 degrees C, platelet adhesion was absent in 10/10 experiments (p less than 0.01). After heating the matrix to 100 degrees C by immersion in PBS, platelet adhesion was reduced to 5(5)% v 31(7)% at 37 degrees C (p less than 0.001).


CONCLUSIONS
These in vitro results, if extrapolated to catheter interventions, suggest that thermal injury to the vessel wall by laser angioplasty or other thermal angioplasty methods may provide a basic and clinically relevant advantage over mechanical angioplasty modalities, because of a potentially reduced risk of complications related to platelet adhesion.
Borst
C
C
Department of Cardiology, University Hospital Utrecht, The Netherlands.
Bos
A N
AN
Zwaginga
J J
JJ
Rienks
R
R
de Groot
P G
PG
Sixma
J J
JJ
D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D016342:Angioplasty, Laser; D046508:Culture Techniques; D004730:Endothelium, Vascular / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D010973:Platelet Adhesiveness; D014469:Umbilical Arteries / Q000502:physiology