Artery wall damage and platelet uptake from so-called atraumatic arterial clamps: an experimental study.

A 'traumatic' clamps are routinely used to control arteries during reconstruction, but little is known about the arterial damage caused and the effects on platelet uptake. This experiment used sheep carotid arteries to correlate the degree of histologic damage observed with the level of indium-111-labelled platelet uptake in clamped arterial segments. Scanning electron microscopy and light microscopy enabled three degrees of injury to be recognized. In mild injuries, endothelial cell orientation was changed but local platelet uptake was little different from controls. In moderate injuries, the endothelial cells directly squeezed by the clamp were morphologically altered, superficial fissures developed which extended into the media, and local platelet uptake was usually increased. Severe injuries caused extensive endothelial cell desquamation, formation of deep cavities in the media and increased platelet uptake (mean 5.51 times that of control). Platelet uptake at the site of clamp application was not significantly different from non-clamped carotids for mild injuries. However, the increased platelet uptakes for moderate (P = 0.007) and severe (P = 0.005) injuries were statistically significant when compared with non-clamped control arterial segments.