Intimal injury from arterial clamps.

Preliminary experimental data have been presented indicating that intimal injury of some degree is a virtually constant finding at the site of application of any arterial occluding clamp. These injuries vary from intimal distortion to complete fracture into the media of the vessel. The degree of injury appears directly proportional to the amount of pressure exerted through a given clamp. Atherosclerotic arteries are particularly subject to severe degrees of intimal injury. Preliminary observations suggest that heparin is not helpful in preventing platelet aggregation and initial thrombus formation at intimal injury sites. The problem of anticoagulation at such injury sites is being studied further.