Thromboembolic sequelae to indwelling silastic cannulas in sheep arteries.

Because they evoke minimal tissue reaction,' Silastic prostheses have become increasingly popular as chronic implants. Within the lumina of vessels, however, Silastic cannulas often result in thrombotic complications.283 At this institution, thromboembolic syndromes developed in six experimental sheep within 2 months after insertion of indwelling arterial Silastic cannulas. Histopathological studies were carried out on these sheep in an effort to define the pathogenesis of the lesions and to confirm their association with the arterial cannulas.