[Small-caliber arterial prostheses: influence of porosity]

Thirty-two pyrolytic carbon coated Weavenit dacron grafts and 32 human umbilical vein segments treated with glutaraldehyde were implanted in the carotid arteries of 32 dogs. Prosthesis samples were removed after periods varying from 10 to 120 days, and sections examined by optical microscopy. Internal surfaces were studied by scanning electron microscopy. Overall permeability was 93.7 p. cent for the dacron prosthesis and 84.3 p. cent for human umbilical vein sections. Fundamental stages of the pseudointimal organization process were compared for the two types of prosthesis.