ROLE OF ENDOTHELIALIZATION OF AORTIC PROS THESIS FOR PROTECTION AGAINST SEPTICEMIC INFECTION - AN EXPERIMENTAL CANINE STUDY

An experimental canine model was developed in order to evaluate the ro le of endothelialization of aortic prostheses for protection against s epticemic infection and the utilization of I-131 radiolabeled bacteria for vascular experimentation. Two groups of dogs were submitted to in sertion of a dacron prosthesis segment in the abdominal aorta with sub sequent infusion of inert I-131 radiolabeled bacteria. In the first gr oup (''A''), formed by five dogs, the infusion was made 30 minutes aft er the insertion of the prosthesis and in the second group (''B''), fo rmed by four dogs, in a new surgery performed 12 weeks after. Fragment s of the animals' prostheses and aortas were collected after 30 minute s of septicemia and analyzed by scan electron microscopy and submitted to reading of radioactivity uptake by a well-type counter. The micros copy recognized a complete endothelialization of the prostheses of dog s of group ''B'' 12 weeks after their insertion. Statistical analysis comparing fragments of non-endothelialized prostheses, of endotheliali zed prostheses and aortas demonstrated that the lower radioactivity up take of the endothelialized prostheses in relation to non-endotheliali zed ones was significant (p = 0,0143) and that there was no significan t statistical difference in uptake in the aortas and in endothelialize d prosthesis (p = 0,3173). It was, therefore, concluded that prosthesi s endothelialization fully protected them against septicemic infection ; bacteremia contaminated all the non-endothelialized prostheses; ther e was no bacterial adhesion in the endothelialized prostheses and the use of bacterias labeled with radioisotope I-131 is appropriate for th e study of infections in vascular prosthetic devices.