Veterinary/zoology session

Autologous vascular grafts developed from the internal rectus sheath were implanted on both sided common iliac vein (8 patches) and jugular vein (7 patches) of 4 experimental beagle dogs. During the procedure incisions were placed on the previously named veins and the resulting openings were closed by 1cm x 0,5cm rectus sheath patches. The grafts were prepared in a way to include the muscular fascia of the rectus abdominis and the parietal peritoneum. By positioning of the grafts the peritoneal surfaces were attached to the luminal surfaces. The dogs received heparine as anticoagulant and were treated by antiinflammatory medicine postoperatively. Immunesuppresants were not required as holografts dont indicate such treatment. During the development and the implanting of the grafts no technical difficulties or perioperative complications were encountered. The follow-up of the common iliac vein grafts lasted 6 months and 3 months on the jugular grafts. In the postoperative period the morphologic and functional characteristics of the implanted venous sections were examined by Doppler ultrasonography 8 times and by CT angiography 3 months after the implanting. None of these check-ups showed obturation or stenosis. 3 and 6 months after the procedures the macroscopic evaluation showed normal flow characteristics in the examined vessels. The implanted sections were then removed and processed for histologic and immunhistologic examinations. The histologic survey showed no mesothel cell layer, but the insides of the grafts showed total restructuring and were covered by normal endothel layers. Histology also showed elastic, collagen and reticular fibers as well as capillary cross sections. No difference could be detected in the samples harvested 3 and 6 months after implanting. The immunehistologic examinations using anti-claudin-5 and anti-CD31 antibodies confirmed the preliminary results of the histologic examinations that the implanted grafts luminal surfaces developed differentiated monolayer endothel which were free of degenerative and inflammatory symptoms. Immunehistology also revealed that the claudin-5 molecule expressing itself in the membranes of the endothel cells took up the form of an intensive linear membrane reaction. Examinations using the anti-CD31 marker also showed positive membrane reaction in the endothel cells covering the grafts, however, corresponding with previous studies showed weaker immunereactivity compared to the claudin-5 protein. The controll examinations show the suitability of the internal rectus sheath as a venous wall donor.