HEALING CHARACTERISTICS OF INTRAARTERIAL STENTED GRAFTS - EFFECT OF INTRALUMINAL POSITION ON PROSTHETIC GRAFT HEALING

Background. The purpose of this study was to investigate the effect of complete intraluminal placement on prosthetic graft healing. Methods, Thirty dogs underwent infrarenal abdominal aorta polytetrafluoroethyl ene interposition (12) ol intraluminal stented (IS) grafting. Crafts w ere removed at 4 and 8 weeks. Length of endothelial ingrowth and intim a to media height ratios (IMHRs) were calculated. Perianastomotic endo thelial (CD31+, factor VIII [FVIII+]), smooth muscle (actin+), macroph age (CD44+), and proliferating (PCNA+) cell content was determined. Re sults. In control grafts mean proximal and distal anastomotic endothel ial cell ingrowth was 0.42 +/- 0.06 and 0.47 +/- 0.08 cm at 4 weeks an d 1.10 +/- 0.24 and 0.94 +/- 0.17 cm at 8 weeks. In intraluminal graft s mean proximal and distal anastomotic endothelial cell ingrowth was 2 .57 +/- 0.09 and 1.54 +/- 0.12 cm at 4 weeks and 1.88 +/- 0.06 and 2.1 1 +/- 0.25 cm at 8 weeks. Endothelial ingrowth was greater in all sten ted grafts (p < 0.001). Mean proximal anastomosis IMHRs were 1.01 +/- 0.16 for 4-week and 1.42 +/- 0.16 for 8-week control grafts and 0.59 /- 0.18 for 4-week and 0.50 +/- 0.14 for 8-week stented grafts. Simila r IMHR values were present at the distal anastomosis. Lower IMHRs were observed in stented grafts (p < 0.05). Content of CD44+, PCNA+, and F VIII+ cells were reduced both proximally and distally in 4-week stente d grafts (p < 0.05). Distal content of CD31+ and actin+ cells runs gre ater in 4-week stented grafts (p < 0.05). At 8 weeks CD44+ cell conten t decreased in controls (p < 0.05). Conclusions. Intraluminal location enhances prosthetic graft reendothelialization and attenuates intimal thickening.