Healing characteristics of intraarterial stented grafts: effect of intraluminal position on prosthetic graft healing.

Abstract

The purpose of this study was to investigate the effect of complete intraluminal placement on prosthetic graft healing. Thirty dogs underwent infrarenal abdominal aorta polytetrafluoroethylene interposition (12) or intraluminal stented (18) grafting. Grafts were removed at 4 and 8 weeks. Length of endothelial ingrowth and intima to media height ratios (IMHRs) were calculated. Perianastomotic endothelial (CD31+, factor VIII [FVIII+]), smooth muscle (actin+), macrophage (CD44+), and proliferating (PCNA+) cell content was determined. In control grafts mean proximal and distal anastomotic endothelial cell ingrowth was 0.42 +/- 0.06 and 0.47 +/- 0.08 cm at 4 weeks and 1.10 +/- 0.24 and 0.94 +/- 0.17 cm at 8 weeks. In intraluminal grafts mean proximal and distal anastomotic endothelial cell ingrowth was 1.57 +/- 0.09 and 1.54 +/- 0.12 cm at 4 weeks and 1.88 +/- 0.06 and 2.11 +/- 0.25 cm at 8 weeks. Endothelial ingrowth was greater in all stented 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. Similar IMHR values were present at the distal anastomosis. Lower IMHRs were observed in stented grafts (p < 0.05). Content of CD44+, PCNA+, and FVIII+ cells were reduced both proximally and distally in 4-week stented grafts (p < 0.05). Distal content of CD31+ and actin+ cells was greater in 4-week stented grafts (p < 0.05). At 8 weeks CD44+ cell content decreased in controls (p < 0.05). Intraluminal location enhances prosthetic graft reendothelialization and attenuates intimal thickening.