EFFECT OF BALLOON-EXPANDABLE AND SELF-EXPANDING STENT FIXATION ON ENDOLUMINAL POLYTETRAFLUOROETHYLENE GRAFT HEALING

PURPOSE: To investigate the effect of stent design and deployment mech anism on endoluminal graft healing. METHOD: Twenty dogs underwent infr arenal abdominal aorta polytetrafluoroethylene (PTFE) interposition (6 ) or intraluminal stented grafting using either a balloon expandable ( BE, n = 8) or self-expanding (SE, n = 6) stent design, Grafts were rem oved at 8 weeks. Length of endothelial ingrowth and intima to media he ight ratios (IMHR) were calculated. Perianastomotic smooth muscle (Act in+), macrophage (CD44+), proliferating (PCNA+), and platelet-derived growth factor (PDGF+) cell content were determined. RESULTS: Mean endo thelial ingrowth was 1.10 +/- 0.15 cm (control), 1.88 +/- 0.13 cm (BES G), and 2.16 +/- 0.18 cm (SESG) proximally; and 0.94 +/- 0.12, 2.11 +/ - 0.11 cm, and 2.16 +/- 0.15 cm, respectively, at the distal anastomos is. Endothelial ingrowth was greater in all stented grafts (P < 0.001) . Mean IMHRs were 1.42 +/- 0.16 (control), 0.50 +/- 0.14 (BESG), and 0 .77 +/- 0.2 (SESG) proximally; and 0.84 +/- 0.1, 0.42 +/- 0.09, and 0. 77 +/- 0.12 (SESG) distally, Lower IMHRs were observed in all stented graft regions (P < 0.05) except the distal anastomosis of SESG, The PD GF+ and PCNA+ cell content was decreased, and Actin+ cell content was increased in all stented grafts (P < 0.05). CONCLUSION: Intraluminal l ocation enhances endothelialization and attenuates intimal thickening in PTFE grafts, The enhanced healing of intraluminal stented grafts is irrespective of the type of stent or deployment mechanism used. (C) 1 997 by Excerpta Medica, Inc.