Effect of polytetrafluoroethylene covering of Palmaz stents on the development of intimal hyperplasia in human iliac arteries.
OBJECTIVE
The occurrence of neointimal hyperplasia within a stent may result in restenosis with recurrent symptoms of end-organ ischemia. This study evaluated the potential of a nonporous covering of a stent to function as a barrier to the formation of intrastent neointimal hyperplasia.


METHODS
Twelve endovascular stent grafts were used to treat 12 high-risk patients with limb-threatening ischemia secondary to long-segment iliac artery occlusion. A 6-mm, thin-walled polytetrafluoroethylene graft was inserted and anchored to the common iliac artery with use of Palmaz stents. Each stent was covered by graft material over one-half of its length. Control angiograms obtained immediately after graft insertion were compared with follow-up angiograms obtained between 4 and 6 months after the initial procedure. On each angiogram, the region of the stent was magnified by 20x to permit computerized luminal diameter measurements.


RESULTS
The mean luminal diameter within the stent was significantly greater on the covered (7.7 mm +/- 0.33 standard deviation) compared with the uncovered (6.7 mm +/- 0.85 standard deviation) portions (P < .01).


CONCLUSIONS
Partially covered stents are a unique model for assessing the effects of an extrinsic stent covering on arterial healing and myointimal hyperplasia. These data suggest that a relatively nonporous covering of polytetrafluoroethylene may inhibit stent-related restenosis in iliac arteries.
Department of Surgery, Montefiore Medical Center, University Hospital, Albert Einstein College of Medicine, New York, NY 10467, USA.
M L
ML
Marin
F J
FJ
Veith
J
J
Cynamon
R E
RE
Parsons
R T
RT
Lyon
W D
WD
Suggs
C W
CW
Bakal
S
S
Waahl
L A
LA
Sanchez
J G
JG
Yuan
T
T
Ohki
D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D007511:Ischemia / Q000209:etiology / Q000628:therapy; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D011138:Polytetrafluoroethylene; D016062:Porosity; D011858:Radiographic Magnification; D012008:Recurrence; D015607:Stents; D013499:Surface Properties; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D014654:Vascular Patency; D014945:Wound Healing
D011138:Polytetrafluoroethylene