Effect of external stents on prevention of intimal hyperplasia in a canine vein graft model.
BACKGROUND
External stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein grafts with different sizes of external stents.


METHODS
A series of paired trials was performed to compare femoral vein grafts with different sizes of external stents, where 30 modeled canines were equally divided into three groups: 6-mm external stent vs non-stent control, 4-mm vs 6-mm external stent, and 4-mm vs 8-mm external stent. At day 3 after operation, color Doppler flow imaging (CDFI) was done to observe blood flow in the lumen. Four weeks later, CDFI was re-checked and the veins were harvested, stained and measured.


RESULTS
All grafts were patent without formation of thrombosis. External stents significantly reduced intimal thickness of the vein grafts with a 6-mm external stent compared with the vein grafts without external stents (P < 0.05). The vein grafts with the 4-mm external stent had similar intimal, medial and adventitial thicknesses compared with those with the 6-mm external stent and the 8-mm external stent.


CONCLUSIONS
External stents can reduce intimal hyperplasia of vein grafts. Stents of different diameters exert the similar effect on prevention of intimal hyperplasia.
Zou
Rong-jiang
RJ
Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
Zou
Liang-jian
LJ
Huang
Sheng-dong
SD
Wang
Yin
Y
Han
Lin
L
Ji
Guang-yu
GY
Xu
Zhi-yun
ZY
D000818:Animals; D001241:Aspirin / Q000627:therapeutic use; D004285:Dogs; D005268:Femoral Vein / Q000637:transplantation*; D006965:Hyperplasia; D015607:Stents; D017539:Tunica Intima / Q000473:pathology*; D018615:Ultrasonography, Doppler, Color
D001241:Aspirin