Brachytherapy for the prevention of stenosis in a canine hemodialysis graft model: preliminary observations.
OBJECTIVE
To determine whether gamma brachytherapy can prevent in-stent stenosis in hemodialysis grafts.


METHODS
Six-millimeter polytetrafluoroethylene arteriovenous grafts were created bilaterally in six dogs. After 1 month, Wallstents spanning the venous anastomosis were placed to accelerate restenosis. Gamma irradiation (12 Gy) was delivered endoluminally to one of the two grafts by using an iridium 192 source; thus, each animal served as its own control. Fistulography was performed monthly for 10 months or until graft thrombosis, with measurement of stenosis at each time point. At the conclusion of the study period, the treated area was examined histologically, and a computer model was used to calculate the volume of intimal hyperplasia.


RESULTS
Delayed stent migration resulted in exclusion of one dog. In the remaining five dogs; maximum stenosis across all time intervals was less for the treated side (P < .04), and the volume of intimal hyperplasia was less for the treated side (P < .045). In one animal studied at 1 year, this trend reversed in terms of percentage stenosis but not total neointimal volume.


CONCLUSIONS
Brachytherapy with 192Ir (gamma) delivered at the time of stent placement reduces restenosis in this hemodialysis graft model, but, depending on the parameter evaluated (stenosis vs total volume of neointima), the benefit may wane or even reverse with time.
Trerotola
S O
SO
Department of Radiology, Indiana University Medical Center, Indianapolis 46202-5253, USA. streroto@iupui.edu
Carmody
T J
TJ
Timmerman
R D
RD
Bergan
K A
KA
Dreesen
R G
RG
Frost
S V
SV
Forney
M
M
D000792:Angiography; D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D001807:Blood Vessel Prosthesis; D001918:Brachytherapy; D004285:Dogs; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000601:surgery; D005268:Femoral Vein / Q000000981:diagnostic imaging / Q000601:surgery; D005720:Gamma Rays; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011138:Polytetrafluoroethylene; D006435:Renal Dialysis; D015607:Stents
D011138:Polytetrafluoroethylene