Endovascular catheter-delivered photodynamic therapy in an experimental response to injury model.
BACKGROUND
The effectiveness of local endovascular photodynamic therapy (PDT) in preventing tissue hyperplasia was evaluated in a vascular injury model.


METHODS
Standardized unidirectional arterial injury with a directional atherectomy catheter was performed in porcine arteries (n = 180). Animals (n = 72) were randomly allocated to unidirectional injury only (Group 1), injury followed by drug delivery of photosensitizer with a porous balloon (Group 2), or by local exposure to monochromatic light (Group 3). In Group 4, injury was followed by local drug delivery of photosensitizer and subsequent exposure to light (PDT). Up to 21 days after treatment, all experimental vessels were excised, fixed and processed for histology, immunohistochemistry and transmission electron microscopy.


RESULTS
After vascular injury an inflammatory and myoproliferative response was observed in Groups 1, 2 and 3 (mean tissue hyperplasia/media ratio 1.0 +/- 0.5 at 21 days; area tissue hyperplasia: 1.57 +/- 0.9 mm2). Proliferation in injured vascular segments (Group 1-3) reached a maximum at 7 days, with 6%. Only in Group 4, after injury followed by photodynamic therapy, was there no significant vascular response (mean tissue hyperplasia/media ratio 0.3 +/- 0.2: area tissue hyperplasia: 0.1 +/- 0.05 mm2 p < 0.001, proliferating cells 0.3%).


CONCLUSIONS
Vascular response after unidirectional injury was suppressed only by endovascular photodynamic therapy.
Gonschior
P
P
Medical Department, Klinikum Grosshadern, Munich, Germany.
Vogel-Wiens
C
C
Goetz
A E
AE
Huehns
T Y
TY
Breger
F
F
Gerheuser
F
F
Fleuchaus
M
M
Welsch
U
U
Sroka
R
R
Dellian
M
M
Lehr
H A
HA
Höfling
B
B
D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects / Q000648:ultrastructure; D020212:Carotid Artery Injuries; D002406:Catheterization, Peripheral; D002455:Cell Division / Q000187:drug effects; D004195:Disease Models, Animal; D005263:Femoral Artery / Q000187:drug effects / Q000293:injuries / Q000648:ultrastructure; D006965:Hyperplasia / Q000473:pathology / Q000517:prevention & control; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010778:Photochemotherapy / Q000295:instrumentation / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D013552:Swine; D014652:Vascular Diseases / Q000188:drug therapy* / Q000473:pathology
D017319:Photosensitizing Agents