Microvascular blood flow dynamics associated with photodynamic therapy, pulsed dye laser irradiation and combined regimens.
OBJECTIVE
Previous in vitro studies demonstrated the potential utility of benzoporphyrin derivative monoacid ring A (BPD) photodynamic therapy (PDT) for vascular destruction. Moreover, the effects of PDT were enhanced when this intervention was followed immediately by pulsed dye laser (PDL) irradiation (PDT/PDL). We further evaluate vascular effects of PDT alone, PDL alone and PDT/PDL in an in vivo rodent dorsal skinfold model.


METHODS
A dorsal skinfold window chamber was installed surgically on female Sprague-Dawley rats. One milligram per kilogram of BPD solution was administered intravenously via a jugular venous catheter. Evaluated interventions were: control (no BPD, no light), PDT alone (576 nm, 16 minutes exposure time, 15 minutes post-BPD injection, 10 mm spot), PDL alone at 7 J/cm2 (585 nm, 1.5 ms pulse duration, 7 mm spot), PDL alone at 10 J/cm2, PDT/PDL (PDL at 7 J/cm2), and PDT/PDL (PDL at 10 J/cm2). To assess changes in microvascular blood flow, laser speckle imaging was performed before, immediately after, and 18 hours post-intervention.


RESULTS
Epidermal irradiation was accomplished without blistering, scabbing or ulceration. A reduction in perfusion was achieved in all intervention groups. PDT/PDL at 7 J/cm2 resulted in the greatest reduction in vascular perfusion (56%).


CONCLUSIONS
BPD PDT can achieve safe and selective vascular flow reduction. PDT/PDL can enhance diminution of microvascular blood flow. Our results suggest that PDT and PDT/PDL should be evaluated as alternative therapeutic options for treatment of hypervascular skin lesions including port wine stain birthmarks.
Smith
Tia K
TK
Beckman Laser Institute, University of California, Irvine, California 92612, USA.
Choi
Bernard
B
Ramirez-San-Juan
Julio C
JC
Nelson
J Stuart
JS
Osann
Kathryn
K
Kelly
Kristen M
KM
D000818:Animals; D005260:Female; D028022:Low-Level Light Therapy; D008833:Microcirculation; D023421:Models, Animal; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011166:Porphyrins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D000077362:Verteporfin
D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin