Microvascular blood flow dynamics associated with photodynamic therapy, pulsed dye laser irradiation and combined regimens.

Abstract

BACKGROUND AND OBJECTIVES:

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.

STUDY DESIGN/MATERIALS AND 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.

• Authors: Tia K Smith, Bernard Choi, Julio C Ramirez-San-Juan, J Stuart Nelson, Kathryn Osann, Kristen M Kelly
• Journal: Lasers in surgery and medicine (Lasers Surg Med) Vol. 38 Issue 5 Pg. 532-9 (Jun 2006) ISSN: 0196-8092 [Print] United States
• PMID: 16615132 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2006 Wiley-Liss, Inc.

Chemical References

• Photosensitizing Agents
• Porphyrins
• Verteporfin

Topics

• Animals
• Female
• Low-Level Light Therapy
• Microcirculation
• Models, Animal
• Photochemotherapy
• Photosensitizing Agents (pharmacology)
• Porphyrins (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Regional Blood Flow
• Skin (blood supply)
• Verteporfin