title: The effect of photodynamic therapy on cisterna chyli patency in rats.
abstract: OBJECTIVE
  To radiographically and histologically evaluate the effects of photodynamic therapy on the cisterna chyli in rats.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Adult male Sprague-Dawley rats (n = 60).
  
  
  METHODS
  Cecal lymph nodes were injected with the photodynamic compound verteporfin. A 690 nm, 500 mW diode laser was then directed at the area of the cisterna chyli for either 0, 1.5, or 3 minutes. Cisterna chyli patency was evaluated using lymphography, and histologic changes were evaluated on postoperative Days 1, 3, 5, 7, and 14.
  
  
  RESULTS
  Histologically, minimal to marked injury to the cisternal and/or pericisternal tissues was present in all treated rats at all time periods. Radiographically, 8/20 cisternae were occluded in the 1.5-minute treatment group (including 1/4 on Day 1, 2/4 on Day 3, 3/4 on Day 5, 0/4 on Day 7, and 2/4 on Day 14), and 9/20 cisternae were occluded in the 3-minute treatment group (including 0/4 on Day 1, 1/4 on Day 3, 3/4 on Day 5, 3/4 on Day 7, and 2/4 on Day 14). There was minimal to no histologic evidence of tissue injury in control rats. All control cisternae were radiographically open.
  
  
  CONCLUSIONS
  Further investigations into the timing of laser application and light dose, or alternative photodynamic agents are required to limit injury to adjacent tissues and to improve the effectiveness of cisternal photoablation.
authors.affiliation: Department of Clinical Sciences, North Carolina State University, College of Veterinary Medicine, Raleigh, North Carolina.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Rowe
authors.forename: Kyle G
authors.initials: KG
authors.lastname: Mathews
authors.forename: Keith E
authors.initials: KE
authors.lastname: Linder
authors.forename: Lloyd P
authors.initials: LP
authors.lastname: Tate
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D007267:Injections; D008198:Lymph Nodes; D008220:Lymphography; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D008517:Phytotherapy; D011166:Porphyrins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013897:Thoracic Duct / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D000077362:Verteporfin
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin