title: Photodynamic effects on rabbit auricular veins after photosensitization with porfimer sodium: Implications of the results with respect to the treatment of esophageal varices with photodynamic therapy.
abstract: BACKGROUND
  There are numerous clinical applications for photodynamic therapy in the GI tract. The principal reason for the wide variety of lesions amenable to photodynamic therapy is the ability to treat large areas of mucosa without the need for complete visualization. This report describes observed hemodynamic and histologic changes in rabbit auricles after photodynamic therapy and the feasibility of photodynamic therapy for esophageal varices.
  
  
  METHODS
  Porfimer sodium and an argon-dye laser (630 nm, 300 mW/cm(2)) were used. Twenty rabbits were grouped according to porfimer sodium dose: group 1 (2.0 mg/kg, n = 10); group 2 (1.0 mg/kg, n = 6); group 3 (0.2 mg/kg, n = 4). Rabbit auricular veins were classified according to time duration of laser illumination: V(0), no illumination; V(5), 5 minutes; V(10), 10 minutes; V(15), 15 minutes. Hemodynamic changes were observed with a laser Doppler blood flow meter. Histologic changes were evaluated by light microscopy.
  
  
  RESULTS
  For groups 1 and 2, there was a significant decrease in blood flow for V(15) after photodynamic therapy, but not in group 3. There was a significant difference in the grade of thrombus between V(5) and V(15) in groups 1 and 2, and between V(10) and V(15) in group 2. There was a significant difference in the grade of venous dilation (congestion) for V(15) between groups 1 and 3 (p < 0.05, Kruskal-Wallis test).
  
  
  CONCLUSIONS
  Endoscopic photodynamic therapy could possibly improve the outcome for endoscopic treatment of esophageal varices beyond that achieved by sclerotherapy or band ligation alone.
authors.affiliation: Department of Gastroenterology, Jichi Medical School, 3311-1 Yakushiji, Minamikawachi-machi, Kawachi-gun, Tochigi 329-0498, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nagamine
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ido
authors.forename: Kouji
authors.initials: K
authors.lastname: Saihuku
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Higashizawa
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ono
authors.forename: Tomosuke
authors.initials: T
authors.lastname: Hirasawa
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sugano
authors.forename: Ja-Mun
authors.initials: JM
authors.lastname: Chong
mesh_terms: D000818:Animals; D017323:Dihematoporphyrin Ether / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004423:Ear / Q000098:blood supply* / Q000473:pathology; D004932:Esophageal and Gastric Varices / Q000188:drug therapy*; D005240:Feasibility Studies; D006414:Hematoporphyrin Photoradiation; D008297:Male; D011817:Rabbits; D013927:Thrombosis / Q000473:pathology; D014680:Veins
chemical_list: D017323:Dihematoporphyrin Ether