title: Photodynamic therapy of malignant biliary strictures using meso-tetrahydroxyphenylchlorin.
abstract: OBJECTIVE
  The palliation of patients with malignant bile duct obstruction using metal or plastic biliary stents may be limited by stent occlusion. The aim of this study was to determine the safety and efficacy of endoscopically delivered meso-tetrahydroxyphenyl chlorin photodynamic therapy in the treatment of irresectable malignant biliary strictures and recurrent stent occlusion.
  
  
  METHODS
  Thirteen patients with malignant biliary obstruction owing to carcinoma of the biliary tract (n=9), pancreas (n=3) or stomach (n=1), were studied. All had been initially palliated with metal (n=10) or polyethylene (n=3) biliary stents, but presented with recurrent obstructive jaundice because of local tumour progression. Patients received meso-tetrahydroxyphenyl chlorin 0.15 mg/kg intravenously 72 h before endoluminal light activation with an endoscopically placed optical fibre, followed by polyethylene stent insertion.
  
  
  RESULTS
  Before photodynamic therapy, patients had a median of three (range 0-5) stent occlusions in the preceding 11 (2-22) months, with a median patency of plastic stents placed inside metal bile duct stents for recurrent stent occlusion of 3.5 (0.5-13) months. After photodynamic treatment, tumour necrosis and/or metal stent recanalization was seen in all patients, with a median of 0 (0-3) stent occlusions during 7 (1-43) months follow-up. The median patency of plastic stents placed inside metal stents after photodynamic therapy was 5 (1-43) months. The median survival after diagnosis and photodynamic therapy administration was 21 (10-56) and 8 (1-43) months, respectively. Photodynamic therapy was generally well tolerated but two patients developed cholangitis within the first week, complicated in one by a fatal liver abscess and two developed haemobilia within 4 weeks of treatment, one of whom died with a gall bladder empyema.
  
  
  CONCLUSIONS
  In patients with malignant biliary obstruction, endoscopically delivered meso-tetrahydroxyphenyl chlorin photodynamic therapy causes efficient tumour necrosis and recanalization of blocked metal stents, but there is a significant risk of complications.
authors.affiliation: Department of Gastroenterology, University College London Hospitals NHS Foundation Trust, London, UK. stephen.pereira@ucl.ac.uk
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Pereira
authors.forename: Lakshmana
authors.initials: L
authors.lastname: Ayaru
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Rogowska
authors.forename: Alexander
authors.initials: A
authors.lastname: Mosse
authors.forename: Adrian R W
authors.initials: AR
authors.lastname: Hatfield
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Bown
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D001652:Bile Ducts / Q000601:surgery; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D002779:Cholestasis / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007902:Length of Stay; D008297:Male; D008652:Mesoporphyrins / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage* / Q000009:adverse effects; D015607:Stents; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D008652:Mesoporphyrins; D017319:Photosensitizing Agents; C072269:temoporfin