title: Intra-arterial photodynamic therapy using 5-ALA in a swine model.
abstract: OBJECTIVE
  To test the hypothesis that intravascular light could be delivered via a balloon catheter for arterial photodynamic therapy (PDT).
  
  
  METHODS
  Pig non-injury model.
  
  
  METHODS
  Clinical catheter equipment.
  
  
  METHODS
  Large White pigs (15-20 micrograms) were photosensitised with 5-aminolaevulinic acid (5-ALA) induced protoporphyrin IX (PpIX) at a concentration of 120 mg/kg. Arterial biopsies were taken at intervals between 30 mins and 24 h and frozen sections analysed using a CCD camera to give a temporal profile of fluorescence in each arterial layer. PDT was given to normal arterial segments via a 4 mm transparent PTA balloon inflated so as to occlude flow, but not distend the artery. Animals were culled at 3 and 14 days and the above segments harvested.
  
  
  RESULTS
  Fluorescence peaked in the adventitia, intima and medial layers at 1.5, 4 and 6 h respectively. PDT at all time points produced VSMC depletion compared with controls. The degree of depletion mirrored the fluorescence profile of PpIX.
  
  
  CONCLUSIONS
  PDT can be delivered via a standard PTA balloon with a transparent channel. This depletes the VSMC population within the arterial wall without complications. Intra-arterial PDT is therefore a potential therapy to reduce the incidence of restenosis post-angioplasty.
authors.affiliation: Department of Surgery, Hatter Institute, University College London, U.K.
authors.forename: M P
authors.initials: MP
authors.lastname: Jenkins
authors.forename: G
authors.initials: G
authors.lastname: Buonaccorsi
authors.forename: A
authors.initials: A
authors.lastname: MacRobert
authors.forename: C C
authors.initials: CC
authors.lastname: Bishop
authors.forename: S G
authors.initials: SG
authors.lastname: Bown
authors.forename: J R
authors.initials: JR
authors.lastname: McEwan
mesh_terms: D000622:Aminolevulinic Acid / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000800:Angioplasty, Balloon; D000818:Animals; D002339:Carotid Arteries; D002404:Catheterization; D007083:Iliac Artery; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011524:Protoporphyrins / Q000627:therapeutic use; D012008:Recurrence; D013552:Swine; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX