Intra-arterial photodynamic therapy using 5-ALA in a swine model.
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.
Jenkins
M P
MP
Department of Surgery, Hatter Institute, University College London, U.K.
Buonaccorsi
G
G
MacRobert
A
A
Bishop
C C
CC
Bown
S G
SG
McEwan
J R
JR
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
D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX