Airway
stenosis in childhood is resistant to conventional treatments.
Endoscope-assisted
photodynamic therapy (
PDT) is a potent candidate for the therapeutic modality owing to the easy approach to the tracheal lesion and low degree of invasiveness. The aim of the present study was to examine whether a
photosensitizer preferentially accumulates in the lesion of airway
stenosis in order to explore the possible applicability of
PDT. The tracheal mucosa of rabbits was scraped off, and the rabbits were intravenously administered with
Photofrin. The tissue concentration of
Photofrin was quantitatively measured by fluorometric analysis. Granulation formation was seen in the mucosa-deprived lesion, causing airway
stenosis.
Photofrin concentration in the granulation tissue was four-fold higher than that in the intact trachea and 10-fold higher than that in the liver, spleen, skin and muscle.
Photofrin preferentially accumulated in the lesion of airway
stenosis. A preliminary experiment on
PDT using transtracheal illumination showed an amelioration of airway
stenosis, resulting in reduction in respiratory
stridor.