Fig. 2From: Outcomes of endoscopic chemo- and laser-cauterizations and open fistulectomy for pyriform sinus fistulaEndoscopic views of the left pyriform sinus fistula (PSF). Arrows show the orifice of the PSF. a The orifice of the PSF before treatment. b A metallic cap of the diode glass fiber tip was inserted into the PSF, and the mucous membrane being cauterized. c The orifice of the PSF turned white after the laser cauterizationBack to article page