CLINICAL TECHNIQUES AND TECHNOLOGY Methylene blue for easy and safe detection of salivary duct papilla in sialendoscopy Jan-Christoffer Luers, MD, Julia Vent, MD, PhD, and Dirk Beutner, MD, Cologne, Germany S ialendoscopy is one of the new challenges in treating salivary gland diseases, mainly sialolithiasis. It is an unpleasant situation if the sialendoscopy operator experi- ences problems in finding the papilla or during introduction of the endoscopic devices, especially because the interven- tion is usually performed under local anesthesia. One key step in performing sialendoscopy is the safe, atraumatic entering of the papilla with the endoscope, which is much more difficult for the submandibular gland than for the parotid. 1 The ostium represents the narrowest part of the Wharton duct with mean diameters between 0.5 and 1.5 mm. 2 The small, single-device sialendoscope measures 1.3 mm (Karl Storz Company, Tuttlingen, Germany). Thus, before a sialendoscopy can be performed, the ostium needs to be dilated with a cone-shaped dilatator and probes. Dam- age to the orifice can result in failure of the whole proce- dure. Therefore, a smooth probe implementation into the duct is the key, which makes secure detection of the ostium necessary. 3 The surgeon should also be familiar with the exact anat- omy of the individual, especially when the duct must be incised. At intraductal sialolithiasis with stones close to the orifice, incision of the duct should start preferably from the position of the caruncula, which therefore needs to be lo- calized first. Especially if the gland and duct are inflamed or if the sialolith is of a significant size, the entire floor of the mouth can be edematous, making the duct entrance invisi- ble. Because we are dealing with a salivary duct, it would be advantageous to identify the ostium by observing its secre- tion. A helpful method is massaging the gland, but even then some glands express only a little saliva; hence, the secretion may not be visualized on the smooth reflecting mucosa (Fig 1). To overcome this problem, we suggest tipping methylene blue (1% methylthioninium chloride; Neopharma GmbH & Co.KG, Aschau, Germany) onto the area of the caruncula. Then massaging the gland followed by a slow sweeping of the duct in a distal direction should express at least minor amounts of saliva. In contrast to no use of dye, after meth- ylene blue application, any secretion will be readily detected because of its contrast to the blue background. Additionally, after 1 or 2 minutes, the saliva will lead to some washout effect of methylene blue, leaving a circle of brighter tissue amid the deep blue of the orifice. This effect enables easy detection of the now highlighted papilla for a couple of minutes. In most cases, the investigator will even be able to see the direction of the duct (Fig 2). Methylene blue has been shown to be a very efficient dye for this situation, because the blue color gives a good contrast to the reddish shade of the floor of the mouth and to the clear, colorless appearance of the saliva. Of course, the dye can also be applied to the Stenson duct, but this orifice is much easier to detect given the larger size of the parotid duct system and the known localization of the papilla opposite the upper second molar. Methylene blue is often used as a bacteriological stain and as an indicator. It is absorbed by the epithelium and stains absorptive cells with a bluish color. It is clinically used to characterize the mucosal surface architecture. There are no medical side effects, nor does the dye colorize the Received April 7, 2008; revised May 15, 2008; accepted May 15, 2008. Figure 1 Typical situation at the caruncula area with no obvi- ous Wharton duct orifice. Otolaryngology–Head and Neck Surgery (2008) 139, 466-467 0194-5998/$34.00 © 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.05.023