Introduction
Laryngeal papillomatosis is one of the most common benign neoplasms. The incidence of recurrent respiratory papilloma is reportedly 4.3 per 100 000 among children and 1.8 per 100 000 among adults,Reference Katada, Nakayama, Tanabe, Koizumi, Masaki and Takeda1 but it may have become more common in recent years. The onset of papilloma is spread in childhood and in adults. It is caused by the human papilloma virus (HPV), most commonly by HPV 6 and 11, although HPV 16 and 18 may rarely be encountered.Reference Watanabe, Tsujie, Taniguchi, Hosokawa, Fujita and Sasaki2 Multiple lesions may be observed in the vocal fold, supraglottis and occasionally in the subglottis. Papilloma presents with hoarseness and dyspnoea in rare cases.
The current treatment for laryngeal papillomatosis is surgery, which aims at debulking or evaporation of the tumor using a microdebridder and laser ablation. Peri-operatively, it is difficult to locate all the superficial papillomatous lesions when the disease is widespread. Therefore, recurrent lesions are often observed after treatment.
Narrow band imaging can be used for observing the superficial layer of the mucosa and can enhance abnormal angiogenesis using 390–445 and 530–550 nm wavelength bands. Narrow band imaging has recently been used for detecting early squamous cell carcinomas of the head and neck.Reference Nguyen, Bashizadeh, Hodge, Agnew, Farah and Clarke3 We have constructed a narrow band imaging-assisted video-laryngomicrosurgery system and used narrow band imaging during video-laryngomicrosurgery for laryngeal papillomatosis in some cases.
Case report
We have used narrow band imaging image at laryngomicrosurgery for the laryngeal papillomatous region more clearly. The system consisted of a video-laryngoscope (Karl Stortz, Model IV Germany) with a high-definition charge-coupled device camera (Olympus, Visera Pro Japan) mounted on the head to provide narrow band imaging (Figure 1). The camera is usually used for laparoscopic operations.
Fig. 1 View during the operation. (a) Far view. When the CO2 laser is used, it is attached to the operation microscope. When the tumor is treated under narrow band imaging, the microscope light must be turned off. (b) Close-up view. The high-definition camera is mounted at the head of the endoscope.
Case 1
A 40-year-old man with recurrent laryngeal papillomatosis underwent laryngomicrosurgery during which the tumor was treated by CO2 laser evaporation and microdebridder debulking. However, the tumor subsequently regrew twice after intervals of 4–6 months. Adjunctive medication, including cidofovir, was not administrated. The third regrowth was observed in the right vocal fold. We treated the tumor by laryngomicrosurgery using a CO2 laser. The affected area was limited, but we used narrow band imaging-assisted video-laryngomicrosurgery to facilitate a more detailed observation. Under xenon light, a tumorous lesion was noted in the right vocal fold (Figure 2). The narrow band imaging showed the papillomatous lesion more clearly, enhancing the visibility of the capillaries (Figure 3).
Fig. 2 Case 1: Image during the operation under white light showing the papillomatous lesion (arrows) in the right vocal fold.
Fig. 3 Case 1: Narrow band imaging showing enhancement of the papillomatous lesion (arrows).
We performed the surgery under narrow band imaging using a microdebridder and CO2 vaporisation. No recurrence of the tumor was observed for 12 months after the operation.
Case 2
A 53-year-old man with fifth recurrent laryngeal papillomatosis underwent laryngomicrosurgery. The tumor was found at the anterior commissure (Figure 4). The region is detected post-operation by narrow band imaging suggested with endoscopic findings. We used narrow band imaging-assisted video laryngomicrosurgery and could observe more details (Figure 5). We used CO2 laser for evaporating the tumor and injected cidofovir.
Fig. 4 Case 2: Image during the operation under white light. The papillomatous lesion (arrows) at the anterior commissure.
Fig. 5 Case 2: Narrow band imaging showing enhancement of the papillomatous lesion (arrows).
Discussion
Narrow band imaging is an optical enhancement technique used for diagnosing malignant lesions – mainly of the mucosa. Since narrow band light is absorbed by hemoglobin, narrow band imaging enhances the microvascular structure and can assist in the identification of malignant lesions. The wavelength bands used in narrow band imaging are 390–445 and 530–550 nm. The former shows the capillaries of the superficial mucosa, whereas the latter reveals submucosal capillaries. Narrow band imaging has recently been applied to the head and neck area,Reference Katada, Nakayama, Tanabe, Koizumi, Masaki and Takeda1 and was used for detecting cancerous lesions.Reference Watanabe, Tsujie, Taniguchi, Hosokawa, Fujita and Sasaki2 The sensitivity of narrow band imaging was found to be superior to that of white light imaging.Reference Nguyen, Bashizadeh, Hodge, Agnew, Farah and Clarke3 Narrow band imaging supported by flexible fiberscopy was recently used during a laryngomicrosurgery procedure.Reference Imaizumi, Okano, Tada and Omori4 It is a very simple method, but has some drawbacks: the inserted fiberscope is cumbersome, and it is not easy to observe and treat the papillomatous lesion simultaneously.
Laryngeal papilloma has characteristic findings, with red spots indicating neovascularisation. The current therapy involves debulking the tumour using laser evaporation and a microdebridder.Reference Goon, Sonnex, Jani, Stanley and Sudhoff5 Adjunctive therapy can include the administration of drugs such as cidofovir or indole-3-carbinol.Reference Goon, Sonnex, Jani, Stanley and Sudhoff5 Since laryngeal papilloma may have extensive lesions, it can be very difficult to detect all the affected areas at the time of operation. Pathological lesions are often overlooked, which may lead to tumor recurrence.
For treating the papillomatous region, it is very important to inspect the area precisely and vaporise all lesions. If we evaporate the mucosa blindly, then it gets scarred broadly, and the voice function may get worse. There are limitations in detecting papillomatous lesions by white light only, but narrow band imaging can enhance the pathological lesions of papilloma, so that they can be observed more clearly. Using the currently described method, lesions can be observed and treated simultaneously, since the optical source of the narrow band imaging is the video-laryngoscope.
The system is not made for laryngomicrosurgery, and so has some deficits. The focal length is limited, and sometimes the illumination of narrow band imaging is insufficient. As the angle of the endoscope is limited, the visualised area is limited to the anterior side and it is difficult to observe the posterior area. From these points the system is imperfect at the moment. This system is preliminary and a more perfect system will be constructed in the future. The same system could be used for checking tumor recurrence post-operatively, and we recognised the usability of this system. Thus, we believe that the narrow band imaging-assisted video-laryngomicrosurgery system is an innovative method, which could potentially be used for the routine treatment of laryngeal papilloma.
• This is a new trial for visualising papillomatous regions more clearly during operation
• We report two cases of laryngeal papilloma and use of the narrow band imaging-assisted video-laryngomicrosurgery system
• The system can aid visualisation of papillomatous regions more clearly, but with some deficits
Sources of funding
None.
