A nerve-preserving strategy for endoscopic submucosal dissection of superficial pharyngeal cancers

Endoscopic submucosal dissection (ESD) as a treatment for superficial pharyngeal cancer has been developed and widely accepted by endoscopists in Japan [1] [2]. However, a lack of anatomical knowledge can cause complications that are not experienced with gastrointestinal ESD. In the subepithelial layer of the pharyngeal region, the superior laryngeal nerve is a branch of the vagus nerve. The nerve consists of two branches, one of which is the internal laryngeal nerve that supplies sensory fibers to the laryngeal mucosa [3]. Damage to this nerve may result in postoperative dysphagia and hoarseness due to laryngeal hyposensitivity [4] [5]. As we have encountered several similar complicated cases, we have developed a strategy for preserving the internal laryngeal nerve during pharyngeal ESD. Here, we present a successful case of nerve preservation ([Video 1]).

Video 1 A nerve-preserving strategy for endoscopic submucosal dissection of superficial pharyngeal cancers.

ESD was performed under general anesthesia. Narrow-band imaging (NBI) and Lugol chromoendoscopy clearly revealed the lesion ([Fig. 1]). We performed a circumferential incision using a dual knife (KD-650Q; Olympus Medical Systems, Tokyo, Japan) from the edge of the aryepiglottic fold. We carefully made a shallow incision to avoid damaging the nerve at the tip of the piriform sinus. After exposing the nerve, we fully injected and continued to dissect the appropriate layer, using the preserved nerve as a landmark ([Fig. 2]). Finally, we applied multidirectional traction using Fraenkel laryngeal forceps (Nagashima Medical Instruments Co., Ltd., Tokyo, Japan). The lesion was removed en bloc, and the internal laryngeal nerve was completely preserved within 45 minutes without complications ([Fig. 3]). The tumor was 51 mm in size, and histological examination showed squamous cell carcinoma, negative lateral and vertical margins, and no lymphovascular invasion. No postoperative complications were observed. Distinctive anatomical knowledge and treatment strategies are essential to prevent postoperative complications when performing ESD in the pharyngeal region.

Fig. 1 Superficial pharyngeal cancer: endoscopic imaging clearly reveals the lesion. a Narrow-band imaging; b Lugol chromoendoscopy.

Fig. 2 The internal laryngeal nerve is recognizable as a white thick band in the subepithelial layer.

Fig. 3 The lesion was removed en bloc, and the internal laryngeal 2anerve was completely preserved. a Overview of the line of the nerve; b preserved visible nerve.

Endoscopy_UCTN_Code_TTT_1AO_2AG

Publication History

Article published online:
13 July 2023

• References

• 1 Iizuka T, Kikuchi D, Suzuki Y. et al. Clinical relevance of endoscopic treatment for superficial pharyngeal cancer: feasibility of techniques corresponding to each location and long-term outcomes. Gastrointest Endosc 2021; 93: 818-827
• 2 Iizuka T, Kikuchi D, Hoteya S. et al. Clinical advantage of endoscopic submucosal dissection over endoscopic mucosal resection for early mesopharyngeal and hypopharyngeal cancers. Endoscopy 2011; 43: 839-843
• 3 Kitagawa J, Shingai T, Takahashi Y. et al. The pharyngeal branch of the glossopharyngeal nerve plays a major role in reflex swallowing of the pharynx. Am J Physiol Regul Comp Physiol 2002; 282: R1342-R1347
• 4 Tateya I, Morita S, Ishikawa S. et al. Voice outcomes in patients treated with endoscopic laryngopharyngeal surgery for superficial hypopharyngeal cancer. Clin Exp Otorhinolaryngol 2016; 9: 70-74
• 5 Park YM, Kim WS, De Virgilio A. et al. Transoral robotic surgery for hypopharyngeal squamous cell carcinoma: a 3-year oncologic and functional analysis. Oral Oncol 2012; 48: 560-566