Introduction
Endoscopic submucosal dissection (ESD) for superficial pharyngeal cancer has been developed and accepted among endoscopists in Japan. Compared with surgical resection, this procedure is less invasive, but it is considered relatively difficult because of the poor maneuverability of the endoscope as a result of a narrow working space. And 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. Damage to this nerve may result in postoperative dysphagia and hoarseness due to laryngeal hyposensitivity.
Aims & Methods
The present study aimed to investigate the method and significance of preserving the superior laryngeal nerve during ESD for superficial pharyngeal cancers.
We retrospectively analyzed 65 consecutive superficial pharyngeal cancers of 50 patients who were treated with ESD between February 2015 and February 2023. Of these, the clinicopathological characteristics and treatment outcomes of lesions in which the superior laryngeal nerve could be recognized during ESD were analyzed.
Results
The nerves were recognized in 32 lesions, of which 7 lesions (22%) were in the nerve damaged group. Univariate analysis revealed that there were no significant differences in the mean age, sex ratio, median tumor size, mean resection time, en bloc resection rate, or R0 resection rate in two groups. However, we had two complicated cases on the nerve damaged group, included severe subcutaneous emphysema and prolonged dysphagia. Therefore, we have developed a strategy for preserving the internal laryngeal nerve during pharyngeal ESD. 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 adequate layer while using the preserved nerve as a landmark.
Conclusion
We need to minimize excessive resection and contributed to reduce unnecessary damage to the deeper structures such as nerves and muscles. Distinctive anatomical knowledge and treatment strategies are essential to prevent postoperative complications.
References
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