Endoscopic submucosal dissection in the pharynx: Let's start at the very beginning!
2021; Elsevier BV; Volume: 93; Issue: 4 Linguagem: Inglês
10.1016/j.gie.2020.09.010
ISSN1097-6779
Autores Tópico(s)Metastasis and carcinoma case studies
ResumoWhen asked why he wanted to climb Mt. Everest, mountaineer George Mallory was famously quoted as simply replying “because it’s there.” To him, the desire to climb was instinctive—a reflection, he said, of man’s desire to conquer the universe.1Climbing Mount Everest is work for supermen. The New York Times March 18, 1923.Google Scholar Although Mallory tragically perished in 1924 while attempting to climb the mountain, he inspired a generation of climbers, including Edmund Hillary and his partner, Tenzing Norgay, who finally achieved the impossible on May 29, 1953, by being the first to ascend the summit of Everest. Much as Mallory possessed an innate drive to challenge the world’s highest mountains, it seems that gastroenterologists today are also driven to push the limits of endoscopy to higher elevations. This is demonstrated both figuratively and technically in this issue of Gastrointestinal Endoscopy, where Iizuka et al2Iizuka 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: 818-827Abstract Full Text Full Text PDF Scopus (3) Google Scholar describe their experience using endoscopic submucosal dissection (ESD) techniques to treat patients with superficial pharyngeal cancer. These investigators present a systematic protocol for performing ESD in the pharynx by categorizing lesions into 4 defined pharyngeal regions and by outlining specific resection techniques for each area. In an impressively large retrospective cohort of 294 patients with superficial pharyngeal squamous cell carcinoma, patients were classified on the basis of the specific location of their pharyngeal lesions. The authors describe their approach to lesions in areas that gastroenterologists typically “drive by” during endoscopy and may therefore be unfamiliar with, such as the piriform sinus, aryepiglottic fold, posterior hypopharyngeal wall, lateral and posterior oropharyngeal wall, and posterior cricoid region, and also areas that may be accessible to, but not commonly evaluated during standard upper endoscopy, such as the supraglottic region, epiglottis, root of the tongue, soft palate, and uvula. They demonstrate overall 99.4% en bloc resection rate, 82.6% R0 resection, and 5-year survival rate of 84.1% with pharyngeal ESD, with only 4 adverse events (1.3%) reported across the entire cohort: 2 cases of subcutaneous emphysema, which is often not considered an adverse event in third-space endoscopy, and 2 patients with bleeding successfully treated with endoscopic hemostasis.2Iizuka 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: 818-827Abstract Full Text Full Text PDF Scopus (3) Google Scholar A first reaction after reviewing this article is that this is just another novel application of ESD, but the reader is soon left pondering a deeper question: is the oral cavity and pharynx an area that gastroenterologists should pay attention to? By definition, the GI tract begins at the mouth and extends to the anus; therefore, all regions in between theoretically fall within the jurisdiction of the gastroenterologist. Along these lines, gastroenterologists have already started performing interventions in the hypopharynx and anorectum. Procedures such as endoscopic myotomy for Zenker’s diverticulum; hemorrhoid treatment; endoscopic therapy of anorectal strictures, fistulas, and abscesses; and per-rectal endoscopic myotomy to treat Hirschprung’s disease, often included in the surgical realm, are now gradually becoming part of the gastroenterologist’s bag of tools.3Mittal C, Diehl D, Draganov P, et al. Practice patterns, techniques, and outcomes of flexible endoscopic myotomy for Zenker's diverticulum: A retrospective, multi-center study. Endoscopy. Epub 2020 Jul 14.Google Scholar, 4Shen B. Endoscopic management of inflammatory bowel disease-associated complications.Curr Opin Gastroenterol. 2020; 36: 33-40Crossref Scopus (1) Google Scholar, 5Bapaye A. Wagholikar G. Jog S. et al.Per rectal endoscopic myotomy for the treatment of adult Hirschsprung's disease: first human case (with video).Dig Endosc. 2016; 28: 680-684Crossref Scopus (16) Google Scholar These bold and innovative procedures indicate that gastroenterologists are not afraid to step into uncharted waters and will readily perform endoscopy in regions usually not considered “gastrointestinal.” Hence, it should come as no surprise that endoscopists are now interested in treating pharyngeal cancers. The advent of narrow-band imaging has allowed gastroenterologists to detect synchronous early-stage pharyngeal cancer in patients with esophageal cancer (up to 10% of patients according to a 2010 study by Nonaka et al6Nonaka S. Saito Y. Oda I. et al.Narrow-band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma.J Gastroenterol Hepatol. 2010; 25: 264-269Crossref PubMed Scopus (39) Google Scholar), and there has been an increasing impetus for gastroenterologists to take a more active role in the detection and management of these malignancies. Several surgical techniques have been developed to treat superficial pharyngeal cancer, including transoral laser microsurgery, endoscopic laryngopharyngeal surgery, and transoral robotic surgery. Recently, traditional endoscopic techniques of EMR and ESD have been adapted from use in the rest of the GI tract and applied to the pharynx with good success.7Shimizu Y. Yamamoto J. Kato M. et al.Endoscopic submucosal dissection for treatment of early stage hypopharyngeal carcinoma.Gastrointest Endosc. 2006; 64: 255-259Abstract Full Text Full Text PDF PubMed Scopus (77) Google Scholar,8Iizuka T. Kikuchi D. Hoteya S. et al.Endoscopic submucosal dissection for treatment of mesopharyngeal and hypopharyngeal carcinomas.Endoscopy. 2009; 41: 113-117Crossref PubMed Scopus (54) Google Scholar A rigid laryngoscope is often used for these procedures to provide a working space in the pharyngeal lumen. Endoscopic laryngopharyngeal surgery differs from ESD in that the resection portion of the procedure, instead of being carried out endoscopically, is performed by a head and neck surgeon while the assistant provides endoscopic visualization of the working field. ESD overcomes this limitation by using the endoscope to provide a platform for both visualization and simultaneous resection and does not require additional specialized equipment or an initial capital investment, as does transoral robotic surgery.9Hanaoka N. Ishihara R. Takeuchi Y. et al.Endoscopic submucosal dissection as minimally invasive treatment for superficial pharyngeal cancer: a phase II study (with video).Gastrointest Endosc. 2015; 82: 1002-1008Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar The authors should be lauded for disseminating knowledge about these techniques, which are not seen as commonly in the Western world as in the East. Their inclusion of a broad range of pharyngeal lesions, large cohort of cases, and systematic resection techniques based on anatomic location sets them apart from previous studies that have been performed in this area. However, the main concern with this study is that it does not compare ESD outcomes with those of existing surgical techniques; hence, the proposed advantages of ESD in the pharynx remain unproven. Also, these results may be difficult to interpret by gastroenterologists without benchmark goals for head and neck cancers, especially because this was a retrospective study that did not control for follow-up treatments including chemotherapy and radiation. The authors acknowledge that their outcomes vary from existing surgical literature, where both advanced and superficial tumors are often pooled together. So should gastroenterologists intervene in this part of the GI tract, which to most readers will undoubtedly be anatomically unfamiliar and technically foreign? Clearly, moving ESD into the pharynx presents a multitude of challenges. Gastroenterologists would need to acquaint themselves with thus far unknown anatomy and to avoid distinct procedural adverse events, such as damage to the delicate muscles and nerves of the pharynx and larynx (eg, branch of the superior laryngeal nerve encountered as a yellowish white bundle during dissection [personal communication from authors]). In addition, it should be noted that ESD in the pharynx entails multiple specific considerations that gastroenterologists should be prepared for, including (1) use of surgical instruments such as laryngoscope with curved blade, laryngeal forceps for traction, and palate retractor for some locations, (2) specialized airway management such as tracheostomy and transnasal intubation to allow visualization and interventions in locations that would otherwise be obscured and limited by orotracheal intubation, (3) resection performed under direct observation without an endoscope for oropharyngeal lesions readily accessed orally, (4) limitation of submucosal injection to minimize laryngeal edema, and (5) keeping patients intubated overnight in cases of suspected laryngeal edema. Another burgeoning question is this: what type of training would be needed for performing pharyngeal ESD? Accounting for the fact that otolaryngologists have been independently performing these procedures for years, it is likely that such endeavors will be embarked upon by surgeons exceptionally facile with the flexible endoscope, or by “maximally invasive” medical interventional endoscopists with a penchant for that adrenaline rush. These endoscopists, highly skilled in ESD, can push the field further and provide much-needed outcomes data. Regardless, these questions in no way detract from the impressive work performed by the authors, and certainly one has to start somewhere. If past endoscopists had spent too much effort bemoaning why something should not be feasible, then the field might have never seen techniques such as endoscopic suturing, endoscopic full-thickness resection (EFTR), and peroral endoscopic myotomy (POEM) arising from efforts at natural orifice translumenal endoscopic surgery (NOTES). Nor might gastroenterologists have developed subsequent POEM spinoffs such as endoscopic myotomy for Zenker’s diverticulum (Z-POEM), endoscopic pyloromyotomy G-POEM or POP), and submucosal tunneling endoscopic resection (STER), which are continuing to gain traction today. But in the effort to explore novel areas and invent new techniques, one cannot forget that patients come first. ESD may yet have a role in the treatment of pharyngeal cancers; however, future studies critically evaluating the efficacy and safety of these interventions in comparison with current standards of care must be carried out to assess their utility in GI practice. Although at this time it remains difficult to augur the future of pharyngeal ESD and the innovations that may arise from it, one can nonetheless appreciate the dedication of these investigators for truly aiming “higher” and for the collaborative efforts between two specialties working together to push the boundaries of what is feasible in the field of third-space endoscopy. To put it in the words of Edmund Hillary: “Nobody climbs mountains for scientific reasons. Science is used to raise money for the expeditions, but you really climb for the hell of it.” Dr Wagh is a consultant for Boston Scientific, Olympus, and Medtronic. The other author disclosed no financial relationships. Clinical relevance of endoscopic treatment for superficial pharyngeal cancer: feasibility of techniques corresponding to each location and long-term outcomesGastrointestinal EndoscopyVol. 93Issue 4PreviewSuperficial pharyngeal cancers are being detected and treated using endoscopy in many medical facilities with increasing frequency. However, the reports focus on the hypopharynx. We identified reliable treatments by adapting the method for each region of the pharynx. Here, we introduce our methods for treating various pharyngeal regions and show their long-term results. Full-Text PDF
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