{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T03:47:51Z","timestamp":1773373671409,"version":"3.50.1"},"reference-count":27,"publisher":"Public Library of Science (PLoS)","issue":"3","license":[{"start":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T00:00:00Z","timestamp":1773273600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    Esophagectomy is a highly invasive and curative procedure for esophageal cancer. Although minimally invasive techniques reduce the incidence of pulmonary complications, postoperative dysphagia remains a common and clinically significant issue. Preoperative expiratory muscle training (EMT) may improve swallowing function by strengthening the relevant muscles; however, its effectiveness in patients with esophageal cancer has not been widely studied. This phase II randomized, controlled, double-blind trial has been designed to evaluate the effects of preoperative EMT on postoperative swallowing function in patients undergoing esophagectomy for thoracic esophageal squamous cell carcinoma. Forty patients will be randomly assigned (1:1) to either the EMT or sham-EMT group. EMT will be performed using the EX-1 Medic\n                    <jats:sup>\u00ae<\/jats:sup>\n                    device at 50\u201370% maximal expiratory pressure, whereas the control group will receive minimal resistance (10 cmH\u2082O). The primary outcome is the Penetration-Aspiration Scale score on the postoperative video-fluoroscopic swallowing study, targeted at postoperative days 10 (allowable window: postoperative days 6\u201314). The secondary outcomes will be assessed perioperatively (preoperative and\/or postoperative, depending on the measure) and include tongue pressure, the Repetitive Saliva Swallowing Test, T he eating assessment test-10, respiratory muscle strength, appendicular skeletal muscle index, and exercise tolerance. This study has been registered at University Hospital Medical Information Network (UMINID:000057795). Recruitment began on June 10, 2025, is expected to continue until September 30, 2028. This trial will clarify whether preoperative EMT can improve swallowing function and reduce postoperative dysphagia in patients with esophageal cancer, potentially establishing a novel prehabilitation strategy in surgical care.\n                    <jats:bold>Trial registration<\/jats:bold>\n                    : UMIN Clinical Trials Registry (UMIN-CTR), UMIN000057795. Registered on May 8, 2025.\n                    <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/center6.umin.ac.jp\/cgi-open-bin\/ctr\/ctr_view.cgi?recptno=R000065994\" xlink:type=\"simple\">https:\/\/center6.umin.ac.jp\/cgi-open-bin\/ctr\/ctr_view.cgi?recptno=R000065994<\/jats:ext-link>\n                    .\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0344456","type":"journal-article","created":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T17:39:11Z","timestamp":1773337151000},"page":"e0344456","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Preoperative expiratory muscle training for swallowing function in patients with esophageal cancer undergoing esophagectomy: A randomized controlled phase II trial protocol"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8324-4294","authenticated-orcid":true,"given":"Hiroki","family":"Mizusawa","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-6652-9912","authenticated-orcid":true,"given":"Masaya","family":"Noguchi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tomomi","family":"Tamura","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masashi","family":"Shiraishi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kengo","family":"Kanki","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Osamu","family":"Shiraishi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoko","family":"Hiraki","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hiroaki","family":"Kato","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9210-9083","authenticated-orcid":true,"given":"Yuji","family":"Higashimoto","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takushi","family":"Yasuda","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2026,3,12]]},"reference":[{"key":"pone.0344456.ref001","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1016\/S0140-6736(12)60643-6","article-title":"Oesophageal carcinoma","author":"A Pennathur","year":"2013","journal-title":"Lancet"},{"issue":"10159","key":"pone.0344456.ref002","doi-asserted-by":"crossref","first-page":"1736","DOI":"10.1016\/S0140-6736(18)32203-7","article-title":"Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017","volume":"392","author":"Collaborators G B D Co D","year":"2018","journal-title":"Lancet"},{"key":"pone.0344456.ref003","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5761\/atcs.ra.16-00162","article-title":"Current Status and Future Prospects for Esophageal Cancer Treatment","author":"M Sohda","year":"2017","journal-title":"Ann Thorac Cardiovasc Surg"},{"key":"pone.0344456.ref004","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1016\/j.eururo.2012.12.010","article-title":"Words of Wisdom: re: trends in hospital volume and operative mortality for high-risk surgery","author":"M Maffezzini","year":"2013","journal-title":"Eur Urol"},{"key":"pone.0344456.ref005","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1001\/jamasurg.2020.7081","article-title":"Five-Year Survival Outcomes of Hybrid Minimally Invasive Esophagectomy in Esophageal Cancer: Results of the MIRO Randomized Clinical Trial","author":"F Nuytens","year":"2021","journal-title":"JAMA Surg"},{"key":"pone.0344456.ref006","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1002\/ags3.12566","article-title":"Risk factors and long-term postoperative outcomes in patients with postoperative dysphagia after esophagectomy for esophageal cancer","author":"T Sugase","year":"2022","journal-title":"Ann Gastroenterol Surg"},{"key":"pone.0344456.ref007","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.1002\/ags3.12839","article-title":"Preoperative geniohyoid muscle mass in esophageal cancer patients is associated with swallowing function after esophagectomy","author":"S Kawata","year":"2024","journal-title":"Ann Gastroenterol Surg"},{"key":"pone.0344456.ref008","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1007\/s00455-022-10541-2","article-title":"Perioperative Decrease in Tongue Pressure is an Intervenable Predictor of Aspiration After Esophagectomy","author":"K Kojima","year":"2023","journal-title":"Dysphagia"},{"key":"pone.0344456.ref009","article-title":"Swallowing safety after remote sub-total esophagectomy: how important is tongue pressure?","author":"J Vergara","year":"2024","journal-title":"Dysphagia"},{"key":"pone.0344456.ref010","doi-asserted-by":"crossref","first-page":"1179","DOI":"10.1016\/j.apmr.2021.10.020","article-title":"Respiratory Muscle Training Reduces Respiratory Complications and Improves Swallowing Function After Stroke: A Systematic Review and Meta-Analysis","author":"W Zhang","year":"2022","journal-title":"Arch Phys Med Rehabil"},{"issue":"4","key":"pone.0344456.ref011","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1002\/lary.26397","article-title":"Expiratory muscle strength training evaluated with simultaneous high-resolution manometry and electromyography","volume":"127","author":"KA Hutcheson","year":"2017","journal-title":"Laryngoscope"},{"key":"pone.0344456.ref012","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1111\/ger.12234","article-title":"Effect of expiratory muscle strength training on swallowing-related muscle strength in community-dwelling elderly individuals: a randomized controlled trial","author":"J-S Park","year":"2017","journal-title":"Gerodontology"},{"issue":"2","key":"pone.0344456.ref013","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1007\/s00455-006-9061-4","article-title":"Surface electromyographic activity of the submental muscles during swallow and expiratory pressure threshold training tasks","volume":"22","author":"KM Wheeler","year":"2007","journal-title":"Dysphagia"},{"key":"pone.0344456.ref014","doi-asserted-by":"crossref","first-page":"592","DOI":"10.1007\/s00455-019-10010-3","article-title":"An Investigation of Factors Related to Food Intake Ability and Swallowing Difficulty After Surgery for Thoracic Esophageal Cancer","author":"T Mafune","year":"2019","journal-title":"Dysphagia"},{"key":"pone.0344456.ref015","article-title":"Association of preoperative sarcopenia with postoperative dysphagia in patients with thoracic esophageal cancer","author":"S Mayanagi","year":"2021","journal-title":"Dis Esophagus"},{"issue":"3","key":"pone.0344456.ref016","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1007\/s00455-023-10618-6","article-title":"Longitudinal Analysis of Dysphagia and Factors Related to Postoperative Pneumonia in Patients Undergoing Esophagectomy for Esophageal Cancer","volume":"39","author":"A Kaneoka","year":"2024","journal-title":"Dysphagia"},{"key":"pone.0344456.ref017","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1007\/BF00417897","article-title":"A penetration-aspiration scale","author":"JC Rosenbek","year":"1996","journal-title":"Dysphagia"},{"key":"pone.0344456.ref018","unstructured":"Takahashi M, Koide K, Suzuki H, Satoh Y, Iwasaki S-I. Evaluation of reliability of perioral muscle pressure measurements using a newly developed device with a lip piece. Acta Bioeng Biomech. 2016;18(1):145\u201353. 27151102"},{"key":"pone.0344456.ref019","article-title":"Repetitive saliva swallowing test: Performance in aspiration prediction","author":"Y-C Chen","year":"2025","journal-title":"J Formos Med Assoc"},{"key":"pone.0344456.ref020","doi-asserted-by":"crossref","first-page":"919","DOI":"10.1177\/000348940811701210","article-title":"Validity and reliability of the Eating Assessment Tool (EAT-10)","author":"PC Belafsky","year":"2008","journal-title":"Ann Otol Rhinol Laryngol"},{"key":"pone.0344456.ref021","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1177\/0003489414558107","article-title":"The Ability of the 10-Item Eating Assessment Tool (EAT-10) to Predict Aspiration Risk in Persons With Dysphagia","author":"DM Cheney","year":"2015","journal-title":"Ann Otol Rhinol Laryngol"},{"key":"pone.0344456.ref022","doi-asserted-by":"crossref","first-page":"1801214","DOI":"10.1183\/13993003.01214-2018","article-title":"ERS statement on respiratory muscle testing at rest and during exercise","author":"P Laveneziana","year":"2019","journal-title":"Eur Respir J"},{"issue":"6","key":"pone.0344456.ref023","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1016\/j.resinv.2022.07.003","article-title":"Comparison of international and Japanese predictive equations for maximal respiratory mouth pressures","volume":"60","author":"R Hamada","year":"2022","journal-title":"Respir Investig"},{"issue":"8","key":"pone.0344456.ref024","doi-asserted-by":"crossref","first-page":"682","DOI":"10.2340\/16501977-2253","article-title":"Prevalence of sarcopenia and its association with dysphagia in cancer patients who require rehabilitation","volume":"49","author":"H Wakabayashi","year":"2017","journal-title":"J Rehabil Med"},{"key":"pone.0344456.ref025","article-title":"Sarcopenia and dysphagia: Position paper by four professional organizations","year":"2019","journal-title":"Geriatr Gerontol Int"},{"issue":"2","key":"pone.0344456.ref026","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1164\/rccm.167.2.211","article-title":"ATS\/ACCP Statement on cardiopulmonary exercise testing","volume":"167","author":"Society American Thoracic","year":"2003","journal-title":"Am J Respir Crit Care Med"},{"issue":"1","key":"pone.0344456.ref027","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.jacasi.2021.10.011","article-title":"Impact of Frailty on Postoperative Dysphagia in Patients Undergoing Elective Cardiovascular Surgery","volume":"2","author":"M Ogawa","year":"2022","journal-title":"JACC Asia"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0344456","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T17:39:17Z","timestamp":1773337157000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0344456"}},"subtitle":[],"editor":[{"given":"Tsutomu","family":"Kumamoto","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2026,3,12]]},"references-count":27,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,3,12]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0344456","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,12]]}}}