Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Sep 26, 2020; 12(9): 1001-1012
Published online Sep 26, 2020. doi: 10.4252/wjsc.v12.i9.1001
Stem cell treatments for oropharyngeal dysphagia: Rationale, benefits, and challenges
Eric K Tran, Kevin O Juarez, Jennifer L Long
Eric K Tran, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA 90095, United States
Kevin O Juarez, Department of Otolaryngology, Yale School of Medicine, New Haven, CT 06511, United States
Jennifer L Long, Department of Head and Neck Surgery, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA 90095, United States
Jennifer L Long, Greater Los Angeles VA Healthcare System, Los Angeles, CA 90073, United States
Author contributions: All authors contributed to literature review, drafting, and revising manuscript.
Conflict-of-interest statement: No potential conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Jennifer L Long, MD, PhD, Associate Professor, Department of Head and Neck Surgery, David Geffen School of Medicine, University of California-Los Angeles, 650 Charles Young Dr, CHS Room 62-150, Los Angeles, CA 90095, United States.
Received: February 28, 2020
Peer-review started: February 28, 2020
First decision: July 5, 2020
Revised: July 28, 2020
Accepted: September 1, 2020
Article in press: September 1, 2020
Published online: September 26, 2020

Dysphagia, defined as difficulty swallowing, is a common symptom negatively impacting millions of adults annually. Estimated prevalence ranges from 14 to 33 percent in those over age 65 to over 70 percent in a nursing home setting. The elderly, those with neurodegenerative diseases, head and neck cancer patients, and those with autoimmune conditions such as Sjögren's syndrome are disproportionately affected. Oropharyngeal dysphagia refers specifically to difficulty in initiating a swallow due to dysfunction at or above the upper esophageal sphincter, and represents a large proportion of dysphagia cases. Current treatments are limited and are often ineffective. Stem cell therapy is a new and novel advancement that may fill a much-needed role in our treatment regimen. Here, we review the current literature regarding stem cell treatments for oropharyngeal dysphagia. Topics discussed include tissue regeneration advancements as a whole and translation of these principles into research surrounding tongue dysfunction, xerostomia, cricopharyngeal dysfunction, and finally an overview of the challenges and future directions for investigation. Although this field of study remains in its early stages, initial promising results show potential for the use of stem cell-based therapies to treat oropharyngeal dysphagia and warrant further research.

Keywords: Dysphagia, Xerostomia, Hemiglossectomy, Stem cells, Myoblasts, Mesenchymal stem cells

Core Tip: Oropharyngeal dysphagia, despite its widespread prevalence, is a difficult condition to treat, particularly in those who have undergone irradiation or resection in the head and neck. This challenge stems from the lack of native functional tissue upon which current therapies such as physical rehabilitation rely. There have been several studies examining the use of stem cell therapy as a potential new treatment option for these patients. Our objective is to review and consolidate the current literature regarding this topic and discuss the recent advancements, challenges, and future directions for research in this field.