METHODS: A search of MEDLINE, Scopus, Google Scholar, and Cochrane databases was done to identify articles published between January 1980 and December 2017. Pediatric series, foreign language articles, series with Zenker\'s diverticulum or following primary surgical treatment including laryngectomy, open UES/CP surgery, or samples with fewer than 5 patients were excluded.
RESULTS: An initial search identified 539 articles. All titles and abstracts were reviewed. One hundred and sixteen potentially relevant articles were inspected in more detail, and 14 retrospective studies met eligibility criteria. Dilation group included 10 studies on anterograde and/or retrograde dilation, with an overall 208 patients. Success rate ranged from 42% to 100%. The endoscopic CPM group included 3 studies with a total of 36 patients, and the success rate ranged from 27% to 90%. In the Botox group, 1 one study with 20 patients met our inclusion criteria, with an overall 65% success rate (13/20). Major complications were only reported in the dilation group, which included esophageal perforation and death.
CONCLUSIONS: The lack of consistency across trials indicates insufficient evidence for guiding clinical practice. This systematic review suggests the need for greater standardization of outcomes and instruments. Future prospective evaluation should use validated patient-rated and clinician-rated assessment tools to optimally measure postoperative swallowing outcomes of head and neck cancer dysphagic patients following organ preservation therapy.