The Use of Pharyngeal High-Resolution (Impedance) Manometry in Patients With Head and Neck Cancer: A Scoping Review

Purpose: This scoping review aims to summarize and explore current literature on the usefulness and clinical implications of pharyngeal high-resolution (impedance) manometry (HRM/HRIM) in head and neck cancer (HNC) patients. Method: Three online databases (MEDLINE, Embase, Scopus, and additionally Google Scholar) were searched until December 2023. Studies using pharyngeal HRM/HRIM to assess swallowing or voicing in HNC patients, written in any language and published in peer-reviewed journals, were considered eligible. Quality check was performed using the Quality Assessment Tool for Quantitative Studies from the Effective Public Healthcare Practice Project. Information about the study population and HRM/HRIM data (equipment, protocol, analysis, and outcomes) were extracted. Results: Eight papers met the inclusion criteria, six utilizing HRM and two HRIM. The study design consisted of case-series (five) and case-control (three). The quality assessment indicated a weak global rating for seven papers and a moderate rating for one for the remaining study. Findings suggest that HNC patients with dysphagia suffer from reduced pressures in the pharynx and upper esophageal sphincter compared to healthy individuals, potentially influenced by tumor characteristics and treatment. Decreased pressures may indicate poor functioning of swallowing musculature and mechanism. Conclusions: Pharyngeal HRM/HRIM is sparsely used for swallowing assessment in HNC patients. However, wider use seems warranted, as it can offer valuable insights into swallowing biomechanics. This can help quantifying the degree and timing of pressures involved in swallowing (problems) and holds potential for clinical applications, such as earlier diagnosis of radiation-induced therapy or surgery complications. Additionally, it can be beneficial in evaluating therapeutic swallowing strategies.