(1) Background: The volume-viscosity swallow test (V-VST) is a clinical tool for screening and diagnosis of oropharyngeal dysphagia (OD). Our aims were to examine the clinical utility of the V-VST against videofluoroscopy (VFS) or fiberoptic endoscopic evaluation of swallow (FEES) and to map the V-VST usage with patients at risk of OD across the years since it was described for the first time, carrying a systematic and a scoping review. (2) Methods: We performed both a systematic review (SR) including studies that look at the diagnostic test accuracy, and a scoping review (ScR) with articles published from September 2008 to May 2020. Searches were done in different databases, including PubMed and EMBASE from September 2008 until May 2020, and no language restrictions were applied. A meta-analysis was done in the SR to assess the psychometric properties of the V-VST. Quality of studies was assessed by Dutch Cochrane, QUADAS, GRADE (SR), and STROBE (ScR) criteria. The SR protocol was registered on PROSPERO (registration: CRD42020136252). (3) Results: For the diagnostic accuracy SR: four studies were included. V-VST had a diagnostic sensitivity for OD of 93.17%, 81.39% specificity, and an inter-rater reliability Kappa = 0.77. Likelihood ratios (LHR) for OD were 0.08 (LHR–) and 5.01 (LHR+), and the diagnostic odds ratio for OD was 51.18. Quality of studies in SR was graded as high with low risk of bias. In the ScR: 34 studies were retrieved. They indicated that V-VST has been used internationally to assess OD’s prevalence and complications. (4) Conclusions: The V-VST has strong psychometric properties and valid endpoints for OD in different phenotypes of patients. Our results support its utility in the screening and clinical diagnosis and management of OD.

Fluid thickening is a valid therapeutic strategy for patients with oropharyngeal dysphagia (OD). The main aim of this study was to determine the therapeutic effect of the xanthan-gum-based thickener Tsururinko Quickly (TQ, Morinaga Milk Co., Tokyo, Japan) in older patients with severe OD. A total of 85 patients (83.32 ± 6.75 y) with OD and a penetration–aspiration score (PAS) of n ≥ 3 were studied by videofluoroscopy while swallowing duplicate 10 mL boluses at <50 mPa·s, 100, 200, 400, 800, and 1600 mPa·s, to assess the safety and efficacy of swallowing and the biomechanics of a swallowing response at each viscosity level. At <50 mPa·s, only 16.25% patients swallowed safely, 45% had penetrations (PAS 3–5), and 38.75% had aspirations (PAS 6–8). Fluid thickening with TQ greatly increased the prevalence of patients with safe swallowing from 62.90% at 100 mPa·s to 95.24% at 1600 mPa·s in a shear-viscosity-dependent manner. The penetrations and aspirations were significantly reduced to 3.60% and 1.19%, respectively, at 1600 mPa·s. The threshold viscosity was 100 mPa·s and the increasing viscosity above 800 mPa·s did not further improve the therapeutic effect significantly. Increasing the shear viscosity significantly reduced the time to laryngeal vestibule closure (−16.70%), increased the time to upper oesophageal sphincter opening (+26.88%), and reduced the pharyngeal bolus velocity (−31.62%) without affecting the pharyngeal residue. TQ has a strong shear-viscosity-dependent effect on the safety of swallowing in older patients with severe OD without increasing the pharyngeal residue. The therapeutic range for TQ is 100–800 mPa·s, with 200 and 800 mPa·s being the optimal doses to cover the needs of older patients with OD.