Oropharyngeal dysphagia is usually either a primary abnormality related to structural aberrations of the oropharynx or a secondary manifestation of neuromuscular disease. Causes for dysfunctional swallowing are protean. Both diagnosis and therapy of oropharyngeal dysphagia are based on functional assessment. Following the performance of a clinical examination, instrumental work-up includes evaluating specific aspects of swallowing function, judging the consequences of the swallowing dysfunction, and assessing factors that may be contributing to swallowing dysfunction.

Videofluoroscopy has long been viewed as the "gold standard" for evaluation of a swallowing disorder for the comprehensive information it provides. However, it is not very efficient and accessible in certain clinical and practical situations. Fiberoptic endoscopic evaluation of swallowing (FEES) has been shown to be safe and effective for assisting in swallowing evaluation, and in therapy as a visual display to help patients learn various swallowing maneuvers.

In FEES, a flexible fiberoptic endoscope is introduced transnasally to the patient's hypopharynx where the clinician can clearly view laryngeal and pharyngeal structures. The patient is then led through various tasks to evaluate the sensory and motor status of the pharyngeal and laryngeal mechanism. Food and liquid boluses are then given to the patient so that the integrity of the pharyngeal swallow can be determined. Information obtained from this examination includes ability to protect the airway, the ability to sustain airway protection for a period of several seconds, the ability to initiate a prompt swallow without spillage of material into the hypopharynx, timing and direction of movement of the bolus through the hypopharynx, ability to clear the bolus during the swallow, presence of pooling and residue of material in the hypopharynx, timing of bolus flow and airway protection, sensitivity of the pharyngeal/laryngeal structures and the effect of anatomy on the swallow.

Appropriate postural changes and swallowing maneuvers are attempted to detect problems and enable the examiner to make recommendations regarding optimal interventions to improve the safety and efficiency of the swallow, the advisability of oral feeding, and use of appropriate behavioral strategies that facilitate safe and efficient swallowing. The most critical finding is aspiration, and the literature demonstrates that FEES is able to detect this finding with good sensitivity.

Giraldo-Cadavid and associates (2017) performed a systematic review and meta-analysis of the literature to compare the accuracy with which FEES and VFSS assessed oropharyngeal dysphagia in adults. Data sources included PubMed, Embase, and the Latin American and Caribbean Health Sciences Literature (LILACS) database. A review of published studies was conducted in parallel by 2 groups of researchers. They evaluated the methodological quality, homogeneity, threshold effect, and publication bias. The results are presented as originally published, then with each test compared against the other as a reference and both compared against a composite reference standard, and then pooled using a random effects model. Software use consisted of Meta-DiSc and SPSS. The search yielded 5,697 articles; 52 of them were reviewed in full text, and 6 articles were included in the meta-analysis. FEES showed greater sensitivity than VFSS for aspiration (0.88 versus 0.77; p = 0.03), penetration (0.97 versus 0.83; p = 0.0002), and laryngopharyngeal residues (0.97 versus 0.80; p < 0.0001). Sensitivity to detect pharyngeal premature spillage was similar for both tests (VFSS: 0.80; FEES: 0.69; p = 0.28). The specificities of both tests were similar (range of 0.93 to 0.98). In the sensitivity analysis there were statistically significant differences between the tests regarding residues but only marginally significant differences regarding aspiration and penetration. The authors concluded that FEES had a slight advantage over VFSS to detect aspiration, penetration, and residues. Moreover, they stated that prospective studies comparing both tests against an appropriate reference standard are needed to define which test has greater accuracy.

In a systematic review, Audag and associates (2019) summarized the different dysphagia screening and evaluation tools, and identified their measurement properties in adults with neuromuscular diseases (NMDs). These researchers conducted a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search strategy was conducted across 3 databases (PubMed, CINAHL and ScienceDirect). Measurement properties of each tools and the Quality Index, developed by Downs and Black, were considered for the different investigated studies. The search strategy produced 2,221 articles. After removal of duplicates and full-text analysis, 19 studies were included. Most of the publications focused on amyotrophic lateral sclerosis (ALS; n = 10) and DMD (n = 4). A total of 12 tools, listed as instrumental and non-instrumental examinations, were retrieved. A total of 5 of them used VFSS. Measurement properties of the tools were not completely described in detail in many studies. The neuromuscular disease swallowing status scale, a non-instrumental tool, was the only one that assessed all measurement properties in ALS patients. The median score reported for the Quality Index was 16. The authors concluded that this systematic review identified 12 different tools for the screening and evaluation of dysphagia in adults with NMD; the majority of the studies presented VFSS as a valid and reliable examination to assess dysphagia in ALS and DMD. Other tools were mainly evaluated in ALS patients, but further studies are needed to complete their measurement properties. In other NMDs, no firm conclusion can be made because of insufficient data and heterogeneity of NMDs. The main drawback of this systematic review was the quality level of the included studies. Indeed, most of them were rated as “fair” and these researchers had noted the absence of randomized controlled trials (RCTs).

Fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST) is an alternative to modified barium swallow evaluation of patients at risk for aspiration. The procedure entails the passage of a specially equipped flexible endoscope into the oropharynx. The special equipment includes a sensory stimulator that allows quantification of stimuli, a television monitor, a video printer, and a videocassette recorder. Sensory evaluation is performed by administering pulses of air at sequentially increased pressures to elicit the laryngeal adductor reflex. Motor evaluation is carried out by delivering various food items with different consistencies while factors such as oral transit time, inhibition of swallowing, laryngeal elevation, spillage, residue, condition of swallow, laryngeal closure, reflux, aspiration, and ability to clear residue, are monitored.

A randomized controlled clinical outcome study of FEESST by Aviv et al (2000) found no significant difference in rates of pneumonia in dysphagic patients evaluated with modified barium swallow and dysphagic patients evaluated with FEESST. The use of laryngopharyngeal sensory testing is controversial. The Veterans Health Administration, Department of Defense (2003) clinical practice guideline for the management of stroke rehabilitation in the primary care setting concluded that “[t]here is insufficient evidence to recommend for or against fiber-optic endoscopic examination of swallowing with sensory testing (FEESST) for the assessment of dysphagia”. The evidence review stated that the overall quality of evidence supporting FEESST is “poor”. An evidence-based guideline on dysphagia from the Scottish Intercollegiate Guidelines Network (SIGN, 2004) concluded that "[l]aryngopharyngeal testing has also been described but insufficient evidence was identified to recommend it". Current clinical guidelines on stroke from the Royal College of Physicians (2004) recommend FEES or some other instrumental investigation to allow visualization of the pharynx in persons who have persistent dysphagia. Although FEESST is listed in an appendix to these guidelines, the guidelines make no recommendation for its use.

FEES for the Evaluation of Oropharyngeal Swallowing Problems in Individuals with Type 2 Diabetes Mellitus

Golac and colleagues (2021) noted that individuals with diabetes mellitus often have gastro-intestinal (GI) problems and related deglutition disorders. In a descriptive cross-sectional study, these researchers examined the symptomatic swallowing complaints and assessed the functionality of oropharyngeal swallowing in patients with type 2 diabetes mellitus (T2DM) by using the Turkish Eating Assessment Tool-10 (T-EAT-10) and FEES. The T-EAT-10 questionnaire was completed by 121 patients with T2DM, and FEES was planned for each individual whose baseline score of the T-EAT-10 was greater than or equal to 3. Before swallowing trials via samples of nectar-thick consistency, laryngeal sensation and severity of secretion in the hypopharynx were observed. While the swallowing safety was determined using the Penetration-Aspiration Scale (PAS), the Yale Pharyngeal Residue Severity Rating Scale was used to evaluate the swallowing efficiency. Of the 121 participants, 27 (22.3 %) were found to have abnormal swallowing function (T-EAT-10 greater than or equal to 3), 33 (27.3 %) had concomitant neuropathy and 34 (28.1 %) mentioned a reflux complaint. The results of the multivariate linear regression analysis exposed that the T-EAT-10 score was significantly associated with neuropathy (r = 3.763, p < 0.001) and reflux complaint (r = 2.254, p = 0.031). Of the 20 FEES-tested subjects, 19 ( 95 %) had a safe swallowing function (PAS = 1). However, diminished laryngeal sensation, increased secretion and presence of residue revealed that patients with T2DM who have self-reported swallowing difficulties have reduced swallowing efficiency. The authors concluded that the findings of this study showed that almost 25 % T2DM patients reported to have swallowing-related problems, and the score of the T-EAT-10 was found to be independently associated with both neuropathy and reflux complaint. These investigators noted that FEES results pointed out that swallowing efficiency was relatively reduced in the target population; however, further research is still needed before obtaining a definitive answer to oropharyngeal swallowing problems in patients with T2DM.

FEES for the Evaluation of Swallowing Dysfunction in Infants and Children

Bockler (2016) noted that although FEES has been established as a valid procedure in instrumental evaluation of swallowing even in young children, the significance of the endoscopic method on infants has not yet been fully clarified. These researchers evaluated FEES in infants by focusing on its feasibility and limits. A total of 27 infants from a neuropediatric hospital presented for FEES were included in this analysis. Compared with Langmore standard FEES was carried out in a modified algorithm. In 24 of the 27 infants information about swallowing pathology could be obtained. Silent aspiration of saliva (Penetration Aspiration Scale (PAS) level 8) or silent deep penetration of test diets to the level of the glottis (PAS level 5) presented in 10 children and overt deep penetration of test diets in 3 children. In no case a sufficient insight into the subglottis or trachea could be obtained. Therefore a differentiation of silent deep penetration and aspiration of test diets was impossible. As a consequence of the FEES results, probe and diet management was changed in 7 children. The authors concluded that FEES in a modified algorithm turned out to be a feasible tool for the diagnostics of swallowing disorders in approximately 89 % of the infants. The procedure was limited in terms of providing direct evidence on aspiration in cases of deep penetrations of test diets.

Vetter-Laracy and colleagues (2018) noted that swallowing disorders that lead to aspiration are common in premature infants with a post-menstrual age (PMA) of greater than 36 weeks. Aspiration is often silent and the unique symptom is desaturation during feeding. These researchers determined the number of premature infants with desaturations during feeding due to aspiration, using FEES; related clinical factors and FEES findings to aspiration; and described type and efficacy of suggested treatments. They carried out a retrospective review of 62 ex-premature babies with a median PMA of 40 weeks who underwent FEES due to persistent feeding desaturations. Aspiration was related to other FEES findings and to clinical and demographic data. The efficacy of the treatment was evaluated during the FEES and by comparing recorded desaturations during feeding 7 days before and after FEES. A total of 44 (71 %) infants were diagnosed with aspiration and/or penetration. No relation was found to demographic or clinical data. The accumulation of saliva and residues post-swallowing were related to aspiration (p < 0.01). In 77.3 % of the infants, use of a thickener appeared to decrease aspiration during FEES and was suggested as a treatment; 13.6 % of infants received anti-reflux treatment after FEES and 9.1 % needed gastrostomy. The authors concluded that aspiration is very frequent in premature infants who present desaturations during feeding and FEES is a useful method for diagnosing and suggesting treatments. This was a small, uncontrolled study; these preliminary findings need to be validated by well-designed studies.

Reynolds et al (2016) stated that the standard procedure to assess an infant in the neonatal intensive care unit (NICU) who is suspected of aspirating on oral feedings is a video-fluoroscopic swallowing study (VFSS). The VFSS has been used for more than 30 years to assess dysphagia and is considered the gold standard. However, there are challenges to the VFSS, including radiation exposure, transport to radiology, usage of barium, limited positioning options, and cost. An alternative approach is FEES, which uses a flexible endoscope passed trans-nasally into the pharynx to assess anatomy, movement/sensation of structures, swallow function, and response to therapeutic interventions. Fiberoptic endoscopic evaluation of swallowing has been established as a valid tool for evaluating dysphagia and utilized as an alternative or supplement to the VFSS in both adults and children. These investigators provided an overview of the current challenges in the NICU with assessing aspiration and introduced a multi-disciplinary FEES program for bottle and breast-feeding. They performed a review of the literature of dysphagia, VFSS, and FEES in the adult, pediatric, infant, and neonatal populations. Clinical competency standards were researched and then implemented through an internal process of validation. Finally, a best practice protocol was designed as it relates to FEES in the NICU. Fiberoptic endoscopic evaluation of swallowing is a safe alternative to the VFSS. It can be utilized at the infant's bedside in a NICU for the diagnosis and treatment of swallowing disorders by allowing the clinician the ability to replicate a more accurate feeding experience, therefore, determining a safe feeding plan. These investigators noted that competency and training are essential to establishing a multi-disciplinary FEES program in the NICU. The authors concluded that further research is needed to compare the effectiveness and validity of FEES versus VFSS for infants in the NICU. Furthermore, they stated that evaluation of the effectiveness of FEES during breast-feeding is needed.

Henderson and co-workers (2016) examined the feasibility of obtaining and utilizing objective measures of timing and displacement from videofluoroscopy performed in pediatrics. Children (n = 121; mean age of 38 months, range of 9 days to 21 years, SD = 4 years) referred for videofluoroscopy were recruited. All underwent a standardized protocol including a mid-feed 20-second loop recorded at 25 frames/second. Videos were analyzed using objective digital measures of timing and displacement. Radiation dose was recorded. Quantitative measures were obtained in all children. Maximum opening of the pharyngo-esophageal segment and timing measures were correlated with increasing age. Values were congruent with validated adult data. Mean radiation time was 1.58 minutes (range of 0.15 to 3.47, SD 0.66), and mean radiation dose was 30.16 cGycm2 (range of 6.5 to 85 SD 15.17). Radiation dose (p = 0.21) and radiation time (p = 0.72) were not significantly different using the increased frame rate compared with an age-matched cohort (n =100) prior to protocol change. The authors concluded that objective quantitative measures of swallowing measurements can be obtained successfully from pediatric videofluoroscopy performed at high frame rates, without increasing radiation dose. Measures were biologically consistent, reproducible, demonstrated internal cross-correlation, and mirror adult data. They stated that these measures have potential to support targeted management and objective monitoring of change by pediatric feeding teams in the future.

Audag and colleagues (2017) noted that dysphagia is frequent in pediatric patients with neuromuscular diseases (pNMD). Its detection is important for initiating early diagnosis and treatment as well as for minimizing related complications. These researchers reviewed the literature on dysphagia screening and evaluation tools in pNMD. They carried out a systematic review on the basis of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines; 3 databases (PubMed, CINAHL, and ScienceDirect) were searched. Measurement properties of tools and the quality index developed by Downs and Black were considered. the search yielded 4 studies and 4 different tools for pediatric patients with Duchenne muscular dystrophy (DMD). The Sydney Swallow Questionnaire, surface electromyography, Neuromuscular Disease Swallowing Status Scale, and videofluoroscopic swallow study showed interesting properties for DMD. No data were available for other NMD and children under 9 years. The mean total score for the quality index was 17.5. the authors concluded that they did not identify any superior validated tools, either for screening or for evaluation of dysphagia, and no widely accepted protocol. They stated that further studies are needed to identify the simplest assessment with the best psychometric properties for pNMD; they recommended establishing a specific tool for pNMD.

Jaffal and colleagues (2020) noted that laryngomalacia (LM) is commonly diagnosed in infants and children with upper aero-digestive symptoms. In the literature, the focus has been on the respiratory impairment, with fewer studies addressing swallowing dysfunction (SwD). These researchers examined the literature for evidence on the prevalence of SwD in children diagnosed with LM. They carried out a search on the following databases: Ovid Medline, Ovid Embase, Ebsco CINAHL, PROSPERO, and Cochrane Library. These investigators included all the studies that reported on children with LM and documented objective swallowing assessment using FEES or VFSS. Two authors independently screened all the studies, examined the level of evidence in the included studies, and extracted data. Risk of bias assessment and pooled data analysis were performed. The search yielded 512 abstracts; four studies met the selection criteria representing 425 children; three studies were retrospective uncontrolled case series and one was a prospective cohort study. In all studies but one, an instrumental assessment of swallowing was selectively performed in patients with clinical indicators of SwD. The pooled estimate (range) of prevalence of SwD was 49 % (13.9 % to 90.6 %). The authors concluded that the literature suggested a high prevalence of SwD in children with LM; however, the level of evidence was low and generalizability was poor. The wide range of prevalence figures suggested a significant variability in the threshold and indications to evaluate swallowing in children with LM.

Christovam et al (2022) noted that the scientific scope of swallowing disorders in the neonatal and pediatric populations is growing exponentially; however, the preponderance of evidence for evaluation protocols has been concentrated in non-instrumental evaluations creating a lack of research about protocols for instrumental swallowing assessment. In a systematic review, these investigators examined the available evidence to identify and to report protocols used in instrumental assessments via VFSS and FEES in the neonatal and pediatric populations to support clinical decision-making. The search strategy was employed in 5 online databases, no filters were used to restrict languages or publication dates and the gray literature was reviewed. The PRISMA statement was employed to guide the construction of this review. The studies included validated and unvalidated protocols, the validated protocols had their risk of bias estimated using the QUADAS-2. A total of 13 studies were included in the final review, of these 11 examined via QUADAS-2, and 2 classified with low-risk of bias. One study was in the process of standardization and validation of an instrumental assessment protocol for swallowing in bottle-fed infants via VFSS. The authors concluded that information regarding validity and reliability of published protocols for instrumental evaluation in the neonatal and pediatric populations is limited; thus, further research is needed to standardize and validate protocols for instrumental assessments in these populations.

Printza et al (2022) stated that dysphagia is any impairment of swallowing that compromises the safety, efficiency, or adequacy of nutritional or liquid intake. It is common in children, especially in some clinical populations, and may result in failure to thrive and respiratory problems due to pulmonary aspiration. Swallowing disorders have a severe impact on children's health, growth, and development, and on the quality of life (QOL) of the child and family. Clinical evaluation could not validly predict aspiration, which is mostly silent. A team management approach is advocated, including instrumental swallowing assessments. FEES has been proven to be safe and is increasingly used in children of all ages. It allows the identification of structural abnormalities, assessment of the child's diet with real-life food and liquids while the child holds the optimal or preferred position, examination during breast-feeding, and assessment of fatigue and treatment strategies. FEES is performed following a protocol that comprises 3 parts: the evaluation of the anatomical and physiological parameters of swallowing, testing of food and liquids of a range of different consistencies, as well as evaluation of treatment methods. Pediatric FEES entails adaptations for infants, and special considerations regarding readiness for nutritive trials and the infant's ability to sustain a coordinated feeding pattern. Varying consistencies and volumes of food or liquids are tried. Care of the dysphagic child involves teamwork. The authors concluded that FEES, as a part of the assessment and management of dysphagia, allows the evaluation of the safety, efficiency, and adequacy of oral food and liquid intake. Moreover, these researchers stated that future perspective studies including standardized training in clinical FEES protocols are needed to ensure clinical competency of the pediatric FESS team members and the development and validation of standardized examination and interpretation protocols for pediatric FEES.

These researchers stated that although pediatric FEES has evolved into a standard in the diagnosis of swallowing disorders; however, examination protocols, rating scales, and interpretation for children mostly lack validation. Some studies indicated that the boluses examined were developmentally appropriate, whereas many studies did not describe the boluses used. The reporting of secretion pooling, laryngeal sensation, premature spillage and swallowing onset, penetration, aspiration, and residue were not consistent in pediatric FEES studies. No validated scale was used, with the exception of the penetration-aspiration scale used in 1 study. Furthermore, even the boundary between normal and abnormal spillage must be clarified in children.

In a retrospective study, Celtik et al (2022) examined the swallowing problems by FEES study in both short-gap and long-gap patients following esophageal atresia (EA) repair. Hospital records of patients who had undergone surgery for EA were reviewed. Patients were divided into 2 groups as short-gap (SG) group (n = 16) and long-gap (LG) group (n = 10) to compare the swallowing problems. FEES study was carried out, and the results were discussed in detail. There were 26 patients (16 males / 10 females) with a mean age at evaluation was 7.52 ∓ 3.68 years. Mean follow-up period was 75.35 ∓ 44.48 months. In FEES study, pharyngeal phase abnormalities were detected in 10 patients (38.4 %). Pharyngeal phase abnormalities were detected significantly higher in LG group (p: 0.015). Laryngeal penetration / aspiration was observed in 4 patients on FEES study (15.3 %). All of them was in LG group (40 %). Laryngeal penetration/aspiration was observed significantly higher in LG group (p: 0.014). The authors concluded that this was the 1st study to conduct FEES study in children following esophageal atresia repair to examine their swallowing conditions. Even though the sample was small, swallowing problems were more common than expected in the cases of LG when compared to SG.

Zang et al (2022) noted that although pediatric FEES has developed into a standard in dysphagia diagnostics, there are no valid protocols and procedures for children available to-date. In a systematic review, these investigators examined implementation protocols for pediatric FEES described in research studies, and analyzed them in detail concerning procedural steps, equipment, and reported outcome. Included were all studies reporting a pediatric FEES protocol for children aged 0 to 18 years, if they described at least 2 criteria defined in advance. The databases Medline and CINHAL were searched from January 2000 to February 2021. Risk of bias for included studies was evaluated using the National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies. A narrative synthesis of the FEES protocols was carried out; and the results compared in tabular form. A total of 22 studies were included, reporting on FEES in 1,547 infants, children, and adolescents with a wide range of diagnoses. It was possible to identify protocols related to all age groups in general as well as to particular groups such as breast-fed or bottle-fed infants. None of the included studies reported a good methodological quality; all studies had missing data. Uniform implementation for sub-groups could not be determined. The reported outcome of FEES examinations could not be compared. The authors concluded that none of the included studies reported good methodological quality and a significant amount of data were missing; the review offered a systematic basis for future research to close the serious gap in the area of pediatric FEES. These researchers made a proposal for a minimum requirement for pediatric FEES protocols in scientific studies.

The authors stated that meta-analysis of the data was not possible because of a large number of missing data and the range of outcome parameters. In particular, the retrospective studies with large samples had significant deficiencies in the sample description and specification of the data, making further analyses and comparisons impossible. In principle, retrospective analyses of patient data are valuable if they meet certain requirements and systematically provide the necessary data. Furthermore, an important issue for future research concerns compliance and general behavior of children during FEES. These investigators stated that future studies should report whether excessive crying, severe resistance, or refusal to eat or drink occurred during the examination and how this affected the acquisition of meaningful swallowing images. By specifying the average duration of the examination and after what time and how it was possible to calm down the child or not, it would help in future to find out more regarding the acceptance of the examination (e.g., in certain age groups). Furthermore, it should be summarized how many examinations had to be prematurely terminated or could not be performed at all. In addition, other reasons for termination of examinations such as choanal stenosis should also be given. Researchers and practitioners using FEES should always keep in mind that swallowing function can be distorted by strong, sustained crying or discomfort; thus, the starting point for a meaningful study should always be the greatest possible comfort for the children and their parents. Future research must deal with how this comfort can be achieved.

In a prospective, pilot study, Zang et al (2023) reported on implementing FEES in infants and toddlers with type 1 spinal muscular atrophy (SMA). Furthermore, a comparison of FEES results, and clinical scores was performed. This trial included 10 symptomatic children with SMA type 1 (2 SMN2 copies). They started treatment with 1 of the 3 currently approved therapies for SMA at a median age of 3.8 months (range of 0.7 to 8.9). FEES was carried out according to a standard protocol using Penetration-Aspiration Scale (PAS) and Murray Secretion Scale as a primary outcome. The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) for motor function, Neuromuscular Disease Swallowing Status Scale (NdSSS), Oral and Swallowing Abilities Tool (OrSAT), and single clinical swallowing-related parameters were also examined. Distinct swallowing disorders were already evident in 8 children at inclusion. The most common findings from FEES were pharyngeal secretion pooling, penetration, and aspiration of saliva and food as well as delayed initiation of swallowing. Despite an average increase in motor function, no comparable improvement was found in swallowing function. None of the surveyed clinical scores showed a significant dependence on PAS in a mixed linear model. The authors concluded that valuable information regarding the status of dysphagia could be gathered endoscopically, especially concerning secretion management and when oral intake was limited. These investigators stated that available clinical tools for children with type 1 SMA may represent a change in nutritional status but are not yet mature enough to conclude swallowing ability; further development is still needed.

The authors stated that this study had several drawbacks. First, the sample consisted of severely symptomatic children who were seen at varying ages. Serious AEs related to the disease and the COVID-19 pandemic made data collection more complex. An evident weakness of the study was that no systematic pre-post and follow-up measurements could be performed. Second, it must be pointed out that the evaluation of PAS only for saliva in 2 children could undoubtedly be viewed critically. However, due to the rarity of the disease, consideration of each case was precious. Based on the authors’ experience, they believed these children would have received an even poorer PAS score for a food bolus. That should be considered for further interpretation of the data. Third, as a result of the recently started SMA newborn screening, a modified study design is needed, and the children will be seen much earlier. This new study design will be implemented as part of the DySMA study (Dysphagia in Children with Spinal Muscular Atrophy). Therefore, clinical instruments are urgently needed to depict swallowing development sensitively and validly predict dysphagia as it progresses. There is no evidence that the swallowing problems could be totally stopped by treatment, even if treated at an early disease stage. In the future, FEES will be conducted regularly as part of routine diagnostics to monitor swallowing function in the context of new therapies. A multi-center approach and international collaboration will be essential for developing an overall protocol for clinical assessment combined with instrumental measurements.

In a case-series study, Schroeder (2023) showed the importance of employing FEES when examining breast-feeding infants with suspected dysphagia. Failure to recognize and account for the fundamentally different physiology of the primarily breast-fed infant could result in false assumptions regarding the safety of breast-feeding in this under-studied patient population. The medical records of patients referred to an urban, university-based, pediatric hospital for FEES from February 2017 to October 2020 were reviewed. Their presenting symptoms, dysphagia severity, co-morbidity, dysphagia work-up, and management were analyzed. The standardized Dysphagia Outcome and Severity Scale was used to evaluate dysphagia severity. A total of 204 FEES examinations were reviewed; 35 were carried out on breast-fed infants. 34 of the 35 infants calmed for the FEES examination while breast-feeding. Cohorts were defined by a particular presenting sign (cough, laryngeal congestion, choking, and respiratory illness) and anatomical characteristic (laryngomalacia, vocal cord paralysis, aspiration, penetration, etc.) and then compared to all other examinations. The average dysphagia score for all the examinations was 2.37. Patients presenting with laryngeal congestion had an average dysphagia score of 2.81. There was no difference in dysphagia score based on co-morbidities or anatomy. The authors concluded that FEES was the instrumental examination of choice when examining a primarily breast-fed infant who has suspected dysphagia. The examination was well-tolerated and provided accurate, objective information while accounting for this population's unique swallowing physiology. Primarily breast-fed infants presenting with laryngeal congestion were more likely to have clinically worse dysphagia than those presenting with other clinical symptoms. Level of Evidence = IV.

FEES for the Evaluation of Swallowing in Early-to-Advanced Stage Huntington's Disease

Schindler and colleagues (2020) stated that Huntington's Disease (HD) is a neurodegenerative disorder characterized by motor disturbances, cognitive decline, and behavioral changes. A well-recognized feature of advanced HD is dysphagia, which leads to malnutrition and aspiration pneumonia, the latter being the primary cause of death in HD. Previous studies have underscored the importance of dysphagia in HD patients with moderate-to-advanced stage disease, but it is unclear if dysphagia affects patients already at an early stage of disease and whether genetic or clinical factors can predict its severity. These researchers carried out FEES in 61 patients with various stages of HD. Dysphagia was found in 35 % of early-stage, 94 % of moderate-stage, and 100 % of advanced-stage HD. Silent aspiration was observed in 7.7 % of early-stage, 11.8 % of moderate-stage, and 27.8 % of advanced-stage HD. A strong correlation was found between disease progression and dysphagia severity: worse dysphagia was associated with worsening of motor symptoms. Dysphagia severity as evaluated by FEES correlated with Huntington's Disease Dysphagia Scale scores (a self-report questionnaire specific for evaluating swallowing in HD). The authors concluded that these findings added to the understanding of dysphagia onset and progression in HD. A better understanding of dysphagia onset and progression in HD may inform guidelines for standard clinical care in dysphagia, its recognition, and management. These researchers stated that hypothesis is emerging that swallowing impairment manifests in the initial phase of diseases and requires prompt evaluation. Moreover, they stated that further studies in larger cohorts are needed to substantiate this finding.

In a descriptive review, Pizzorni and associates (2020) discussed the state of the art on the assessment and treatment of dysphagia in HD. These investigators carried out a literature search of the last 10 years using PubMed and Embase. A total of 24 studies were included: 16 cross-sectional studies, 2 case reports, 2 case series, 2 open-label trials, 1 pre-post study, and 1 RCT. Based on the studies retrieved, dysphagia should be evaluated from the early stage of the disease, especially when specific clinical markers occur. Timing for dysphagia re-assessment should be based on the recommendation of the swallowing experts on the individual case. Instrumental assessment of swallowing by videofluoroscopy or videoendoscopy is feasible and recommended to diagnose dysphagia in patients with HD. Clinical assessment tools and patient-reported outcome measures may be used to complete the swallowing examination, but not to replace instrumental assessment. The impact of pharmacological and rehabilitative treatments on dysphagia in HD has been little studied in literature. While the effect of tetrabenazine on swallowing is still controversial, compensatory strategies appeared to be applicable and effective. The authors concluded that to-date, there are no well-proven rehabilitative strategies to improve swallowing function in patients with HD; and the topic of dysphagia in HD remains poorly studied compared with its clinical relevance.

Lingual Resistance Training

Smaoui and colleagues (2019) noted that lingual resistance training has been proposed as an intervention to improve decreased tongue pressure strength and endurance in patients with dysphagia. However, little is known about the impact of lingual resistance training on swallow physiology. In a systematic review, these researchers examined available evidence regarding the effects of lingual resistance training on swallowing function in studies using VFSS with adults. A total of 7 articles met the inclusion criteria and underwent detailed review for study quality, data extraction, and planned meta-analysis. Included studies applied this intervention to a stroke and brain injury patient populations or to healthy participants, applied different training protocols, and used a number of outcome measures, making it difficult to generalize results. Lingual resistance training protocols included anterior and posterior tongue strengthening, accuracy training, and effortful press against hard palate with varying treatment durations. VFSS protocols typically included a thin barium stimulus along with one other consistency to evaluate the effects of the intervention. Swallowing measures included swallow safety, efficiency, and temporal measures. Temporal measures significantly improved in 1 study, while safety improvements showed mixed results across studies. Reported improvements in swallowing efficiency were limited to reductions in thin liquid barium residue in 2 studies. Overall, the evidence regarding the impact of lingual resistance training for dysphagia was mixed. Meta-analysis was not possible due to differences in methods and outcome measurements across studies. Reporting all aspects of training and details regarding VFSS protocols was crucial for the reproducibility of these interventions. The authors stated that future investigations should focus on completing robust analyses of swallowing kinematics and function following tongue pressure training to determine efficacy for swallowing function.

Modified Barium Swallow Study

Modified barium swallow study (MBSS; also known as videofluoroscopic swallowing study [VFSS]) is a fluoroscopic procedure; it is used for evaluating the oral, pharyngeal, and upper 1/3 of the esophageal phases of the swallow. This is accomplished by observing various consistencies of barium and mixed food/barium as it passes from the mouth to the stomach.

In a modified barium swallow study (MBSS; also known as videofluorographic swallow study or videofluoroscopic swallow evaluation) a patient is presented with various foods and liquids to swallow, with or without assistance, specialized feeding equipment, and swallowing maneuvers or strategies. The entire procedure is recorded and can be replayed in slow motion, providing a detailed analysis of swallowing function.

Performance of a modified barium swallowing study requires that the patient be able to swallow and be positioned for study. The candidate for a MBSS should not need frequent oral or pharyngeal suctioning, and tachypnea should be absent. It is contraindicated in persons with an allergy to barium.

Concerns have been expressed that the use of such services in a mobile setting lacks evidence of medical effectiveness (Novitas, 2019). Questions of patient safety have yet to be resolved for these types of procedures to be performed in a skilled nursing facility, nursing home, or home environment, thus requiring physician presence during the procedure in such settings.

Laryngopharyngeal Endoscopic Esthesiometer (LPEER) for Evaluating Laryngopharyngeal Mechano-Sensitivity

Giraldo-Cadavid and colleagues (2018) stated that recent studies have shown an association between alterations in laryngopharyngeal mechano-sensitivity (LPMS) and dysphagia, obstructive sleep apnea (OSA), and chronic cough hypersensitivity syndrome. A previous reliability study of a new laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER) showed high intra- and inter-rater reliability; however, its accuracy has not been tested. These researchers performed an accuracy study of the LPEER in a prospectively and consecutively recruited cohort of 118 patients at 2 tertiary care university hospitals. Most of the patients were suffering from dysphagia, and all of them underwent a standard clinical evaluation and FEESST using a new sensory testing protocol. The sensory test included determinations of the laryngeal adductor reflex threshold (LART), the cough reflex threshold (CRT) and the gag reflex threshold (GRT). Abnormalities on these reflex thresholds were evaluated for associations with major alterations in swallowing safety (pharyngeal residues, penetration, and aspiration). These investigators evaluated the discriminative capacity of the LPMS test using receiver operating characteristic (ROC) curves and the area under the curve (AUC-ROC) and its relationship with the 8-point penetration-aspiration scale (PAS) using the Spearman's ρ correlation coefficient (SCC). They found a positive correlation between the PAS and LART (SCC 0.47; p < 0.001), CRT (SCC 0.46; p < 0.001) and GRT (SCC 0.34; p = 0.002). The AUC-ROC values for detecting a PAS greater than or equal to 7 were as follows: LART, 0.83 (p < 0.0001); CRT, 0.79 (p < 0.0001); GRT, 0.72 (p < 0.0001). The authors concluded that the LPEER showed good accuracy for evaluating LPMS; these findings justified further validation studies in independent populations.

Fiberoptic Endoscopic Evaluation of Swallowing (FEES) for Evaluation of Individuals with Disorder of Consciousness

Checklin and colleagues (20222022;37(4):778-787.) stated that individuals with disorders of consciousness (DOC) often receive nutrition via a feeding tube and the swallowing ability in this population is not fully understood. In particular, FEES for individuals with DOC requires further investigation. In a systematic review, these investigators examined the available evidence of whether FEES is feasible and safe for individuals with DOC. Multiple health databases were searched in November 2019 to identify studies that employed FEES for individuals with DOC. Data extraction included demographic information, adverse events (AEs) reported, and outcomes related to oral feeding. The Diagnostic Accuracy Quality Scale (DAQS) was used to evaluate the quality of the studies. A total of 4 studies were found, all of which had a high risk of bias. Many subjects went from nil by mouth to some degree of oral diet sometime following the completion of FEES with low reporting of AEs associated with FEES. The authors concluded that the findings of this review suggested a potential for the use of FEES in individuals with DOC; however, the evidence is low and further studies are needed to improve the understanding of FEES in individuals with DOC.

Scope of Policy

This Clinical Policy Bulletin addresses fiberoptic endoscopic evaluation of swallowing (FEES)/fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST) and laryngopharyngeal endoscopic esthesiometer (LPEER).

Medical Necessity

Aetna considers the following interventions medically necessary:

Experimental and Investigational

The following interventions are considered experimental and investigational because the effectiveness of these approaches has not been established: