Predicting penetration-aspiration through quantitative swallow measures of children: a videofluoroscopic study

Prevalence of Oropharyngeal Dysphagia in Children: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to determine the prevalence of oropharyngeal dysphagia (OD) in children, as diagnosed through instrumental evaluation, and to identify associated risk factors.

METHODS

A systematic search was conducted across six databases (Embase, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, and Web of Science), as well as gray literature sources (ASHA, Google Scholar, and ProQuest). Studies involving children (under 12 years of age), diagnosed using instrumental methods such as videofluoroscopic swallow study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES), were included. A random-effects meta-analysis was performed to estimate the prevalence, with heterogeneity assessed through meta-regression. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

A total of 31 studies were included, yielding a pooled prevalence estimate of 69% (95% CI: 61%-77%; I² = 94%). Most studies involved children with predisposing conditions, potentially contributing to an overestimation of OD prevalence in the general pediatric population. Four studies were assessed as having a moderate risk of bias, while 27 were rated as having a low risk of bias.

CONCLUSION

The findings suggest a high prevalence of OD, especially in children with underlying health conditions. These results underscore the importance of early diagnosis and tailored interventions to mitigate the health risks associated with deglutition disorders in pediatric populations.

Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3 years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10 mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Temporal Characteristics of Penetration and Aspiration in Patients with Severe Dysphagia Associated with Lateral Medullary Syndrome

To assess the severity and timing of penetration and aspiration (PA) of severe dysphagia after lateral medullary syndrome (LMS) and its association with temporal characteristics. We performed videofluoroscopic swallowing studies (VFSS) in 48 patients with LMS and severe dysphagia and 26 sex- and age-matched healthy subjects. The following temporal measures were compared between groups: velopharyngeal closure duration (VCD); hyoid bone movement duration (HMD); laryngeal vestibular closure duration (LCD); upper esophageal sphincter (UES) opening duration (UOD); stage transition duration (STD) and the interval between laryngeal vestibular closure and UES opening (LC-UESop). The association between temporal measures and Penetration-Aspiration Scale (PAS) scores was analyzed. Differences in timing measures were compared between subgroups (safe swallows, and swallows with PA events during and after the swallow). PAS scores ≥ 3 were seen in 48% of swallows (4% occuring before, 35% occurred during and 61% after the swallow) from the LMS patients. Significantly longer STD and LC-UESop were found in the patients compared to the healthy subjects (p < 0.05). Significant negative correlations with PA severity were found for HMD, LCD, and UOD. Short UOD was the strongest predictor with an area under the receiver-operating-characteristic curve of 0.66. UOD was also significantly shorter in cases of PA after the swallow (p < 0.01). Patients with LMS involving severe dysphagia exhibit a high frequency of PA (mostly during and after swallowing). PA events were associated with shorter UOD, HMD, and LCD. Notably, shortened UOD appears to be strongly associated with PA.

Clinical outcomes before and after videofluoroscopic swallow study in children 24 months of age or younger

OBJECTIVE

To evaluate the combined impact of videofluoroscopic swallow study (VFSS) and therapeutic feeding and swallowing interventions on clinical outcomes in children with oropharyngeal dysphagia (OPD).

METHODS

This was an uncontrolled longitudinal analytical study in which OPD patients were evaluated before and after VFSS. Children ≤ 24 months of age diagnosed with OPD in a clinical setting and undergoing VFSS for investigation and management of OPD were included in the study. The study participants received therapeutic feeding and swallowing interventions after having undergone VFSS, being followed at an outpatient clinic for pediatric dysphagia in order to monitor feeding and swallowing difficulties. Respiratory and feeding outcomes were compared before and after VFSS.

RESULTS

Penetration/aspiration events were observed in 61% of the VFSSs (n = 72), and therapeutic feeding and swallowing interventions were recommended for 97% of the study participants. After the VFSS, there was a reduction in the odds of receiving antibiotic therapy (OR = 0.007) and in the duration of antibiotic therapy (p = 0.014), as well as in the odds of being admitted to hospital (p = 0.024) and in the length of hospital stay (p = 0.025). A combination of oral and enteral feeding became more common than oral or enteral feeding alone (p = 0.002).

CONCLUSIONS

A high proportion of participants exhibited penetration/aspiration on VFSS. Therapeutic feeding and swallowing interventions following a VFSS appear to be associated with reduced respiratory morbidity in this population.

Risk of Aspiration Increased by Post-swallow Residue in Infant Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

OBJECTIVE

To assess the risk of aspiration associated with post-swallow residue subsites in Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in bottle-fed infants <1 year of age.

METHODS

This is a retrospective matched-pairs cohort study at an academic tertiary children's hospital. FEES and Videofluoroscopic Swallowing Study (VFSS) trials performed within the same infant <5 days apart were paired by matching bolus consistency and bottle flow rate. Positive aspiration was defined by the "or rule" in which aspiration is positive when either FEES or VFSS within a matched pair is positive.

RESULTS

Eighty-seven FEES-VFSS matched pairs from 29 patients (16 males; mean [SD] age, 2.9 [2.8] months) were included. The rate of positive aspiration, as defined by the "or rule", was 59% (51/87). In FEES, post-swallow pyriform sinus residue was present in 16% (14/87) and anterior commissure residue 27% (31/87). Risk of positive aspiration was increased by pyriform sinus residue (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.9-19.3, p < 0.01) and anterior commissure residue in FEES (OR 2.5, 95% CI 1.1-6.1, p = 0.03). In the neonate subgroup, <1 month of age, multivariate-adjusted analysis showed that anterior commissure residue had better diagnostic accuracy for aspiration than in older infants (overall 70% vs. 42%, p < 0.01; sensitivity 60% vs. 10%, p < 0.01), whereas pyriform sinus residue had worse accuracy (overall 41% vs. 70%, p = 0.02; sensitivity 13% vs. 43%, p = 0.02).

CONCLUSION

This study demonstrates that pyriform sinus and anterior commissure residue during infant FEES were associated with fivefold and twofold increased risk of aspiration, respectively.

LEVEL OF EVIDENCE: 3

Using a retrospective matched-pairs cohort, this study assesses the diagnostic accuracy of post-swallow residue in FEES for predicting aspiration. Laryngoscope, 134:1431-1436, 2024.

Predictive Value of Laryngeal Penetration to Aspiration in a Cohort of Pediatric Patients

Videofluoroscopic swallow studies (VFSS) provide dynamic assessment of the phases of swallowing under fluoroscopic visualization and allow for identification of abnormalities in the process, such as laryngeal penetration and aspiration. While penetration and aspiration both reflect degrees of swallowing dysfunction, the predictive potential of penetration for subsequent aspiration is not fully elucidated in the pediatric population. As a result, management strategies for penetration vary widely. Some providers may interpret any depth or frequency of penetration as a proxy for aspiration and implement various therapeutic interventions (e.g., modification of liquid viscosity) to eliminate penetration episodes. Some may recommend enteral feeding given the presumed risk of aspiration with penetration, even when aspiration is not identified during the study. In contrast, other providers may advise continued oral feeding without modification even when some degree of laryngeal penetration is identified. We hypothesized that the depth of penetration is associated with the likelihood of aspiration. Identification of predictive factors for aspiration following laryngeal penetration events has significant implications for selection of appropriate interventions. We performed a retrospective cross-sectional analysis of a random sample of 97 patients who underwent VFSS in a single tertiary care center over a 6 month period. Demographic variables including primary diagnosis and comorbidities were analyzed. We examined the association between aspiration and degrees of laryngeal penetration (presence or absence, depth, frequency) across diagnostic categories. Infrequent and shallow penetration events of any type of viscosity were less likely to be associated with aspiration event(s) during the same clinical encounter regardless of diagnosis. In contrast, children with consistent deep penetration of thickened liquids invariably demonstrated aspiration during the same study. Our findings show that shallow, intermittent laryngeal penetration of any viscosity type on VFSS was not consistent with clinical aspiration. These results provide further evidence that penetration-aspiration is not a uniform clinical entity and that nuanced interpretation of videofluoroscopic swallowing findings is necessary to guide appropriate therapeutic interventions.

Influence of frame rate in detecting oropharyngeal aspiration in paediatric videofluoroscopic swallow studies - An observational study

OBJECTIVES

The videofluoroscopic swallow study (VFSS), currently the gold standard for assessing aspiration in children, incurs radiation. Adhering to the ALARA principle is crucial in minimising radiation dose whilst obtaining accurate diagnostic information in children. International adult VFSS guidelines recommend a capture rate of 30 frames per second (fps). Higher capture rates increase radiation yet there is limited evidence on best practice VFSS capture rates in children, particularly on thin fluid consistency-the fastest viscosity with the highest potential for missed aspiration on slower capture rates. We aimed to determine if image acquisition at 30fps versus 15fps alters the accuracy of detecting aspiration when assessing thin fluids during paediatric VFSS.

MATERIALS & METHODS

Seventeen speech language pathologists (SLPs) blindly rated a total of 2,356 swallow loops for the presence/absence of aspiration from VFSS recordings of 13 infants/children drinking thin fluids. 76 swallow loops were randomly presented at 15 versus 30fps, on two occasions. Area under receiver operating curve (aROCs) was used to compare the accuracy of aspiration ratings at 15 versus 30fps compared to a comparison set. The intraclass correlation coefficient (ICC) was used to examine rater reliability.

RESULTS

Accuracy for detecting aspiration was near-identical at 15fps (aROC:0.97; 95%CI:0.96-0.97) and 30fps (0.96; 95%CI 0.96-0.97). Good inter-rater (ICC:0.82; 95%CI:0.72-0.89) and intra-rater reliability among the raters (ICC:0.89; 95%CI:0.82-0.93) was found.

CONCLUSION

Using 15fps in paediatric VFSS when assessing thin fluid consistency aspiration provides a similar detection rate to using 30fps. As 15fps would have a lower radiation dose than 30fps, we recommend using 15fps when undertaking VFSS in children.

CLINICAL RELEVANCE STATEMENT

Adhering to the ALARA principles, a capture rate of 15fps should be used in paediatric VFSS for assessment on thin fluids.

Findings of a videofluoroscopic swallowing study in patients with dysphagia

Objective

Swallowing examination is crucial in patients with dysphagia. We aimed to compare qualitative and quantitative videofluoroscopic swallowing study (VFSS) results to provide reference for standardizing quantitative parameters.

Materials and methods

In total, 117 patients with dysphagia were included, 38 with Parkinson's disease and 39 and 40 in convalescence following cerebral hemorrhage and infarction. VFSS was both qualitatively and quantitatively analyzed.

Results

A significant difference of Oral transit time was found between the oral motor function grades (p < 0.001), also was swallowing reaction times found between swallowing reaction duration grades (p < 0.001), and soft palate lift duration between the soft palate lift grades (p < 0.001). Superior hyoid bone movement (p < 0.001), anterior hyoid bone movement (p < 0.001), hyoid pause time (p < 0.001), and hyoid movement duration (p = 0.032) had significant differences between the hyoid laryngeal complex movement grades, as did the pharyngeal cavity transit time among the cricopharyngeal muscle opening duration grades (p < 0.001). The laryngeal vestibule closure duration differed among the glottic closure grades (p < 0.001). No statistically significant difference in upper esophageal sphincter opening diameter (p = 0.682) or duration (p = 0.682) among the cyclopharyngeal muscle opening duration grades. The pharyngeal area at rest did not significantly differ among the different vallecular residue (p = 0.202) and pyriform sinus residue (p = 0.116) grades.

Conclusion

Several quantitative parameters can reflect the swallowing assessment process well. Further optimization of quantitative parameters is recommended.

Laryngeal Penetration and Risk of Aspiration Pneumonia in Children with Dysphagia-A Systematic Review

This study was a systematic review and meta-analysis that assessed the risk of aspiration pneumonia in children with laryngeal penetration or tracheal aspiration via a video-fluoroscopic study (VFSS) and compared the results to those for children with neither condition. Systematic searches were conducted using databases, including PubMed, Cochrane Library, and Web of Science. Meta-analysis was used to obtain summary odds ratios (OR) and 95% confidence intervals (CI). The overall quality of evidence was assessed using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. In total, 13 studies were conducted with 3159 participants. Combined results from six studies showed that laryngeal penetration on VFSS may be associated with aspiration pneumonia compared to no laryngeal penetration; however, the summary estimate was imprecise and included the possibility of no association (OR 1.44, 95% CI 0.94, 2.19, evidence certainty: low). Data from seven studies showed that tracheal aspiration might be associated with aspiration pneumonia compared to no tracheal aspiration (OR 2.72, 95% CI 1.86, 3.98, evidence certainty: moderate). The association between aspiration pneumonia and laryngeal penetration through VFSS seems to be weaker than that for tracheal aspiration. Prospective cohort studies with clear definitions of laryngeal penetration and that measure clinical and patient reported outcomes are needed to further define the association between laryngeal penetration and aspiration pneumonia.

Videofluoroscopic Profiles of Swallowing and Airway Protection Post-traumatic Cervical Spinal Cord Injury

Videofluoroscopic analyses of swallowing in survivors of traumatic cervical spinal cord injury (tCSCI) have been largely limited to case reports/series and qualitative observations. To elucidate the disrupted physiology specifically underlying dysphagia post-tCSCI, this prospective observational study analyzed videofluoroscopic swallow studies (recorded at 30 frames per second) across 20 tCSCI survivors. Norm-referenced measures of swallow timing or displacement, and calibrated area measures of laryngeal vestibule closure (LVC) were explored in relation to the severity of aspiration or pharyngeal residue. Videofluoroscopic performance was compared by injury level, surgical intervention, tracheostomy status, and in relation to clinical bedside assessments. Reduced pharyngeal constriction, delayed hyoid elevation, and impaired LVC characterized post-tCSCI dysphagia. Reduced extent of hyoid excursion and of pharyngoesophageal segment (PES) opening were not as prominent, only present in approximately half or less of the sample. Ten participants aspirated and 94% of aspiration events were silent. Severity of aspiration significantly correlated with pharyngeal constriction and prolonged pharyngeal transit times. Post-swallow residue correlated with delayed PES distention/closure and prolonged pharyngeal transit. Clinical inference regarding the integrity of the pharyngeal phase at bedside was limited; however, EAT-10 scores demonstrated promise as an adjuvant clinical marker of post-tCSCI dysphagia. This exploratory study further describes the pathophysiology underlying post-tCSCI dysphagia to promote deficit-specific rehabilitation and functional recovery.

Developing a Protocol for Quantitative Analysis of Liquid Swallowing in Children

PURPOSE

Objective measures in videofluoroscopic swallow studies (VFSSs) can quantify swallow biomechanics. There are a wide array of validated measures studied in infants, children, and adults. There is a need for a pediatric VFSS protocol that consists of a small number of vital, time efficient, and clinically relevant measures. In this study, we aimed to establish a standard protocol for quantitative VFSS analysis in children.

METHOD

Protocol development began with a systematic literature review, which identified 22 quantitative and eight descriptive measures available in the literature. A pediatric VFSS database of 553 children was collected using a standardized VFSS protocol. Studies were evaluated using the 30 previously reported measures covering displacement and timing parameters as well as penetration-aspiration and residue. Measures were tested for rater reliability and internal consistency. Measures meeting acceptable values for protocol inclusion were included in the final protocol (Cronbach's alpha > .53).

RESULTS

Interrater and intrarater reliability of 17 measures met acceptable reliability levels. During internal consistency testing, we removed six further measures based on Cronbach's alpha levels indicating that two or more measures were equivalent in measuring the same aspect of swallow biomechanics in children. A VFSS protocol of reliable, valid, and obtainable objective quantitative (n = 6) and descriptive measures (n = 3) with separate protocols for young infants (≤ 9 months) and older children was established.

CONCLUSIONS

A standardized quantitative VFSS protocol for children has been developed to suit two age groups (≤ 9 and > 9 months old). Consistent VFSS administration and reporting support assessment over time and across disease groups. Future research should focus on how this information can be used by clinicians to produce individualized treatment plans for children with swallowing impairment.

Variability in Swallowing Biomechanics in Infants with Feeding Difficulties: A Videofluoroscopic Analysis

Clinicians performing feeding evaluations in infants often report swallow variability or inconsistency as concerning. However, little is known about whether this represents pathological incoordination or normal physiologic variance in a developing child. Our retrospective study explored quantitative videofluoroscopic measures in 50 bottle-fed infants (0-9 months) referred with feeding concerns. Our research questions were as follows: Is it possible to assess swallow to swallow variability in an infant with feeding concerns, is there variability in pharyngeal timing and displacement in infants referred for videofluoroscopy, and is variability associated with aspiration risk? Measures were taken from a mid-feed, 20-s loop recorded at 30 frames per second. Each swallow within the 20-s loop (n = 349 swallows) was analysed using quantitative digital measures of timing, displacement and coordination (Swallowtail™). Two blinded raters measured all swallows with strong inter-rater reliability (ICC .78). Swallow frequency, suck-swallow ratio, residue and aspiration were also rated. Variability in timing and displacement was identified across all infants but did not correlate with aspiration (p > .05). Sixteen infants (32%) aspirated. Across the cohort, swallow frequency varied from 1 to 15 within the 20-s loops; suck-swallow ratios varied from 1:1 to 6:1. Within-infant variability in suck-swallow ratios was associated with higher penetration-aspiration scores (p < .001). In conclusion, pharyngeal timing and displacement variability is present in infants referred with feeding difficulties but does not correlate with aspiration. Suck-swallow ratio variability, however, is an important risk factor for aspiration that can be observed at bedside without radiation. These objective measures provide insight into infant swallowing biomechanics and deserve further exploration for their clinical applicability.