Bolus Transit Research Articles

Comparing Patients Diagnosed With Ineffective Esophageal Motility by the Chicago Classification Version 3.0 and Version 4.0 Criteria.

The Chicago Classification version 4.0 (CCv4.0) of ineffective esophageal motility (IEM) is more stringent than the Chicago Classification version 3.0 (CCv3.0) definition. We aimed to compare the clinical and manometric features of patients meeting CCv4.0 IEM criteria (group 1) versus patients meeting CCv3.0 IEM but not CCv4.0 criteria (group 2). We collected retrospective clinical, manometric, endoscopic, and radiographic data on 174 adults diagnosed with IEM from 2011 to 2019. Complete bolus clearance was defined as evidence of exit of the bolus by impedance measurement at all distal recording sites. Barium studies included barium swallow, modified barium swallow, and barium upper gastrointestinal series studies, and collected data from these reports include abnormal motility and delay in the passage of liquid barium or barium tablet. These data along with other clinical and manometric data were analyzed using comparison and correlation tests. All records were reviewed for repeated studies and the stability of the manometric diagnoses. Most demographic and clinical variables were not different between the groups. A lower mean lower esophageal sphincter pressure was correlated with greater percent of ineffective swallows in group 1 (n = 128) (r = -0.2495, P = 0.0050) and not in group 2. In group 1, increased percent of failed contractions on manometry was associated with increased incomplete bolus clearance (r = 0.3689, P = 0.0001). No such association was observed in group 2. A lower median integrated relaxation pressure was correlated with greater percent of ineffective contractions in group 1 (r = -0.1825, P = 0.0407) and not group 2. Symptom of dysphagia was more prevalent (51.6% versus 69.6%, P = 0.0347) in group 2. Dysphagia was not associated with intrabolus pressure, bolus clearance, barium delay, or weak or failed contractions in either group. In the small number of subjects with repeated studies, a CCv4.0 diagnosis appeared more stable over time. CCv4.0 IEM was associated with worse esophageal function indicated by reduced bolus clearance. Most other features studied did not differ. Symptom presentation cannot predict if patients are likely to have IEM by CCv4.0. Dysphagia was not associated with worse motility, suggesting it may not be primarily dependent on bolus transit.

Physiological Alterations in Swallowing in Elderly People: A Systematic Review

Many changes in swallowing function occur in the elderly, age-related swallowing alterations are well-researched and frequently identify people above sixty as older people. The effect of age on swallowing should be clarified to improve. Understanding the impact of age on swallowing has implications for differentiating between swallowing difficulties associated with ageing and those associated with specific medical conditions. Older folks are living longer and in better health than ever before, with many living past 85 years of age. To effectively address swallowing issues in elderly patients, doctors must comprehend healthy swallowing modifications in the "oldest old". This systematic review compiled and evaluated papers that used instrumental evaluation to look at alterations in swallowing in persons over 85. Participants over 85 who were in good health were required for participation. Studies that focused on oral functioning and anatomy were prohibited .Two thousand two hundred thirty-six (2236) papers from investigations up to 2018 were gathered from Scopus, Embase, CINAHL, Medline, and BIOSIS. Because the oldest old were not enrolled, 86% of investigations examining age-related swallowing alterations were disregarded after data screening. Thirteen articles passed the PRISMA assessment and were considered. These were then examined for quality, bias, and data extractions. The primary quantitative abnormalities in swallowing associated with ageing were an increase in the swallow onset delays, bolus transit times. Identify of the ‘normal’ for swallowing in elderly is important to clinical and instrumental swallow examinations and to inform interventions that might effect on the person’s life. Fewer papers found elevated residue or aspiration-related airway impairment. Due to differences in age groups, criteria for classifying individuals as "healthy," measurements employed to define swallowing physiology, and swallowing activities, findings could not be easily compared. There are identified swallowing alterations that are caused by ageing but do not endanger safety. Normative deglutition study underrepresents the oldest old. It is crucial that future research consider recruiting people above 85 years old.

Sincronización entre la videodeglución y la electromiografía de superficie en pacientes con afectación neurológica y síntomas de disfagia

Introducción. La disfagia se define como la dificultad para movilizar la comida desde la boca hasta el estómago. La prueba diagnóstica para esta condición es la videofluoroscopia, la cual no es totalmente inocua pues utiliza radiación ionizante. La electromiografía de superficie registra la actividad eléctrica de los músculos de manera no invasiva, por lo que puede considerarse como una alternativa para evaluar la deglución y estudiar la disfagia. Objetivo. Evaluar la relación entre los tiempos relativos de activación de los músculos implicados en la fase oral y faríngea de la deglución, con los movimientos registrados durante la videofluoroscopia. Materiales y métodos. Se analizaron las señales de la electromiografía de superficie de 10 pacientes neurológicos con síntomas de disfagia, captadas en forma simultánea con la videofluoroscopia. Se suministraron 5 ml de yogur y 10 ml de agua, y 3 g de galleta. Se estudiaron bilateralmente los grupos musculares maseteros, suprahioideos e infrahioideos. Se analizó el paso del bolo por la línea mandibular, las valleculas y el músculo cricofaríngeo, correlacionándolo con el tiempo inicial y el final de la activación de cada uno de los grupos musculares. Resultados. El tiempo promedio de la fase faríngea fue de 0,89 ± 0,12 s. En la mayoría de los casos, hubo activación muscular antes del paso por la línea mandibular y las valleculas. La terminación de la actividad muscular parece corresponder al momento en que se completa el paso del bolo alimenticio por el músculo cricofaríngeo. Conclusión. Se determinaron los tiempos de actividad muscular, la duración de la fase faríngea y la secuencia de la activación de los grupos musculares involucrados en la deglución, mediante electromiografía de superficie, validada con la videofluoroscopia.

Pharyngeal Bolus Transit During Swallowing Before and Short-Term After Thyroidectomy

Background: Thyroid nodules are common in the population and may be associated with dysphagia. The surgical treatment of these nodules is a risk for lesion of cranial nerves branches with the possibility of swallowing and voice impairment. Dysphagia may be a complaint after the surgery even without nerves lesions. The objective of this investigation was to evaluate the pharyngeal bolus transit before and short-term after surgical treatment of thyroid nodules. Methods: Thirty-eight consecutive patients with thyroid nodules had videofluoroscopic evaluation of swallowing timing before the surgery. Dysphagia was a complaint in 20 (53%). In 21 (55%) the nodules were benign. Twenty-seven (71%) were submitted to total thyroidectomy. In 26 the swallow was also evaluated one to five days (median two days) after the surgery. The control group comprised 21 healthy volunteers. In videofluoroscopy patients and volunteers swallowed, in duplicate and random sequence, 5 mL and 10 mL of boluses of two consistencies, moderately thick and extremely thick. Results: Before the surgery patients had a delay in upper esophageal sphincter opening after the bolus arrived at the sphincter. After the surgery the patients had a shorter swallowing reaction time with 5 mL moderately thick bolus and shorter pharyngeal clearance with 10 mL extremely thick bolus. Conclusion: Before thyroid surgery patients with thyroid nodules had a delay in the upper esophageal sphincter opening related to bolus reach the sphincter. Few days after thyroidectomy there is an improvement of pharyngeal clearance of an extremely thick bolus.

Virtual disease landscape using mechanics-informed machine learning: Application to esophageal disorders

Esophageal disorders are related to the mechanical properties and function of the esophageal wall. Therefore, to understand the underlying fundamental mechanisms behind various esophageal disorders, it is crucial to map mechanical behavior of the esophageal wall in terms of mechanics-based parameters corresponding to altered bolus transit and increased intrabolus pressure. We present a hybrid framework that combines fluid mechanics and machine learning to identify the underlying physics of various esophageal disorders (motility disorders, eosinophilic esophagitis, reflux disease, scleroderma esophagus) and maps them onto a parameter space which we call the virtual disease landscape (VDL). A one-dimensional inverse model processes the output from an esophageal diagnostic device called the functional lumen imaging probe (FLIP) to estimate the mechanical “health” of the esophagus by predicting a set of mechanics-based parameters such as esophageal wall stiffness, muscle contraction pattern and active relaxation of esophageal wall. The mechanics-based parameters were then used to train a neural network that consists of a variational autoencoder that generated a latent space and a side network that predicted mechanical work metrics for estimating esophagogastric junction motility. The latent vectors along with a set of discrete mechanics-based parameters define the VDL and formed clusters corresponding to specific esophageal disorders. The VDL not only distinguishes among disorders but also displayed disease progression over time. Finally, we demonstrated the clinical applicability of this framework for estimating the effectiveness of a treatment and tracking patients' condition after a treatment.

Contrast-enhanced ultrasound for assessing blood flow modulation of hepatocellular carcinoma by hydralazine.

Modulating aberrant tumor microvasculature provides unique opportunities for enhancing ultrasound imaging of hepatocellular carcinoma (HCC). This study aims to use contrast-enhanced ultrasound to evaluate the potential of a potent vasodilator, hydralazine, to attenuate blood flow in HCC while enhancing it in the surrounding liver tissue. The "steel effect," where blood flow is diverted from the lesion to the surrounding tissue aims to enhance lesion-tissue contrast. Methods: HCC was induced in six rats by oral ingestion of diethylnitrosamine for 12 weeks. 10 tumors were studied to assess the enhancement in HCC tumors and surrounding tissue. Contrast-enhanced ultrasound images (CEUS) of each tumor were acquired before and after hydralazine injection. The enhancement of images was analyzed for the qualitative and quantitative assessment of HCC enhancement. Peak enhancement (PE) was calculated, representing the maximum signal intensity reached during the transit of the contrast bolus for both the tumor and the surrounding tissue. Intravenous administration of hydralazine significantly reduced CEUS signals in HCC tumors. The visual examination of images showed that the enhancement of tumors dramatically decreased after hydralazine injection. On the other hand, the surrounding tissue showed an increased enhancement. PE for the HCC changed from (71.8 ± 5) pre hydralazine to (28.7± 4.9), a 61.7% reduction after hydralazine injection, p=0.01. Future studies validating the technique in clinical settings for enhancing lesion-tissue contrast may allow physicians greater precision and accuracy in HCC surveillance for early detection of small tumors.

Voluntary Cough Testing as a Clinical Indicator of Airway Protection in Cervical Spinal Cord Injury.

Voluntary cough testing (VCT) may be useful for determining aspiration risk in neurogenic dysphagia; however, has yet to be investigated in traumatic cervical spinal cord injury (tCSCI). The study explored if VCT may elucidate swallowing safety and kinematics related to airway protection in tCSCI survivors. Ten inpatients, 13-73 days post-tCSCI (7 incomplete injuries), completed VCT and a modified barium swallowing study that was analyzed via the Penetration Aspiration Scale (PAS) and norm-referenced measures of swallowing events related to airway protection. Spearman rho correlations explored relations among cough airflow, median PAS, and airway protection. Mann-Whitney U tests explored group differences based on clinical airway invasion (PAS > 2) and receiver operating characteristic statistics probed the sensitivity/specificity of VCT measures. Safe (PAS > 2) and unsafe swallowers differed by cough volume acceleration (CVA) for the total sample and by inspiratory duration for incomplete injuries (p= 0.03, r> 0.7). A cut-off value of 24.8 L/s for CVA predicted airway invasion (AUC= 0.917, p= 0.03) with sensitivity=100%/specificity=75%. CVA correlated with delayed laryngeal vestibule closure during swallowing for both the total sample and for incomplete injuries (rs > 0.6, p< 0.05). Blunted peak flow and prolonged cough phases were associated with disordered laryngeal kinematics and prolonged bolus transit during swallowing (p< 0.05). Reduced CVA, blunted peak flow, and prolonged cough phases reflected PAS and disrupted mechanisms of airway protection in tCSCI survivors, demonstrating promise for VCT as a clinical assessment for post-tCSCI dysphagia. 3 Laryngoscope, 133:1434-1441, 2023.

High-resolution impedance manometry for comparing bolus transit between patients with non-obstructive dysphagia and asymptomatic controls.

Currently, there are no high-resolution impedance manometry (HRIM)-based diagnostic criteria for non-obstructive dysphagia (NOD). New impedance parameters, such as the esophageal impedance integral (EII) and volume of inverted impedance (VII) ratios, have shown strong correlations with bolus transit. This study compared the EII and VII ratios as diagnostic tools for NOD. We analyzed 36 participants (12 patients with achalasia, 12 patients with NOD [7 with normal motility and 5 with ineffective esophageal motility], and 12 asymptomatic controls) who underwent HRIM with a maximum of 5 swallows per participant. The EII and VII ratios were calculated as Z2 (post-swallow)/Z1 (pre-swallow). Bolus transit was retrospectively evaluated using transluminal impedance analysis. Both EII and VII ratios could effectively distinguish the achalasia group from the non-achalasia groups (area under the receiver operating characteristic curve [AUROC]: 0.83 for VII vs. 0.80 for EII; p=0.73). However, the VII ratio was significantly better in discriminating asymptomatic controls from patients with dysphagia (NOD + achalasia) (AUROC: 0.81 vs. 0.68; p=0.01). Moreover, the VII ratio was better in discriminating asymptomatic controls from patients with NOD (AUROC: 0.68 vs. 0.51; p=0.06). In repeated swallows, the VII ratio was consistently the lowest in controls and the highest in patients with achalasia, whereas the EII ratio did not show a consistent pattern. The VII ratio was more reliable than the EII ratio for describing bolus transit and distinguishing patients with NOD from asymptomatic controls, even during repeated measures of subsequent swallows.

Longitudinal dysphagia assessment in adult patients with nephropathic cystinosis using the Modified Barium Swallow Impairment Profile.

Nephropathic cystinosis is a lysosomal storage disorder with known myopathic features, including dysphagia. Evaluation of oropharyngeal swallowing physiology can be standardized using the Modified Barium Swallow Impairment Profile (MBSImP), a validated assessment tool used to analyze and rate swallowing across 17 distinct physiologic domains. Our objective was to better characterize swallowing impairments in nephropathic cystinosis using MBSImP analysis. We retrospectively evaluated 40 video fluoroscopic swallowing studies performed at two time points over 1y in patients with nephropathic cystinosis with various levels of oral and pharyngeal stage dysphagia. Patients completed two self-administered dysphagia outcome measures (the M. D. Anderson Dysphagia Inventory [MDADI] and the 10-item Eating Assessment Tool [EAT-10]). We demonstrated oral stage and pharyngeal stage dysphagia across domains that impacted bolus control, transit, and clearance through both the oral cavity and pharyngeal lumen. Also captured were deficits related to onset and completeness of laryngeal closure that impact airway protection during swallow. There were significant correlations between pharyngeal total score and EAT-10 (r= 0.5, p< 0.001) and between oral total score and EAT-10 (r= 0.7, p< 0.001), MDADI-e (r= -0.6, p< 0.001), MDADI-p (r= -0.5, p< 0.001) and MDADI-c (r= -0.6, p< 0.001). There were no differences in oral or pharyngeal total scores across the 1-y time span. This study identifies oral and pharyngeal stage dysphagia as crucial to patients with nephropathic cystinosis and paves the path for future studies of treatment targets.

Normative values of intra-bolus pressure and esophageal compliance based on 4D high-resolution impedance manometry.

This study aimed to quantify normative values of phase-specific intra-bolus pressure (IBP) and esophageal distensibility using 4D analysis of high-resolution-impedance manometry (HRIM). HRIM studies of supine swallows from 34 normal controls were analyzed with respect to the four phases of bolus transit: (1) accommodation, (2) compartmentalization, (3) peristalsis/esophageal emptying, and (4) ampullary emptying. Phase-specific IBP, bolus volume, and distensibility index (DI) in the esophageal body and esophagogastric junction (EGJ) during phases 1-3 were extracted. The median (5-95th/IQR) IBP values were as follows: phase 1: 4.0 (-2.0-10.4/1.9-5.8)mmHg, phase 2: 5.7 (0.2-14.1/3.6-8.9)mmHg, and phase 3: 11.2 (2.9-19.4/7.7-15.1)mmHg. The median bolus volume calculated by integrating impedance planimetry cross-sectional areas was 4.1ml during the compartmentalization phase. The EGJ-DI at max EGJ diameter during phase 2 and 3 was 2.8 (1.1-9.5/1.8-3.7)mm2 /mmHg and 6.0 (3.2-20.3/5.1-7.8)mm2 /mmHg, respectively. The phase 3 EGJ-DI values (6.0 (3.2-20.3/5.1-7.8)mm2 /mmHg) were similar to those calculated using functional lumen imaging probe (FLIP) at the 60 ml volume on the same subjects (5.8 [3.5-7.2/5.0-6.4]mm2 /mmHg). 4D-HRIM provides a standardized methodology to track the nadir impedance and provide measurements of IBP during maximal distention across phases 1-3 of bolus transit. Median IBP and delta IBP were different across the phases, supporting the need to define IBP by phase. Additionally, the EGJ-DI calculated during phase 3 was similar to the 60-ml EGJ-DI from FLIP in the same subjects suggesting that 4D-HRIM can quantify EGJ opening during primary peristalsis.

Swallowing Kinematics in Rats Treated with Low Dose Chemotherapy Concurrently with Fractionated Radiation

Dysphagia is a common consequence of chemotherapy and radiation treatment for oropharyngeal cancer. Injury is thought to occur due to damage to the muscle and/or nerves. This can severely impair swallowing function, leading to serious negative outcomes such as aspiration related pneumonia or tube feeding placement to maintain nutrition. Currently, there are only strategies to prevent swallowing dysfunction; however, the development of chronic radiation associated dysphagia persists effecting ~25% of head and neck cancer survivors. Therefore, there is a need to study the mechanisms associated with radiation associated dysphagia to help guide new treatments to improve swallowing outcomes. The present study investigated the effects of concurrent chemoradiation on swallowing function. We tested the hypothesis that fractionated radiation with low doses of chemotherapy alters swallowing kinematics and bolus transit compared to radiation alone or normal controls. We monitored the functional extent of chemoradiation or radiation treatment using videofluoroscopy swallow study in self feeding rats (n=16) at four weeks post treatment. Twelve rats underwent 48Gy of fractionated radiation to the submental muscles using a clinical linear accelerator given in 12 fractions of 4Gy. Irradiated rats received either cisplatin 1mg/kg or saline IP once per week for four weeks during radiation treatment. Four rats received no treatment. During videofluoroscopy, thin liquids and puree consistencies mixed with 40% w/v barium sulfate were given ad libitum. The movement trajectories of the tongue, mandible, and hyoid bone were quantitatively tracked from video data. Changes in the speed of the jaw and hyoid during swallowing were observed between treated and control rats. No differences were observed in bolus flow parameters i.e. pharyngeal transit speed, inter‐swallow interval, and swallow frequency between treatment groups. The average size of the bolus in vallecula decreased by ~4% prior to initiating pharyngeal swallow with chemoradiated rats (p &lt; 0.05). Results suggest that low doses of chemotherapy in conjunction with radiation appear to have minimal differences in swallowing kinematics compared to radiation alone. Higher doses of chemotherapy may be needed to induce similar abnormalities in swallowing as seen clinically.

The Utility of Functional Luminal Imaging Probes Measurements to Diagnose Dysmotility and Their Relationship to Impaired Bolus Clearance.

Functional luminal imaging probes (FLIP) have been used by multiple centers to assess esophagogastric junction (EGJ) function in patients at risk for esophageal obstruction but its role in diagnosing peristaltic disorders is less well studied. In particular, there are no studies comparing the sensitivity of FLIP to diagnose motility abnormalities and impaired bolus transit by high-resolution esophageal manometry with impedance. We prospectively recruited 42 patients undergoing high-resolution esophageal manometry with impedance (HRIM) who also underwent FLIP between 2018 and 2020. HRIM parameters were analyzed using Swallow Gateway software to determine peristaltic and lower esophageal sphincter pressure measurements as well as bolus flow parameters. FLIP tracings were analyzed for the presence of repetitive antegrade contractions (RACs), EGJ distensibility, and associated parameters. Forty-two patients were included (11 controls, 7 achalasia, 16 fundoplication, 8 dysmotility). The mean age of patients was 10.1 ± 0.9 years. There were significant differences in bolus flow parameters across diagnosis with longer bolus presence (BPT) in control patients compared with fundoplication and dysmotility patients. There was a significant correlation between EGJ diameter, EGJ distensibility and bolus flow time (BFT) for solid foods (r2 > 0.518, P < 0.02). The presence of RACs and EGJ relaxation during RACs was associated with a greater BFT and BPT across textures (P < 0.05). Forty-two percentage of patients with absent RACs, however, had clear peristalsis by HRIM. The presence of RACs and EGJ relaxation by FLIP correlate with improved bolus flow. Patients with an absence of RACs need HRIM to confirm any diagnoses of dysmotility.

Association of Bolus Transit Time on Barium Esophagram With Esophageal Peristalsis on High-resolution Manometry and Nonobstructive Dysphagia.

The goal of this study was to correlate upright and prone bolus transit time (BTT) on barium esophagography (BE) with esophageal peristalsis on high-resolution manometry (HRM) and self-reported dysphagia in patients with normal lower esophageal sphincter parameters on HRM. BTT on BE could be the gold standard for assessing the effectiveness of esophageal peristalsis if it can be quantified. Patients with normal lower esophageal sphincter parameters and standard-protocol BE from 2017 to 2020 were included. Patients were divided, based on the number of normal swallows (distal contractile integral >450 mm Hg-s-cm), into 11 groups (10 normal swallows to 0 normal swallows). Liquid barium swallows in prone position were objectively evaluated for prone BTT. Patients reported difficulty in swallowing on a scale from 0 (none) to 4 (very severe). Fractional polynomial and logistic regression analysis were used to study the association (along with the rate of change) between BTT, peristalsis, and dysphagia. A total of 146 patients were included. Prone BTT increased as the number of normal swallows decreased ( P <0.001). Two deflection points were noted on the association between peristalsis and prone BTT at 50% normal swallows, 40 seconds and 30% normal swallows, 80 seconds, after which peristaltic function declined independently of prone BTT. Patients with prone BTT>40 seconds had nearly 6-fold higher odds of 0% normal swallows on HRM than patients with prone BTT<40 seconds ( P =0.002). Increasing prone BTT was associated with increasing dysphagia grades 1 and 2 ( P ≤0.036). Esophageal motility can be quantified by BE. Prone BTT correlates with the proportion of normal esophageal swallows and dysphagia.

Thin Liquid Bolus Volume Alters Pharyngeal Swallowing: Kinematic Analysis Using 3D Dynamic CT.

The previous studies reported that different volumes of thick liquid had an impact on spatiotemporal characteristics and pharyngeal response of swallowing. However, the bolus flow and swallowing motion pattern were different between thick and thin liquids. The effects of thin bolus volume on pharyngeal swallowing, especially true vocal cord (TVC) closure is still unclear. This study assessed the temporal characteristics when swallowing different volumes of thin liquid to determine the mechanical adaptation using 320-row area detector computed tomography (320-ADCT) and investigated a change of swallowing physiology including laryngeal closure, particularly TVC closure. Fourteen healthy women (28-45years) underwent 320-ADCT while swallowing of 3, 10, and 20ml of thin liquid barium in 45° semi-reclining position. Kinematic analysis was performed for each swallow including temporal characteristic, structural movements while swallowing, and maximal cross-sectional area of the upper esophageal sphincter (UES) opening. Bolus head reached to pharynx and esophagus earlier in larger volume significantly, indicating faster bolus transport as volume increased. There were significant effects on swallowing mechanism revealing earlier TVC closure and UES opening with increasing volume. Maximum cross-sectional area of the UES opening was increased to accommodate a larger bolus. Differences in mechanical adaptation through bolus transit and motion of swallowing structures were detected across increasing volumes. These volume-dependent adaptations potentially reduce the risk of aspiration. Understanding the swallowing physiological changes as volume increased is helpful for diagnosis and treatment of dysphagia patients as well as outcomes of swallowing rehabilitation in clinical practice.

Esophageal Virtual Disease Landscape Using Mechanics-Informed Machine Learning

The pathogenesis of esophageal disorders is related to the esophageal wall mechanics. Therefore, to understand the underlying fundamental mechanisms behind various esophageal disorders, it is crucial to map the esophageal wall mechanics-based parameters onto physiological and pathophysiological conditions corresponding to altered bolus transit and supraphysiologic IBP. In this work, we present a hybrid framework that combines fluid mechanics and machine learning to identify the underlying physics of the various esophageal disorders and maps them onto a parameter space which we call the virtual disease landscape (VDL). A one-dimensional inverse model processes the output from an esophageal diagnostic device called endoscopic functional lumen imaging probe (EndoFLIP) to estimate the mechanical health of the esophagus by predicting a set of mechanics-based parameters such as esophageal wall stiffness, muscle contraction pattern and active relaxation of esophageal walls. The mechanics-based parameters were then used to train a neural network that consists of a variational autoencoder (VAE) that generates a latent space and a side network that predicts mechanical work metrics for estimating esophagogastric junction motility. The latent vectors along with a set of discrete mechanics-based parameters define the VDL and form clusters corresponding to the various esophageal disorders. The VDL not only distinguishes different disorders but can also be used to predict disease progression in time. Finally, we also demonstrate the clinical applicability of this framework for estimating the effectiveness of a treatment and track patient condition after a treatment.

Can FLIP guide therapy in idiopathic esophagogastric junction outflow obstruction?

Esophagogastric junction outflow obstruction (EGJOO) has a variable disease course. Currently, barium swallow (BaS) and manometric parameters are used to characterize clinically significant EGJOO. The esophagogastric junction distensibility index (EGJ-DI) measured via functional lumen imaging probe (FLIP) can provide complementary information. Our aim was to assess symptom response in patients with EGJOO and an abnormal EGJ-DI after botulinum toxin (BT) treatment. A prospective cohort study of adults with idiopathic EGJOO was performed from September 2019 to March 2021. Patients with dysphagia underwent upper endoscopy with FLIP. If the EGJ-DI was abnormally low, BT was injected. Data examined included demographics, medical history, endoscopic and FLIP findings, BaS, manometry, and Eckardt score (ES). ES improvement was assessed via paired samples t-test. Pearson's chi-square tests were used to assess for associations. Of the 20 patients, 75% had an abnormal EGJ-DI and underwent BT injections. Mean ES for patients with abnormal EGJ-DIs significantly improved from baseline to 1, 3, and 6month follow-up (P-values: 0.01, 0.05, and 0.02, respectively). There was a significant association between an abnormal EGJ-DI with delayed bolus transit and presence of rapid drink challenge panesophageal pressurization on manometry: P = 0.03 and P = 0.03. This prospective study revealed that an abnormal EGJ-DI can guide BT as assessed via symptomatic response. Additionally, abnormal EGJ-DI measurements were significantly associated with other parameters used previously to determine clinically relevant EGJOO. Larger follow-up studies are warranted to further elucidate guidance for therapy in EGJOO.

Bolus transit of upper esophageal sphincter on high-resolution impedance manometry study correlate with the laryngopharyngeal reflux symptoms

Laryngopharyngeal reflux symptom is a troublesome upper esophageal problem, and reflux symptom index (RSI) is commonly applied for the assessment of clinical severity. We investigated the relationship between the upper esophageal sphincter impedance integral (UESII) and RSI scores in this study. Totally 158 subjects with high-resolution esophageal impedance manometry (HRIM) with RSI questionnaire assessment were recruited. There are 57 (36.08%), 74 (46.84%), 21 (13.29%), and 6 (3.79%) patients were categorized as normal, ineffective esophageal motility disorder, absent contractility, and achalasia by HRIM examination, respectively. Subjects with RSI > 13 were noted to have lower UESII than others with RSI ≦ 13 (7363.14 ± 1085.58 vs. 11,833.75 ± 918.77 Ω s cm; P < 0.005). The ROC analysis yielded a UESII cutoff of < 2900 Ω s cm for the best prediction of subjects with RSI > 13 (P = 0.002). Both female gender and UESII cutoff of < 2900 Ω s cm were significant predictors of RSI > 13 in logistic regression analysis (OR = 3.84 and 2.83; P = 0.001 and 0.01; respectively). Lower UESII on HRIM study, indicating poor bolus transit of UES during saline swallows, is significantly associated with prominent laryngopharyngeal reflux symptoms scored by RSI score.

Quantitative contrast-enhanced ultrasound for the evaluation and early detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with high mortality mainly due to pre-existing liver disease and delay in diagnosis, limiting treatment options. Currently, the state-of-the-art diagnostic metric for HCC is LiRADS (Liver Imaging Reporting and Data System), a qualitative image assessment based on the bolus transit characteristics of microbubbles that stratifies liver tumors suspected for HCC. However, with contrast-enhanced ultrasound, liver tumor perfusion can be quantifiably characterized to identify abnormal arterial flow after an initial portal venous and hepatic arterial flow reduction in the liver, which are typical features of HCCs. The image intensity in a region of interest (ROI) in the HCC is used to form a time-intensity curve (TIC) of the bolus transit (wash-in/washout). A lognormal curve is fitted to the TIC and parameters related to blood flow in the tumor are extracted. Respiratory gating and motion compensation are applied to the video loops before forming the TIC to remove noise and improve the accuracy of the HCC perfusion measurements. Parametric images of the rise time and peak intensity provide an HCC classification algorithm. Utilizing this approach, we provide an improvement to the LiRADS method for an earlier and more accurate diagnosis of HCC.

153 THE CLINICAL SIGNIFICANCE OF INCOMPLETE BOLUS CLEARANCE IN PATIENTS WITH DYSPHAGIA

Abstract The primary function of the esophagus is to facilitate bolus transport to the stomach. High-resolution manometry assesses the functions of esophageal motility, but not the clearance of bolus transit through the esophagus. The development of combined multichannel intraluminal impedance and manometry (MII-EM) has enabled simultaneous measurement of bolus transport and manometry. This study investigated the effects of bolus transit on esophageal motility disorders and its effect on the quality of life of patients with dysphagia. Methods A total of 810 wet swallows were reviewed and analyzed in 81 patients with dysphagia who underwent MII-EM. Incomplete bolus clearance (IBC) was defined based on impedance measurement. IBC was classified into four types (A: normal, B: incomplete clearance in the upper esophagus, C: incomplete clearance in the lower esophagus, D: incomplete clearance of the whole esophagus), and was also evaluated according to the appearance rate of complete bolus transit. Then, the clinical significance of IBC was determined by our previously validated dysphagia symptom score and the SF8 quality of life instrument (physical component summary and mental component summary). Results There were 16 cases of esophageal achalasia (Ach), 9 of esophagogastric junction outflow obstruction (EGJOO), 8 of distal esophageal spasm (DES), 7 of Jackhammer esophagus (JE), 2 of absent contractility (AC), 10 of ineffective esophageal motility (IEM) and 29 normal cases. The figure shows the breakdown of IBC for each disorder. Complete bolus transit was found in 27.8% in EGJOO, 52.5% in DES, 14.2% in JE, 4.0% in IEM, and 83.3% in normal; no CBT was found in Ach and AC. Patients with IBC had significantly higher dysphagia symptom scores (p &amp;lt; 0.05) and lower mental component summaries (p &amp;lt; 0.05) than those without. Conclusion Patients with dysphagia with esophageal dysmotility were classified into two groups: those with and without IBC. Assessment of bolus transport is an important clinical marker for patients with dysphagia, because those with IBC had a significantly higher dysphagia symptom scores and impaired quality of life.

807 ASSOCIATION OF BOLUS TRANSIT TIME ON BARIUM ESOPHAGOGRAM WITH ESOPHAGEAL PERISTALSIS

Abstract The threshold criteria for diagnosing ineffective esophageal motility (IEM) has changed over the years and is based on the proportion of failed and weak peristalses. Bolus transit time (BTT) on barium esophagogram (BE) can intuitively be the ‘gold standard' for assessing the effectiveness of esophageal peristalsis. The aim of this study was to associate upright and prone BTT with esophageal peristalsis and dysphagia in patients with normal lower esophageal sphincter (LES) parameters. Methods Patients with normal LES on high-resolution manometry (HRM) who also had a standard-protocol BE from 2017 to 2020 were included. Patients with previous foregut surgery, hiatal hernia, jackhammer esophagus, distal esophageal spasm, fragmented peristalsis, and those with &amp;lt; or &amp;gt; 10 single swallows on HRM were excluded. Based on the number of normal swallows (DCI &amp;gt;450 mmHg.s.cm), the patients were divided into 11 groups (10 normal to 0 normal). Upright and prone BTT were measured on BE. Fractional polynomial and logistic regression analysis were used to study association (along with rate of change) between BTT, dysphagia, and peristalsis. Results In total, 146 patients met the inclusion criteria. Prone BTT increased in tandem with a decrease in the number of normal peristalses (p &amp;lt; 0.001), but no difference was noted in upright BTT (p = 0.317). Two deflection points were noted on the association between peristalsis and prone BTT at 50%, 40 seconds and 30%, 80 seconds on the y and x-axes, respectively, after which declining peristaltic function was independent of prone BTT. Patients with prone BTT &amp;gt;40 seconds had nearly 6-fold higher odds of having zero normal peristalses (p = 0.002). Increasing prone BTT was associated with increasing dysphagia (p &amp;lt; 0.05). Conclusion Prone, but not upright BTT, correlates with the proportion of normal esophageal peristalses and dysphagia. The phenotype of abnormal swallows (failed, weak) appears to have minimal impact on BTT. The current perspective of manometric classification may need to be adjusted to use the proportion of normal peristalses as a criterion.