A multi-stage machine learning model for diagnosis of esophageal manometry

High-resolution manometry (HRM) is the primary procedure used to diagnose esophageal motility disorders. Its manual interpretation and classification, including evaluation of swallow-level outcomes and then derivation of a study-level diagnosis based on Chicago Classification (CC), may be limited by inter-rater variability and inaccuracy of an individual interpreter. We hypothesized that an automatic diagnosis platform using machine learning and artificial intelligence approaches could be developed to accurately identify esophageal motility diagnoses. Further, a multi-stage modeling framework, akin to the step-wise approach of the CC, was utilized to leverage advantages of a combination of machine learning approaches including deep-learning models and feature-based models. Models were trained and tested using a dataset comprised of 1741 patients' HRM studies with CC diagnoses assigned by expert physician raters. In the swallow-level stage, three models based on convolutional neural networks (CNNs) were developed to predict swallow type and swallow pressurization (test accuracies of 0.88 and 0.93, respectively), and integrated relaxation pressure (IRP)(regression model with test error of 4.49 mmHg). At the study-level stage, model selection from families of the expert-knowledge-based rule models, xgboost models and artificial neural network(ANN) models were conducted. A simple model-agnostic strategy of model balancing motivated by Bayesian principles was utilized, which gave rise to model averaging weighted by precision scores. The averaged (blended) models and individual models were compared and evaluated, of which the best performance on test dataset is 0.81 in top-1 prediction, 0.92 in top-2 predictions. This is the first artificial-intelligence style model to automatically predict esophageal motility (CC) diagnoses from HRM studies using raw multi-swallow data and it achieved high accuracy. Thus, this proposed modeling framework could be broadly applied to assist with HRM interpretation in a clinical setting.

Validation of secondary peristalsis classification using FLIP panometry in 741 subjects undergoing manometry

BACKGROUND AND AIMS

This study aimed to systematically evaluate a classification scheme of secondary peristalsis using functional luminal imaging probe (FLIP) panometry through comparison with primary peristalsis on high-resolution manometry (HRM).

METHODS

706 adult patients that completed FLIP and HRM for primary esophageal motility evaluation and 35 asymptomatic volunteers ("controls") were included. Secondary peristalsis, that is, contractile responses (CRs), was classified on FLIP panometry by the presence and pattern of contractility as normal (NCR), borderline (BCR), impaired/disordered (IDCR), absent (ACR), or spastic-reactive (SRCR). Primary peristalsis on HRM was assessed according to the Chicago Classification.

RESULTS

All 35 of the controls had antegrade contractions on FLIP panometry with either NCR (89%) or BCR (11%). The average percentages of normal swallows on HRM varied across contractile response patterns from 84% in NCR, 68% in BCR, 39% in IDCR, to 11% in ACR, as did the percentage of failed swallows on HRM: 4% in NCR, 12% in BCR, 36% in IDCR, and 79% in ACR. SRCR on FLIP panometry was observed in 18/57 (32%) patients with type III achalasia, 4/15 (27%) with distal esophageal spasm, and 7/15 (47%) with hypercontractile esophagus on HRM.

CONCLUSIONS

The FLIP panometry contractile response patterns reflect a pathophysiologic transition from normal to abnormal esophageal peristaltic function with shared features with primary peristaltic function/dysfunction on HRM. Thus, these patterns of the contractile response to distension can facilitate the evaluation of esophageal motility using FLIP panometry.

Variability in endoscopic assessment of Nissen fundoplication wrap integrity and hiatus herniation

BACKGROUND

Upper endoscopy (EGD) is frequently performed in patients with esophageal complaints following anti-reflux surgery such as fundoplication. Endoscopic evaluation of fundoplication wrap integrity can be challenging. Our primary aim in this pilot study was to evaluate the accuracy and confidence of assessing Nissen fundoplication integrity and hiatus herniation among gastroenterology (GI) fellows, subspecialists, and foregut surgeons.

METHODS

Five variations of post-Nissen fundoplication anatomy were included in a survey of 20 sets of EGD images that was completed by GI fellows, general GI attendings, esophagologists, and foregut surgeons. Accuracy, diagnostic confidence, and inter-rater agreement across providers were evaluated.

RESULTS

There were 31 respondents in the final cohort. Confidence in pre-survey diagnostics significantly differed by provider type (mean confidence out of 5 was 1.8 for GI fellows, 2.7 for general GI attendings, 3.6 for esophagologists, and 3.6 for foregut surgeons, P = 0.01). The mean overall accuracy was 45.9%, which significantly differed by provider type with the lowest rate among GI fellows (37%) and highest among esophagologists (53%; P = 0.01). The accuracy was highest among esophagologists across all wrap integrity variations. Inter-rater agreement was low across wrap integrity variations (Krippendorf's alpha <0.30), indicating low to no agreement between providers.

CONCLUSION

In this multi-center survey study, GI fellows had the lowest accuracy and confidence in assessing EGD images after Nissen fundoplication, whereas esophagologists had the highest. Diagnostic confidence varied considerably and inter-rater agreement was poor. These findings suggest experience may improve confidence, but highlight the need to improve the evaluation of fundoplication wraps.

Dysphagia: Novel and Emerging Diagnostic Modalities

Among recent advances in diagnostics for dysphagia and esophageal motility disorders is the update to the Chicago Classification (version 4.0) for interpretation of high-resolution manometry (HRM) and diagnosis of esophageal motility disorders. The update incorporates application of complementary testing strategies during HRM, such as provocative HRM maneuvers, and recommendation for barium esophagram or functional luminal imaging probe (FLIP) panometry to help clarify inconclusive HRM findings. FLIP panometry also represents an emerging technology for evaluation of esophageal distensibility and motility at the time of endoscopy.

New materials for improving catches of horseflies (Diptera: Tabanidae) in Nzi traps

New materials in 85 configurations were tested relative to standard fabric Nzi traps to improve catches of tabanids based on artificial visual cues that mimic those used in nature for locating hosts or water. Colour-fast synthetic fabrics and photo-selective horticultural mesh were tested to facilitate insecticide impregnation and for improved durability. Many plastics were explored to document how flies react to polarized and visible vs. ultraviolet light. Lastly, sticky horizontal, linearly polarizing ground-level shiny plastic targets were tested for capturing water-seeking tabanids relative to traps and vertical fabric targets. Based on the capture of 281 786 female Tabanidae (Tabanus Linnaeus, Hybomitra Enderlein, Chrysops Meigen), four alternative formats provided higher catches and/or durability. They were substituting: (1) phthalogen turquoise for phthalogen blue, (2) solution-dyed fabrics for blue and black cotton, (3) clear/white horticultural mesh for mosquito netting, and (4) clear, reflective plastic for some or all netting. A Sunbrella/BioNet fabric trap (portable) and a blue-black Plexiglas®/netting trap (fixed applications) consistently performed best (1.5-3 × higher catches). Ground-level targets captured many male and gravid female Hybomitra but were ineffective for Tabanus. Traps and vertical fabric or transparent sticky targets captured mainly unfed females.

Symptom Severity Related With Contraction Peaks in Patients With Jackhammer Esophagus

Background/Aims

Jackhammer esophagus is an uncommon heterogeneous motility disorder associated with a distal contractile integral > 8000 mmHg∙sec∙cm. The spectrum of abnormality ranges from a relatively normal looking contraction to chaotic repetitive contractions akin to a jackhammer. Although previous studies have shown an uncertain correlation between peristaltic vigor and symptoms, we hypothesize that symptoms may be more severe with repetitive contractions as opposed to an elevated contractile measure. Thus, this study aims to investigate whether symptom severity is related to the contraction pattern in the patients with hypercontractile esophagus.

Methods

Patients with hypercontractile esophagus were retrospectively identified, their demographic and high-resolution manometry characteristics were collected. Contraction pattern on high-resolution manometry was categorized into single-peak and multiple-peak. Comparison was performed between patients with single-peak and multiple-peak.

Results

Altogether 35 patients (age range, 45-70 years; femalemale, 2411) were included. Seven patients presented with single-peak hypercontractile swallows, while 28 patients presented with multiple-peak hypercontractile swallows. The patients with multiple-peak showed higher Brief Esophageal Dysphagia Questionnaire scores compared with patients with single-peak. The jackhammer swallows with multiple-peak were associated with higher distal contractile integral values, longer distal latency intervals, and a lower integrated relaxation pressure.

Conclusions

Repetitive contractions akin to a jackhammer were common amongst patients with hypercontractile esophagus. Patients with the jackhammer pattern also presented with more severe symptoms. Further distinction of hypercontractile esophagus into a jackhammer dominant subtype may be warranted.

Esophageal Hypervigilance and Symptom-Specific Anxiety in Patients with Eosinophilic Esophagitis

BACKGROUND & AIMS

Patient symptom reporting often does not correlate with the pathophysiological markers of esophageal disease, including eosinophilic esophagitis (EoE). Esophageal hypervigilance and symptom-specific anxiety are emerging as important considerations in understanding symptom reporting. As such, we aimed to conduct the first study of these constructs in EoE.

METHODS

A retrospective review of an EoE patient registry was conducted and included eosinophils per high power field (from esophagogastroduodenoscopy biopsy: proximal, distal), endoscopic reference score, distal distensibility plateau (functional luminal imaging probe), Brief Esophageal Dysphagia Questionnaire, Visual Dysphagia Question of EoE Activity Index, Northwestern Esophageal Quality of Life scale, and the Esophageal Hypervigilance and Anxiety Scale. Correlational and regression analyses evaluated relationships of hypervigilance and anxiety with Brief Esophageal Dysphagia Questionnaire, Visual Dysphagia Question of EoE Activity Index, and Northwestern Esophageal Quality of Life scale when controlling for histology and endoscopic severity.

RESULTS

One hundred and three patients had complete data, 69.9% were male, and the mean (SD) age was 40.66 (13.85) years. Forty-one percent had elevated dysphagia and 46% had elevated hypervigilance and anxiety. Esophageal symptom-specific anxiety emerged as the most important predictor of Brief Esophageal Dysphagia Questionnaire severity (44.8% of the variance), Visual Dysphagia Question of EoE Activity Index severity (26%), and poor health-related quality of life (HRQoL) (55.3%). Hypervigilance was also important, but to a lesser extent. Pathophysiological variables did not significantly predict symptoms or HRQoL. Recent food impaction can predict symptom-specific anxiety and proton pump inhibitor use can reduce hypervigilance.

CONCLUSIONS

Hypervigilance and symptom-specific anxiety are important for our understanding of self-reported patient outcomes in EoE. These processes outweigh endoscopic and histologic markers of EoE disease activity across dysphagia, difficulty eating, and HRQoL. Clinicians should assess hypervigilance and anxiety, especially in patients with refractory symptoms and poor HRQoL.

Evaluating esophageal motility beyond primary peristalsis: Assessing esophagogastric junction opening mechanics and secondary peristalsis in patients with normal manometry

BACKGROUND

Functional luminal imaging probe (FLIP) Panometry assesses the esophageal response to distention and may complement the assessment of primary peristalsis on high-resolution manometry (HRM). We aimed to investigate whether FLIP Panometry provides complementary information in patients with normal esophageal motility on HRM.

METHODS

Adult patients that completed FLIP and had an HRM classification of normal motility were retrospectively identified for inclusion. 16-cm FLIP studies performed during endoscopy were evaluated to assess EGJ distensibility, secondary peristalsis, and identify an abnormal response to distention involving sustained LES contraction (sLESC). Clinical characteristics and esophagram were assessed when available.

KEY RESULTS

Of 164 patients included (mean(SD) age 48(16) years, 75% female), 111 (68%) had normal Panometry with EGJ-distensibility index (DI) ≥2.0 mm2 /mmHg, maximum EGJ diameter ≥16mm and antegrade contractions. Abnormal EGJ distensibility was observed in 44/164 (27%), and 38/164 (23%) had an abnormal contractile response to distension. sLESC was observed in 11/164 (7%). Among 68 patients that completed esophagram, abnormal EGJ distensibility was more frequently observed with an abnormal esophagram than normal EGJ opening: 14/23 (61%) vs 10/45 (22%); P=0.003. Epiphrenic diverticula were present in 3/164 patients: 2/3 had sLESC.

CONCLUSIONS & INFERENCES

Symptomatic patients with normal esophageal motility on HRM predominantly have normal FLIP Panometry; however, abnormal FLIP findings can be observed. While abnormal Panometry findings appear clinically relevant via an association with abnormal bolus retention, complementary tests, such as provocative maneuvers with HRM and timed barium esophagram, are useful to determine clinical context.

The Spanish version of the esophageal hypervigilance and anxiety score shows strong psychometric properties: Results of a large prospective multicenter study in Spain and Latin America

BACKGROUND

Anxiety is a significant modulator of sensitivity along the GI tract. The recently described Esophageal Hypervigilance and Anxiety Score (EHAS) evaluates esophageal-specific anxiety. The aims of this study were as follows: 1. translate and validate an international Spanish version of EHAS. 2. Evaluate its psychometric properties in a large Hispano-American sample of symptomatic individuals.

METHODS

A Spanish EHAS version was developed by a Delphi process and reverse translation. Patients referred for high-resolution manometry (HRM) were recruited prospectively from seven Spanish and Latin American centers. Several scores were used: EHAS, Hospital Anxiety and Depression Scale (HADS), Eckardt score (ES), Gastroesophageal Reflux Questionnaire (GERDQ), and the Brief Esophageal Dysphagia Questionnaire (BEDQ). Standardized psychometric analyses were performed.

KEY RESULTS

A total of 443 patients were recruited. Spanish EHAS showed excellent reliability (Cronbach´s alpha = 0.94). Factor analysis confirmed the presence of two factors, corresponding to the visceral anxiety and hypervigilance subscales. Sufficient convergent validity was shown by moderate significant correlations between EHAS and other symptomatic scores. Patients with high EHAS scores had significantly more dysphagia. There was no difference in EHAS scores when compared normal vs abnormal or major manometric diagnosis.

CONCLUSIONS AND INFERENCES

A widely usable Spanish EHAS version has been validated. We confirm its excellent psychometric properties in our patients, confirming the appropriateness of its use in different populations. Our findings support the appropriateness of evaluating esophageal anxiety across the whole manometric diagnosis spectrum.

Comparison of preoperative, intraoperative, and follow-up functional luminal imaging probe measurements in patients undergoing myotomy for achalasia

BACKGROUND AND AIMS

The functional luminal imaging probe (FLIP) is a novel catheter-based device that measures esophagogastric junction (EGJ) distensibility index (DI) in real time. Previous studies have demonstrated DI to be a predictor of post-treatment clinical outcomes in patients with achalasia. We sought to evaluate EGJ DI in patients with achalasia before, during, and after peroral endoscopic myotomy (POEM) and laparoscopic Heller myotomy (LHM) and to assess the correlation of DI with postoperative outcomes.

METHODS

DI (defined as the minimum cross-sectional area at the EGJ divided by distensive pressure) was measured at 4 time points in patients undergoing surgical myotomy for achalasia: (1) during outpatient preoperative endoscopy (preoperative DI), (2) at the start of each operation after the induction of anesthesia (induction DI), (3) at the conclusion of each operation (postmyotomy DI), and (4) at routine follow-up endoscopy 12 months postoperatively (follow-up DI). Routine Eckardt symptom score, endoscopy, timed barium esophagram, and pH study were obtained 12 months postoperatively.

RESULTS

Forty-six patients (35 POEM, 11 LHM) underwent FLIP measurements at all 4 time points. Preoperative and induction mean DI were similar for both groups (POEM, 1 vs .9 mm²/mm Hg; LHM, 1.7 vs 1.5 mm²/mm Hg). POEM resulted in a significant increase in DI (induction .9 vs postmyotomy 7 mm²/mm Hg, P < .001). There was a subsequent decrease in DI in the follow-up period (postmyotomy 7 vs follow-up 4.8 mm²/mm Hg, P < .01), but DI at follow-up was still significantly improved from preoperative values (P < .001). For LHM patients, DI also increased as a result of surgery (induction 1.5 vs postmyotomy 5.9 mm²/mm Hg, P < .001); however, the increase was smaller than in POEM patients (DI increase 4.4 vs 6.2 mm²/mm Hg, P < .05). After LHM, DI also decreased in the follow-up period, but this change was not statistically significant (5.9 vs 4.4 mm²/mm Hg, P = .29). LHM patients with erosive esophagitis on follow-up endoscopy had a significantly higher postmyotomy DI compared with those without esophagitis (9.3 vs 4.8 mm²/mm Hg, P < .05).

CONCLUSIONS

EGJ DI improved dramatically as a result of both POEM and LHM, with POEM resulting in a larger increase. Mean DI decreased at intermediate follow-up but remained well above previously established thresholds for symptom recurrence. DI at the conclusion of LHM was predictive of erosive esophagitis in the postoperative period, which supports the potential use of FLIP for calibration of partial fundoplication construction during LHM.

Normal Values of High-resolution Manometry Parameters With Provocative Maneuvers

Background/Aims

Incorporation of complementary and provocative test swallows to the high-resolution manometry (HRM) protocol offers potential to address limitations posed by HRM protocols that involve only a single swallow type. The aim of this study is to describe normal findings of a comprehensive HRM testing protocol performed on healthy asymptomatic volunteers.

Methods

Thirty healthy asymptomatic volunteers completed HRM with 5-mL liquid swallows in the supine position. They also completed 5-mL liquid swallows in the upright position, viscous swallows, solid test swallows, multiple rapid swallows, and a rapid drink challenge. HRM studies were analyzed via Chicago classification version 3.0.

Results

The median (5th-95th percentiles) for integrated relaxation pressure (IRP) on supine swallows was 11 (4-16) mmHg; IRP was lower than supine on upright liquid 9 (0-17) mmHg, viscous 6 (0-15) mmHg, solid 9 (1-19) mmHg, multiple rapid swallows 3 (0-12) mmHg, and rapid drink challenge 5 (–3-12) mmHg; P < 0.005. While an “elevated” IRP value was observed on 1 to 2 test maneuvers in 8/30 (27%) subjects, all 30 subjects had an IRP value < 12 mmHg on at least one of the test maneuvers.

Conclusions

Normal values and findings from a comprehensive HRM testing protocol are reported based on evaluation of 30 healthy asymptomatic volunteers. Isolated “abnormalities” of IRP and contractile parameters were observed in the majority (80%) of these asymptomatic subjects, while all subjects also had normal features observed. Thus, the definition of “normal” should be recalibrated to focus on the entirety of the study and not individual metrics.

Esophagogastric junction morphology and contractile integral on high-resolution manometry in asymptomatic healthy volunteers: An international multicenter study

BACKGROUND

Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited.

METHODS

Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions.

RESULTS

Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P < 0.001). 5^th percentile EGJ-CI values ranged from 6.9 to 12.1 mm Hg cm. EGJ-CI values were consistent across world regions, but different between manufacturers even within the same world region (P ≤ 0.001). Within Medtronic studies, EGJ-CI and basal LESP were similar in younger and older individuals (P ≥ 0.3) but higher in women (P < 0.001).

CONCLUSIONS

EGJ morphology is predominantly type 1 in healthy adults. EGJ-CI varies widely in health, with significant gender influence, but is consistent within each HRM system. Manufacturer-specific normative values should be utilized for clinical HRM interpretation.

Outcomes of 100 Patients More Than 4 Years After POEM for Achalasia

OBJECTIVE

We aim to describe the long-term follow-up data from our institution's POEM experience.

SUMMARY BACKGROUND DATA

Per-oral endoscopic myotomy (POEM) is a well-established endoscopic therapy for achalasia with excellent short-term efficacy, but long-term outcomes data are limited.

METHODS

Patients older than 4 years removed from POEM for treatment of achalasia were studied. Clinical success was defined as an Eckardt Symptom (ES) score ≤3 and freedom from reintervention for achalasia. Patients underwent esophagogastroduodenoscopy (EGD), high-resolution manometry, impedance planimetry, and timed barium esophagram (TBE) preoperatively and at least 4 years postoperatively. Objective gastroesophageal reflux disease (GERD) was defined LA Grade B or worse esophagitis on EGD.

RESULTS

One hundred and nineteen consecutive patients were included. Five patients died or had catastrophic events unrelated to achalasia or POEM. One hundred of the remaining patients (88%, 100/114) had long-term data available. Clinical follow-up for all patients was greater than 4 years postoperatively and the mean was 55 months. Mean current ES was significantly improved from preop (n = 100, 1 ± 1 vs 7 ± 2, P < 0.001). Overall clinical success was 88% and 92%. Five patients had a current ES >3 and 4 patients required procedural reintervention on the lower esophageal sphincter. Reinterventions were successful in 75% of patients (3/4), with current ES ≤3. The rate of objective GERD was 33% (15/45). Esophageal physiology was improved with a decrease in median integrated relaxation pressure (11 ± 4 vs 33 ± 15 mm Hg, P < 0.001), a decrease in median TBE column height (3 ± 3 vs 13 ± 8 cm, P < 0.001), and an increase in median distensibility index (5.1 ± 2 vs 1.1 ± 1 mm2/mm Hg, P < 0.001).

CONCLUSIONS

POEM provides durable symptom relief and improvement in physiologic esophagogastric junction relaxation parameters over 4.5 years postoperatively. Reinterventions are rare and effective.

Estimation of mechanical work done to open the esophagogastric junction using functional lumen imaging probe panometry

In this study, we quantify the work done by the esophagus to open the esophagogastric junction (EGJ) and create a passage for bolus flow into the stomach. Work done on the EGJ was computed using functional lumen imaging probe (FLIP) panometry. Eighty-five individuals underwent FLIP panometry with a 16-cm catheter during sedated endoscopy including asymptomatic controls (n = 14), 45 patients with achalasia (n = 15 each, three subtypes), those with gastroesophageal reflux disease (GERD; n = 13), those with eosinophilic esophagitis (EoE; n = 8), and those with systemic sclerosis (SSc; n = 5). Luminal cross-sectional area (CSA) and pressure were measured by the FLIP catheter positioned across the EGJ. Work done on the EGJ (EGJW) was computed (millijoules, mJ) at 40-mL distension. Additionally, a separate method was developed to estimate the "work required" to fully open the EGJ (EGJROW) when it did not open during the procedure. EGJW for controls had a median [interquartile range (IQR)] value of 75 (56-141) mJ. All achalasia subtypes showed low EGJW compared with controls (P < 0.001). Subjects with GERD and EoE had EGJW 54.1 (6.9-96.3) and 65.9 (10.8-102.3) mJ, similar to controls (P < 0.08 and P < 0.4, respectively). The scleroderma group showed low values of EGJW, 12 mJ (P < 0.001). For patients with achalasia, EGJROW was the greatest and had a value of 210.4 (115.2-375.4) mJ. Disease groups with minimal or absent EGJ opening showed low values of EGJW. For patients with achalasia, EGJROW significantly exceeded EGJW values of all other groups, highlighting its unique pathophysiology. Balancing the relationship between EGJW and EGJROW is potentially useful for calibrating achalasia treatments and evaluating treatment response.NEW & NOTEWORTHY Changes in pressure and diameter occur at the EGJ during esophageal emptying. Similar changes can be observed during FLIP panometry. Data from healthy and diseased individuals were used to estimate the mechanical work done on the EGJ during distension-induced relaxation or, in instances of failed opening, work required to open the EGJ. Quantifying these parameters is potentially valuable to calibrate treatments and gauge treatment efficacy for subjects with disorders of EGJ function, especially achalasia.

Esophagogastric Junction Opening Parameters Are Consistently Abnormal in Untreated Achalasia

Achalasia is a disorder of impaired lower esophageal sphincter (LES) relaxation and failed peristalsis traditionally characterized by manometry.¹ As impaired LES relaxation is a mechanism of reduced esophagogastric junction (EGJ) opening, abnormally reduced EGJ distensibility assessed with functional luminal imaging probe (FLIP) was reported among patients with untreated achalasia.^2-5 Therefore, we aimed to describe the performance characteristics of EGJ opening parameters on FLIP panometry among a large cohort of treatment-naïve achalasia patients.

Validation in French of the Brief Esophageal Dysphagia Questionnaire in Patients Referred For Esophageal Manometry

A brief esophageal dysphagia questionnaire (BEDQ) was recently developed in English to evaluate frequency and intensity of dysphagia. Our aim was to validate this questionnaire in French in a cohort of patients referred for esophageal manometry. Patients referred for esophageal high resolution manometry were offered to fill out different questionnaires including Eckart score, GERDQ score and BEDQ. BEDQ was translated in French by two French native speakers and experts in esophageal motility. Patients were grouped according to the indications of esophageal high resolution manometry (dysphagia, GERD, others). The total BEDQ score was calculated and compared between groups. The validation method used the assessment of internal consistency with Cronbach's alpha and reliability with Guttman split-half reliability. BEDQ questionnaire was completed by 608 patients (44% males, mean age 54 years). The total score had an excellent internal consistency (Cronbach's alpha = 0.90) and reliability (Guttman statistic = 0.92). The correlation was good with Eckardt score (r = 0.65, p < 0.001) but poor with the GERDQ score (r = 0.21, p < 0.01). Patients referred for dysphagia (n = 197) had an Eckardt score and a BEDQ score significantly higher than those referred for GERD or other indications (5.48 vs 3.65 and 3.53 respectively for Eckardt score and 15.85 vs 4.64 and 5.78 for BEDQ, p < 0.001). BEDQ is a valid questionnaire in French to assess dysphagia in clinical practice. It remains to be determined if this score is sensitive to symptom variation and thus useful for the follow up of patients with dysphagia.

Validation and psychometric evaluation of the Spanish version of Brief Esophageal Dysphagia Questionnaire (BEDQ): Results of a multicentric study

BACKGROUND

The recently developed Brief Esophageal Dysphagia Questionnaire (BEDQ) evaluates esophageal obstructive symptoms. Its initial evaluation showed strong psychometric properties. The aims of this study were to (a) translate and validate an international Spanish version of BEDQ and (b) evaluate its psychometric properties in a large Hispano-American sample of symptomatic individuals.

METHODS

A Spanish BEDQ version was performed by Hispano-American experts using a Delphi process and reverse translation. Patients were prospectively recruited from seven centers in Spain and Latin America among individuals referred for high-resolution manometry (HRM). Patients completed several scores: Hospital Anxiety & Depression Scale (HADS), Eckardt score (ES), Gastroesophageal Reflux Questionnaire (GERDQ), and the BEDQ. Standardized psychometric analyses were performed.

KEY RESULTS

A total of 426 patients were recruited. Spanish BEDQ showed excellent reliability (Cronbach's alpha = 0.91). Factor analysis confirmed its unidimensional character. Moderate significant correlations between BEDQ and other symptomatic scores were found, suggesting sufficient convergent validity. Patients with abnormal or obstructive HRM findings scored significantly higher when compared to normal or non-obstructive findings, respectively. Using a cutoff of 10, BEDQ showed a sensitivity of 65.38% and a specificity of 66.21% and an area under the curve of 0.71 for obstructive or major manometric diagnosis.

CONCLUSIONS AND INFERENCES

A widely usable Spanish BEDQ version has been validated. We confirm its excellent psychometric properties in our patients, confirming the appropriateness of its use in different populations.

Blown-out myotomy: an adverse event of laparoscopic Heller myotomy and peroral endoscopic myotomy for achalasia

BACKGROUND AND AIMS

Although laparoscopic Heller myotomy (LHM) or peroral endoscopic myotomy (POEM) is highly effective, 10% to 20% of patients with achalasia remain symptomatic after treatment. In evaluating such patients, we have observed a pattern of failure associated with a pseudodiverticulum, or blown-out myotomy (BOM), in the distal esophagus. We aimed to assess risk factors and patient-reported outcomes associated with a BOM.

METHODS

We reviewed our manometry database for patients with achalasia previously treated with LHM or POEM. We included patients who had a post-treatment esophagram within 1 year of their follow-up manometry. A BOM was defined radiographically as a wide-mouthed outpouching (>50% increase in esophageal diameter) in the area of the myotomy.

RESULTS

One hundred twenty-nine patients with achalasia who underwent treatment were included; 23 (17.8%) had a BOM. Comparing patients with a BOM with those without, post-treatment Eckardt scores were significantly greater (5 vs 2, P = .002), type III achalasia was more common (39.1% vs 14.2%, P = .005), and LHM was more common than POEM (73.9% vs 26.1%, P = .013). The integrated relaxation pressure was also significantly greater in the BOM group (15.0 mm Hg vs 11.0 mm Hg, P = .025).

CONCLUSIONS

BOM is a common adverse event after myotomy for achalasia but is not seen after pneumatic dilation. Pretreatment type III achalasia, LHM as opposed to POEM, and a greater post-treatment integrated relaxation pressure were risk factors for developing a BOM. We speculate that esophageal wall strain in the area weakened by myotomy, whether from residual spastic contractility or continued esophageal outflow obstruction, may be the underlying mechanism of BOM development.

Pumping Patterns and Work Done During Peristalsis in Finite-Length Elastic Tubes

Balloon dilation catheters are often used to quantify the physiological state of peristaltic activity in tubular organs and comment on their ability to propel fluid which is important for healthy human function. To fully understand this system's behavior, we analyzed the effect of a solitary peristaltic wave on a fluid-filled elastic tube with closed ends. A reduced order model that predicts the resulting tube wall deformations, flow velocities, and pressure variations is presented. This simplified model is compared with detailed fluid-structure three-dimensional (3D) immersed boundary (IB) simulations of peristaltic pumping in tube walls made of hyperelastic material. The major dynamics observed in the 3D simulations were also displayed by our one-dimensional (1D) model under laminar flow conditions. Using the 1D model, several pumping regimes were investigated and presented in the form of a regime map that summarizes the system's response for a range of physiological conditions. Finally, the amount of work done during a peristaltic event in this configuration was defined and quantified. The variation of elastic energy and work done during pumping was found to have a unique signature for each regime. An extension of the 1D model is applied to enhance patient data collected by the device and find the work done for a typical esophageal peristaltic wave. This detailed characterization of the system's behavior aids in better interpreting the clinical data obtained from dilation catheters. Additionally, the pumping capacity of the esophagus can be quantified for comparative studies between disease groups.

Validation of the French version of the esophageal hypervigilance and anxiety scale

INTRODUCTION

An esophageal hypervigilance and anxiety scale (EHAS) was developed in English to assess the psychological process in patients with esophageal disorders. The aim of the current study was to validate this scale in French.

PATIENTS AND METHODS

Patients referred for esophageal high resolution manometry (HRM) were offered to fill out different questionnaires including EHAS, Eckart score and gastro-esophageal reflux disease-questionnaire (GERDQ) score. EHAS was translated in French by 2 French native speaker experts in esophageal motility. Patients were grouped according to the indications of HRM (dysphagia, reflux, other). The total EHAS score was calculated and compared between groups. The validation method used the assessment of internal consistency with Cronbach's α and reliability with Guttman split-half reliability.

RESULTS

Among the 607 patients who accepted to fill out questionnaires, the EHAS questionnaire was completed and analyzable in 469 patients. The total score had an excellent internal consistency (Cronbach's α = 0.91) and reliability (Guttman statistic = 0.86). EHAS score was not different between groups while Eckardt score was logically higher in patients with dysphagia than in others (p < 0.001) and GERDQ score was higher in patients with reflux than in those with dysphagia (p < 0.001). Despite different load on anxiety and hypervigilance scales, inter-item correlations and average scores did not differ between the original and the French EHAS.

CONCLUSION

EHAS is a valid questionnaire in French. It can be interpreted using the original EHAS score. Further studies are required to demonstrate the utility of this score in patients' management.

Multiple rapid swallows and rapid drink challenge in patients with esophagogastric junction outflow obstruction on high-resolution manometry

BACKGROUND

Esophagogastric junction outflow obstruction (EGJOO) as defined by Chicago Classification of esophageal motility disorders (CCv3.0) encompasses a broad range of diagnoses, thus posing clinical challenges. Our aims were to evaluate multiple rapid swallow (MRS) and rapid drink challenge (RDC) during high-resolution manometry (HRM) to aid identifying clinically relevant EGJOO.

METHODS

Patients with a HRM diagnosis of EGJOO based on CCv3.0 that also completed MRS and RDC during HRM and barium esophagram were retrospectively identified. Radiographic EGJOO (RAD-EGJOO) was defined by either liquid barium retention or delayed passage of a barium tablet on barium esophagram. Thirty healthy asymptomatic controls that completed HRM were also included. MRS involved drinking 2 mL for 5 successive swallows. RDC involved rapid drinking of 200 mL liquid. Integrated relaxation pressure (IRP) and presence of panesophageal pressurization (PEP) during MRS and RDC were assessed.

KEY RESULTS

One hundred one patients, mean (SD) age 56 (16) years, were included; 32% had RAD-EGJOO, 68% did not. RAD-EGJOO patients more frequently had elevated (>12 mmHg) upright IRP (100%), MRS-IRP (56%), RDC-IRP (53%), and PEP during RDC (66%) than both controls [17%; 0%; 7%; 3%] and patients without RAD-EGJOO [83%; 35%; 39%; 41%] Having IRP >12 mmHg during both MRS and RDC was twice as likely to be associated with RAD-EGJOO (19%) than those without RAD-EGJOO (9%) among patients with upright IRP >12 mmHg.

CONCLUSIONS AND INFERENCES

Adjunctive HRM maneuvers MRS and RDC appear to help identify clinically significant EGJOO. While future outcome studies are needed, comprehensive multimodal evaluation helps clarify relevance of EGJOO on HRM.

Achalasia subtypes can be identified with functional luminal imaging probe (FLIP) panometry using a supervised machine learning process

BACKGROUND

Achalasia subtypes on high-resolution manometry (HRM) prognosticate treatment response and help direct management plan. We aimed to utilize parameters of distension-induced contractility and pressurization on functional luminal imaging probe (FLIP) panometry and machine learning to predict HRM achalasia subtypes.

METHODS

One hundred eighty adult patients with treatment-naïve achalasia defined by HRM per Chicago Classification (40 type I, 99 type II, 41 type III achalasia) who underwent FLIP panometry were included: 140 patients were used as the training cohort and 40 patients as the test cohort. FLIP panometry studies performed with 16-cm FLIP assemblies were retrospectively analyzed to assess distensive pressure and distension-induced esophageal contractility. Correlation analysis, single tree, and random forest were adopted to develop classification trees to identify achalasia subtypes.

KEY RESULTS

Intra-balloon pressure at 60 mL fill volume, and proportions of patients with absent contractile response, repetitive retrograde contractile pattern, occluding contractions, sustained occluding contractions (SOC), contraction-associated pressure changes >10 mm Hg all differed between HRM achalasia subtypes and were used to build the decision tree-based classification model. The model identified spastic (type III) vs non-spastic (types I and II) achalasia with 90% and 78% accuracy in the train and test cohorts, respectively. Achalasia subtypes I, II, and III were identified with 71% and 55% accuracy in the train and test cohorts, respectively.

CONCLUSIONS AND INFERENCES

Using a supervised machine learning process, a preliminary model was developed that distinguished type III achalasia from non-spastic achalasia with FLIP panometry. Further refinement of the measurements and more experience (data) may improve its ability for clinically relevant application.

Assessment of esophageal body peristaltic work using functional lumen imaging probe panometry

The goal of this study was to conceptualize and compute measures of "mechanical work" done by the esophagus using data generated during functional lumen imaging probe (FLIP) panometry and compare work done during secondary peristalsis among patients and controls. Eighty-five individuals were evaluated with a 16-cm FLIP during sedated endoscopy, including asymptomatic controls (n = 14) and those with achalasia subtypes I, II, and III (n = 15, each); gastroesophageal reflux disease (GERD; n = 13); eosinophilic esophagitis (EoE; n = 9); and systemic sclerosis (SSc; n = 5). The FLIP catheter was positioned to have its distal segment straddling the esophagogastric junction (EGJ) during stepwise distension. Two metrics of work were assessed: "active work" (during bag volumes ≤ 40 mL where contractility generates substantial changes in lumen area) and "work capacity" (for bag volumes ≥ 60 mL when contractility cannot substantially alter the lumen area). Controls showed median [interquartile range (IQR)] of 7.3 (3.6-9.2) mJ of active work and 268.6 (225.2-332.3) mJ of work capacity. Patients with all achalasia subtypes, GERD, and SSc showed lower active work done than controls (P ≤ 0.003). Patients with achalasia subtypes I and II, GERD, and SSc had lower work capacity compared with controls (P < 0.001, 0.004, 0.04, and 0.001, respectively). Work capacity was similar between controls and patients with achalasia type III and EoE. Mechanical work of the esophagus differs between healthy controls and patient groups with achalasia, EoE, SSc, and GERD. Further studies are needed to fully explore the utility of this approach, but these work metrics would be valuable for device design (artificial esophagus), to measure the efficacy of peristalsis, to gauge the physiological state of the esophagus, and to comment on its pumping effectiveness.NEW & NOTEWORTHY Functional lumen imaging probe (FLIP) panometry assesses esophageal response to distension and provides a simultaneous assessment of pressure and dimension during contractility. This enables an objective assessment of "mechanical work" done by the esophagus. Eighty-five individuals were evaluated, and two work metrics were computed for each subject. Controls showed greater values of work compared with individuals with achalasia, gastroesophageal reflux disease (GERD), and systemic sclerosis (SSc). These values can quantify the mechanical behavior of the distal esophagus and assist in the estimation of muscular integrity.

Normal Functional Luminal Imaging Probe Panometry Findings Associate With Lack of Major Esophageal Motility Disorder on High-Resolution Manometry

BACKGROUND & AIMS

A normal esophageal response to distension on functional luminal imaging probe (FLIP) panometry during endoscopy might indicate normal esophageal motor function. We aimed to investigate the correlation of normal FLIP panometry findings with esophageal high-resolution manometry (HRM) and outcomes of discrepant patients.

METHODS

We performed a retrospective study using data from a registry of patients who completed FLIP during sedated endoscopy. We identified 111 patients with normal FLIP panometry findings (mean age, 42 y; 69% female) and corresponding HRM data. A normal FLIP panometry was defined as an esophagogastric junction (EGJ) distensibility index greater than 3.0 mm²/mm Hg, an absence of repetitive retrograde contractions, and a repetitive antegrade contraction pattern that met the Rule-of-6s: ≥6 consecutive antegrade contractions of ≥6-cm in length, at a rate of 6 ± 3 contractions per minute. HRM findings were classified by the Chicago classification system version 3.0.

RESULTS

HRM results were classified as normal motility in 78 patients (70%), ineffective esophageal motility in 10 patients (9%), EGJ outflow obstruction in 20 patients (18%), and 3 patients (3%) as other. In patients with EGJ outflow obstruction based on HRM, the integrated relaxation pressure normalized on adjunctive swallows in 16 of 20 patients (80%), and in 8 of 9 patients (88%) who completed a barium esophagram and had normal barium clearance. Thus, although 23 of 111 patients (21%) with normal FLIP panometry had abnormal HRM findings, these HRMs often were considered to be false-positive or equivocal results. All patients with an abnormal result from HRM were treated conservatively.

CONCLUSIONS

In a retrospective cohort study, we found that patients with normal FLIP panometry results did not have a clinical impression of a major esophageal motor disorder. Normal FLIP panometry results can exclude esophageal motility disorders at the time of endoscopy, possibly negating the need for HRM in select patients.

A deep-learning-based unsupervised model on esophageal manometry using variational autoencoder

High-resolution manometry (HRM) is the primary method for diagnosing esophageal motility disorders and its interpretation and classification are based on variables (features) from data of each swallow. Modeling and learning the semantics directly from raw swallow data could not only help automate the feature extraction, but also alleviate the bias from pre-defined features. With more than 32-thousand raw swallow data, a generative model using the approach of variational auto-encoder (VAE) was developed, which, to our knowledge, is the first deep-learning-based unsupervised model on raw esophageal manometry data. The VAE model was reformulated to include different types of loss motivated by domain knowledge and tuned with different hyper-parameters. Training of the VAE model was found sensitive on the learning rate and hence the evidence lower bound objective (ELBO) was further scaled by the data dimension. Case studies showed that the dimensionality of latent space have a big impact on the learned semantics. In particular, cases with 4-dimensional latent variables were found to encode various physiologically meaningful contraction patterns, including strength, propagation pattern as well as sphincter relaxation. Cases with so-called hybrid L2 loss seemed to better capture the coherence of contraction/relaxation transition. Discriminating capability was further evaluated using simple linear discriminative analysis (LDA) on predicting swallow type and swallow pressurization, which yields clustering patterns consistent with clinical impression. The current work on modeling and understanding swallow-level data will guide the development of study-level models for automatic diagnosis as the next stage.