Estimating Probability for Esophageal Obstruction: A Diagnostic Decision Support Tool Applying Machine Learning to Functional Lumen Imaging Probe Panometry.

Background/Aims: This study aimed to develop a diagnostic tool using machine learning to apply functional luminal imaging probe (FLIP) panometry data to determine the probability of esophagogastric junction (EGJ) obstruction as determined using the Chicago Classification version 4.0 (CCv4.0) and high-resolution manometry (HRM). Methods: Five hundred and fifty-seven adult patients that completed FLIP and HRM (with a conclusive CCv4.0 assessment of EGJ outflow) and 35 asymptomatic volunteers ("controls") were included. EGJ opening was evaluated with 16-cm FLIP performed during sedated endoscopy via EGJ-distensibility index and maximum EGJ diameter. HRM was classified according to the CCv4.0 as conclusive disorders of EGJ outflow or normal EGJ outflow (timed barium esophagram applied when required and available). The probability tool utilized Bayesian additive regression treesBART, which were evaluated using a leave-one-out approach and a holdout test set. Results: Per HRM and CCv4.0, 243 patients had a conclusive disorder of EGJ outflow while 314 patients (and all 35 controls) had normal EGJ outflow. The model accuracy to predict EGJ obstruction (based on leave-one-out/holdout test set, respectively) was 89%/90%, with 87%/85% sensitivity, 92%/97% specificity, and an area under the receiver operating characteristic curve of 0.95/0.97. A free, open-source tool to calculate probability for EGJ obstruction using FLIP metrics is available at https://www.wklytics.com/nmgi/prob_flip.html. Conclusions: Application of FLIP metrics utilizing a probabilistic approach incorporates the diagnostic confidence (or uncertainty) into the clinical interpretation of EGJ obstruction. This tool can provide clinical decision support during application of FLIP Panometry for evaluation of esophageal motility disorders.

Heterogeneity of primary and secondary peristalsis in systemic sclerosis: A new model of "scleroderma esophagus".

BACKGROUND: Although esophageal dysmotility is common in systemic sclerosis (SSc)/scleroderma, little is known regarding the pathophysiology of motor abnormalities driving reflux severity and dysphagia. This study aimed to assess primary and secondary peristalsis in SSc using a comprehensive esophageal motility assessment applying high-resolution manometry (HRM) and functional luminal imaging probe (FLIP) Panometry. METHODS: A total of 32 patients with scleroderma (28 female; ages 38-77; 20 limited SSc, 12 diffuse SSc) completed FLIP Panometry and HRM. Secondary peristalsis, i.e., contractile responses (CR), was classified on FLIP Panometry by pattern of contractility as normal (NCR), borderline (BCR), impaired/disordered (IDCR), or absent (ACR). Primary peristalsis on HRM was assessed according to the Chicago classification. RESULTS: The manometric diagnoses were 56% (n = 18) absent contractility, 22% (n = 7) ineffective esophageal motility (IEM), and 22% (n = 7) normal motility. Secondary peristalsis (CRs) included 38% (n = 12) ACR, 38% (n = 12) IDCR, 19% (n = 6) BCR, and 15% (n = 5) NCR. The median (IQR) esophagogastric junction (EGJ) distensibility index (DI) was 5.8 mm2 /mmHg (4.8-10.1) mm2 /mmHg; EGJ-DI was >8.0 mm2 /mmHg in 31%, and >2.0 mm2 /mmHg in 100% of patients. Among 18 patients with absent contractility on HRM, 11 had ACR, 5 had IDCR, and 2 had BCR. Among 7 patients with IEM, 1 had ACR, 5 had IDCR, and 1 NCR. All of the patients with normal peristalsis had NCR or BCR. CONCLUSIONS: This was the first study assessing combined HRM and FLIP Panometry in a cohort of SSc patients, which demonstrated heterogeneity in primary and secondary peristalsis. This complementary approach facilitates characterizing esophageal function in SSc, although future study to examine clinical outcomes remains necessary.

Validation of Clinically Relevant Thresholds of Esophagogastric Junction Obstruction Using FLIP Panometry.

BACKGROUND & AIMS: This study aimed to assess the accuracy of functional luminal imaging probe (FLIP) panometry to detect esophagogastric junction (EGJ) obstruction assigned by high-resolution manometry (HRM) and the Chicago Classification version 4.0 (CCv4.0). METHODS: Six hundred eighty-seven adult patients who completed FLIP and HRM for primary esophageal motility evaluation and 35 asymptomatic volunteers (controls) were included. EGJ opening was evaluated with 16-cm FLIP during sedated endoscopy via EGJ-distensibility index (DI) and maximum EGJ diameter. HRM was classified according to CCv4.0 and focused on studies with a conclusive disorder of EGJ outflow (ie, achalasia subtypes I, II, or III; or EGJ outflow obstruction with abnormal timed barium esophagogram) or normal EGJ outflow. RESULTS: All 35 controls had EGJ-DI >3.0 mm2/mmHg and maximum EGJ diameter >16 mm. Per HRM and CCv4.0, 245 patients had a conclusive disorder of EGJ outflow, and 314 patients had normal EGJ outflow. Among the 241 patients with reduced EGJ opening (EGJ-DI <2.0 mm2/mmHg and maximum EGJ diameter <12 mm) on FLIP panometry, 86% had a conclusive disorder of EGJ outflow per CCv4.0. Among the 203 patients with normal EGJ opening (EGJ-DI ≥2.0 mm2/mmHg and maximum EGJ diameter ≥16 mm) on FLIP panometry, 99% had normal EGJ outflow per CCv4.0. CONCLUSIONS: FLIP panometry accurately identified clinically relevant conclusive EGJ obstruction as defined by CCv4.0 in patients evaluated for esophageal motor disorders. Thus, FLIP panometry is a valuable tool for both independent and complementary evaluation of esophageal motility.

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.

Esophageal Dysmotility Is Associated With Disease Severity in Eosinophilic Esophagitis.

BACKGROUND & AIMS: An association of eosinophilic esophagitis (EoE) with esophageal dysmotility has been described, however, the related mechanism remains unclear. We aimed to evaluate clinical and physiologic characteristics, including esophageal distensibility, associated with secondary peristalsis in patients with EoE. METHODS: A total of 199 consecutive adult patients with EoE (age, 18-78 y; 32% female) who completed a 16-cm functional luminal imaging probe (FLIP) during endoscopy were evaluated in a cross-sectional study. FLIP panometry contractile response (CR) patterns were classified as normal CR or borderline CR if antegrade contractions were present, and abnormal CRs included impaired/disordered CR, absent CR, or spastic-reactive CR. The distensibility plateau of the esophageal body and esophagogastric junction distensibility was measured with FLIP. RESULTS: FLIP CR patterns included 68 (34%) normal CR, 65 (33%) borderline CR, 44 (22%) impaired/disordered CR, 16 (8%) absent CR, and 6 (3%) spastic-reactive CR. Compared with normal CRs, abnormal CRs more frequently had reduced esophageal distensibility (distensibility plateau <17 mm in 56% vs 32%), greater total EoE reference scores (median, 5; interquartile range [IQR], 3-6 vs median, 4; IQR, 3-5) with more severe ring scores, and a greater duration of symptoms (median, 10 y; IQR, 4-23 y vs median, 7 y; IQR, 3-15 y). Mucosal eosinophil density, however, was similar between abnormal CRs and normal CRs (median, 34 eosinophils/high-power field [hpf]; IQR, 14-60 eosinophils/hpf vs median, 25 eosinophils/hpf; IQR, 5-50 eosinophils/hpf). CONCLUSIONS: Although normal secondary peristalsis was observed frequently in this EoE cohort, abnormal esophageal CRs were related to EoE disease severity, especially features of fibrostenosis. This study evaluating secondary peristalsis in EoE suggests that esophageal wall remodeling, rather than eosinophilic inflammatory intensity, was associated with esophageal dysmotility in EoE.

Classifying Esophageal Motility by FLIP Panometry: A Study of 722 Subjects With Manometry.

INTRODUCTION: Functional luminal imaging probe (FLIP) panometry can evaluate esophageal motility in response to sustained esophageal distension at the time of sedated endoscopy. This study aimed to describe a classification of esophageal motility using FLIP panometry and evaluate it against high-resolution manometry (HRM) and Chicago Classification v4.0 (CCv4.0). METHODS: Five hundred thirty-nine adult patients who completed FLIP and HRM with a conclusive CCv4.0 diagnosis were included in the primary analysis. Thirty-five asymptomatic volunteers ("controls") and 148 patients with an inconclusive CCv4.0 diagnosis or systemic sclerosis were also described. Esophagogastric junction (EGJ) opening and the contractile response (CR) to distension (i.e., secondary peristalsis) were evaluated with a 16-cm FLIP during sedated endoscopy and analyzed using a customized software program. HRM was classified according to CCv4.0. RESULTS: In the primary analysis, 156 patients (29%) had normal motility on FLIP panometry, defined by normal EGJ opening and a normal or borderline CR; 95% of these patients had normal motility or ineffective esophageal motility on HRM. Two hundred two patients (37%) had obstruction with weak CR, defined as reduced EGJ opening and absent CR or impaired/disordered CR, on FLIP panometry; 92% of these patients had a disorder of EGJ outflow per CCv4.0. DISCUSSION: Classifying esophageal motility in response to sustained distension with FLIP panometry parallels the swallow-associated motility evaluation provided with HRM and CCv4.0. Thus, FLIP panometry serves as a well-tolerated method that can complement, or in some cases be an alternative to HRM, for evaluating esophageal motility disorders.

Prediction of Esophageal Retention: A Study Comparing High-Resolution Manometry and Functional Luminal Imaging Probe Panometry.

INTRODUCTION: High-resolution manometry (HRM) is generally considered the primary method to evaluate esophageal motility; functional luminal imaging probe (FLIP) panometry represents a novel method to do so and is completed during sedated endoscopy. This study aimed to compare HRM and FLIP panometry in predicting esophageal retention on timed barium esophagram (TBE). METHODS: A total of 329 adult patients who completed FLIP, HRM, and TBE for primary esophageal motility evaluation were included. An abnormal TBE was defined by a 1-minute column height >5 cm or impaction of a 12.5-mm barium tablet. The integrated relaxation pressure (IRP) on HRM was assessed in the supine and upright patient positions. Esophagogastric junction (EGJ) opening was evaluated with 16-cm FLIP performed during sedated endoscopy through EGJ-distensibility index and maximum EGJ diameter. RESULTS: Receiver operating characteristic curves to identify an abnormal TBE demonstrated AUC (95% confidence interval) of 0.79 (0.75-0.84) for supine IRP, 0.79 (0.76-0.86) for upright IRP, 0.84 (0.79-0.88) for EGJ-distensibility index, and 0.88 (0.85-0.92) for maximum EGJ diameter. Logistic regression to predict abnormal TBE showed odds ratios (95% confidence interval) of 1.8 (0.84-3.7) for consistent IRP elevation and 39.7 (16.4-96.2) for reduced EGJ opening on FLIP panometry. Of 40 patients with HRM-FLIP panometry discordance, HRM-IRP was consistent with TBE in 23% while FLIP panometry was consistent with TBE in 78%. DISCUSSION: FLIP panometry provided superior detection of esophageal retention over IRP on HRM. However, application of a complementary evaluation involving FLIP panometry, HRM, and TBE may be necessary to accurately diagnose esophageal motility disorders.

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.

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.

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.

Performing High-resolution Impedance Manometry After Endoscopy With Conscious Sedation Has Negligible Effects on Esophageal Motility Results.

Background/Aims: High-resolution manometry (HRM) performed without sedation is the standard procedure. However, some patients cannot tolerate transnasal placement of the manometry catheter. We aim to assess the practice of performing manometry after endoscopy with conscious sedation by evaluating its impact on esophageal motility findings. Methods: Twelve asymptomatic adult volunteers and 7 adult patients completed high-resolution impedance manometry (HRIM) approximately 1 hour after conscious sedation with midazolam and fentanyl (post-sedation) and again on a different day with no-sedation. The nosedation HRIM involved 2 series of swallows separated in time by 20 minutes (no-sedation-1 and no-sedation-2) for the volunteers; patients completed only 1 series of swallows for no-sedation HRM. Results: A motility diagnosis of normal motility was observed in all 12 volunteers post-sedation. Two volunteers had a diagnosis of borderline ineffective esophageal motility, one during the no-sedation-1 period and the other during the no-sedation-2 period; all of the other no-sedation HRIM studies yielded a normal motility diagnosis. Six of seven patients had the same diagnosis in both no-sedation and post-sedation HRM, including 1 distal esophageal spasm, 3 achalasia (2 type II and 1 type III), and 2 esophagogastric junction outflow obstruction. Only one patient's HRM classification changed from ineffective esophageal motility at no-sedation to normal esophageal motility at post-sedation. Conclusions: Performing HRIM after endoscopy with conscious sedation had minimal clinical impact on the motility diagnosis or motility parameters. Thus, this approach may be a viable alternative for patients who cannot tolerate unsedated catheter placement.

Esophageal Hypervigilance and Visceral Anxiety Are Contributors to Symptom Severity Among Patients Evaluated With High-Resolution Esophageal Manometry.

OBJECTIVES: Symptoms are inconsistently associated with esophageal motor findings on high-resolution manometry (HRM). We aimed to evaluate predictors of dysphagia severity, including esophageal hypervigilance and visceral anxiety, among patients evaluated with HRM. METHODS: Adult patients undergoing HRM at 4 academic medical centers (United States and France) were prospectively evaluated. HRM was completed and analyzed per the Chicago Classification v3.0. Validated symptom scores, including the Brief Esophageal Dysphagia Questionnaire and Esophageal Hypervigilance and Anxiety Scale, were completed at the time of HRM. RESULTS: Two hundred thirty-six patients, aged 18-85 (mean 53) years, 65% female, were included. Approximately 59 (25%) patients had a major motor disorder on HRM: 19 achalasia, 24 esophagogastric junction outflow obstruction, 12 absent contractility, and 4 jackhammer. Approximately 177 (75%) patients did not have a major motor disorder: 71 ineffective esophageal motility and 106 normal motility. Having a major motor disorder was a significant predictor of dysphagia severity (Radj = 0.049, P < 0.001), but the Esophageal Hypervigilance and Anxiety Scale score carried a predictive relationship of Brief Esophageal Dysphagia Questionnaire that was 2-fold higher than having a major motor disorder: Radj = 0.118 (P < 0.001). This finding remained when evaluated by the major motor disorder group. HRM metrics were nonsignificant. DISCUSSION: In a prospective, international multicenter study, we found that esophageal hypervigilance and visceral anxiety were the strongest predictors of dysphagia severity among patients evaluated with HRM. Thus, an assessment of esophageal hypervigilance and visceral anxiety is important to incorporate when evaluating symptom severity in clinical practice and research studies.

Esophageal motility classification can be established at the time of endoscopy: a study evaluating real-time functional luminal imaging probe panometry.

BACKGROUND AND AIMS: A novel device that provides real-time depiction of functional luminal image probe (FLIP) panometry (ie, esophagogastric junction [EGJ] distensibility and distension-induced contractility) was evaluated. We aimed to compare real-time FLIP panometry interpretation at the time of sedated endoscopy with high-resolution manometry (HRM) in evaluating esophageal motility. METHODS: Forty consecutive patients (aged 24-81 years; 60% women) referred for endoscopy with a plan for future HRM from 2 centers were prospectively evaluated with real-time FLIP panometry during sedated upper endoscopy. The EGJ distensibility index and contractility profile were applied to derive a FLIP panometry classification at the time of endoscopy and again (post-hoc) using a customized program. HRM was classified according to the Chicago classification. RESULTS: Real-time FLIP panometry motility classification was abnormal in 29 patients (73%), 19 (66%) of whom had a subsequent major motility disorder on HRM. All 9 patients with an HRM diagnosis of achalasia had abnormal real-time FLIP panometry classifications. Eleven patients (33%) had normal motility on real-time FLIP panometry and 8 (73%) had a subsequent HRM without a major motility disorder. There was excellent agreement (κ = .939) between real-time and post-hoc FLIP panometry interpretation of abnormal motility. CONCLUSIONS: This prospective, multicentered study demonstrated that real-time FLIP panometry could detect abnormal esophageal motility, including achalasia, at the endoscopic encounter. Additionally, normal motility on FLIP panometry was predictive of a benign HRM. Thus, real-time FLIP panometry incorporated with endoscopy appears to provide a suitable and well-tolerated point-of-care esophageal motility assessment.

Normal Values of Esophageal Distensibility and Distension-Induced Contractility Measured by Functional Luminal Imaging Probe Panometry.

BACKGROUND & AIMS: Functional luminal imaging probe (FLIP) panometry provides a comprehensive evaluation of esophageal functional at the time of endoscopy, including assessment of esophageal distensibility and distension-induced esophageal contractility. However, the few and inconsistent findings from healthy individuals pose challenges to the application of FLIP to research and clinical practice. We performed FLIP panometry in asymptomatic volunteers. METHODS: We performed a prospective study of 20 asymptomatic volunteers (ages, 23-44; 14 women) who were evaluated with 16-cm FLIP positioned across the esophagogastric junction (EGJ) and distal esophagus (and in 8 subjects also repositioned at the proximal esophagus) during sedated upper endoscopy. FLIP data were analyzed with a customized program that generated FLIP panometry plots and calculated the EGJ-distensibility index (DI) and distensibility plateaus (DP) of distal and proximal esophageal body. Distension-induced esophageal contractility was also assessed. RESULTS: The median EGJ-DI was 5.8 mm2/mm Hg (interquartile range [IQR], 4.9-6.7 mm2/mm Hg); all 20 subjects had an EGJ-DI greater than 2.8 mm2/mm Hg. The median DP values from all subjects tested were 20.2 mm (IQR, 19.8-20.8 mm) at the distal body, 21.1 mm (IQR, 20.3-22.9 mm) at the proximal body, and greater than 18 mm at both locations. Repetitive antegrade contractions (RACs) were observed in all 20 subjects; in 19 of 20 (95%) subjects, the RAC pattern persisted for 10 or more consecutive antegrade contractions. CONCLUSIONS: Normal parameters of FLIP panometry are EGJ-DI greater than 2.8 mm2/mm Hg, DP greater than 18 mm, and antegrade contractions that occur in a repetitive pattern (RACs)-these can be used as normal findings for esophageal distensibility and distension-induced contractility. These values can be used in comparative studies of esophageal diseases, such as achalasia and eosinophilic esophagitis, and will facilitate application of FLIP panometry to clinical practice.