Esophagogastric junction outflow obstruction

Discriminating "impaired" from "disordered" contractile response on FLIP panometry by utilizing pressure measurement

BACKGROUND

Functional lumen imaging probe (FLIP) panometry evaluates esophageal motility, including the contractile response to distension, that is, secondary peristalsis. Impaired/disordered contractile response (IDCR) is an abnormal, but nonspecific contractile response that can represent either hypomotility or spastic motor disorders on high-resolution manometry (HRM). We hypothesized that FLIP pressure could be incorporated to clarify IDCR and aimed to determine its utility in a cohort of symptomatic esophageal motility patients.

METHODS

173 adult patients that had IDCR on FLIP panometry and HRM with a conclusive Chicago Classification v4.0 (CCv4.0) diagnosis were included and analyzed as development (n = 118) and validation (n = 55) cohorts. FLIP pressure values were assessed for prediction of either hypomotility or spasm, defined on HRM/CCv4.0.

KEY RESULTS

HRM/CCv4.0 diagnoses were normal motility in 48 patients (28%), "hypomotility" (ineffective esophageal motility, absent contractility, or Type I or II achalasia) in 89 (51%), and "spasm" (Type III achalasia, distal esophageal spasm, or hypercontractile esophagus) in 36 (21%). The pressure at esophagogastric junction-distensibility index (DI) (60 mL) was lower in hypomotility (median [interquartile range] 34 [28-42] mmHg) than in spasm (49 [40-62] mmHg; p < 0.001) and had an area under the receiver operating characteristic curve of 0.80 (95% CI 0.73-0.88) for hypomotility and 0.76 (0.69-0.83) for spasm. For "spasm" on HRM, a threshold FLIP pressure of >35 mmHg provided 90% sensitivity (47% specificity) while >55 mmHg provided 93% specificity (40% sensitivity).

CONCLUSION & INFERENCES

Pressure on FLIP panometry can help clarify the significance of IDCR, with low-pressure IDCR associated with hypomotility and high-pressure IDCR suggestive of spastic motor disorders.

Four-dimensional impedance manometry volume metrics for predicting abnormal bolus retention

BACKGROUND

The objective measurement for esophageal bolus volume and bolus clearance could classify abnormal high-resolution manometry (HRM) beyond the current Chicago classification. We aimed to compare the novel four-dimensional impedance manometry (4D HRM) volume metrics with timed barium esophagram (TBE).

METHODS

Adults with esophageal symptoms undergoing HRM and TBE were included. A custom-built program for 4D HRM analysis measured esophageal luminal cross-sectional area (CSA) from impedance and subsequently derived esophageal bolus volume and clearance. 4D HRM volume metrics included pre-swallow residual volume, maximal volume, retention volume, and clearance ratio defined as 1.0-retention volume divided by the maximal volume. An abnormal TBE was defined as a column height >5 cm at 1 min or 5 min.

KEY RESULTS

A total of 95 patients (normal motility: 33%; ineffective esophageal motility: 12%; absent contractility: 10%; esophagogastric junction outflow obstruction: 30%; type I achalasia: 5%; type II achalasia: 12%) were categorized into normal TBE (58%), abnormal TBE at 1 min (17%), and abnormal TBE at 5 min (25%). The AUROC demonstrated that, among all 4D HRM volume metrics, the clearance ratio had the best performance in predicting abnormal TBE at 5 min (AUROC, 95% confidence interval: 0.89, 0.82-0.96), and exhibited a strong negative correlation with TBE at 5 min (r = -0.65; p < 0.001).

CONCLUSIONS & INFERENCES

Novel 4D HRM volume metrics provide objective measurement of esophageal bolus volume and bolus clearance. The clearance ratio has a strong correlation with TBE and could potentially serve as a substitute for TBE to measure esophageal retention.

Recent Advancement and Future Perspective of Per Oral Endoscopic Myotomy

Per oral endoscopic myotomy (POEM) has emerged as a preferred approach for the treatment of idiopathic achalasia and various esophageal motility disorders, offering a minimally invasive alternative to traditional laparoscopic Heller's myotomy. Over the past decade, POEM has solidified its status as the primary therapeutic choice in these conditions through constant improvements. Its evolution has been marked by continuous progress, driven by the integration of innovative technologies and sophisticated techniques. Notable advancements in the techniques include the advent of shorter myotomies and sling fiber-preserving gastric myotomies. The introduction of novel image-enhanced endoscopic techniques, such as red dichromatic imaging and much safer bipolar devices, promises to enhance safety and reduce the technical demands of the POEM procedure. Furthermore, significant strides have been made in understanding gastroesophageal reflux (GERD) following POEM, enabling the differentiation of "true reflux" from acidification resulting from fermentation through manual pH tracing assessment. This distinction aids in identifying cases necessitating treatment with proton pump inhibitors. Other treatment strategies of post-POEM GERD have expanded to the incorporation of NOTES fundoplication and device-assisted fundoplication if the necessity arises. This comprehensive review delves into recent developments in POEM, encompassing technical variations, the assessment and management of post-POEM reflux, outcomes in special populations, and future prospects. By exploring these facets, we aim to provide a comprehensive overview of the current state of POEM, shedding light on its evolution and the promising directions it is poised to take in the field of third-space endoscopy.

Impaired esophagogastric junction relaxation and lung transplantation outcomes

The implications of impaired esophagogastric junction relaxation (i.e. esophagogastric junction outflow obstruction and achalasia) in lung transplants recipients (LTRs) are unclear. Thus, we examined the prevalence and clinical outcomes of LTRs with an abnormally elevated integrated relaxation pressure (IRP) on high-resolution manometry before lung transplantation (LTx). After IRB approval, we reviewed data on LTRs who underwent LTx between January 2019 and August 2022 with a preoperative median IRP >15 mmHg. Differences in overall survival and chronic lung allograft dysfunction (CLAD)-free survival between LTRs with a normalized median IRP after LTx (N-IRP) and those with persistently high IRP (PH-IRP) were assessed using Kaplan-Meier curves and the log-rank test. During the study period, 352 LTx procedures were performed; 44 (12.5%) LTRs had an elevated IRP before LTx, and 37 (84.1%) completed a postoperative manometry assessment (24 [70.6%] males; mean age, 65.2 ± 9.1 years). The median IRP before and after LTx was 18.7 ± 3.8 mmHg and 12 ± 5.6 mmHg, respectively (P < 0.001); the median IRP normalized after LTx in 24 (64.9%) patients. Two-year overall survival trended lower in the N-IRP group than the PH-IRP group (77.2% vs. 92.3%, P = 0.086), but CLAD-free survival (P = 0.592) and rates of primary graft dysfunction (P = 0.502) and acute cellular rejection (P = 0.408) were similar. An abnormally elevated IRP was common in LTx candidates; however, it normalized in roughly two-thirds of patients after LTx. Two-year survival trended higher in the PH-IRP group, despite similar rates of primary graft dysfunction and acute cellular rejection as well as similar CLAD-free survival between the groups.

Fifteen-year symptomatic outcome of patients with nonactionable motor findings on high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) is performed for evaluation of esophageal symptoms, but patient outcome is unclear when no actionable motor disorder is identified. We evaluated long-term symptomatic outcome of patients with nonactionable HRM findings.

METHODS

Patients who underwent (HRM) studies in 2006-2008 were tracked. Patients with achalasia spectrum disorders, foregut surgery before or after HRM, and incomplete symptom documentation were excluded. Symptom questionnaires assessing dominant symptom intensity (DSI, product of symptom severity and frequency recorded on 5-point Likert scales) and global symptom severity (GSS, from 10 cm visual analog scale) were repeated. Change in symptom burden was compared against HRM motor findings using Chicago Classification 4.0 (CCv4.0), applied retroactively to 2006-2008 data.

KEY RESULTS

Overall, 134 patients (median age 68 years, 64.5% female) could be contacted. The majority (73.1%) had normal motility; others had ineffective esophageal motility (8.2%), esophagogastric junction outflow obstruction (13.4%), hypercontractile esophagus (3.0%), or absent contractility (2.2%), none managed invasively. Over 15 years of follow-up, DSI decreased from 8.0 (4.0-16.0) to 1.0 (0.0-6.0) (p < 0.001) and GSS improved from 5.5 (3.3-7.7) to 2.0 (0.0-4.0) (p < 0.001); improvement was consistent across CCv4.0 diagnoses and subgroups. The majority (82.8%) reported improvement over time, and antisecretory medication was the most effective intervention (83.0% improvement). There was no difference in medication efficacy (p = 0.75) or improvement in symptoms (p = 0.20) based on CCv4 diagnosis.

CONCLUSIONS AND INFERENCES

Esophageal symptoms improve with conservative symptomatic management over long-term follow-up when no conclusive obstructive motor disorders or achalasia spectrum disorders are found on HRM.

Peroral endoscopic myotomy and its use in non-achalasia disorders

The aim of this review is to provide an overview of per-oral endoscopic myotomy (POEM) and its utilization in non-achalasia disorders of the esophagus. POEM, a relatively novel endoscopic technique, involves submucosal tunneling to access esophageal muscle layers, enabling selective myotomy and mitigating the consequences of motor disorders of the esophagus. POEM is an effective treatment modality for diffuse esophageal spasm providing resolution of chest pain and dysphagia in a majority of patients who have refractory symptoms despite medical therapy. The results of POEM are more equivocal compared to esophagogastric junction outflow obstruction (EGJOO). POEM in EGJOO has been shown to have a 93% clinical success rate in 6 months. POEM appears to be more effective in motor disorders that affect the lower esophageal sphincter, such as EGJOO and opioid-induced esophageal dysfunction. While the current data for POEM in other entities such as DES and HE are positive, more supportive data are required to make POEM a consistent recommendation for patients.

Modern insights into the pathophysiology and treatment of pseudoachalasia

BACKGROUND

Secondary achalasia or pseudoachalasia is a clinical presentation undistinguishable from achalasia in terms of symptoms, manometric, and radiographic findings, but associated with different and identifiable underlying causes.

METHODS

A literature review was conducted on the PubMed database restricting results to the English language. Key terms used were "achalasia-like" with 63 results, "secondary achalasia" with 69 results, and "pseudoachalasia" with 141 results. References of the retrieved papers were also manually reviewed.

RESULTS

Etiology, diagnosis, and treatment were reviewed.

CONCLUSIONS

Pseudoachalasia is a rare disease. Most available evidence regarding this condition is based on case reports or small retrospective series. There are different causes but all culminating in outflow obstruction. Clinical presentation and image and functional tests overlap with primary achalasia or are inaccurate, thus the identification of secondary achalasia can be delayed. Inadequate diagnosis leads to futile therapies and could worsen prognosis, especially in neoplastic disease. Routine screening is not justifiable; good clinical judgment still remains the best tool. Therapy should be aimed at etiology. Even though Heller's myotomy brings the best results in non-malignant cases, good clinical judgment still remains the best tool as well.

[Diagnosis of esophageal motility disorders - Significance of the new Chicago classification v4.0]

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2021 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

The integrated relaxation pressure may not be an appropriate gold standard for deglutitive relaxation due to reliance on a single intragastric reference sensor

BACKGROUND

Integrated relaxation pressure (IRP) calculation depends on the selection of a single gastric reference sensor. Variable gastric pressure readings due to sensor selection can lead to diagnostic uncertainty. This study aimed to examine the effect of gastric reference sensor selection on IRP measurement and diagnosis.

METHODS

We identified high-resolution manometry (HRM) conducted between January and November 2017 with at least six intragastric reference sensors. IRP measurements and Chicago Classification 3.0 (CCv3) diagnoses were obtained for each of six gastric reference sensors. Studies were categorized as "stable" (no change in diagnosis) or "variable" (change in diagnosis with gastric reference selection). Variable diagnoses were further divided into "variable normal/dysmotility" (≥1 normal IRP measurement and ≥1 CCv3 diagnosis), or "variable dysmotility" (≥1 CCv3 diagnosis, only elevated IRP measurements). Bland-Altman plots were used to compare IRP measurements within HRM studies.

KEY RESULTS

The analysis included 100 HRM studies, among which 18% had variable normal/dysmotility, and 10% had variable dysmotility. The average IRP difference between reference sensors was 6.7 mmHg for variable normal/dysmotility and 5.9 mmHg for variable dysmotility. The average difference between the proximal-most and distal-most sensors was -1.52 mmHg (lower limit of agreement -10.03 mmHg, upper limit of agreement 7.00 mmHg).

CONCLUSIONS & INFERENCES

IRP values can vary greatly depending on the reference sensor used, leading to inconsistent diagnoses in 28% of HRM studies. Choosing the correct gastric reference sensor is crucial for accurate test results and avoiding misdiagnosis. Standardization of reference sensor selection or supportive testing for uncertain results should be considered.

Esophageal Motility Disorders: Diagnosis and Treatment Strategies

BACKGROUND

Esophageal motility disorders (EMDs) are caused by the impaired relaxation of the upper/lower esophageal sphincter and/or defective esophageal peristaltic contractions, resulting in dysphagia and noncardiac chest pain. High-resolution manometry (HRM) is essential for the diagnosis of primary EMD; however, the recognition of EMD and HRM by general practitioners in Japan is limited. This review summarizes the diagnosis of and treatment strategies for EMD.

SUMMARY

HRM is a specific test for the diagnosis of EMD, whereas endoscopy and barium swallow as screening tests provide characteristic findings (i.e., esophageal rosette and bird's beak sign) in some cases. It is important to note that manometric diagnoses apart from achalasia are often clinically irrelevant; therefore, the recently updated guidelines suggest additional manometric maneuvers, such as the rapid drink challenge, and further testing, including functional lumen imaging, for a more accurate diagnosis before invasive treatment. Endoscopic/surgical myotomy, pneumatic dilation, and botulinum toxin injections need to be considered for patients with achalasia and clinically relevant esophagogastric junction outflow obstruction.

KEY MESSAGE

Since the detailed pathophysiology of EMD remains unclear, their diagnosis needs to be cautiously established prior to the initiation of invasive treatment.

Interrater Reliability of Functional Lumen Imaging Probe Panometry and High-Resolution Manometry for the Assessment of Esophageal Motility Disorders

INTRODUCTION

High-resolution manometry (HRM) and functional lumen imaging probe (FLIP) are primary and/or complementary diagnostic tools for the evaluation of esophageal motility. We aimed to assess the interrater agreement and accuracy of HRM and FLIP interpretations.

METHODS

Esophageal motility specialists from multiple institutions completed the interpretation of 40 consecutive HRM and 40 FLIP studies. Interrater agreement was assessed using intraclass correlation coefficient (ICC) for continuous variables and Fleiss' κ statistics for nominal variables. Accuracies of rater interpretation were assessed using the consensus of 3 experienced raters as the reference standard.

RESULTS

Fifteen raters completed the HRM and FLIP studies. An excellent interrater agreement was seen in supine median integral relaxation pressure (ICC 0.96, 95% confidence interval 0.95-0.98), and a good agreement was seen with the assessment of esophagogastric junction (EGJ) outflow, peristalsis, and assignment of a Chicago Classification version 4.0 diagnosis using HRM (κ = 0.71, 0.75, and 0.70, respectively). An excellent interrater agreement for EGJ distensibility index and maximum diameter (0.91 [0.90-0.94], 0.92 [0.89-0.95]) was seen, and a moderate-to-good agreement was seen in the assignment of EGJ opening classification, contractile response pattern, and motility classification (κ = 0.68, 0.56, and 0.59, respectively) on FLIP. Rater accuracy for Chicago Classification version 4.0 diagnosis on HRM was 82% (95% confidence interval 78%-84%) and for motility diagnosis on FLIP Panometry was 78% (95% confidence interval 72%-81%).

DISCUSSION

Our study demonstrates high levels of interrater agreement and accuracy in the interpretation of HRM and FLIP metrics and moderate-to-high levels for motility classification in FLIP, supporting the use of these approaches for primary or complementary evaluation of esophageal motility disorders.

[Diagnosis of esophageal motility disorders - Significance of the new Chicago classification v4.0]

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2021 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

Benefit of extending the protocol for high resolution manometry according to the version 4.0 of the Chicago criteria. A multicenter study

BACKGROUND

The last version of the Chicago Criteria for high resolution esophageal manometry proposes an expanded protocol including complementary maneuvers to improve the diagnostic yield of the exploration. Our aim was to determine the diagnostic gain of the CCv4.0 protocol compared to the CCv3.0 protocol.

METHODS

All manometry recordings performed in 4 reference centers during the first 10 months after the implementation of the new protocol were retrospectively reviewed. The time spent to complete the protocol was measured, and the changes in diagnosis resulting from the new CCv4.0 were compared to CCv3.0.

KEY RESULTS

From a total of 756 HRM performed, 606 studies could be properly analyzed. The duration of the studies was 18.3 ± 4.3 min. From these, 11.3 ± 3.4 min were spent to complete the CCv3.0 protocol, and 7.4 ± 3.6 min were spent for the remaining maneuvers. A discordant diagnosis between CCv3.0 and CCv4.0 was obtained in 12% of patients: 32% of patients with ineffective esophageal motility turned to normal motility; 24% of patients with esophagogastric junction outlet obstruction (EGJOO) turned to a non-obstructive disorder; and 1% of patients with an apparently normal EGJ relaxation, turned to an obstructive disorder. EGJOO according to CCv4.0 was more prevalent in patients referred for dysphagia (11%) than those referred for GERD (4%; p = 0.003).

CONCLUSIONS AND INFERENCES

Prolongation of the time spent to complete the CCv4.0 protocol leads to a change in the diagnosis of 12% of patients. Clinically relevant changes are mainly related to the evaluation of EGJOO.

An artificial intelligence platform provides an accurate interpretation of esophageal motility from Functional Lumen Imaging Probe Panometry studies

BACKGROUND

Functional lumen imaging probe (FLIP) Panometry is performed at the time of sedated endoscopy and evaluates esophageal motility in response to distension. This study aimed to develop and test an automated artificial intelligence (AI) platform that could interpret FLIP Panometry studies.

METHODS

The study cohort included 678 consecutive patients and 35 asymptomatic controls that completed FLIP Panometry during endoscopy and high-resolution manometry (HRM). "True" study labels for model training and testing were assigned by experienced esophagologists per a hierarchical classification scheme. The supervised, deep learning, AI model generated FLIP Panometry heatmaps from raw FLIP data and based on convolutional neural networks assigned esophageal motility labels using a two-stage prediction model. Model performance was tested on a 15% held-out test set (n = 103); the remainder of the studies were utilized for model training (n = 610).

KEY RESULTS

"True" FLIP labels across the entire cohort included 190 (27%) "normal," 265 (37%) "not normal/not achalasia," and 258 (36%) "achalasia." On the test set, both the Normal/Not normal and the achalasia/not achalasia models achieved an accuracy of 89% (with 89%/88% recall, 90%/89% precision, respectively). Of 28 patients with achalasia (per HRM) in the test set, 0 were predicted as "normal" and 93% as "achalasia" by the AI model.

CONCLUSIONS

An AI platform provided accurate interpretation of FLIP Panometry esophageal motility studies from a single center compared with the impression of experienced FLIP Panometry interpreters. This platform may provide useful clinical decision support for esophageal motility diagnosis from FLIP Panometry studies performed at the time of endoscopy.

Advances in the Diagnosis and Management of Achalasia and Achalasia-Like Syndromes: Insights From HRM and FLIP

High-resolution manometry, Chicago Classification v4.0, the functional lumen imaging probe, Panometry, and peroral endoscopic myotomy (POEM) are all now integral parts of the landscape for managing achalasia or, more precisely, achalasia-like syndromes. This narrative review examines the impact of these innovations on the management of achalasia-like syndromes. High-resolution manometry was the disruptive technology that prompted the paradigm shift to thinking of motility disorders as patterns of obstructive physiology involving the esophagogastric junction and/or the distal esophagus rather than as siloed entities. An early observation was that the cardinal feature of achalasia-impaired lower esophageal sphincter relaxation-can occur in several subtypes: without peristalsis, with pan-esophageal pressurization, with premature (spastic) distal esophageal contractions, or even with preserved peristalsis (esophagogastric junction outlet obstruction). Furthermore, there being no biomarker for achalasia, no manometric pattern is perfectly sensitive or specific for 'achalasia' and there is also no 'gold standard' for the diagnosis. Consequently, complimentary physiological testing with a timed barium esophagram or functional lumen imaging probe are employed both to improve the detection of patients likely to respond to treatments for 'achalasia' and to characterize other syndromes also likely to benefit from achalasia therapies. These findings have become particularly relevant with the development of a minimally invasive technique for performing a tailored esophageal myotomy, POEM. Now and in the future, optimal achalasia management is to render treatment in a phenotype-specific manner, that is, POEM calibrated in a patient-specific manner for obstructive physiology including the distal esophagus and more conservative strategies such as a short POEM or pneumatic dilation for obstructive physiology limited to the lower esophageal sphincter.

Identifying hiatal hernia with impedance planimetry during esophageal distension testing

INTRODUCTION

Functional luminal imaging probe (FLIP) Panometry evaluates the esophageal response to distension involving biomechanics and motility. We have observed that hiatus hernia (HH) is evident during FLIP studies as a separation between the crural diaphragm (CD) and lower esophageal sphincter (LES) like what is seen with high-resolution manometry (HRM). The aim of this study was to compare FLIP findings to endoscopy and HRM in the detection of HH.

METHODS

A total of 100 consecutive patients that completed FLIP during sedated endoscopy and HRM were included. LES-CD separation was assessed on FLIP and HRM with the presence of HH defined as LES-CD ≥1 cm. The agreement was evaluated using the kappa (κ) statistic.

RESULTS

Hiatal hernia was detected in 32% of patients on HRM and 44% of patients on FLIP with a substantial agreement between studies (84% agreement; κ = 0.667). On FLIP, a 'new' HH (i.e. HH not observed on HRM) occurred in 14 patients and an "enlarged" HH (i.e., LES-CD ≥2 cm larger than on HRM) occurred in 11 patients. Among patients that also completed, timed barium esophagogram (TBE), delayed esophageal emptying on TBE was more common in patients with new or enlarged HH on FLIP than those without: 7/11 (64%) versus 2/12 (17%); p = 0.017.

CONCLUSION

FLIP can detect HH with a substantial agreement with HRM, though esophageal distension with FLIP testing appeared to elicit and/or enlarge a HH in an additional 25% of patients. Although this unique response to esophageal distension may represent a mechanism of dysphagia or susceptibility to reflux, additional study is needed to clarify its significance.

Functional Lumen Imaging Probe Panometry Helps Identify Clinically Relevant Esophagogastric Junction Outflow Obstruction per Chicago Classification v4.0

INTRODUCTION

Esophagogastric junction (EGJ) outflow obstruction (EGJOO) per Chicago Classification v4.0 (CCv4.0) represents a high-resolution manometry (HRM) diagnosis with uncertain clinical significance. This study aimed to evaluate functional lumen imaging probe (FLIP) panometry among patients with EGJOO on HRM/CCv4.0 to assess clinical/manometric associations and treatment outcomes.

METHODS

An observational cohort study was performed on patients who completed FLIP during endoscopy and had an HRM/CCv4.0 diagnosis of EGJOO, i.e., HRM-EGJOO (inconclusive). Abnormal FLIP panometry motility classifications were applied to identify FLIP-confirmed conclusive EGJOO. Rapid drink challenge on HRM and timed barium esophagram were also assessed. Clinical management plan was determined by treating physicians and assessed through chart review. Clinical outcome was defined using the Eckardt score (ES) during follow-up evaluation: ES < 3 was considered a good outcome.

RESULTS

Of 139 adult patients with manometric EGJOO (inconclusive per CCv4.0), a treatment outcome ES was obtained in 55 after achalasia-type treatment (i.e., pneumatic dilation, peroral endoscopic myotomy, laparoscopic Heller myotomy, or botulinum toxin injection) and 36 patients after other nonachalasia-type treatment. Among patients with conclusive EGJOO by HRM-FLIP complementary impression, 77% (33/43) had a good outcome after achalasia-type treatment, whereas 0% (0/12) of patients had a good outcome after nonachalasia-type treatment. Of patients with normal EGJ opening on FLIP, one-third of patients treated with achalasia-type treatment had a good outcome, while 9 of the 10 treated conservatively had a good outcome.

DISCUSSION

FLIP panometry provides a useful complement to clarify the clinical significance of an HRM/CCv4.0 EGJOO diagnosis and help direct management decisions.

Using high resolution manometry impedance to diagnose upper esophageal sphincter and pharyngeal motor disorders

BACKGROUND

Oro-pharyngeal pathophysiology, including upper esophageal sphincter (UES) and pharyngeal disorders, can be assessed by pharyngeal high-resolution manometry impedance (P-HRM-I). We aimed to establish methodology to diagnose disorders utilizing P-HRM-I, hypothesizing that the objective measures could be used to diagnose disordered deglutition evidenced by greater aspiration scores.

METHODS

Patients (n = 509, 18-91 years) were compared to controls (n = 120, 20-94 years). Variables measuring UES relaxation, UES opening extent, intrabolus pressure, and pharyngeal contractile strength were derived for 10 ml liquid swallows. Three associated pharyngeal pressurization patterns, which may be indicative of obstructed flow, were characterized: pan-pressurization (Type 1), distal compartmentalized pressurization (Type 2), and transient pressurization (Type 3). Deglutitive aspiration was determined from video fluoroscopy.

RESULTS

UES relaxation pressure was best able to differentiate patients from controls (T 6.528, p < 0.0001). Patients with abnormal relaxation pressure (>8 mmHg) more frequently exhibited pharyngeal pressurization patterns and had adjunct evidence of reduced luminal distensibility (high intrabolus pressure and/or reduced UES opening). Utilizing this information, a diagnostic scheme was devised identifying 138 patients with UES disorder. A further 96 patients without evidence of UES disorder had abnormally weak pharyngeal pressures, confirming propulsive disorder. Amongst a sub-sample of 320 patients undergoing video fluoroscopy, those with pharyngeal pressurizations and adjunct evidence of reduced UES relaxation and/or distensibility had higher aspiration scores (Chi-square 60.169, p < 0.0001).

CONCLUSION

P-HRM-I can provide evidence for UES disorder based on pharyngeal pressurization patterns and abnormal findings for UES relaxation pressure, UES opening, and intrabolus pressure. Measuring pharyngeal contractility requires further optimization.

High-resolution manometry with additional maneuvers using the Starlet system: normative thresholds and diagnostic yields for relevant esophagogastric junction outflow disorders

BACKGROUND

Chicago classification version 4.0 suggests additional maneuvers, such as upright testing, multiple rapid swallows (MRS), and the rapid drink challenge (RDC), for high-resolution manometry (HRM) to minimize ambiguity in the diagnosis of esophageal motility disorders. The present study investigated normative thresholds for these new metrics using the Starlet system as well as their diagnostic yields for relevant esophagogastric outflow disorders (EGJOD).

METHODS

In study 1, 30 asymptomatic volunteers prospectively performed HRM including MRS and RDC in the supine/upright positions. We calculated normative thresholds for the new metrics, such as upright integrated relaxation pressure (IRP), upright intrabolus pressure (IBP), and IRP during RDC (RDC-IRP). In study 2, we retrospectively analyzed the HRM tracings of 82 patients who underwent HRM in both positions at our hospital to assess the diagnostic yields of HRM metrics.

RESULTS

Based on the results of study 1, we adopted the following normative thresholds: upright IRP < 20 mmHg, upright IBP < 21 mmHg, and RDC-IRP < 16 mmHg. In study 2, 45 patients with dysphagia or chest pain were included in the analysis to identify predictive factors for clinically relevant esophagogastric outflow disorders (true EGJOD). Supine/upright IRP, RDC-IRP, and pan-esophageal pressurization > 20 mmHg during RDC (RDC-PEP) predicted true EGJOD with RDC-PEP with the highest sensitivity of 91.7%.

CONCLUSIONS

HRM with additional maneuvers may facilitate the diagnosis of clinically relevant EGJOD.

Normative values for esophageal functional lumen imaging probe measurements: A meta-analysis

BACKGROUND

The functional lumen imaging probe (Endoflip™) is increasingly used for evaluation of patients with esophageal symptoms. To improve the interpretation of Endoflip™ in clinical practice, normative values with appropriate cut-off values are required.

METHODS

Original clinical studies describing Endoflip™ use for measurements of esophageal motility in healthy adults were considered. Meta-analysis was performed based on published values.

RESULTS

A total of 17 articles were included in the systematic review, 15 of which were included in the meta-analysis, representing 154 unique subjects. At 40 ml distention, the 5th-95th and 10th-90th percentiles for esophagogastric junction distensibility index (EGJ-DI) were 1.96-10.95 mm² /mmHg and 2.36-8.95 mm² /mmHg, respectively. An EGJ-DI below 2 mm² /mmHg was found in 5.4%, and below 3 mm² /mmHg in 20.1% of healthy subjects. At 50 ml distention, the 5th-95th and 10th-90th percentiles for EGJ-DI are 2.86-10.66 mm² /mmHg and 3.28-9.12 mm² /mmHg, respectively (below 2 mm² /mmHg: 0.6%, 3 mm² /mmHg: 6.3%). The 5th-95th and 10th-90th percentiles for EGJ-DI at 60 ml distention were 3.06-8.14 mm² /mmHg and 3.33-7.18 mm² /mmHg, respectively (below 2 mm² /mmHg: 0.0%, 3 mm² /mmHg: 7%). A clear cut-off for lower values was identified while a large spread in values was observed for upper limits of normal for EGJ-DI for all filling volumes.

CONCLUSIONS

Given these observations, we recommend using a cut-off of 2 mm² /mmHg for clinical practice, values below can be considered abnormal. Given that 5.4% of the healthy subjects will have an EGJ-DI below 2 mm² /mmHg at 40 ml, we recommend using the 50 and 60 ml distention volumes. The clinical use of an upper limit for normality of EGJ-DI seems questionable.

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.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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 4.1 ml 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).

CONCLUSIONS AND INFERENCES

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.

Editorial: reducing false alarms with oesophagogastric junction outflow obstruction

LINKED CONTENT

This article is linked to Visaggi et al papers. To view these articles, visit https://doi.org/10.1111/apt.17101

Distension contraction plots of pharyngeal/esophageal peristalsis: next frontier in the assessment of esophageal motor function

Esophageal peristalsis consists of initial inhibition (relaxation) followed by excitation (contraction), both of which move sequentially in the aboral direction. Initial inhibition results in receptive relaxation and bolus-induced luminal distension, which allows propulsion by the contraction with minimal resistance to flow. Similar to the contraction wave, luminal distension has unique waveform characteristics in normal subjects; both are modulated by bolus volume, bolus viscosity, and posture, suggesting a possible cause-and-effect relationship between the two. Distension contraction plots in patients with dysphagia with normal bolus clearance [high-amplitude esophageal contractions (HAECs), esophagogastric junction outflow obstruction (EGJOO), and functional dysphagia (FD)] reveal two major findings: 1) unlike normal subjects, there is luminal occlusion distal to bolus during peristalsis in certain patients, i.e., with type 3 achalasia and nonobstructive dysphagia; and 2) bolus travels through a narrow lumen esophagus during peristalsis in patients with HAECs, EGJOO, and FD. Aforementioned findings indicate a relative dynamic obstruction to the bolus flow during peristalsis and reduced distensibility of esophageal wall in the bolus segment of the esophagus. We speculate that a normal or supernormal contraction wave pushing bolus against resistance is the mechanism of dysphagia sensation in significant number of patients. Representations of distension and contraction, combined with objective measures of flow timing and distensibility are complementary to the current scheme of classifying esophageal motility disorders based solely on the characteristics of contraction phase of peristalsis. Better understanding of the distensibility of the bolus-containing segment of the esophagus during peristalsis will lead to the development of novel medical and surgical therapies in the treatment of dysphagia in significant number of patients.

Chicago classification v4.0 protocol improves specificity and accuracy of diagnosis of oesophagogastric junction outflow obstruction

BACKGROUND

Chicago classification version 4.0 (CCv4.0) introduced stringent diagnostic criteria for oesophagogastric junction outflow obstruction (EGJOO), in order to increase the clinical relevance of the diagnosis, although this has not yet been demonstrated.

AIMS

To determine the prevalence of EGJOO using CCv4.0 criteria in patients with CCv3.0-based EGJOO, and to assess if provocative manoeuvres can predict a conclusive CCv4.0 diagnosis of EGJOO.

METHODS

Clinical presentation, high resolution manometry (HRM) with rapid drink challenge (RDC), and timed barium oesophagogram (TBE) data were extracted for patients diagnosed with EGJOO as per CCv3.0 between 2018 and 2020. Patients were then re-classified according to CCv4.0 criteria, using clinically relevant symptoms (dysphagia and/or chest pain), and abnormal barium emptying at 5 min on TBE. Receiver operating characteristic (ROC) analyses identified HRM predictors of EGJOO.

RESULTS

Of 2010 HRM studies, 144 (7.2%) fulfilled CCv3.0 criteria for EGJOO (median age 61 years, 56.9% female). Upon applying CCv4.0 criteria, EGJOO prevalence decreased to 1.2%. On ROC analysis, integrated relaxation pressure during RDC (RDC-IRP) was a significant predictor of a conclusive EGJOO diagnosis by CCv4.0 criteria (area under the curve: 96.1%). The optimal RDC-IRP threshold of 16.7 mm Hg had 87% sensitivity, 97.1% specificity, 95.7% negative predictive value and 91.3% positive predictive value for a conclusive EGJOO diagnosis; lower thresholds (10 mmHg, 12 mmHg) had better sensitivity but lower specificity.

CONCLUSION

CCv4.0 criteria reduced the prevalence of EGJOO by 80%, thereby refining the diagnosis and identifying clinically relevant outflow obstruction. Elevated RDC-IRP can predict conclusive EGJOO per CCv4.0.

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.

Achalasia

Achalasia is a rare disorder of the oesophageal smooth muscle characterized by impaired relaxation of the lower oesophageal sphincter (LES) and absent or spastic contractions in the oesophageal body. The key pathophysiological mechanism is loss of inhibitory nerve function that probably results from an autoimmune attack targeting oesophageal myenteric nerves through cell-mediated and, possibly, antibody-mediated mechanisms. Achalasia incidence and prevalence increase with age, but the disorder can affect all ages and both sexes. Cardinal symptoms consist of dysphagia, regurgitation, chest pain and weight loss. Several years can pass between symptom onset and an achalasia diagnosis. Evaluation starts with endoscopy to rule out structural causes, followed by high-resolution manometry and/or barium radiography. Functional lumen imaging probe can provide complementary evidence. Achalasia subtypes have management and prognostic implications. Although symptom questionnaires are not useful for diagnosis, the Eckardt score is a simple symptom scoring scale that helps to quantify symptom response to therapy. Oral pharmacotherapy is not particularly effective. Botulinum toxin injection into the LES can temporize symptoms and function as a bridge to definitive therapy. Pneumatic dilation, per-oral endoscopic myotomy and laparoscopic Heller myotomy can provide durable symptom benefit. End-stage achalasia with a dilated, non-functioning oesophagus may require oesophagectomy or enteral feeding into the stomach. Long-term complications can, rarely, include oesophageal cancer, but surveillance recommendations have not been established.

[Chicago Classification ver. 4.0: Diagnosis of Achalasia and Esophagogastric Junction Outflow Obstruction]

Achalasia is a common esophageal motility disorder characterized by inappropriate relaxation of the lower esophageal sphincter and a loss of normal peristalsis in the esophageal body. The newly suggested Chicago Classification ver. 4.0 recommends conclusive diagnoses of types 1, 2, and 3. A conclusive diagnosis of type 3 achalasia requires no appreciable peristalsis compared to the previously used ver. 3.0. In the case of inconclusive diagnosis of achalasia, additional tests, including timed barium esophagogram (TBE) or functional lumen imaging probe (FLIP), are strongly recommended in ver. 4.0. Esophagogastric junction outflow obstruction (EGJOO) in Chicago Classification ver. 3.0 was defined as an elevated median integrated relaxation pressure (IRP) without evidence of achalasia. On the other hand, the diagnosis of EGJOO in Chicago Classification ver. 4.0 requires elevated IRP in both positions, elevated intrabolus pressure, positive clinical symptoms, and additional positive test by TBE or FLIP. The newly suggested Chicago Classification Classification ver. 4.0 will be helpful in an accurate diagnosis of esophageal motility disorders, including achalasia and EGJOO.

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.

How Updates in Chicago Classification Impact Clinical Practice

Chicago Classification version 4.0 (CC v4.0), published in 2021, presents several modifications largely aimed at minimizing over-diagnosis of inconclusive patterns on high-resolution manometry (HRM). These include: 1) introduction of a standardized HRM protocol for consistency among centers, 2) emphasis on the need for supportive data in instances of inconclusive manometric patterns, 3) required presence of relevant symptoms in certain instances to reduce over-diagnosis and inappropriate interventions, and 4) classification as disorders of EGJ outflow or disorders of peristalsis. These updates aim to improve the clinical application of HRM and patient outcomes.