Functional Lumen Imaging Probe Research Articles

A comparison of function lumen imaging probe measurements of anal sphincter function in fecal incontinence.

The functional lumen imaging probe (FLIP) is a test of anal sphincter distensibility under evaluation by specialist centers. Two measurement protocols termed "stepwise" and "ramp" are used, risking a lack of standardization. This study aims to compare the performance of these protocols to establish if there are differences between them. Patients with fecal incontinence were recruited and underwent measurement with both protocols at a tertiary pelvic floor referral unit. Differences in minimum diameter, FLIP bag pressure, and distensibility index (DI) at rest and during squeeze were calculated at various FLIP bag volumes. Twenty patients (19 female, mean age 61 [range: 38-78]) were included. The resting minimum diameter at 30 and 40 mL bag volumes were less in the stepwise protocol (mean bias: -0.55 mm and -1.18 mm, p < 0.05) along with the DI at the same bag volumes (mean bias: -0.37 mm2/mmHg and -0.55 mm2/mmHg, p < 0.05). There was also a trend towards greater bag pressures at 30 mL (mean bias: +2.08 mmHg, p = 0.114) and 40 mL (mean bias: +2.81 mmHg, p = 0.129) volumes in the stepwise protocol. There were no differences between protocols in measurements of minimum diameter, maximum bag pressure, or DI during voluntary squeeze (p > 0.05). There are differences between the two commonly described FLIP measurement protocols at rest, although there are no differences in the assessment of squeeze function. Consensus agreement is required to agree the most appropriate FLIP measurement protocol in assessing anal sphincter function.

Esophagogastric Junction Outflow Obstruction (EGJOO): A Manometric Phenomenon or Clinically Impactful Problem.

Esophagogastric junction outflow obstruction (EGJOO), defined manometrically by impaired esophagogastric junction relaxation (EGJ) with preserved peristalsis, can be artifactual, due to secondary etiologies (mechanical, medication-induced), or a true motility disorder. The purpose of this review is to go over the evolving approach to diagnosing and treating clinically relevant EGJOO. Timed barium esophagram (TBE) and the functional lumen imaging probe (FLIP) are useful to identify clinically relevant EGJOO that merits lower esophageal sphincter (LES) directed therapies. There are no randomized controlled trials evaluating EJGOO treatment. Uncontrolled trials show effectiveness for pneumatic dilation and peroral endoscopic myotomy to treat confirmed EGJOO; Botox and Heller myotomy may also be considered but data for confirmed EGJOO is more limited. Diagnosis of clinically relevant idiopathic EGJOO requires symptoms, exclusion of mechanical and medication-related etiologies, and confirmation of EGJ obstruction by TBE or FLIP. Botox LES injection has limited durability, it can be used in patients who are not candidates for other treatments. PD and POEM are effective in confirmed EGJOO, Heller myotomy may also be considered but data for confirmed EGJOO is limited. Randomized controlled trials are needed to clarify optimal management of EGJOO.

Effect of esophageal body recoil on clinical outcomes in non-spastic achalasia.

Despite the established efficacy of achalasia treatments on symptomatic outcomes, there are limited data evaluating the treatment effect on esophageal dilatation. This study aimed to assess the effect achalasia treatment on esophageal dilatation and the effect of esophageal width reduction ("recoil") on clinical outcomes. Patients with type I or type II achalasia that completed high-resolution manometry (HRM), functional lumen imaging probe (FLIP), and timed barium esophagram (TBE) pre and post treatment were included. Esophageal width was measured using TBE. Focused subgroup analysis was performed on patients with normal posttreatment EGJ opening on FLIP. Good clinical outcomes were defined as barium column height of <5 cm at 5 min and Eckardt Score ≤3. Sixty-nine patients (41% type I and 59% type II) were included. Esophageal width decreased from pre to post treatment mean (SD) 4.2 (1.3) cm-2.8 (1.2) cm; p < 0.01. In the normal post treatment EGJ opening subgroup, esophageal width was less in patients with good TBE outcome compared to poor outcome mean (SD) 2.2 (0.7) cm versus 3.2 (1.4) cm (p < 0.01), but did not differ in good versus poor symptomatic outcome groups. Esophageal width recoil >25% posttreatment was associated with a greater rate of good TBE outcome (71% vs. 50%, p = 0.04) and good symptomatic outcome (88% vs. 50%; p = 0.04). Esophageal recoil was associated with good achalasia treatment outcome in patients without posttreatment EGJ obstruction. This suggests that mechanical properties of the esophageal wall, likely associated with tissue remodeling, play a role in clinical outcomes following achalasia treatment.

Research gap in esophageal achalasia: a narrative review.

In recent years, new translational evidence, diagnostic techniques, and innovative therapies have shed new light on esophageal achalasia and revamped the attention on this relatively rare motility disorder. This narrative review aims to highlight the most recent progress and the areas where further research is needed. The four senior authors identified five topics commonly discussed in achalasia management: i.e. pathogenesis, role of functional lumen imaging probe in the diagnostic flow chart of achalasia, how to define the outcome of achalasia treatments, how to manage persistent chest pain after the treatment, and if achalasia patients' may benefit from a regular follow-up. We searched the bibliographic databases to identify systematic reviews, meta-analyses, randomized control trials, and original research articles in English up to December 2023. We provide a summary with the most recent findings in each of the five topics and the critical points where to address future research, such as the immune-genetic patterns of achalasia that might explain the transition among the different phenotypes, the need for a validated clinical definition of treatment success, the use of neuromodulators to manage chest pain, and the need for identifying achalasia patients at risk for cancer and who may benefit of long-term follow-up. Although undoubtedly, progress has been made on the definition and management of achalasia, unmet needs remain. Debated aspects range from mechanistic insights, symptoms, objective measure relationships, and accurate clinical responses to therapeutic interventions. Translational research is eagerly awaited to answer these unresolved questions.

Imaging and endoscopic tools in pediatric inflammatory bowel disease: What's new?

Pediatric inflammatory bowel disease (IBD) is a chronic inflammatory disorder, with increasing incidence and prevalence worldwide. There have been recent advances in imaging and endoscopic technology for disease diagnosis, treatment, and monitoring. Intestinal ultrasound, including transabdominal, transperineal, and endoscopic, has been emerging for the assessment of transmural bowel inflammation and disease complications (e.g., fistula, abscess). Aside from surgery, IBD-related intestinal strictures now have endoscopic treatment options including through-the-scope balloon dilatation, injection, and needle knife stricturotomy and new evaluation tools such as endoscopic functional lumen imaging probe. Unsedated transnasal endoscopy may have a role in patients with upper gastrointestinal Crohn's disease or those with IBD with new upper gastrointestinal symptoms. Improvements to dysplasia screening in pediatric patients with longstanding colonic disease or primary sclerosing cholangitis hold promise with the addition of virtual chromoendoscopy and ongoing research in the field of artificial intelligence-assisted endoscopic detection. Artificial intelligence and machine learning is a rapidly evolving field, with goals of further personalizing IBD diagnosis and treatment selection as well as prognostication. This review summarized these advancements, focusing on pediatric patients with IBD.

Identification of Achalasia Within Absent Contractility Phenotypes on High-Resolution Manometry: Prevalence, Predictive Factors, and Treatment Outcome.

Absent contractility on high-resolution manometry (HRM) defines severe hypomotility but needs distinction from achalasia. We retrospectively identified achalasia within absent contractility using HRM provocative maneuvers, barium esophagography, and functional lumen imaging probe (FLIP). Adult patients with absent contractility on HRM during the 4-year study period were eligible for inclusion. Inadequate studies, achalasia after therapy, or prior foregut surgery were exclusions. Upright integrated relaxation pressure (IRP) >12 mm Hg, panesophageal pressurization, and/or elevated IRP on multiple rapid swallows and rapid drink challenge (RDC) were considered abnormal. Esophageal barium retention and abnormal esophagogastric junction distensibility index (<2.0 mm 2 /mm Hg) on FLIP defined achalasia. Clinical, endoscopic, and motor characteristics of patients with achalasia were compared with absent contractility without obstruction. Of 164 patients, 20 (12.2%) had achalasia (17.9% of 112 patients with adjunctive testing), while 92 did not, and 52 did not undergo adjunctive tests. Achalasia was diagnosed regardless of IRP value, but the median supine IRP was higher (odds ratio 1.196, 95% confidence interval 1.041-1.375, P = 0.012). Patients with achalasia were more likely to present with dysphagia (80.0% vs 35.9%, P < 0.001), with obstructive features on HRM maneuvers (83.3% vs 48.9%, P = 0.039), but lower likelihood of GERD evidence (20.0% vs 47.3%, P = 0.027) or large hiatus hernia (15.0% vs 43.8%, P = 0.002). On multivariable analysis, dysphagia presentation ( P = 0.006) and pressurization on RDC ( P = 0.027) predicted achalasia, while reflux and presurgical evaluations and lack of RDC obstruction predicted absent contractility without obstruction. Despite HRM diagnosis of absent contractility, achalasia is identified in more than 1 in 10 patients regardless of IRP value.

Secondary peristalsis and esophagogastric junction distensibility in symptomatic post-fundoplication patients.

The impact of esophageal dysmotility among patients with post-fundoplication esophageal symptoms is not fully understood. This study aimed to investigate secondary peristalsis and esophagogastric junction (EGJ) opening biomechanics using functional lumen imaging probe (FLIP) panometry in symptomatic post-fundoplication patients. Eighty-seven adult patients post-fundoplication who completed FLIP for symptomatic esophageal evaluation were included. Secondary peristaltic contractile response (CR) patterns and EGJ opening metrics (EGJ distensibility index (EGJ-DI) and maximum EGJ diameter) were evaluated on FLIP panometry and analyzed against high-resolution manometry (HRM), patient-reported outcomes, and fundoplication condition seen on esophagram and/or endoscopy. FLIP CR patterns included 14 (16%) normal CR, 30 (34%) borderline CR, 28 (32%) impaired/disordered CR, 13 (15%) absent CR, and 2 (2%) spastic reactive CR. Compared with normal and borderline CRs (i.e., CR patterns with distinct, antegrade peristalsis), patients with impaired/disordered and absent CRs demonstrated significantly greater time since fundoplication (2.4 (0.6-6.8) vs. 8.9 (2.6-14.5) years; p = 0.002), greater esophageal body width on esophagram (n = 50; 2.3 (2.0-2.8) vs. 2.9 (2.4-3.6) cm; p = 0.013), and lower EGJ-DI (4.3 (2.7-5.4) vs. 2.6 (1.7-3.7) mm2/mmHg; p = 0.001). Intact fundoplications had significantly higher rates of normal CRs compared to anatomically abnormal (i.e., tight, disrupted, slipped, herniated) fundoplications (9 (28%) vs. 5 (9%); p = 0.032), but there were no differences in EGJ-DI or EGJ maximum diameter. Symptomatic post-fundoplication patients were characterized by frequent abnormal secondary peristalsis after fundoplication, potentially worsening with time after fundoplication or related to EGJ outflow resistance.

A New Method to Evaluate Lower Esophageal Distension Capacity in Eosinophilic Esophagitis by Using Functional Lumen Imaging Probe (EndoFLIP™).

Endoluminal functional lumen impedance planimetry (EndoFLIPTM) has become the gold standard to evaluate esophageal distensibility, although the study itself and its analysis present challenges. We propose here a new method to assess lower esophageal distension capacity that overcomes several limitations of prior approaches, including incomplete and corrupted EndoFLIPTM recordings. Esophageal distension capacity was evaluated with a 16-channel EndoFLIPTM in 10 controls and 14 patients with eosinophilic esophagitis (EoE). Controls were evaluated once. EoE patients were evaluated at baseline and after at least six weeks of treatment with orodispersible budesonide tablets, 1 mg bd. Balloon volumes were increased by 5 mL stepwise, either reaching a maximum volume of 60 mL or a maximum balloon pressure of 60 mmHg. Recordings were analyzed with a homemade R script. The mean esophageal diameter at 60 mL, D (60 mL), was calculated or extrapolated depending on whether the 60 mL volume was reached. By fitting a Michaelis-Menten curve across all measured diameters throughout all constant volume steps, the mean D (60 mL) was estimated. For control subjects, the mean ± SD value of D (60 mL) was 17.08 ± 1.69 mm, and for EoE patients at baseline, D (60 mL) was 14.51 ± 2.68 mm. After six weeks of treatment of EoE patients, D (60 mL) significantly increased to 16.22 ± 1.86 mm (paired Wilcoxon signed test: p = 0.0052), although the values for control subjects were not reached. The estimated mean esophageal diameter at 60 mL is a good proxy for esophageal distension capacity, which correlates with clinical outcomes in EoE. The method presented in this study overcomes difficulties encountered during the standard measurement protocol, allowing the analysis of recordings from incomplete and corrupted registries.

Utility of Intraprocedural Luminal Diameter and Distensibility Measurements During the Esophageal Peroral Endoscopic Myotomy Procedure.

Through evaluation of the lower esophageal sphincter immediately before and after myotomy using an endoluminal functional lumen imaging probe (EFLIP), our study aimed to determine the clinical response to peroral endoscopic myotomy (POEM) and the incidence of postprocedure reflux. Achalasia is a rare esophageal motility disorder characterized by impaired relaxation of the lower esophageal sphincter (LES) and diminished peristalsis. POEM is a therapeutic option for durable management of achalasia. However, symptomatic acid reflux and esophagitis are well-known adverse effects of the procedure. Electronic medical records of 168 patients who underwent POEM for achalasia at 2 tertiary care referral centers from May 2014 to May 2021 were reviewed. EFLIP was used at a range of catheter fill volumes to assess LES dynamics. Preprocedure and postprocedure Eckardt Symptom Scores were recorded. Significant clinical improvement from POEM was sustained in over 94% of patients after 1 year. EFLIP changed intraprocedural management 5% of the time by means of myotomy extension. In patients with reflux>1 year following POEM, there was no significant difference in post-POEM LES diameter or change in LES diameter compared with those without reflux. However, post-POEM LES distensibility index (DI) was significantly higher in patients with reflux after 1 year compared with those without reflux. POEM is a safe and increasingly effective therapy for patients with symptomatic achalasia. Intraprocedural EFLIP measurements suggest that post-POEM reflux may be correlated more with DI than LES diameter. Yet, more data is needed to substantiate these outcomes.

Presence of esophageal contractility after achalasia treatment is associated with improved esophageal emptying.

Some achalasia patients exhibit esophageal contractile activity on follow-up after treatment, yet its importance remains unclear. We aimed to identify factors associated with presence of contractility after treatment and to assess its impact on timed barium esophagram (TBE) and clinical outcomes. Patients with type I or II achalasia on baseline high-resolution manometry (HRM) who completed HRM, TBE, and functional lumen imaging probe (FLIP) after treatment were retrospectively identified. Contractility was defined on post-treatment HRM as presence of at least 1 supine swallow with DCI ≥100 mmHg s cm. One hundred twenty-two patients were included (mean age 48 ± 17 years, 50% female). At follow-up evaluation after treatment (54% peroral endoscopic myotomy, 24% pneumatic dilation, 22% laparoscopic Heller myotomy), 61 (50%) patients had contractility on HRM. Patients with contractility (compared to those without) more frequently had type II achalasia (84% vs 57%, p = 0.001) and a post-treatment normal EGJ opening classification on FLIP (69% vs 49%; p < 0.001). In the subgroup of patients with post-treatment integrated relaxation pressure <15 mmHg and normal EGJ opening on FLIP (n = 53), those with contractility had a lower median column height on TBE at 1 min (4 vs 7 cm, p = 0.002) and 5 min (0 vs 5 cm, p = 0.001). In patients with "abnormal" EGJ metrics, patients with contractility showed lower symptom scores (median Eckardt score 2 vs 3, p = 0.03). Occurring more frequently in type II achalasia, and if adequate EGJ opening is achieved after treatment, esophageal contractility may contribute to improved esophageal emptying and improved symptoms in non-spastic achalasia. Preservation of esophageal body muscle could improve outcomes in these patients.

Anesthesia choice and its potential impact on endoluminal functional lumen imaging probe measurements in esophageal motility disorders

The widespread use of peroral endoscopic myotomy (POEM) has revolutionized the management of esophageal motility disorders (EMDs). The introduction of an endoluminal functional lumen imaging probe (EndoFLIP, Medtronic, Dublin, Ireland) can serve as a complementary diagnostic tool to assess the mechanical properties (ie, pressure, diameter, distensibility, topography) of the esophagus. During EndoFLIP measurements, different anesthesia techniques may induce variable degrees of neuromuscular blockade, potentially affecting esophageal motility and altering the results of EndoFLIP metrics. The aim of this study was to compare the impact of using total intravenous anesthesia (TIVA) versus general anesthesia with inhalational anesthetics (GAIA) on diagnostic EndoFLIP measurements. This retrospective study included all adult patients (≥18 years) undergoing EndoFlip during the POEM procedure at our institution between February 2017 and February 2022. Differences in pressure, diameter, and distensibility index were obtained by using propofol-based TIVA versus sevoflurane-based GAIA with a 30 mL and a 60 mL balloon. The differences were divided into terciles and compared between diagnoses by using univariate comparisons and logistic regression models. A total of 49 patients were included (39% type I achalasia, 43% type II or III achalasia, and 18% jackhammer esophagus [JE]). Compared with spastic disorders (types II and III achalasia and JE), type I had lower values of pressure differences at 60 mL in univariate (3.75 vs 15.20, P= .001) and multivariate (adjusted odds ratio, .89; 95% confidence interval, .82-.978) analyses. Compared with type I, types II and III achalasia had higher rates of pressure differences at 60 mL in the univariate (9.85 vs 3.75, P= .04) analysis and nearly reached significance in the multivariate analysis (1.09; 95% confidence interval, 1-1.20). Compared with type I achalasia, JE exhibited higher values in pressure differences at 60 mL (27.7 vs 3.75, P< .001). Esophageal pressure, as measured by EndoFLIP, was significantly reduced when patients were sedated with sevoflurane-based GAIA. The use of sevoflurane-based GAIA for diagnostic EndoFLIP may potentially lead to the misclassification of spastic disorders as type I achalasia. Propofol-based TIVA should therefore be considered over sevoflurane-based GAIA for sedation during the diagnostic test.

Esophageal anatomy and physiology vary across spastic and non-spastic phenotypes of disorders of esophagogastric junction outflow.

Pathophysiologic mechanisms of disorders of esophagogastric junction (EGJ) outflow are poorly understood. We aimed to compare anatomic and physiologic characteristics among patients with disorders of EGJ outflow and normal motility. We retrospectively evaluated adult patients with achalasia types 1, 2, 3, EGJ outflow obstruction (EGJOO) or normal motility on high-resolution manometry who underwent endoscopic ultrasound (EUS) from January 2019 to August 2022. Thickened circular muscle was defined as ≥1.6 mm. Characteristics from barium esophagram (BE) and functional lumen imaging probe (FLIP) were additionally assessed. Of 71 patients (mean age 56.2 years; 49% male), there were 8 (11%) normal motility, 58 (82%) had achalasia (5 (7%) type 1, 32 (45%) classic type 2, 21 (30%) type 3 [including 12 type 2 with FEPs]), and 7 (7%) had EGJOO. A significantly greater proportion of type 3 achalasia had thickened distal circular muscle (76.2%) versus normal motility (0%; p < 0.001) or type 2 achalasia (25%; p < 0.001). Type 1 achalasia had significantly wider mean maximum esophageal diameter on BE (57.8 mm) compared to type 2 achalasia (32.8 mm), type 3 achalasia (23.4 mm), EGJOO (15.9 mm), and normal motility (13.5 mm). 100% type 3 achalasia versus 0% type 1 achalasia/normal motility had tertiary contractions on BE. Mean EGJ distensibility index on FLIP was lower for type 3 achalasia (1.2 mmHg/mm2 ) and EGJOO (1.2 mmHg/mm2 ) versus type 2 (2.3 mmHg/mm2 ) and type 1 achalasia (2.9 mmHg/mm2 ). Our findings suggest distinct pathologic pathways may exist: type 3 achalasia and EGJOO may represent a spastic outflow phenotype consisting of a thickened, spastic circular muscle, which is distinct from type 1 and 2 achalasia consisting of a thin caliber circular muscle layer with more prominent esophageal dilation.

Functional lumen imaging probe topography identifies patients with normal acid exposure and esophageal hypervigilance amongst proton-pump inhibitor non-responders.

Multiple factors contribute to symptom generation and treatment response in proton-pump inhibitor non-responders (PPI-NRs). We aimed to test whether PPI-NRs with normal acid exposure have a higher degree of esophageal hypersensitivity and hypervigilance and can be identified using functional lumen imaging probe (FLIP) topography at the time of endoscopy. Data from PPI-NRs whom underwent endoscopy, FLIP and wireless 96-h pH-metry were retrospectively analyzed. Patients were grouped according to acid exposure time (AET) as (a) 0days abnormal (AET > 6%), (b) 1-2days abnormal, or (c) 3-4days abnormal. The esophageal hypervigilance and anxiety scale (EHAS) score and other symptom scores were compared between groups. The discriminatory ability of the esophagogastric junction (EGJ) distensibility index (DI) and max EGJ diameter in identifying patients with 0days abnormal AET was tested via receiver-operating-characteristic (ROC) curve analysis. EHAS score was 38.6 in the 0days abnormal AET group, 30.4 in the 1-2days abnormal AET group (p = 0.073 when compared to 0days abnormal) and 28.2 in the 3-4days abnormal AET group (p = 0.031 when compared to 0days abnormal). Area-under-the-curve (AUC) for the DI in association with 0days AET > 6% was 0.629. A DI of < 2.8 mm2/mmHg had a sensitivity of 83.3%, and negative predictive value of 88% in classifying patients with 0days abnormal acid exposure (p = 0.004). FLIP complements prolonged wireless pH-metry in distinguishing the subset of PPI-NRs with completely normal acid exposure and a higher burden of esophageal hypervigilance. Proper identification of patients along the functional heartburn spectrum can improve overall surgical outcomes.

Modern Achalasia: Diagnosis, Classification, and Treatment.

Achalasia is a major esophageal motor disorder featured by the altered relaxation of the esophagogastric junction in the absence of effective peristaltic activity. As a consequence of the esophageal outflow obstruction, achalasia patients present with clinical symptoms of dysphagia, chest pain, weight loss, and regurgitation of indigested food. Other less specific symptoms can also present including heartburn, chronic cough, and aspiration pneumonia. The delay in diagnosis, particularly when the presenting symptoms mimic those of gastroesophageal reflux disease, may be as long as several years. The widespread use of high-resolution manometry has permitted earlier detection and uncovered achalasia phenotypes which can have prognostic and therapeutic implications. Other tools have also emerged to help define achalasia severity and which can be used as objective measures of response to therapy including the timed barium esophagogram and the functional lumen imaging probe. Such diagnostic innovations, along with the increased awareness by clinicians and patients due to the availability of alternative therapeutic approaches (laparoscopic and robotic Heller myotomy, and peroral endoscopic myotomy) have radically changed the natural history of the disorder. Herein, we report the most recent advances in the diagnosis, classification, and management of esophageal achalasia and underline the still-grey areas that needs to be addressed by future research to reach the goal of personalizing treatment.

Composite score of physiomechanical esophageal function using functional lumen imaging probe panometry in eosinophilic esophagitis

Background and AimsThe evaluation provided by functional lumen imaging probe (FLIP) Panometry includes esophageal distensibility/compliance (mechanics) of the esophageal body and esophagogastric junction (EGJ) and esophageal motility (secondary peristalsis). We aimed to develop a composite score using these parameters to characterize physiomechanical function in patients with eosinophilic esophagitis (EoE). Methods215 adult patients with EoE that completed FLIP Panometry during sedated endoscopy with esophageal biopsies were included. FLIP metrics of esophageal body Compliance, Contractile response, Distensibility plateau, and maximum EGJ Diameter (C2D2) were scored as 0 for normal, vs 1 or 2 for increasing degree of abnormality. Scores were summed to calculate the composite “C2D2” score. ResultsThe C2D2 score had a significant positive correlation with mucosal eosinophil count (rho=0.241) and total endoscopic (EREFS) score (rho=0.467). Among patients off treatment at baseline evaluation (n=46), future proton pump inhibitor (PPI)-responders (i.e. achieved mucosal eosinophil count <15 per hpf after PPI treatment) had lower C2D2 scores than PPI-non-responders (median (IQR) 2 (1-3) vs 4 (2-6); P=0.003). A regression model (that controlled for age, sex, and baseline eosinophil count) showed a C2D2 score ≤3 had an odds ratio (95% confidence interval) of 14.5 (2.6-85) to predict future PPI-response. However, total EREFS scores (P=0.142) and baseline eosinophil count (P=0.480) did not differ between PPI-responders and PPI-non-responders. ConclusionsThis composite score of FLIP Panometry metrics, the C2D2 score, may facilitate characterizing physiomechanical function in EoE and serve as an objective outcome measure.

Assessing mechanical function of peristalsis with functional lumen imaging probe panometry: Contraction power and displaced volume.

The distal contractile integral (DCI) quantifies the contractile vigor of primary peristalsis on high-resolution manometry (HRM), whereas no such metric exists for secondary peristalsis on functional lumen imaging probe (FLIP) panometry. This study aimed to evaluate novel FLIP metrics of contraction power and displaced volume in asymptomatic controls and a patient cohort. Thirty-five asymptomatic controls and adult patients (with normal esophagogastric junction outflow/opening and without spasm) who completed HRM and FLIP panometry were included. The patient group also completed timed barium esophagram (TBE). Contraction power (estimate of esophageal work over time) and displaced volume (estimate of contraction-associated fluid flow) were computed from FLIP. HRM was analyzed per Chicago Classification v4.0. In controls, median (5th-95th percentile) contraction power was 27 mW (10-44) and displaced volume was 43 mL (17-66). 95 patients were included: 72% with normal motility on HRM, 17% with ineffective esophageal motility (IEM), and 12% with absent contractility. Among patients, DCI was significantly correlated with both contraction power (rho = 0.499) and displaced volume (rho = 0.342); p values < 0.001. Both contraction power and displaced volume were greater in patients with normal motility versus IEM or absent contractility, complete versus incomplete bolus transit, and normal versus abnormal retention on TBE; p values < 0.02. FLIP panometry metrics of contraction power and displaced volume appeared to effectively quantify peristaltic vigor. These novel metrics may enhance evaluation of esophageal motility with FLIP panometry and provide a reliable surrogate to DCI on HRM.

Aberrant placement of functional lumen imaging probe into mediastinum during peroral endoscopic myotomy

Video 1Aberrant placement of functional lumen imaging probe into mediastinum during peroral endoscopic myotomy.

Relaxation of the lower esophageal sphincter in response to reduced volume distension during FLIP Panometry.

The esophageal response to stepwise distension during the functional lumen imaging probe (FLIP) Panometry study often parallels high-resolution manometry (HRM) motility diagnoses. This study aimed to describe the changes in FLIP metrics during FLIP emptying, that is, reduced volume distension. Adult patients who completed FLIP and HRM for esophageal motility evaluation were included. Esophagogastric junction (EGJ) opening parameters were assessed during stepwise FLIP filling to volumes of 60 mL ("filling 60 mL"), then 70 mL, and then back to 60 mL ("emptying 60 mL"). HRM studies were analyzed per Chicago classification version 4.0 (CCv4.0). Among 265 patients included, HRM/CCv4.0 diagnoses included achalasia in 80 patients (30%), normal motility in 70 (26%), and ineffective esophageal motility (IEM) in 43 (16%). EGJ-distensibility index (DI) and EGJ diameter were greater during emptying 60 mL than filling 60 mL in achalasia, normal motility, and IEM (p values <0.002). If applying the emptying 60 mL EGJ-DI (vs. filling 60 mL EGJ-DI), EGJ opening classification changed from reduced EGJ opening to borderline EGJ opening in 31% of achalasia patients and in 2% of patients with normal motility or IEM. EGJ opening classification was unchanged in 69% achalasia and 96% of normal motility/IEM. This study suggests that isotonic or auxotonic relaxation of the lower esophageal sphincter occurs with reduced volume distension in patients with achalasia and normal motility. The study also supports the importance of utilizing a standardized FLIP motility study protocol (i.e., controlled, stepwise filling to 50 mL, 60 mL, then 70 mL) to provide reliable and generalizable FLIP metrics to facilitate diagnosis of esophageal motility disorders.

Use of endolumenal functional lumen imaging probe in investigating paediatric gastrointestinal motility disorders.

Investigating gastrointestinal (GI) motility disorders relies on diagnostic tools to assess muscular contractions, peristalsis propagation and the integrity and coordination of various sphincters. Manometries are the gold standard to study the GI motor function but it is increasingly acknowledged that manometries do not provide a complete picture in relation to sphincters competencies and muscle fibrosis. Endolumenal functional lumen imaging probe (EndoFLIP) an emerging technology, uses impedance planimetry to measure hollow organs cross sectional area, distensibility and compliance. It has been successfully used as a complementary tool in the assessment of the upper and lower oesophageal sphincters, oesophageal body, the pylorus and the anal canal. In this article, we aim to review the uses of EndoFLIP as a tool to investigate GI motility disorders with a special focus on paediatric practice. The majority of EndoFLIP studies were conducted in adult patients but the uptake of the technology in paediatrics is increasing. EndoFLIP can provide a useful complementary data to the existing GI motility investigation in both children and adults.

Role of short interval FLIP panometry in predicting long-term outcomes after per-oral endoscopic myotomy.

The Eckardt score (ES) is used to assess symptom response to Per-Oral Endoscopic Myotomy (POEM), but reliable methods to assess physiologic success are needed. Functional lumen imaging probe (FLIP) panometry has a potential role in post-POEM follow-up to predict long-term outcomes. The aim of this study was to assess the correlation between clinical success and FLIP parameters following POEM to determine if short interval FLIP could predict long-term outcomes. This was a prospective study of adult patients who underwent POEM with short interval follow-up FLIP between 11/2017 and 3/2020. Clinical success was defined as post-procedure ES ≤ 3. Physiologic success was based on an esophago-gastric junction distensibility index (EGJ-DI) > 2.8mm2/mmHg on FLIP. 47 patients (55% female, mean age 55years) were included in the study. Clinical success after POEM was seen in 45 (96%) patients (mean ES 6.5 ± 2.2 pre and 0.83 ± 1.0 post-POEM, p < 0.001). Physiologic success was noted in 43 (91.5%) patients (mean EGJ-DI 6.1mm2/mmHg ± 2.5). Among 4 patients not meeting criteria for physiologic success, EGJ-DI was 2.5-2.6. There was no correlation between post-POEM EGJ-DI and ES in the short term or long term. Significant reflux esophagitis was seen in 6 (12.8%) patients with no difference in mean EGJ-DI with vs without esophagitis (5.9 vs 6.1, p = 0.44). Post-POEM endoscopy with FLIP is useful to both assess EGJ physiology and to examine for reflux esophagitis. Short interval FLIP has limited utility to predict long-term patient outcomes or risk of acid reflux.