Integrated Relaxation Pressure Classification and Probe Positioning Failure Detection in High-Resolution Esophageal Manometry Using Machine Learning

High-resolution esophageal manometry is used for the study of esophageal motility disorders, with the help of catheters with up to 36 sensors. Color pressure topography plots are generated and analyzed and using the Chicago algorithm a final diagnosis is established. One of the main parameters in this algorithm is integrated relaxation pressure (IRP). The procedure is time consuming. Our aim was to firstly develop a machine learning based solution to detect probe positioning failure and to create a classifier to automatically determine whether the IRP is in the normal range or higher than the cut-off, based solely on the raw images. The first step was the preprocessing of the images, by finding the region of interest—the exact moment of swallowing. Afterwards, the images were resized and rescaled, so they could be used as input for deep learning models. We used the InceptionV3 deep learning model to classify the images as correct or failure in catheter positioning and to determine the exact class of the IRP. The accuracy of the trained convolutional neural networks was above 90% for both problems. This work is just the first step in fully automating the Chicago Classification, reducing human intervention.

Comparison of 180° anti-reflux mucosectomy versus 270° anti-reflux mucosectomy for treatment of refractory gastroesophageal reflux disease: a retrospective study

Background Anti-reflux mucosectomy (ARMS) is a novel endoscopic treatment for refractory gastroesophageal reflux disease (rGERD). Several studies have validated its safety and effectiveness, but postoperative dysphagia remains in concern. Since the influence of different resection ranges on efficacy and complications of ARMS has rarely been studied, this study aimed to compare outcomes of 180°ARMS and 270°ARMS in treatment of rGERD. Methods This study was conducted from August 2017 to September 2020. 39 eligible patients underwent either 180° ARMS or 270° ARMS and followed up at 6 months postoperation. Primary outcome measure was assessed by Gastroesophageal Reflux Disease Questionnaire (GERD-Q). Secondary outcomes included quality of life, PPI use, gastroesophageal flap valve grade, presence of reflux esophagitis, acid exposure time (AET), distal contractile integral (DCI), and integrated relaxation pressure (IRP) measured by high-resolution manometry (HRM) and complication rate. Per-protocol analysis was performed. Results Among 39 patients, 18 underwent 180° ARMS, while 21 underwent 270° ARMS. At postoperative 6 months follow-up period, primary outcome showed no significant difference between two groups (p = 0.34). Similarly, no significant difference was demonstrated between groups regarding most secondary outcomes except for fewer complaints of newly dysphagia in 180° ARMS group. No other serious complications were observed in both groups. Conclusion Although 180° ARMS and 270° ARMS could be equally effective for treatment of rGERD, 180° ARMS might be more recommended due to lower incidence of newly post-procedural dysphagia.

Evaluation of timed barium esophagram after per-oral endoscopic myotomy to predict clinical response

Background and study aims The aim of this study was to evaluate whether timed barium esophagram within 24 hours post-per-oral endoscopic myotomy (POEM) (TBE-PP) could predict clinical outcomes. Patients and methods This was a single-center retrospective study of prospectively collected data on consecutive patients with ≥ 6-month follow-up who underwent POEM followed by TBE-PP. Esophageal contrast retention 2 minutes after TBE-PP was assessed as Grade 1 (< 10 %), 2 (10 %–49 %), 3 (50 %–89 %) or 4 (> 90 %). Eckardt score, esophagogastroduodenoscopy (EGD), high-resolution manometry (HRM) and function lumen imaging probe (FLIP) of the esophagogastric junction (EGJ) were obtained at baseline. These tests along with pH testing of antisecretory therapy were repeated 6 and 24 months after POEM. Clinical response by Eckardt score ≤ 3, EGJ-distensibility index (EGJ-DI) > 2.8 mm2/mm Hg, and integrated relaxation pressure (IRP) < 15 mm Hg and incidence of gastroesophageal reflux disease (GERD) were compared by transit time. Results Of 181 patients (58 % male, mean 53 ± 17 yr), TBE-PP was classified as Grade 1 in 122 (67.4 %), Grade 2 in 41 (22.7 %), Grade 3 in 14 (7.7 %) and Grade 4 in 4 (2.2 %). At 6 months, overall clinical response by ES (91.7 %), IRP (86.6 %), EGJ-DI (95.7 %) and the diagnosis of GERD (68.6 %) was similar between Grade 1 and Grade 2–4 TBE-PP. At 24 months, Grade 1 had a higher frequency of a normal IRP compared to Grades 2–4 (95.7 % vs. 60 %, P = 0.021) but overall response by ES (91.2 %), EGJ-DI (92.3 %) and the diagnosis of GERD (74.3 %) were similar. Conclusions Contrast emptying rate by esophagram after POEM has limited utility to predict clinical response or risk of post-procedure GERD.

810 REPRODUCIBILITY OF REPEATED MEASUREMENTS OF OESOPHAGEAL MOTILITY METRICS WITHIN A STUDY

To compare reproducibility of repeated measurements of oesophageal motility metrics after 5 wet swallows within a study. Methods Patients referred for high-resolution esophageal manometry (HREM) to assess oesophageal motor function were enrolled. Solid-state 36-channel 10 Fr catheter (Unisensor AG) and Solar (MMS) software were used. Minimum 10 water swallows by 5 mL each were obtained. Two operators independently assessed the results of examination. Records of swallows were divided into 2 series by 5 measurements each. These series were compared by key metrics: integrated relaxation pressure (IRP), distal contractile integral (DCI), distal latency (DL), and contractile front velocity (CFV). Non-parametric statistics was used to compare the results. Results We enrolled 46 men and 68 women, age (mean ± SD) 48.8 ± 11.5 y.o. Of them, 52 patients had GERD, 25-different types of achalasia and 37 had no oesophageal disorders. The inter-observer agreement between 2 series of measurements reached 98%. No significant difference was found between the mean results of IRP, DCI, DL and CFV in 2 series of measurements (table 1). Conclusion No significant differences between studied HREM metrics in two series of measurements were found. The results of two series by 5 measurements within a study are reproducible. This may indicate the possibility of reducing the standard number of measurements. Reduction of time necessary for standard examination may allow additional time for functional tests (solid food swallows, RDC or MRS).

800 ASSOCIATION OF MULTIPLE RAPID SWALLOW PARAMETERS WITH SYMPTOMS IN PATIENTS WITH INEFFECTIVE AND NORMAL ESOPHAGEAL MOTILITY

Multiple rapid swallows (MRS) is a provocative test to assess inhibitory swallowing mechanisms and esophageal peristaltic reserve. MRS response has been purposed to predict post-fundoplication dysphagia and has been associated with increased acid exposure time. Recently it was added to the Chicago classification v 4.0 protocol as an adjunctive test. This study aimed to understand the association of MRS parameters with symptoms in patients within ineffective (IEM) or normal esophageal motility (NEM). Methods After IRB approval, a prospectively maintained esophageal motility database was retrospectively reviewed to identify patients with IEM and NEM who also had an MRS evaluation. Patients with previous gastroesophageal surgery, manometric hiatal hernia, or a diagnosed motility disorder (except IEM) were excluded. Patient-reported symptoms (0–4) (heartburn, regurgitation, dysphagia, and chest pain) were grouped by score: 0, 1–2, or 3–4. We compared the prevalence of normal or abnormal MRS and individual MRS parameters (distal contractile integral [DCI], integrated relaxation pressure, distal latency, adequate inhibition, and post-MRS DCI/mean single swallow DCI ratio) with patient-reported symptoms. Results From 2019–2020, a total of 531 patients (254 = IEM, 277 = NEM) met the inclusion criteria and formed the study cohort. The presence of normal or abnormal MRS results was not associated with any patient-reported symptom in either the NEM or IEM group. Furthermore, patient-reported symptoms were not associated with individual MRS parameters in either group. Conclusion In patients with IEM and NEM, adjunct assessment with MRS does not correlate with patient-reported symptoms. Further studies are needed to assess the role of MRS as an adjunctive test during routine manometry.

Esophageal Physiologic Testing of Obese Subjects as a Part of Bariatric Surgery Planning

Background: Choice of bariatric procedure may be impacted by esophageal motor disorders and reflux disease, which are not routinely evaluated in obese subjects. Methods: Clinical characteristics on validated questionnaires and esophageal physiologic test findings were collected in 110 consecutive obese subjects (median age 48.5 years, 82% F, median BMI 46.9 kg/m2) evaluated for bariatric surgery. High resolution manometry (HRM) metrics included intragastric pressure (IGP), basal lower esophageal sphincter pressures (LESP), end-expiratory LESP, EGJ contractile integral (EGJ-CI), integrated relaxation pressure (IRP), distal contractile integral (DCI), and Chicago classification (CC) v4.0 diagnoses; acid exposure time (AET, normal if <4%) was obtained from ambulatory reflux monitoring. Comparative analyses determined differences between obese subjects and 15 institutional normal controls (median age 24.7 years, 53% F, median BMI 24.7 kg/m2) and if symptoms predicted abnormal tests. Results: Basal LESP and EGJ-CI were higher in obese subjects ( P = .03) compared to controls, while end-expiratory LESP was similar ( P = .97). IGP was also higher in obese subjects ( P < .0001), which modestly correlated with BMI. The most common CC 4.0 diagnosis was ineffective esophageal motility (IEM, 11.8%). EGJ outflow obstruction was seen in 9.1% and achalasia in 0.9%. Hiatus hernia (type 2 or 3 EGJ morphology) was found in 28%. Of 34 patients completing ambulatory reflux monitoring, 15 (44%) had elevated AET, without symptom or motor predictors. Conclusions: Achalasia, esophageal outflow obstruction, and reflux were encountered in higher than expected proportions without specific symptoms in pre-bariatric surgery patients. Thus, esophageal physiologic testing may be of value prior to bariatric surgery.

High-resolution esophageal manometry in patients with achalasia

Introduction. At present, high-resolution esophageal manometry is the «gold standard» for the diagnosis of esophageal achalasia, based on the determination of the integrated relaxation pressure of the lower esophageal sphincter, the value of which in the case of achalasia must exceed 15 mm Hg (MMS System). However, in some patients with clinically and radiologically confirmed achalasia, this value is normal. There is no unified view of the cause of this phenomenon. We assumed that low pressure figures may be affected by incorrect installation of the manometric catheter.Methods and materials. This research included 149 patients (61 by retrospective estimating the patients data and 88 new patients) with achalasia established during the period from January 2017 to March 2020. When it was impossible to localize the lower esophageal sphincter and take correct measurements during high-resolution manometry in new patients, the X-rays or upper endoscopy was performed to control the manometric catheter placement. If its’ placement was incorrect and the integrated relaxation pressure level was lower than 15 mmHg, repeated high-resolution manometry was performed with the over-the-guidewire manometric catheter placing.Results. In 36 patients of both groups (24.2 %), the manometric data did not correspond to esophageal achalasia; in the prospective group, 12 out of the 19 patients had incorrect manometric data due to inability to visualize lower esophageal sphincter. In the prospective group, the manometric catheter was reinstalled by a guidewire, which allowed visualizing the signs of the lower esophageal sphincter in all cases, and in 15 out of 19 patients (79 %), the integrated relaxation pressure of the lower esophageal sphincter was more than 15 mm Hg.Conclusions. In some cases, the over-the-guidewire installing makes it possible to pass catheter through the lower esophageal sphincter correctly, visualize the lower esophageal sphincter during the high-resolution manometry examination and obtain true pressure values.

Safety and efficacy of biodegradable stents in octogenarian patients with esophageal achalasia

Backgrounds and study aims Treatment of octogenarian patients with achalasia with conventional treatments is effective but with compromised safety. Biodegradable stents (BS) are promising. We aimed to evaluate their safety, efficacy and clinical outcomes at early, mid and long-term in this population. Patients and methods Naïve or previously-treated achalasic octogenarian patients underwent to BS placement (BSP) between December, 2010 and November, 2011, and were followed-up for 9-years. A strict follow-up was performed. Results Thirty-two patients were included, (17 men [53.1 %]; median age 82 years [78–92]). BSP was performed in all patients. At 9y, 18/32 (56.2 %) completed protocol. Mean BSP time was 37.5±12.1 min and 34.4 % presented thoracic pain. At 1 m, six BS were migrated (18.7 %), requiring a second BSP fixed with hemoclips. At 3 m, twenty-three (72.8 %) completed degradation process. At 6 m, eighteen (56.2 %) presented clinical dysphagia, of whom 5/32 (15.6 %) presented stenotic-tissue hyperplasia, responding to balloon dilation in all cases. Pre-BSP Eckardt, Timed barium esophagram and integrated relaxation pressure improved post-BSP 6 m values (9 vs 2, p = 0.001; < 50 % = 93.8 % vs > 80 % = 81.5 %, p = 0.003 and 18.8 ± 3.2 vs 11.1 ± 2.6 mmHg, p = 0.001, respectively), and there were no significant changes up to 9y post-BSP. Esophagitis grade A or B was presented between 4.7 % to 11.2 % and controlled with PPI. After 9 years we had clinical success rates of 94.4 %, 72 %, and 65.4 % for time point evaluation, per protocol and intention to treat analysis, respectively. Conclusions BSP represents a feasible alternative option in octogenarian patients with achalasia who are high risk with other treatments, presenting acceptable early, mid-, and long-term outcomes.