Over the past decade, research involving the bioengineering of esophageal tissue replacements for repair of congenital defects, cancer, and caustic injuries has advanced rapidly. This is due to the development of innovative biomaterials combined with stem cells that recapitulate tissue ultrastructure, mechanics, and biochemical properties. However, a limitation in the field is a lack of data demonstrating development of innervated tissue exhibiting peristalsis. Currently, no clinically available stem cell therapies/esophageal tissue substitutes exist that restore motility.

This review will discuss advances and limitations in the assessment of esophageal motility in bioengineered tissues along with metrics of success. Additionally, innovative technologies (i.e., 3D bioprinting, electrospinning, and AI) and neuronal cellular approaches for promoting gut innervation will be highlighted to reveal their use for the development of clinical therapies for esophageal replacement. Future directions for development of patient-specific implants will also be discussed to emphasize the importance of access to all populations.

Functional lumen imaging probe (FLIP) panometry provides assessment of the esophagogastric junction opening and esophageal body contractile activity during an endoscopic procedure and is increasingly being incorporated into comprehensive esophageal motility assessments. The aim of this study was to provide a standardized approach and vocabulary to the procedure and interpretation and update the motility classification scheme.

A working group of 19 FLIP panometry experts convened in a modified Delphi consensus process to produce and assess statements on the FLIP panometry procedure and interpretation. Three rounds of voting were conducted on an agreement scale of 1-9 for appropriateness, followed by face-to-face discussions and an opportunity for revisions of statements. The "percent agreement" was the proportion of votes with score ≥7 indicating level of agreement on appropriateness.

A total of 40 statements were selected for final inclusion in the Dallas Consensus, including FLIP panometry protocol, interpretation of esophagogastric junction opening and contractile response, and motility classification scheme. Key statements included: "FLIP panometry should be interpreted in the context of the clinical presentation, the accompanying EGD [esophagogastroduodenoscopy] findings and other relevant complementary testing" (median response 9.0; 100% agreement). "A major motor disorder is unlikely in the setting of a 'normal' FLIP panometry classification" (median response 9.0; 94% agreement). "Diminished or absent contractile response with reduced esophageal opening (ie, nonspastic obstruction) supports the diagnosis of a disorder of EGJ [esophagogastric junction] outflow" (median response 8.5; 94% agreement).

The standardized approach for performance and interpretation of the Dallas Consensus can facilitate use of FLIP panometry in broad clinical settings.

No definitive treatment has been established for refractory gastroesophageal reflux disease (GERD). Antireflux mucosectomy (ARMS) and antireflux mucosal ablation (ARMA) using argon plasma coagulation are promising methods. However, no study has compared these two. This study compared the efficacy and safety of the two procedures.

This multicenter, retrospective, observational study included 274 patients; 96 and 178 patients underwent ARMA and ARMS, respectively. The primary outcome was subjective symptom improvement based on GERD questionnaire (GERDQ) scores. The secondary outcomes included changes in the presence of Barrett's esophagus, Los Angeles grade for reflux esophagitis, flap valve grade, and proton pump inhibitor withdrawal rates.

The ARMS group had higher baseline GERDQ scores (10.0 vs. 8.0, P < 0.001) and a greater median postprocedure improvement than the ARMA group (4.0 vs. 2.0, P = 0.002), and even after propensity score matching adjustment, these findings remained. ARMS significantly improved reflux esophagitis compared with ARMA, with notable changes in Los Angeles grade (P < 0.001) and flap valve grade scores (P < 0.001). Improvement in Barrett's esophagus was comparable between the groups (P = 0.337), with resolution rates of 94.7% and 77.8% in the ARMS and ARMA groups, respectively. Compared with the ARMA group, the ARMS group experienced higher bleeding rates (P = 0.034), comparable stricture rates (P = 0.957), and more proton pump inhibitor withdrawals (P = 0.008).

Both ARMS and ARMA showed improvements in GERDQ scores, endoscopic esophagitis, flap valve grade, and the presence of Barrett's esophagus after the procedures. However, ARMS demonstrated better outcomes than ARMA in terms of both subjective and objective indicators.

Previous studies suggested that antireflux mucosectomy (ARMS) is effective in reducing reflux symptoms and total acid exposure, although the mechanism is unknown. Our objective was to investigate the effect of ARMS on reflux parameters and its mechanism of action.

Gastroesophageal reflux disease (GERD) patients with insufficient symptom control despite a twice-daily proton pump inhibitor (PPI) underwent a piecemeal multiband mucosectomy of 50% of the circumference of the esophagogastric junction (EGJ), extending 2 cm into the cardia. The primary end point was the total number of reflux episodes during 24-hour pH-impedance studies.

11 patients (8 men; median age 37 [interquartile range (IQR) 32-57] years) were treated, with one patient subsequently lost to follow-up. ARMS reduced the median (IQR) number of total reflux episodes (74 [60-82] vs. 37 [28-66]; P = 0.008) and total acid exposure time (8.7% [6.4%-12.7%] vs. 5.3% [3.5%-6.7%]; P = 0.03). Treatment reduced the median (IQR) number of transient lower esophageal sphincter relaxations (TLESRs) during a 90-minute postprandial period (4 [1-8] vs. 2 [1-4]; P = 0.03) and reflux symptom scores (3.6 [3.6-3.9] vs. 1.6 [0.7-2.7]; P = 0.005). Treatment did not increase the mean (SD) dysphagia scores (8.2 [7.3] vs. 8.5 [6.5]) or change the EGJ distensibility on impedance planimetry (4.4 [2.1] vs. 4.3 [2.2] mm2/mmHg). One delayed post-procedural bleed requiring repeat endoscopy occurred (10%); no strictures developed.

ARMS is an effective treatment option in PPI-refractory GERD, reducing acid exposure, reflux episodes, and symptoms. While its working mechanism could not be explained by a difference in distensibility, a reduction in TLESRs might play a role.

The functional lumen imaging probe (FLIP) relies on the principle of impedance planimetry that enables direct measurement of intraluminal pressure, cross-sectional areas, and wall biomechanical properties. The aim of our pilot project was to introduce this method to assess function of the lower oesophageal sphincter and pyloric muscle in experimental pigs.

All measurements were accomplished in one session in six adult female pigs (mean weight 34.2 ± 3.6 kg), using the EndoFLIP 1.0 System with EndoFLIP catheters. Five major parameters were evaluated: balloon pressure (mm Hg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mm Hg), and zone compliance (mm3/mm Hg).

In total, 180 readings were successfully accomplished. Most of the measured values were nearing lower average figures for the lower oesophageal sphincter, and upper average figures for the pylorus in healthy humans. The porcine pyloric sphincter is composed of the Torus pyloricus. It serves as a study "gatekeeper" between the stomach and D1 duodenum, thus explaining higher pyloric readings. There was a clear trend for increasing values of CSA (cross-sectional area), diameter, and balloon pressure with increased filling balloon volumes. However, the sphincter distensibility did not change with increasing filling volumes, either for the lower oesophageal sphincter or pylorus.

Endoscopic functional luminal planimetry in experimental pigs is feasible, both for the lower oesophageal sphincter and the pylorus. This is an important starting point for future experimental endoscopic trials and pharmacology studies.

Background/Objectives: Tacrine is a centrally active non-competitive reversible acetylcholinesterase inhibitor. It also exerts antagonising activity against N-methyl-D-aspartate receptors. Tacrine was approved for the treatment of Alzheimer's disease in 1993, but was withdrawn from clinical use in 2013 because of its hepatotoxicity and gastrointestinal side effects. Nevertheless, tacrine is currently facing a renewed wave of interest primarily due to several new tacrine-incorporated hybrids and derivates. There were two specific aims for this study: firstly, to explain the mechanisms of the adverse action of tacrine, as a distinctive example of a highly effective acetylcholinesterase inhibitor; and secondly to check whether luminal impedance planimetry is feasible for preclinical testing of possible side effects of compounds potentially toxic to the gastrointestinal tract. Methods: Six experimental pigs were used as the animal model in this study. Five major parameters were evaluated: luminal pressure (mmHg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mmHg), and zone compliance (mm3/mmHg). All measurements were performed before and 360 min after intragastric administration of 200 mg tacrine (at the porcine tacrine Tmax). Results: This study consistently demonstrated an increase in luminal pressure (a directly measured indicator) for the particular balloon filling volumes used, and inversely a reciprocal decrease in the other parameters after tacrine administration. Conclusions: Endoscopic luminal impedance planimetry is a feasible method to evaluate functional response of the lower oesophageal sphincter to tacrine in experimental pigs. Tacrine did not compromise the function of the lower oesophageal sphincter either toward oesophageal spasms or, in contrast, decreased competence of the lower oesophageal sphincter.

The lower gastrointestinal (GI) tract, formed from the midgut and hindgut, encompasses the colon, rectum and anal canal.

The aim of this review is to provide an overview of the anatomy and physiology of the lower GI tract.

Literature review on anatomy and physiology of the lower GI tract, including normal motility and phases of defecation. It derives its blood supply from the superior and inferior mesenteric arteries while it is innervated by the extrinsic autonomic (the thoracolumbar and sacral nerves) and the intrinsic enteric nervous system. The colon has four layers: mucosa, submucosa, muscularis externa and serosa. The anal canal ends in the internal and external anal sphincters (EASs) involved in continence and defecation. The lower GI tract is predominantly involved in digestion, absorption, defecation and protection. Defecation is a complex process that requires inter-neural (enteric and autonomic nervous systems), neurohormonal and neuromuscular coordination. It has four phases which include basal, pre-expulsive, expulsive and end phase. High-propagating contractions in the colon propel stool to the rectum leading to rectal distention and the recruitment of the recto-anal inhibitory reflex. Once able, the EAS, under full conscious control, is then relaxed allowing stool to be evacuated. Other defecation reflexes include the gastrocolic, gastroileal and coloanal reflexes.

Recent advances provide novel techniques to investigate motility patterns including high-resolution manometry protocols with automated assessments, magnetic resonance imaging techniques for defecography, wireless motility capsules and fecobionics.

Despite the increasing number of bariatric procedures over the recent years, the physiological changes in secondary esophageal motility and distensibility parameters after surgery remain unknown.

This is a retrospective, single-center cohort study comparing esophageal planimetry and gastroesophageal junction (GEJ) distensibility in post-bariatric surgery patients (Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and conversion/revisional patients (DH)) and native-anatomy patients with obesity (NAC). Distensibility refers to the area achieved with a certain amount of pressure, and secondary peristalsis represents the esophageal response to an intended obstruction. Patients with pre-surgical dysmotility symptoms were excluded from the study.

From November 2018 to January 2023, 167 patients were evaluated and eligible for this study (RYGB = 87, SG = 33, NAC = 22, DH = 25). In NAC cohort, 17/22 (77%) patients presented normal motility patterns compared to 35/87 (40%) RYGB, 12/33 (36%) SG, and 5/25 (20%) DH (p < 0.05 for all comparisons). The most common abnormal motility pattern for all three bariatric cohorts was absent contractions. DH patients generally had the highest mean maximum distensibility index averages, followed by SG, RYGB, and NAC.

Bariatric surgery affects esophageal and GEJ physiology, and it is associated with higher rates of secondary dysmotility. DH patients have even higher rates of dysmotility. Further studies assessing clinical data and their correlation with manometric and pH-metric findings are needed.

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.

Distal esophageal spasm is characterized by premature contractions of the distal esophageal smooth muscle leading to non-obstructive dysphagia and non-cardiac chest pain. Diagnosis requires the presence of symptoms along with evidence of at least 20% premature contractions in the setting of a normal lower esophageal sphincter relaxation on high-resolution manometry. New updates to the Chicago Classification have improved the diagnostic accuracy of this method. Functional lumen imaging probe is a growing diagnostic modality that gives a more complete picture of esophageal motility. Pharmacologic treatment remains inadequate. Endoscopic myotomy might be of benefit for non-achalasia esophageal motility disorders. More research is required to better understand the pathophysiology and develop safe and long-lasting management for this disease.

Body surface gastric mapping (BSGM) is a new noninvasive test of gastric function. BSGM offers several novel and improved biomarkers of gastric function capable of differentiating patients with overlapping symptom profiles. The aim of this study was to define normative reference intervals for BSGM spectral metrics in a population of healthy controls.

BSGM was performed in healthy controls using Gastric Alimetry (Alimetry, New Zealand) comprising a stretchable high-resolution array (8 × 8 electrodes; 196 cm 2 ), wearable Reader, and validated symptom-logging App. The evaluation encompassed a fasting baseline (30 minutes), 482 kCal meal, and 4-hour postprandial recording. Normative reference intervals were calculated for BSGM metrics including the Principal Gastric Frequency, Gastric Alimetry Rhythm Index (a measure of the concentration of power in the gastric frequency band over time), body mass index (BMI)-adjusted amplitude (μV), and fed:fasted amplitude ratio. Data were reported as median and reference interval (5th and/or 95th percentiles).

A total of 110 subjects (55% female, median age 32 years [interquartile range 24-50], median BMI 23.8 kg/m 2 [interquartile range 21.4-26.9]) were included. The median Principal Gastric Frequency was 3.04 cycles per minute; reference interval: 2.65-3.35 cycles per minute. The median Gastric Alimetry Rhythm Index was 0.50; reference interval: ≥0.25. The median BMI-adjusted amplitude was 37.6 μV; reference interval: 20-70 μV. The median fed:fasted amplitude ratio was 1.85; reference interval ≥1.08. A higher BMI was associated with a shorter meal-response duration ( P = 0.014).

This study provides normative reference intervals for BSGM spectral data to inform diagnostic interpretations of abnormal gastric function.