Transient lower esophageal sphincter relaxations do not result from passive opening of the cardia by gastric distention

The yield of solid swallows in high resolution esophageal manometry among patients with dysphagia and gastro-esophageal reflux symptoms

BACKGROUND

Swallowing disorders are frequently reported esophageal symptoms and represent a common cause for referrals to gastroenterology consultations. Esophageal high-resolution manometry (HRM) is considered the gold standard modality for the evaluation of esophageal peristalsis and esophageal sphincter. The standard protocol of HRM includes water swallows only, that may not assess appropriately esophageal function and symptoms. Hence, we investigated the diagnostic yield of combining solid food swallows (SFS) to standard HRM.

METHODS

We conducted a retrospective study at the Unit of Gastroenterology of EMMS Nazareth Hospital, Israel. Patients who underwent manometry mainly due to dysphagia or reflux symptoms between November 2019 and November 2020 were enrolled. All patients underwent routine HRM and completed ten 5 mL water swallows and 5 bread swallows. Analysis and reports were done by an expert gastroenterologist, based on the Chicago Classification version 3.

RESULTS

Overall, 99 patients (45.5% men, mean age 52.1±16 years) who underwent HRM were included. The addition of solid swallows to the test changed manometry results in 43 patients (43.4%) (P<0.005). Furthermore, SFS improved the contractility in 26/42 cases of ineffective and/or absent motility (61%) (P<0.005). Finally, SFS aggravated symptoms in 44 patients (44.6% more aggravation than in liquid only) (P<0.005).

CONCLUSIONS

Combining SFS to HRM can improve the diagnostic yield of the study. Adding solid swallows is of special value in cases of ineffective esophageal motility but induces a high rate of symptoms aggravation.

Impaired sliding between the lower esophageal sphincter and crural diaphragm (esophageal hiatus) in patients with achalasia esophagus

Swallow-related axial shortening of the esophagus results in the formation of phrenic ampulla in normal subjects; whether it is the case in achalasia esophagus is not known. The goal is to study axial shortening of the esophagus and relative movement between the lower esophageal sphincter (LES) and crural diaphragm (CD) in normal subjects and patients with achalasia. A novel method, isoimpedance contour excursion at the lower edger of LES, as a marker of axial esophageal shortening was validated using X-ray fluoroscopy (n = 5) and used to study axial shortening and separation between the LES and CD during peristalsis in normal subjects (n = 15) and patients with achalasia type 2 esophagus (n = 15). Abdominal CT scan images were used to determine the nature of tissue in the esophageal hiatus of control (n = 15) and achalasia patients (n = 15). Swallow-induced peristalsis resulted in an axial excursion of isoimpedance contours, which was quantitatively similar to the metal clip anchored to the LES on X-ray fluoroscopy (2.3 ± 1.4 vs. 2.1 ± 1.4 cm with deep inspiration and 2.7 ± 0.6 cm vs. 2.7 ± 0.6 cm with swallow-induced peristalsis). Esophageal axial shortening with swallows in patients with achalasia was significantly smaller than normal (1.64 ± 0.5 cm vs. 3.59 ± 0.4 cm, P < 0.001). Gray-level matrix analysis of CT images suggests more "fibrous" and less fat in the hiatus of patients with achalasia. Lack of sliding between the LES and CD explains the low prevalence of hiatus hernia, and low compliance of the LES in achalasia esophagus, which likely plays a role in the pathogenesis of achalasia.NEW & NOTEWORTHY Swallow-related axial shortening of the esophagus is reduced, and there is no separation between the lower esophageal sphincter and crural diaphragm (CD) with swallowing in patients with achalasia esophagus. Fat in the hiatal opening of the esophagus appears to be replaced with fibrous tissue in patients with achalasia, resulting in tight anchoring between the LES and CD. The above findings explain low prevalence of hiatus hernia and the low compliance of the LES in achalasia esophagus.

Comparison of scope holding sign on endoscopy and lower esophageal sphincter contraction on high‐resolution manometry: A pilot study

Objectives

Lower esophageal sphincter (LES) plays a key role in gastroesophageal reflux disease (GERD) pathogenesis. In retroflexion and under sufficient insufflation, it can be seen how the lower esophagus grasps the endoscope, which we named scope holding sign (SHS). This study aimed to compare the SHS and LES pressure on high‐resolution manometry (HRM), to elucidate whether the sphincter can be visualized endoscopically.

Methods

This was a single‐center, prospective pilot study. Patients with symptoms of GERD, who underwent endoscopy and HRM between February 2021 and April 2021, were included. A manometry catheter and an ultra‐slim endoscope were inserted, and the resting LES pressure was measured. The lower esophagus holding (SHS‐positive) and releasing (SHS‐negative) the endoscope and catheter were observed. The LES pressures during SHS‐positive and SHS‐negative were compared.

Results

Eleven patients (median age: 57 years; eight men) with normal esophageal motility were analyzed. The median LES pressure in SHS‐positive was significantly higher than the resting LES pressure (40.4 [22.9–74.0] vs. 25.9 [2.0–66.7] mm Hg; p = 0.001) and the LES pressure in SHS‐negative (4.6 [1.5–9.3]; p = 0.001). Furthermore, the LES pressure in SHS‐negative was significantly lower than the resting LES pressure (4.6 [1.5–9.3] vs. 25.9 [2.0–66.7] mm Hg; p = 0.005).

Conclusions

This study demonstrated that the SHS parallels LES pressure, indicating that the sphincter can be observed endoscopically. This may enable us to evaluate LES function during endoscopy in patients with GERD, thus, deserving further evaluation in future studies.

Non-surgical animal model of gastroesophageal reflux disease by overeating induced in mice

Previous animal models of gastroesophageal reflux disease (GERD) were not physiological and required a variety of surgical procedures. Therefore, the animal model developed by conditions that are similar to the pathogenesis of GERD is necessary. The aim is to establish a non-surgical animal model with GERD caused by overeating induced in mice. To induce mice to overeat, we designed dietary control protocols including repetitive fasting and feeding. The esophageal tissues were evaluated with GERD markers to prove the establishment of a GERD animal model. Mice fasted every other day (group 2) showed more pronounced overeating feature and demonstrated evident changes similar to the macroscopic and microscopic findings of GERD, the expressions of inducible nitric oxide synthase and substance P were stronger. The higher frequency of fasting and overeating could cause GERD effectively. The dietary control can make mice overeat, which elicits the change of lower esophageal mucosa similar to GERD. Thus, the overeating-induced mouse may be used as a GERD mouse model.

Remodifying Omentopexy Technique Used with Laparoscopic Sleeve Gastrectomy: Does It Change any Outcomes?

BACKGROUND

Gastric obstructions, leaks and staple line bleeding are reported after laparoscopic sleeve gastrectomy (LSG). There is no ideal method or technique to avoid these mishaps. We added modified omentopexy (OP) to LSG to determine if there is any effect on gastric leaks and some other complications.

METHODS

This single institution case control study included two groups of morbidly obese patients undergoing LSG. They were grouped as omentopexy (OP) or no omentopexy (NP). Patient characteristics such as age, sex, ASA (American Society of Anesthesiologists) risk, body mass index (BMI), nutritional status and comorbidities were comparable. Postoperative follow-up was scheduled at 1 week, 1 month, 3 months, 6 months and 12 months. All received standard postoperative clinical, nutritional evaluation and PPI therapy for at least 3 months.

RESULTS

Total 737 patients underwent LSG from January 2012 to December 2017. Out of these, 370 that had OP and 367 that had NP were analyzed. NP group was subdivided into Lemberted Staple line (LS) and bioabsorbable staple line reinforcement (BSLR) groups. Gastric leaks and perforations were clubbed together as gastric disruptions (GD). Patients with at least 15 months of postoperative follow-up were included. Those who failed to follow up were excluded. GD was reported in 7 out of 367 NP patients (1.9%), while no GD was seen in 370 OP patients (P = 0.01). Bleeding was seen in 1 OP versus 2 NP patients (P = 0.6). Venous thromboembolism was reported in 2 OP versus 1 NP patients (P = 1). Wound infection was seen in 1 OP versus 2 NP patients (P = 0.6). Readmissions were noted in 2 OP versus 6 NP patients (P = 0.1). Pneumonia was seen in 2 OP and 2 NP patients (P = 1). Postoperative dehydration was seen in zero OP versus 1 NP patients (P = 0.4). Gastric obstruction was not seen in any of the patients. Postoperative gastric reflux was present in 49/370(13.2%) OP versus 57/367(15.4%) NP patients (P = 0.4). Within NP group, LS (Lemberting of Staple line) patients (286/367) had 4 GD (1.39%) versus no GD in OP (P = 0.03). BSLR (Bioabsorbable Staple line re-enforcement) patients (81/367) had 3 GD (3.7%) versus no GD in OP (P = 0.005). None of the groups had any mortality.

CONCLUSIONS

GD (gastric disruptions) were statistically significant, but the following bleeding, venous thromboembolism and gastroesophageal reflux did not reach statistical significance, which indicates that OP, if performed correctly with LSG, has favorable effects on gastric leaks.

Flip Technology for Assessing Esophageal Structural and Motor Disorders: a Skeptic's View

PURPOSE OF REVIEW

Functional lumen impedance (FLIP) technology has become commercially available to assess structural and motor abnormalities of the esophagus. Increasing numbers of papers have described novel findings with this technology. This review examines the validity of the FLIP technique, how it compares with existing diagnostic modalities, and evidence to date on diagnostic accuracy.

RECENT FINDINGS

FLIP studies require deep sedation at the time of endoscopy to complete. They assess a simulated state of esophageal obstruction in only a distal part of the esophagus rather than deglutitive motor function of the entire esophagus. The available normative dataset is small and not matched to the older age of patients typically being evaluated. The test-retest agreement in health and disease is unknown, as is the operator dependence on performing and interpreting findings. Studies to date have largely excluded patients with structural disorders, which FLIP cannot reliably distinguish from motor disorders. FLIP is an expensive technology that has been made clinically available without its true utility being established. For FLIP to be deemed a device ready for widespread clinical use, additional studies on validity, diagnostic accuracy, and outcomes need to be performed. Prospective clinical studies need to include all patients and assess the incremental cost-effectiveness of FLIP over more innovative use of existing technology, such as high-resolution manometry with provocative challenges.

Use of Bioelectronics in the Gastrointestinal Tract

Gastrointestinal (GI) motility disorders are major contributing factors to functional GI diseases that account for >40% of patients seen in gastroenterology clinics and affect >20% of the general population. The autonomic and enteric nervous systems and the muscles within the luminal GI tract have key roles in motility. In health, this complex integrated system works seamlessly to transport liquid, solid, and gas through the GI tract. However, major and minor motility disorders occur when these systems fail. Common functional GI motility disorders include dysphagia, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction, postoperative ileus, irritable bowel syndrome, functional diarrhea, functional constipation, and fecal incontinence. Although still in its infancy, bioelectronic therapy in the GI tract holds great promise through the targeted stimulation of nerves and muscles.

Effect of a Partially Hydrolysed Whey Infant Formula Supplemented with Starch and Lactobacillus reuteri DSM 17938 on Regurgitation and Gastric Motility

Functional regurgitation (FR) is common in early infancy and represents a major drain on healthcare resources. This double-blind, randomized controlled trial investigated the effects of a formula containing partially hydrolysed, 100% whey protein, starch and Lactobacillus reuteri (DSM 17938) on gastric emptying rate (GErate) and regurgitation frequency in infants with FR. Enrolled infants were randomly allocated to receive either the test formula or a standard starter formula for four weeks. Ultrasound GErate assessment was performed at baseline (week 0) and at week 4; the number of regurgitations, feed volumes and potential adverse events were recorded in a daily diary. Eighty infants aged four weeks to five months were enrolled; 72 (test group = 37; control group = 35) completed the study. Compared to controls, the test group showed greater percentage changes in GErate (12.3% vs. 9.1%, p < 0.01). Mean daily regurgitations decreased from 7.4 (0.8) at week 0 to 2.6 (1.0) at week 4 in the test group and from 7.5 (1.0) to 5.3 (1.0) in controls (between-group difference, p < 0.0001). Compared to a standard formula, a starch-thickened partially hydrolysed whey protein formula supplemented with Lactobacillus reuteri is more effective in decreasing the frequency of regurgitation and improving GErate, and can be of benefit to infants with FR.

Normal and abnormal physiology, pharmacology, and anatomy of the gastroesophageal junction high-pressure zone

The high-pressure zone of the gastroesophageal junction acts as a multifunctional valve that comprises different groups of smooth muscles located in the distal esophagus and the proximal stomach, in addition to the extrinsic crural diaphragm, composed of skeletal muscle. In this review article, we evaluate the current literature with respect to human subjects, discussing the anatomic locations and physiologic and pharmacologic processes controlling these muscles. These muscles work individually and as a group to prevent reflux of gastric contents while allowing anterograde passage of food and liquid and retrograde passage of gas. We also reviewed new findings with respect to abnormalities that are permissive of reflux of gastric contents into the esophagus, which may lead to gastroesophageal reflux disease.

Specific movement of esophagus during transient lower esophageal sphincter relaxation in gastroesophageal reflux disease

Background/Aims

Transient lower esophageal sphincter relaxation (TLESR) is the main mechanism of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the characteristics of transient lower esophageal sphincter movement in patients with or without gastroesophageal reflux by high-resolution manometry (HRM).

Methods

From June 2010 to July 2010, we enrolled 9 patients with GERD (GERD group) and 9 subjects without GERD (control group), prospectively. The manometry test was performed in a semi-recumbent position for 120 minutes following ingestion of a standardized, mixed liquid and solid meal. HRM was used to identify the frequency and duration of TLESR, esophageal shortening length from incomplete TLESR, upper esophageal sphincter (UES) response, and the related esophageal motor responses during TLESR.

Results

TLESR occurred in 33 in the GERD group and 34 in the control group after 120 minutes following food ingestion. Duration of TLESR and length of esophageal shortening did not differ between 2 groups. UES pressure increase during TLESR was mostly detected in patients with GERD, and UES relaxation was observed frequently in the control group during TLESR. TLESR-related motor responses terminating in TLESR were predominantly observed in the control group.

Conclusions

Increased UES pressure was noted frequently in the GERD group, suggesting a mechanism for preventing harmful reflux, which may be composed mainly of fluid on the larynx or pharynx. However, patients with GERD lacked the related motor responses terminating in TLESR to promote esophageal emptying of refluxate.

Measuring movement and location of the gastroesophageal junction: research and clinical implications

Understanding the physiology of gastroesophageal junction (GEJ) is important as failure of its function is associated with reflux disease, hiatus hernia, and cancer. In recent years, there have been impressive developments in high resolution technologies allowing measurement of luminal pressure, pH, and impedance. One obvious deficiency is the lack of technique to monitor the movement and location of the GEJ over a prolonged period of time. Proximal movement of the GEJ during peristalsis and transient lower esophageal sphincter relaxations (TLESRs) is due to shortening of the longitudinal muscle of the esophagus. Techniques for measuring shortening include fluoroscopic imaging of mucosal clip, high-frequency intraluminal ultrasound, and high resolution manometry, but these techniques have limitations. Short segment reflux is recently found to be more common than traditional reflux and may account for the high prevalence of intestinal metaplasia and cancer seen at GEJ. While high resolution pHmetry is available, there is no technique that can reliably and continuously measure the position of the squamocolumnar junction. A new technique is recently reported allowing a precise and continuous measurement of the GEJ based on the principle of Hall effect. Reported studies have validated its accuracy both on the bench and against the gold standard, fluoroscopy. It has been used alongside high resolution manometry in studying the behavior of the GEJ during TLESRs and swallows. While there are challenges associated with this new technique, there are promising ongoing developments. There is exciting time ahead in research and clinical applications for this new technique.

Lactobacillus reuteri accelerates gastric emptying and improves regurgitation in infants

BACKGROUND

Young infants are frequently affected by uncomplicated regurgitation that may persist despite dietetic and conservative interventions. On this basis, we studied the putative effects of probiotics on the frequency of regurgitation and gastric emptying time in infants with functional gastroesophageal reflux (GER).

PATIENTS AND METHODS

Forty-two infants with regurgitation were randomized to assume Lactobacillus reuteri DSM 17938 at a dose of 1 × 10(8) CFU per day and placebo for 30 days. The episodes of regurgitation were recorded by the parents each day. Gastric emptying time was recorded using real-time ultrasound at baseline and at the end of the study. Twenty-one infants without regurgitation were enroled to compare anthropometric and physiological parameters before the intervention diet.

RESULTS

Thirty-four infants completed the study (19 infants receiving probiotics and 15 placebo).At baseline, the whole group of infants was similar to the control group as regards anthropometric and physiological data. The median fasting antral area was significantly reduced, (P = 0·01) the delta in gastric emptying rate was significantly increased (P = 0·01) and the median episodes per day of regurgitation was reduced (, P < 0·001) in the probiotic group compared to the placebo group. In the whole group, the frequency of regurgitation and the basal antral area showed a positive correlation (r = 0·53, P = 0·004).

CONCLUSIONS

In infants with functional GER, L. reuteri DSM 17938 reduce gastric distension and accelerate gastric emptying. In addition, this probiotic strain seems to diminish the frequency of regurgitation.

Induced opening of the gastroesophageal junction occurs at a lower gastric pressure in gerd patients and in hiatal hernia subjects than in normal control subjects

Purpose. To determine intragastric pressure threshold for inducing gastroesophageal junction (GEJ) opening in normal control subjects with and without hiatal hernia, and in patients with gastroesophageal reflux disease. Methods. This study was performed in 13 normal volunteers, 5 volunteers with hiatal hernia, and 3 patients with gastroesophageal reflux disease. During endoscopy a pressure transducer was used to measure baseline gastric pressures. The pressure in the stomach was measured while air was insufflated into the stomach until the gastroesophageal junction opened on endoscopic view. Results. There were two patterns of GEJ opening in normal volunteers. The mean opening pressure for Gastroesophageal junction in normal pattern-I, normal pattern-II, hiatal hernia, and Gastroesophageal reflux patients was 11.5, 12.6, 3.4, and 1.3 mmHg, respectively. Conclusions. GEJ opening is induced at a significantly lower pressure in subjects with hiatal hernia and in patients with gastroesophageal reflux disease than in normal volunteers.

Transient lower oesophageal sphincter relaxation in achalasia: everything but LOS relaxation

In conducting clinical high-resolution oesophageal pressure topography (HROPT) studies we observed that after subjects sat upright between series of supine and upright test swallows, they frequently had a transient lower oesophageal sphincter relaxation (TLOSR). When achalasia patients were studied in the same protocol, they exhibited a similar HROPT event leading to the hypothesis that achalasics had incomplete TLOSRs. We reviewed clinical HROPT studies of 94 consecutive non-achalasics and 25 achalasics. Studies were analyzed for a TLOSR-like event during the study and, when observed, that TLOSR-like event was characterized for the degree and duration of distal oesophageal shortening, the degree of LOS relaxation, associated crural diaphragm (CD) inhibition, oesophageal pressurization and upper oesophageal sphincter (UOS) relaxation. About 64/94 (68%) non-achalasics and 15/24 (63%) of achalasics had a pressure topography event after the posture change characterized by a prolonged period of distal oesophageal shortening and/or LOS relaxation. Events among the non-achalasics and achalasics were similar in terms of magnitude and duration of shortening and all were associated with CD inhibition. Similar proportions had associated non-deglutitive UOS relaxations. The only consistent differences were the absence of associated LOS relaxation and the absence of HROPT evidence of reflux among the achalasics leading us to conclude that their events were incomplete TLOSRs. Achalasic patients exhibit a selective defect in the TLOSR response suggesting preservation of all sensory, central and efferent aspects of the requisite neural substrate with the notable exception of LOS relaxation, a function of inhibitory (nitrergic) myenteric plexus neurons.

Detection of acid reflux and esophageal motor function for asymptomatic patulous cardia patients and its significance

AIM: To explore the impact of dilated cardia on gastric-esophageal acid reflux and esophageal motor function.

METHODS: Twenty-five patients with patulous cardia without any obvious reflux symptoms and 10 asymptomatic healthy volunteers as controls underwent 24 h ambulatory esophageal pH monitoring and esophageal manometry simultaneously. In order to observe gastroesophageal reflux, configuration of the cardia and to exclude hiatal hernia, the patients were previously given a barium meal.

RESULTS: All parameters about 24 h esophageal monitoring were greater in patulous cardia group than in control group. However, only the total time of esophageal acid exposure (pH < 4) and DeMeester score were significantly higher in patulous cardia group than in control group (38.44 ± 50.89 min vs 10.60 ± 7.75 min, 11.98 ± 14.84 vs 5.06 ± 3.19, both P < 0.05). More patulous cardia patients presented pathologic reflux than controls (28% vs 0%, P < 0.05). There were, however, no significant differences between two groups in esophageal sphincter esophageal manometry readings, including LES resting pressure, length, amplitude of the contractile waves of distal and proximal esophagus, peristalsis velocity in the middle-lower part of esophagus and the success rate of wet swallowing.

CONCLUSION: Pathological acid reflux occurres more often in patulous cardia patients than healthy ones. Some patients with patulous cardia and pathological acid reflux are asymptomatic.

Transient lower esophageal sphincter relaxation in morbid obesity

BACKGROUND

There is strong evidence that morbid obesity is often accompanied by gastroesophageal reflux. Gastroesophageal reflux is caused predominantly by transient lower esophageal sphincter relaxations (TLESRs). Only few data are available about TLESRs in patients with stage III obesity (body mass index > 35). The aim of this study was to analyze the frequency and types of TLESRs in patients with morbid obesity in different physiological stages (postprandial: upright and recumband) compared to patients with normal weight gastroesophageal reflux disease (GERD) and diffuse esophagus spasm (DES).

METHODS

In order to measure TLESRs in obese patients with and without GERD, three subgroups were prospectively performed: group I consisted of seven healthy controls, group II consisted of seven obese patients, group III consisted of seven non-obese patients with GERD, and in group IV, five patients were recruited with diffuse esophageal spasm. All participants underwent both conventional water-perfused stationary esophagus manometry and a 24-h ambulatory esophagus manometry, 24-h ambulatory pH monitoring, and esophago-gastroscopy. In order to measure the lower esophageal sphincter pressure (LESP) over a prolonged time under physiological conditions, a special solid-state sleeve catheter was used. Additionally, all patients were interviewed using a standardized questionnaire.

RESULTS

Compared to normal subjects, patients with morbid obesity and patients with gastroesophageal reflux show a substantial increase of TLESRs in the postprandial phase. There was a tendency towards more TLESRs per hour in patients with DES than in healthy subjects, but the difference was not statistically significant. The types of TLESRs differed with the LESP. The majority of isolated TLESRs were complete and incomplete. Some of the isolated TLESRs were accompanied by contractions of the tubular esophagus.

CONCLUSION

Morbid obesity is associated with gastroesophageal reflux. The frequency of TLESRs has significantly increased compared to healthy subjects and does not differ statistically from patients with GERD. Isolated TLESRs are mostly incomplete in patients with a hypotonic LES.

Compliance and capacity of the normal human rectum--physical considerations and measurement pitfalls

The assessment of parameters which adequately represent rectal and neorectal compliance is complex. Biological properties of the rectum during distension and relaxation show significant departures from in vitro physical compliance measurements; as much dependent upon the viscoelastic charateristics of hollow organ deformation as upon the technique of compliance calculation. This review discusses the pressure/volume characteristics of importance in the rectum during distension from a bioengineering perspective and outlines the disparities of such measurements in living biological systems. Techniques and pitfalls of newer methods to assess rectal wall stiffness (impedance planimetry and barostat measurement) are discussed.

Review article: the pathophysiology of gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications.

AIM

To review the current knowledge on the underlying factors contributing to GERD, with particular emphasis on the most recent research.

METHODS

Literature searches were conducted in Medline and EMBASE. The abstracts from recent large congresses were also reviewed to ensure coverage of the latest findings.

RESULTS

The pathophysiological factors causing GERD can be split into those inducing greater exposure of the oesophagus to stomach contents, and those that provide increased perception of reflux or increased mucosal damage. Transient lower oesophageal sphincter relaxations, which are likely to be triggered by gastric distension, appear to be a key physiological cause of GERD. Excessive reflux may also be provoked by impaired oesophageal or gastric clearance mechanisms. Pre-epithelial, epithelial and post-epithelial defences all normally protect the oesophagus from injury, and may be compromised in individuals with GERD. Heartburn could also be caused by oesophageal hypersensitivity as a result of visceral neural pathway dysfunction.

CONCLUSION

The pathophysiology of GERD is multifactorial, and abnormalities in the gastro-oesophageal junction, the stomach, the oesophagus and the nervous system may all contribute to this disease state.

Recent developments in esophageal motor disorders

PURPOSE OF REVIEW

Every year more insight into the pathogenesis and treatment of esophageal motor disorders is obtained. This review highlights some interesting literature published in this area during the last year.

RECENT FINDINGS

Longitudinal and circular muscle contractions act in a well coordinated fashion to allow normal peristalsis. Techniques such as intraluminal impedance, high-resolution manometry and intraluminal ultrasound provide useful additional information on esophageal function both in the normal and abnormal situation. The dynamics of the gastroesophageal junction can be studied with a newly developed probe, and the mechanism behind transient lower esophageal sphincter relaxations is still being unravelled. New manometric criteria for nutcracker esophagus have been proposed, whereas further evidence is reported supporting an association between diabetes mellitus and cardiovascular disease and esophageal dysmotility and spasm, respectively. Finally, several long-term follow-up results of surgical myotomy and pneumodilatation have been reported.

SUMMARY

Due to the perfection of esophageal measuring techniques, our knowledge of esophageal function continues to increase. The studies reviewed here provide interesting information on the pathogenesis and treatment of several esophageal motor disorders.

Stress signaling pathways activated by weaning mediate intestinal dysfunction in the pig

Weaning in the piglet is a stressful event associated with gastrointestinal disorders and increased disease susceptibility. Although stress is thought to play a role in postweaning intestinal disease, the mechanisms by which stress influences intestinal pathophysiology in the weaned pig are not understood. The objectives of these experiments were to investigate the impact of weaning on gastrointestinal health in the pig and to assess the role of stress signaling pathways in this response. Nineteen-day-old pigs were weaned, and mucosal barrier function and ion transport were assessed in jejunal and colonic tissues mounted on Ussing chambers. Weaning caused marked disturbances in intestinal barrier function, as demonstrated by significant (P < 0.01) reductions in transepithelial electrical resistance and increases in intestinal permeability to [3H]mannitol in both the jejunum and colon compared with intestinal tissues from age-matched, unweaned control pigs. Weaned intestinal tissues exhibited increased intestinal secretory activity, as demonstrated by elevated short-circuit current that was sensitive to treatment with tetrodotoxin and indomethacin, suggesting activation of enteric neural and prostaglandin synthesis pathways in weaned intestinal tissues. Western blot analyses of mucosal homogenates showed increased expression of corticotrophin-releasing factor (CRF) receptor 1 in the jejunum and colon of weaned intestinal tissues. Pretreatment of pigs with the CRF receptor antagonist alpha-helical CRF(9-41), which was injected intraperitoneally 30 min prior to weaning, abolished the stress-induced mucosal changes. Our results indicate that weaning stress induces mucosal dysfunction mediated by intestinal CRF receptors and activated by enteric nerves and prostanoid pathways.

Emerging questions regarding eosinophil's role in the esophago-gastrointestinal tract

PURPOSE OF REVIEW

Eosinophilic inflammation of the gastrointestinal tract is either increasing in frequency or being better recognized. Whichever is the case, clinical needs to meet this new challenge include establishing diagnostic criteria, identifying the natural history and determining effective, tolerable treatments.

RECENT FINDINGS

During the last 5 years, the emergence of eosinophilic esophagitis stimulated many case series; the new frontiers relate to understanding disease pathogenesis and maintenance treatments. Eosinophilic gastrointestinal diseases involving the rest of the gastrointestinal tract pose new challenges in understanding the role of eosinophils in intestinal dysmotility and protein loss.

SUMMARY

This review will focus on new clinical developments in the field of eosinophilic gastrointestinal diseases and the contribution of basic studies in understanding eosinophils impact on gastrointestinal inflammation.