Impaired bolus clearance in asymptomatic older adults during high-resolution impedance manometry

Esophageal motor disorders across ages: A retrospective multicentric analysis

BACKGROUND

Age-related changes in the gastrointestinal system are common and may be influenced by physiological aging processes. To date, a comprehensive analysis of esophageal motor disorders in patients belonging to various age groups has not been adequately reported.

METHODS

We conducted a retrospective assessment of high-resolution manometry (HRM) studies in a multicenter setting. HRM parameters were evaluated according to the Chicago Classification version 4.0. Epidemiological, demographic, clinical data, and main manometric parameters, were collected at the time of the examination. Age groups were categorized as early adulthood (<35 years), early middle-age (35-49 years), late middle-age (50-64 years), and late adulthood (≥65 years).

RESULTS

Overall, 1341 patients (632, 47.0% male) were included with a median age of 55 years. Late adulthood patients reported more frequently dysphagia (35.2%) than early adulthood patients (24.0%, p = 0.035), early middle-age patients (21.0%, p < 0.0001), and late middle-aged patients (22.7%, p < 0.0001). Esophagogastric junction outflow obstruction was more prevalent in late adulthood (16.7%) than in early adulthood (6.1%, p = 0.003), and in early middle-age (8.1%, p = 0.001). Patients with normal esophageal motility were significantly younger (52.0 years) than patients with hypercontractile esophagus (61.5 years), type III achalasia (59.6 years), esophagogastric junction outflow obstruction (59.4 years), absent contractility (57.2 years), and distal esophageal spasm (57.0 years), in multivariate model (p < 0.0001).

CONCLUSION

The rate of esophageal motor disorders is higher in older patients, in particular esophagogastric junction outflow obstruction and hypercontractile esophagus. Future prospective studies are necessary to confirm our results and to find tailored strategies to improve clinical outcomes.

Magnetic-controlled capsule endoscopy performance in aging patients

BACKGROUND

The increasing elderly population and wide use of magnetic capsule endoscopy (MCE) have led to more attention to elderly patients.

AIM

The aim of this study was to assess the performance (including transit time, cleanliness score, positive findings and safety) of MCE in aging patients (≥ 60 years), especially patients over 80 years old.

METHODS

Consecutive patients of ≥ 60 years undergoing MCE at our center from August 2017 to August 2022 were classified into the oldest (≥ 80 years) and the older (60-79 years) groups. Esophageal transit time (ETT), gastric examination time (GET), small bowel transit time (SITT), and the quality of gastric preparation were compared. Information on examination indications, subjective discomforts, adverse events, and MCE outcomes were compared.

RESULTS

Of 293 enrolled patients, 128 patients were in the oldest group and 165 patients were in the older group. ETT and GET were longer in the oldest group, whereas SITT was slightly longer in the oldest patients. Visualization scores were significantly lower in the body and antrum in the oldest patients. The total visualization score was lower in the older group compared with the oldest group; however, the difference was not significant. Cleanliness scores at the fundus and antrum and total cleanliness scores were lower in the oldest patients compared with the older patients. Positive findings and ulcers and erosions in the small intestine were more common in the oldest group. One patient had nausea during the gastric examination. Capsule retention in the cecum occurred in one case.

CONCLUSION

MCE was feasible and safe for aging patients. ETT and GET were markedly longer and gastric cleanliness and visualization were worse, while overall small intestine-positive findings were higher in the oldest patients compared with the older patients.

Latent changes in the pharyngeal stage of swallowing in non-aspirating older adults

PURPOSE

The characteristic changes in the swallowing mechanism with aging are collectively termed presbyphagia. Although several studies have investigated presbyphagia in older adults, few have assessed oldest-old adults. We aimed to characterize the latent changes of swallowing function in oldest-old adults and to consider risk ages for presbyphagia.

METHODS

We analyzed the records of 85 individuals (44 males and 41 females, aged 25-101 years) who underwent videofluoroscopic swallowing studies. The included participants had penetration and aspiration scores of ≤ 2 and no history of aspiration, pneumonia, or diseases that affect swallowing. They were divided into four age groups: 25-64 years (non-older), 65-74 years (young-old), 75-84 years (middle-old), and ≥ 85 years (oldest-old). We analyzed and compared the pharyngeal delay time (PDT), duration of tongue base and posterior pharyngeal wall contact, duration and dimension of upper esophageal sphincter opening (UES-O), and maximal hyoid bone displacement between the age groups.

RESULTS

Among the older groups, the oldest-old showed significantly longer PDT than younger-old adults, and the UES-O tended to be wider in the former. However, no other remarkable differences were found between the oldest-old and other old groups. Statistical comparisons between the < 75 and ≥ 75-year age groups revealed significant age-related changes in the PDT and duration and dimension of UES-O.

CONCLUSION

On videofluoroscopic evaluation, physiological changes with aging affected few parameters of swallowing in our cohort. These findings indicate that in non-aspirating oldest-old adults, any deterioration may be adjusted for by compensatory changes to maintain swallowing function.

Effect of Topical Nasal Anesthetic on Comfort and Swallowing in High-Resolution Impedance Manometry

OBJECTIVES/HYPOTHESIS

Use of topical nasal anesthetic (TNA) is common in high-resolution impedance manometry (HRIM). This study investigated the effect of TNA on swallowing and procedure tolerability during HRIM with a 4.2-mm catheter, a more commonly used catheter size with impedance capabilities.

STUDY DESIGN

Randomised experimental study with blinding of participants.

METHODS

Twenty healthy participants (mean age = 33 years, 16 female) were randomized to undergo HRIM using the ManoScan™ ESO Z 4.2-mm catheter twice, 1 week apart, under two conditions: with TNA (viscous lidocaine) and with placebo. Analyses included esophageal data of three saliva, three saline (5 mL), and three bread swallows (2 cm × 2 cm) performed while reclined 45°, and pharyngeal data under the same conditions while seated upright. Pharyngeal and upper esophageal sphincter (UES) HRIM parameters were analyzed using the Swallow Gateway analysis platform. Visual analogue scale (VAS) scores rating procedural comfort were analyzed.

RESULTS

There were no significant physiological differences in pharyngeal and UES parameters between conditions. There were also no significant differences in VAS scores under placebo (mean = 54.8, standard deviation (SD) = 19.3) and TNA (mean = 60.0, SD = 21.9) (t[19] = -0.9, P = .4) conditions; however, there was a significant difference in the first versus second session (t[19]) = 5.1, P < .05).

CONCLUSIONS

TNA did not improve comfort, but it also did not significantly affect swallowing behavior. There was, however, a practice effect regardless of TNA use with improved tolerance of the 4.2-mm catheter and likely more natural swallowing behavior during the second session of HRIM.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Prevalence of Different Types of Primary Esophageal Motility Disorders and Their Associated Factors in Patients Referring to Shariati Hospital during 2018-2019

BACKGROUND: Esophageal motility disorders (EMDs) are common in patients with dysphagia and are effectively diagnosed with high-resolution manometry (HREM). In this study, we aimed to evaluate the prevalence of different types of primary EMDs in patients referred for HREM and to further investigate the factors associated with EMDs. METHODS: In this cross-sectional study, all patients referred to the endoscopy section of Shariati Hospital during 2018-2019 (279 patients) were subjected to HREM and were evaluated according to their diagnosis, and the effect of each factor and each symptom on motility disorders was investigated. RESULTS: 84.5% (235) of the participants were diagnosed with at least one esophageal motility disorder; of them, achalasia was the most common form (52.6%). None of the predictive factors showed a statistically significant correlation with EMDs. However, regarding the symptoms, regurgitation and nocturnal cough were significantly more common in patients with EMD (P=0.001 and 0.009, respectively). CONCLUSION: This study demonstrates the high prevalence of EMDs in patients undergoing manometry. None of the factors studied, such as age, sex, diabetes, hypothyroidism, smoking, and alcohol and opium consumption, had a statistically significant correlation with EMDs.

Efficacy and Safety of Peroral Endoscopic Myotomy for Esophageal Achalasia and Achalasia-Related Diseases in Patients Aged 75 Years and Over

Peroral endoscopic myotomy (POEM) has become a popular treatment for esophageal achalasia and other esophageal motility disorders. However, its efficacy and safety in elderly patients are unclear. To clarify that, we reviewed the medical records of patients who underwent POEM in our hospital. A total of 11 patients who underwent POEM for esophageal achalasia (n = 10) and jackhammer esophagus (n = 1) were included. Procedural success, defined as the completion of an esophageal and gastric myotomy, was 100%. Clinical success, defined as an Eckardt score of 3 or less, without the use of additional treatments at 2 months, was 100%. The median Eckardt score significantly decreased after the POEM (baseline vs. 2 months after POEM; 7 (2–8) vs. 0 (0–1), p < 0.01). In the second and third years, the cumulative treatment effect maintenance rate was 88.9%. All patients taking antithrombotic agents had safe operations with the temporary discontinuation of these agents. There were four adverse events (two pneumoperitoneum, one mucosal injury, and one pneumonia), all of which improved with fasting or antibiotics. In conclusion, POEM is an effective and safe treatment for esophageal achalasia and achalasia-related diseases in patients aged 75 years and over.

The mechanism of esophagus dysmotility in diabetes and research progress of relating treatments

Introduction: Esophagus dysmotility is a crucial risk factor of gastroesophageal reflux disease (GERD), which is one of the most common diseases in digestive medicine globally. This review emphasizes the mechanisms of esophagus dysmotility in diabetes and summarizes more targeted treatments for these patients to avoid the overuse of proton pump inhibitors (PPIs).Areas covered: Diabetes mellitus (DM) is a clear factor that must not be neglected in the development of GERD. Previous studies have preliminarily researched the esophagus deterioration in diabetes. However, the multi-faceted mechanisms of esophagus dysmotility in diabetes need more studies. Besides, targeted treatments for these patients rather than conventional PPIs are urgently needed.Expert opinion: The treatments for GERD patients with diabetes should be further explored. Pharmacological approaches such as prokinetic agents, psychotherapy can be adopted. Meanwhile, it's feasible to explore non-drug treatments. For example, Electroacupuncture (EA) at Zusanli (ST-36) may be effective to protect the networks of intestinal cells of Cajal (ICCs) in diabetes. More effective approaches should be explored to achieve individualized treatment for these patients.

Normative reference values for esophageal high-resolution manometry in healthy adults: A systematic review

Establishing normative values of high-resolution esophageal manometry is necessary for accurate interpretation and comparison of measurements. In this systematic review, we aimed to summarize normal values for different esophageal high-resolution manometry systems. Moreover, we assessed the effect of body position, bolus consistency, and provocative maneuvers on these normative thresholds. We searched Medline, Embase, and the Cochrane Library from January 1st, 2006, to January 20th, 2020, for studies that reported normative data of high-resolution manometry in healthy volunteers. We assessed methodological quality of the included studies and planned a descriptive analysis. We analyzed data from 54 articles describing normative thresholds in high-resolution manometry using solid-state or water-perfused systems. Forty-six studies performed the manometry study in the supine position with liquid swallows, whereas sixteen studies described normative values in the upright position. Twelve studies assessed normative values for different bolus consistencies, and nine studies evaluated different provocative maneuvers. There is a considerable variety of normative values for esophageal high-resolution manometry depending on the equipment used and the protocols performed to obtain measurements. This should be taken into account when evaluating measurements in clinical practice and when comparing results of published research studies.

The esophageal mucosal barrier in health and disease: mucosal pathophysiology and protective mechanisms

Diseases of the esophagus, such as gastroesophageal reflux (GER), can result in changes to mucosal integrity, neurological function, and the microbiome. Although poorly understood, both age and GER can lead to changes to the enteric nervous system. In addition, the esophagus has a distinct microbiome that can be altered in GER. Mucosal integrity is also at risk due to persistent damage from acid. Diagnostic tools, such as ambulatory pH/impedance testing and esophageal mucosal impedance, can assess short-term and longitudinal GER burden, which can also assess the risk for mucosal compromise. The quality of the mucosal barrier is determined by its intercellular spaces, tight junctions, and tight junction proteins, which are represented by claudins, occludins, and adhesion molecules. Fortunately, there are protective factors for mucosal integrity that are secreted by the esophageal submucosal mucous glands and within saliva that are augmented by mastication. These protective factors have potential as therapeutic targets for GER. In this article, we aim to review diagnostic tools used to predict mucosal integrity, aging, and microbiome changes to the esophagus and esophageal mucosal defense mechanisms.

Esophageal motility patterns are altered in older adult patients

INTRODUCTION AND AIMS

Since the 1960s, several studies have shown the effect of aging on esophageal motility, with inconsistent results. The aim of the present study was to evaluate the manometric results in older adult patients (=60 years of age) with an esophageal disorder and compare them with adults under 60 years of age.

MATERIALS AND METHODS

A cross-sectional, retrospective study was conducted that included a sample of 1,175 patients (936 older adults and 239 non-older adults). The patients were evaluated and compared with respect to (i) sex, (ii) main complaint for which esophageal manometry was indicated, (iii) comorbidities, (iv) current medications, (v) smoking, and (vi) manometry results.

RESULTS

Patient age ranged from 19 to 92 years (women made up 76.5% of the older adults and 72.8% of the non-older adults). Normal lower esophageal sphincter relaxation and normal peristalsis were more frequent in the non-older patient group (91.1% vs. 84.8% and 87.4% vs. 76%, respectively). The manometry results for the non-older adults vs. the older adults, respectively, were: achalasia (2.9% vs. 5.9%); hypercontractile disorder (9.2% vs. 10.4%); hypocontractile disorder (38.5% vs. 47.6%); and normal values (49.4% vs. 36.1%). After excluding the variables that could change esophageal motility, the results revealed significant differences between the two study groups.

CONCLUSIONS

Esophageal manometry demonstrated statistically significant differences between the older adult and non-older adult study population evaluated.

Upper Gastrointestinal Function in Morbidly Obese Adolescents Before and 6 Months After Gastric Banding

BACKGROUND

The effects of laparoscopic adjustable gastric band (LAGB) placement on upper gastrointestinal tract function in obese adolescents are unknown. Therefore, our aim was to determine the short-term effects of LAGB on esophageal motility, gastroesophageal reflux, gastric emptying, appetite-regulatory hormones, and perceptions of post-prandial hunger and fullness.

METHODS

This study was part of a prospective cohort study (March 2009-December 2015) in one tertiary referral hospital. The study included obese adolescents (14-18 years) with a body mass index (BMI) > 40 (or ≥ 35 with comorbidities). Gastric emptying was assessed by ¹³C-octanoic acid breath test, pharyngeal, and esophageal motor function by high-resolution manometry with impedance (HRIM), and appetite and other perceptions using 100-mm visual analogue scales. Dysphagia symptoms were scored using a Dakkak questionnaire. Data were compared pre- and post-LAGB placement and at a 6-month follow-up.

RESULTS

Based upon analysis of 15 adolescents, at the 6-month follow-up, LAGB placement: (i) led to a significant reduction in weight and BMI; (ii) increased fullness and decreased hunger post-meal; (iii) increased symptoms of dysphagia after solid food; and, despite these effects, (iv) caused little or no changes to appetite hormones, while (v) effects on gastric emptying, esophageal motility, esophageal bolus transport, and esophageal emptying were not significant.

CONCLUSION

In adolescents, LAGB improved BMI and altered the sensitivity to nutrients without significant effects on upper gastrointestinal tract physiology at the 6-month follow-up.

A Systematic Review of Physiological Changes in Swallowing in the Oldest Old

Age-related swallowing changes are well-researched in deglutology, usually distinguishing those over 60 years as older aged. World-wide, older adults are healthier and forecast to live longer: many over 85 years. It is necessary for clinicians to understand healthy swallowing changes in this 'oldest old' in order to appropriately manage swallowing complaints in older patients. This systematic review collated and critically appraised studies investigating swallowing changes in adults over 85 years using instrumental assessment. Criteria for inclusion were healthy subjects over 85 years. Exclusion criteria included studies focused on anatomy and oral processing. Studies published until December 2018 were retrieved from BIOSIS, CINAHL, Embase, Medline, and Scopus, totaling 2125 articles. During data screening, 64% of studies investigating age-related swallowing changes were excluded, as the oldest old were not recruited. After PRISMA screening, 44 articles met criteria. These were further reviewed for data extraction, bias and quality. Main quantitative age-related changes in swallowing included increases in delay in swallow onset, bolus transit times, duration of UES opening, pressure above the UES and UES relaxation pressure, and reduction in pressure at the UES. Few studies detected increased residue or airway compromise in the form of aspiration. Results were not easily comparable due to differences in age ranges, methods for deeming participants 'healthy', measures used to define swallowing physiology, and swallowing tasks. Age-related swallowing changes are identified that do not compromise safety. The oldest old are underrepresented in normative deglutition research. It is essential future studies plan accordingly to recruit those over 85 years.

Systematic Review of Pharyngeal and Esophageal Manometry in Healthy or Dysphagic Older Persons (>60 years)

We undertook a systematic review of swallowing biomechanics, as assessed using pharyngeal and esophageal manometry in healthy or dysphagic older individuals aged over 60 years of age, comparing findings to studies of younger participants. PRISMA-P methodology was used to identify, select, and evaluate eligible studies. Across studies, older participants had lower upper esophageal sphincter (UES) resting pressures and evidence of decreased UES relaxation when compared to younger groups. Intrabolus pressures (IBP) above the UES were increased, demonstrating flow resistance at the UES. Pharyngeal contractility was increased and prolonged in some studies, which may be considered as an attempt to compensate for UES flow resistance. Esophageal studies show evidence of reduced contractile amplitudes in the distal esophagus, and an increased frequency of failed peristaltic events, in concert with reduced lower esophageal sphincter relaxation, in the oldest subjects. Major motility disorders occurred in similar proportions in older and young patients in most clinical studies, but some studies show increases in achalasia or spastic motility in older dysphagia and noncardiac chest pain patients. Overall, study qualities were moderate with a low likelihood of bias. There were few clinical studies specifically focused on swallowing outcomes in older patient groups and more such studies are needed.

High-resolution esophageal manometry in a Mexican population: diagnostic outcome

High-resolution esophageal manometry (HREM) has become the method of choice for evaluation of esophageal motility disorders. There is a paucity of data with this technique from Hispanic countries. This study aims to characterize the diagnostic outcome of HREM in a large cohort of consecutive patients in Mexico.This study was conducted in Monterrey, Mexico from March 1, 2013 to March 31, 2015. Our diverse study population included patients from a major academic institution and the community. HREM was done applying the Chicago Classification 3. Diagnostic outcome was grouped as weak peristaltic disorders, gastroesophageal junction disorders, and hypertensive/uncoordinated peristalsis.We studied 670 consecutive patients, 57% were women, mean age was 43.8 years. The majority (465 [69%]) were referred for preoperative evaluation of gastroesophageal reflux disease (GERD), 365 (78%) of whom had a normal study. Overall, 193 (29%) patients had abnormal motility, the most common disorder being weak peristalsis (104 [54%]). In patients with dysphagia, the most frequent finding was achalasia (23/46 [50%]).To our knowledge, this is the first study to characterize the diagnostic outcome of HREM in a large cohort of Hispanic patients in Latin America. At our open access center, 69% of patients were referred for preoperative evaluation of GERD, reflecting the popularity of antireflux surgery. This study confirms the high prevalence of weak peristalsis and highlights the importance of addressing its pathophysiology and management. The finding of achalasia in 50% of our patients with dysphagia is consistent with recent reports regarding the rising incidence of this disorder and underscores the need of prompt motility testing in this population.

An international multicenter study evaluating the clinical efficacy and safety of per-oral endoscopic myotomy in octogenarians

BACKGROUND AND AIMS

Per-oral endoscopic myotomy (POEM) for achalasia is particularly appealing in the elderly because it is minimally invasive. However, data in patients aged ≥80 years are scarce. The aim of this study was to assess the clinical outcome of POEM in octogenarians.

METHODS

This was a multicenter retrospective study at 8 centers. Consecutive octogenarians with achalasia who underwent POEM between 2010 and 2016 were included. Rates of technical success (completion of myotomy), clinical response (Eckardt score ≤3), and adverse events (severity graded as per American Society for Gastrointestinal Endoscopy lexicon) were assessed.

RESULTS

A total of 76 patients (47.4% female, mean age 84 years) underwent POEM for treatment of achalasia: type I, 17.1%; type II, 35.5%; type III, 17.1%; and unspecified, 30.3%. Overall, 41.1% were treatment naïve, whereas others had previous botulinum toxin injection and/or pneumatic dilation. The mean (± standard deviation [SD]) age-adjusted Charlson comorbidity index score was 6.2 ± 2.4, with the majority of patients having American Society of Anesthesiologists Physical Status Classification System (ASA) scores of II/III. Technical success was 93.4%, with a median follow-up of 256 days. Fourteen adverse events occurred in 11 patients (14.5%). There were 3 inadvertent mucosotomies, 6 cases of symptomatic capnoperitoneum and/or capnomediastinum, 2 esophageal leaks, 1 cardiac arrhythmia, and 2 other). The severities of these adverse events were mild (78.6%), moderate (14.3%), and severe (7.1%). Clinical success was achieved in 90.8% of patients, with a mean (± SD) Eckardt score reduction from 7.0 ± 2.3 to 0.8 ± 0.1 (P < .001), a median follow-up of 256 days, and interquartile range of 66 to 547.

CONCLUSION

Although the rate of technical success may be somewhat lower and the rate of adverse events slightly higher than previously reported, our data suggest that POEM in octogenarians is safe and effective, supporting its role as a primary modality for achalasia in this patient population.

Changes in the interstitial cells of Cajal and neuronal nitric oxide synthase positive neuronal cells with aging in the esophagus of F344 rats

The aging-associated cellular and molecular changes in esophagus have not been established, yet. Thus we evaluated histological structure, interstitial cells of Cajal (ICCs), neuronal nitric oxide synthase (nNOS)-positive cells, and contractility in the esophagus of Fischer 344 rat at different ages (6-, 31-, 74-weeks, and 2-years). The lamina propria thickness and endomysial area were calculated. The immunoreactivity of c-Kit, nNOS and protein gene product (PGP) 9.5 was counted after immunohistochemistry. Expression of c-Kit, stem cell factor (SCF), nNOS and PGP 9.5 mRNA was measured by real-time PCR, and expression of c-Kit and nNOS protein was detected by Western blot. Isovolumetric contractile force measurement and electrical field stimulation (EFS) were conducted. The lamina propria thickness increased (6 week vs 2 year, P = 0.005) and the endomysial area of longitudinal muscle decreased with aging (6 week vs 2 year, P<0.001), while endomysial area of circular muscle did not significantly decrease. The proportions of NOS-immunoreactive cells and c-Kit-immunoreactive areas declined with aging (6 week vs 2 year; P<0.001 and P = 0.004, respectively), but there was no significant change of PGP 9.5-immunopositiviy. The expressions of nNOS, c-Kit and SCF mRNA also reduced with aging (6 week vs 2 year; P = 0.006, P = 0.001 and P = 0.006, respectively), while the change of PGP 9.5 mRNA expression was not significant. Western blot showed the significant decreases of nNOS and c-Kit protein expression with aging (6 week vs 2 year; P = 0.008 and P = 0.012, respectively). The EFS-induced esophageal contractions significantly decreased in 2-yr-old rat compared with 6-wk-old rats, however, L-NG-Nitroarginine methylester did not significantly increase the spontaneous and EFS-induced contractions in the 6-wk- and 2-yr-old rat esophagus. In conclusion, an increase of lamina propria thickness, a decrease of endomysial area, c-Kit, SCF and NOS expression with preserved total enteric neurons, and contractility in aged rat esophagus may explain the aging-associated esophageal dysmotility.

Age-related impairment of esophagogastric junction relaxation and bolus flow time

AIM

To investigate the functional effects of abnormal esophagogastric (EGJ) measurements in asymptomatic healthy volunteers over eighty years of age.

METHODS

Data from 30 young controls (11 M, mean age 37 ± 11 years) and 15 aged subjects (9 M, 85 ± 4 years) were compared for novel metrics of EGJ-function: EGJ-contractile integral (EGJ-CI), “total” EGJ-CI and bolus flow time (BFT). Data were acquired using a 3.2 mm, 25 pressure (1 cm spacing) and 12 impedance segment (2 cm) solid-state catheter (Unisensor and MMS Solar GI system) across the EGJ. Five swallows each of 5 mL liquid (L) and viscous (V) bolus were analyzed. Mean values were compared using Student’s t test for normally distributed data or Mann Whitney U-test when non-normally distributed. A P value < 0.05 was considered significant.

RESULTS

EGJ-CI at rest was similar for older subjects compared to controls. “Total” EGJ-CI, measured during liquid swallowing, was increased in older individuals when compared to young controls (O 39 ± 7 mmHg.cm vs C 18 ± 3 mmHg.cm; P = 0.006). For both liquid and viscous bolus consistencies, IRP4 was increased (L: 11.9 ± 2.3 mmHg vs 5.9 ± 1.0 mmHg, P = 0.019 and V: 14.3 ± 2.4 mmHg vs 7.3 ± 0.8 mmHg; P = 0.02) and BFT was reduced (L: 1.7 ± 0.3 s vs 3.8 ± 0.2 s and V: 1.9 ± 0.3 s vs 3.8 ± 0.2 s; P < 0.001 for both) in older subjects, when compared to young. A matrix of bolus flow and presence above the EGJ indicated reductions in bolus flow at the EGJ occurred due to both impaired bolus transport through the esophageal body (i.e., the bolus never reached the EGJ) and increased flow resistance at the EGJ (i.e., the bolus retained just above the EGJ).

CONCLUSION

Bolus flow through the EGJ is reduced in asymptomatic older individuals. Both ineffective esophageal bolus transport and increased EGJ resistance contribute to impaired bolus flow.