Introduction

Solid gastric emptying scintigraphy (GES) is used to assess gastric motility by measuring the transit of a radioactively labelled solid meal, however it can be non-specific and insensitive by itself. Liquid gastric emptying scintigraphy provides an additional modality of motility testing using a similar process with a liquid meal. Gastric Alimetry is a non-invasive test that measures gastric electrophysiological activity through body surface gastric mapping (BSGM) and validated symptom profiling¹.

Aims & Methods

This study aimed to assess the additional diagnostic value of performing liquid GES and Gastric Alimetry in addition to solid GES alone.
Patients with chronic gastroduodenal symptoms underwent simultaneous solid GES and Gastric Alimetry, comprising of a 30-minute baseline recording followed by a 99mTC-labelled egg meal, and 4-hour postprandial recording. Patients would also have a glucose liquid GES study on a different date. Delayed emptying was defined as greater than 10% retention at 4 hours for solid GES and more than 50% retention at 2 hours for liquid GES^2,3. Gastric Alimetry spectral metrics were referenced to normative ranges that included principal gastric frequency (cpm), Gastric Alimetry Rhythm Index (GA-RI) and BMI-adjusted amplitude⁴.

Results

36 patients with chronic gastroduodenal symptoms were prospectively recruited (30 female, median age 38.0 years, median BMI 24.6 kg/m²). 10 (27.8%) patients had delayed solid GES whilst 7 (19.4%) patients had delayed liquid GES. 9 (25.0%) patients had abnormal Gastric Alimetry spectral metrics. Combining solid and liquid GES detected an abnormality in 13 (36.1%) patients which was further enhanced when combined with Gastric Alimetry, detecting an abnormality in 17 (47.2%) of patients. Of those 13 patients with either a delayed solid or liquid GES, 38.5% of them had abnormal Gastric Alimetry spectral metrics (3 High Frequency, 1 Low Rhythm Stability, 1 High Amplitude) while those with a normal solid and liquid GES had abnormal spectral metrics in 17.4%.

Conclusion

Combining solid and liquid GES with Gastric Alimetry detected a higher yield of motility abnormalities than solid GES alone. GES and Gastric Alimetry assess different aspects of gastric function with further studies required to understand their complementary roles as biomarkers in clinical practice to help tailor therapy.

References

1. Sebaratnam G, Karulkar N, Calder S, et al. Standardized system and app for continuous patient symptom logging in gastroduodenal disorders: Design, implementation, and validation. Neurogastroenterology & Motility 2022; 34.
2. Abell TL, Camilleri M, Donohoe K, et al. Consensus recommendations for Gastric Emptying Scintigraphy: A joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine. Journal of Nuclear Medicine Technology; 36: 44–54.
3. Phillips WT, McMahan CA, Lasher JC, et al. Anterior, posterior, left anterior oblique, and geometric mean views in gastric emptying studies using a glucose solution. European Journal of Nuclear Medicine; 22: 154–157.
4. Varghese C, Schamberg G, Calder S, et al. Normative values for body surface gastric mapping evaluations of gastric motility using gastric alimetry: Spectral analysis. American Journal of Gastroenterology; 118: 1047–1057.

Disclosure

Greg O'Grady holds intellectual property and grants in gastric electrophysiology and is a Director of the University of Auckland spin-out companies Alimetry and Insides Company. Stefan Calder is a member of Alimetry. The remaining authors have no relevant conflicts of interest to declare.

Introduction

Gastric emptying is controlled by phasic gastric contractions which occur at a frequency of ~3 cycles per minute (cpm) in phase with gastric slow waves. Tests to measure slow waves cannot directly detect abnormal contractions. The Atmo Capsule possesses an accelerometer that measures changes in capsule orientation and can thus detect gastric contractions. We analyzed accelerometer data to define its capability to characterize gastric contraction frequency and amplitude in patients with suspected dysmotility, and to assess if frequency or amplitude vary in relation to transit delay.

Aims & Methods

Gut transit was measured by the Atmo Capsule in 209 subjects: 48 with predominant upper GI (UGI) symptoms alone (suspected gastroparesis), 21 with lower GI (LGI) symptoms (suspected slow colon transit) alone, and 140 with combined UGI+LGI symptoms. This analysis utilized data from subjects recording valid gastric emptying time (GET) measures and did not incur protocol deviations affecting gastric transit. Delays in GET were categorized as: normal, <5 h; delayed, 5-10 h; severely delayed, ≥10 h. Fast Fourier Transformation (FFT) of the accelerometer data allows for the identification and analysis of the dominant gastric frequency and amplitude using 10-minute windows and a cutoff frequency of 4.5 cpm. Variability of frequency and amplitude measures were estimated by calculating interquartile range (IQR) and range (max-min) values and were analyzed in relation to presenting symptoms and gastric emptying delays.

Results

Gastric data from 190 subjects were suitable for analysis: gastric contractions with dominant frequencies of 3.30 cpm (IQR 0.47, range 1.47) and amplitudes of 0.10 arbitrary units (au) (IQR 0.04, range 0.14) were detected in 185 (97%) of subjects. Mean contraction frequency tended to be higher in those with delayed GET compared with no delay (p=0.016) and severe delay (p=0.005) (Table 1). Frequency IQR (p=0.002) and range (p=0.002) were higher for GET delay vs. no delay, while range was higher in severe GET delay vs no delay (p<0.001). Mean amplitude was higher in subjects with severe GET delay compared with normal delay (p=0.008) and normal transit (p=0.001). Amplitude IQR and range were both higher in those with severe GET delay compared with normal delay (p=0.002; p=0.001) and no delay (p<0.001 for both). Frequency metrics were similar irrespective of predominant symptoms. Amplitude means (p=0.022), IQR (p=0.030) and range (p=0.0004) were higher for UGI vs. LGI symptoms.

Table 1. Dominant gastric frequencies and amplitudes in relation to gastric emptying delays. Data shown as median (interquartile range) and analyzed via Kruskal-Wallis test.

Conclusion

The Atmo Capsule accelerometer reliably characterizes 3 cpm gastric contraction frequency and amplitude in subjects with proposed delays in gut transit. Increased variabilities in contraction frequency and amplitude were defined in those with severely delayed gastric emptying and increased amplitude variability was found for predominant upper GI symptoms. We propose these higher variations identified by accelerometry may reflect hypomotility or contractile dropout, suggesting additional clinical utility of the Atmo Capsule in suspected gastroparesis.

Disclosure

These authors disclose the following: Braden Kuo, Anthony J. Lembo, Eammon M.M. Quigley, Satish S.C. Rao, and William D. Chey serve on the Medical Advisory Board of Atmo Biosciences. Michael Cline and Baharak Moshiree served on the Medical Advisory Board of Atmo Biosciences. Braden Kuo has received funding from NIH, Vanda, Atmo Biosciences, and Takeda and has consulted for Evoke, Takeda, Ironwood, Novo Nordisk, Cindome, and Neurogastrx. Thomas Abell has received funding from Gastric Dysrhythmias, Neurogastrx, NIH GpCRC, and Vanda and has consulted for Enterra Medical, Novo Nordisk, Nuvaira, and Vanda. Anthony J. Lembo has received funding from Ardelyx, Biomerica, GSK, Ironwood, Takeda, and Vibrant and holds stock with Allurion, Bristol Myer Squibb, and J&J. Abigail Stocker has received funding from Cindome, Enterra Medical, and Vanda. William D. Chey has received funding from Atmo Biosciences, Commonwealth Diagnostics Intl, QOL Medical, and Salix; has consulted for AbbVie, Ardelyx, Biomerica, Comvita, Gemelli, Ironwood, Nestle, QOL Medical, Phathom, Redhill, Salix, Vibrant, and Takeda; has filed patents with My Nutrition Health, Digital Manometry, and Rectal Expulsion Device; and holds stock options with Coprata, Evinature, Food Marble, Kiwi Bioscience, and Modify Health. The remaining authors disclose no conflicts.

Introduction

Gastric emptying testing (GET) is used to assess gastric motility, however is non-specific and insensitive for neuromuscular disorders. Gastric Alimetry® is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling.

Aims & Methods

This study aimed to assess patient-specific phenotyping using Gastric Alimetry with comparison to GET.
Patients with chronic gastroduodenal symptoms underwent simultaneous GET and Gastric Alimetry. Tests comprised a 30-minute baseline, ^99mTC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges^1,2. Symptoms were profiled in real-time during testing in the validated Gastric Alimetry App³, phenotyped with rule-based criteria, and compared to long-term symptom questionnaires of Rome IV criteria, Patient Assessment of Upper Gastrointestinal Symptom Severity Index (PAGI-SYM), Gastroparesis Cardinal Symptom Index (GCSI), Patient Assessment of Upper Gastrointestinal Disorders Quality of Life (PAGI-QoL), Patient Health Questionnaire-2 (PHQ-2), and State-Trait Anxiety Inventory-6 (STAI-6). Three Gastric Alimetry symptom profiles were phenotyped: i) continuous (symptoms do not correlate with meal or gastric activity); ii) gastric sensorimotor (symptoms increase within 30 minutes of the meal and decay as gastric activity decreases); and iii) Other (symptoms that do not fit the other two symptom profiles).

Results

75 patients with chronic gastroduodenal symptoms were assessed; 77% female, median age 43, median BMI 24.0. Motility abnormality detection rates were: GET 22.7% (14 delayed, 3 rapid); Gastric Alimetry spectral analysis 33.3% (14 dysrhythmic / low amplitude; 5 high amplitude; 6 abnormal frequency); combined yield 42.7%. In patients with normal spectral analysis, Gastric Alimetry symptom phenotypes included: gastric sensorimotor 17%; continuous 30%; other 53%. The sensorimotor phenotype correlated strongly with gastric amplitude (median r=0.61 vs r=0.08 and r=0.06 respectively; p=0.0002). Abnormal Gastric Alimetry phenotypes showed superior correlations with GCSI, PAGI-SYM, and STAI-6 anxiety scores (p<0.05), while Rome IV Criteria and delayed gastric emptying did not correlate (p>0.05). Delayed gastric emptying was not predictive of specific Gastric Alimetry phenotypes.

Conclusion

Gastric Alimetry generated a higher yield for motility abnormalities than GET in patients with chronic gastroduodenal symptoms. Gastric Alimetry also identified patient-specific symptom phenotypes, showing correlations with health psychology variables not observed with Rome IV and delayed gastric emptying. GET and Gastric Alimetry assess different aspects of gastric function, indicating these tests may have complementary roles.

References

1. Varghese C, Schamberg G, Calder S, et al. Normative values for body surface gastric mapping evaluations of gastric motility using gastric alimetry: Spectral analysis. American Journal of Gastroenterology 2022; Publish Ahead of Print. Epub ahead of print 2022. DOI: 10.14309/ajg.0000000000002077.
2. Abell TL, Camilleri M, Donohoe K, et al. Consensus recommendations for Gastric Emptying Scintigraphy: A joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine. Journal of Nuclear Medicine Technology; 36: 44–54.
3. Sebaratnam G, Karulkar N, Calder S, et al. Standardized system and app for continuous patient symptom logging in gastroduodenal disorders: Design, implementation, and validation. Neurogastroenterology & Motility 2022; 34. Epub ahead of print 2022. DOI: 10.1111/nmo.14331.

Disclosure

Greg O'Grady, Armen Gharibans and Peng Du hold intellectual property and grants in gastric electrophysiology and are Directors of University of Auckland spin-out companies (Greg O'Grady: Alimetry, Insides Company; Armen Gharibans: Alimetry; Peng Du: FlexiMap); Stefan Calder, Gabriel Schamberg, Stephen Waite, and Christopher N. Andrews are members of Alimetry. The remaining authors have no relevant conflicts of interest to declare.

Introduction

Gastroparesis is a disorder characterized by delayed gastric emptying without mechanical obstruction, leading to symptoms such as nausea, vomiting, abdominal pain, and bloating. Cannabis and its active compounds are thought to interact with the gastrointestinal system through cannabinoid receptors, influencing motility, sensation, and inflammation. Nevertheless, data pertaining to the interactions between cannabis use, gastric motility and gastrointestinal (GI) symptoms is still scant¹.

Aims & Methods

The aim of the current study was to compare GI symptoms and gastric motility in a cohort of patients referred for gastric emptying breath test (GEBT). In this prospective study, all consecutive patients referred for motility testing in a tertiary hospital were recruited. Following obtaining written informed consent, questionnaires, including ROME, SCL-90-R and SF36 were filled out by the patients. Carbon-13 spirulina GEBT was done performed according to protocol, following consumption of a standardized meal. Patients with ongoing (regular or occasional) cannabis use were compared with non-cannabis users for all symptoms, quality of life and GEBT testing results. An additional healthy cohort of volunteers was recruited for validation of GEBT cut-off values and comparison to the symptomatic cohort.

Results

A total of 88 patients and 14 healthy volunteers were included in the current study. Among patients, 15 (17%) were identified as cannabis users, and these were compared with 73 non-users. Mean age and gender did not differ between users and non-users (52.4 vs 43.0, and 21% vs 33% males, respectively, p=NS). Gastric emptying breath test results did not significantly differ between groups, both in terms of mean values (t^1/2 127.2 vs 129.2 minutes, users versus non-users, respectively; p=NS) and in the proportion of delayed gastric emptying (26.7% versus 32.9%, users versus non-users, respectively; p=NS). None of the healthy volunteers displayed delayed gastric emptying results. Cannabis users demonstrated a higher gastrointestinal symptom burden and a greater number of diagnosed disorders of gut-brain interaction (DGBI) compared to non-users.

Conclusion

In our cohort of patients referred for gastric emptying breath tests, gastric emptying was similar between cannabis users and non-users. This is in line with previous studies suggesting that cannabis does not improve delayed gastric emptying. Nevertheless, previous studies suggested that cannabis may alleviate gastroparesis-associated symptoms². In this context, our results show that cannabis use was rather associated a more severe and systemic symptomatic manifestation of gut-brain disorders, in contrast to a more localized upper gastrointestinal involvement seen in non-users. Although causality cannot be established, we do note that despite ongoing cannabis use, treatment response was sub-optimal in the user patient group. Factors contributing to these differences, such as physiological or psychological constructs, should be further explored.

References

¹Parkman HP et al. Marijuana Use in Patients with Symptoms of Gastroparesis: Prevalence, Patient Characteristics, and Perceived Benefit. Dig Dis Sci. 2020
²Barbash, B et al. Cannabinoids Lead to Significant Improvement in Gastroparesis—Related Abdominal Pain: 1204. American Journal of Gastroenterology 2018.

Introduction

Gastric emptying (GE) of liquids and solids is differentially regulated. GE of liquids follows an exponential kinetic and mainly depends on fundic tone, GE of solids requires trituration by antral contractions for passage through the adequately opened pylorus into the duodenum. Adler et al. showed that liquid GE was more often delayed in systemic sclerosis patients compared with GE of solids (Rheumatology 2022), but knowledge on the association between GE of solids and liquids in dyspeptic patients, in general, is limited.

Aims & Methods

To investigate this association and the correlation of GE times with symptoms, we compared results of breath tests using 13C-acetate (13C-ABT, GE-liquids) and 13C-octanoic acid (13C-OBT, GE-solids) in consecutive dyspeptic patients undergoing both tests (Keller et al. UEG J 2021). Normal ranges at our institution for 13C-ABT are 20-35 min (T lag-liquids), for 13C-OBT 50-150 min (T ½-solids). All patients additionally answered the gastroparesis cardinal symptom index questionnaire (GCSI, Revicki APT 2003).

Results

302 patients were included (230 women, age 45.9 (31.7-59.5) yrs, median(IQR)). Median T lag-liquids was 25 (20-35) min, median T ½-solids 78 (60-104) min. T lag-liquids and T ½-solids were weakly associated (R=0.165, p=0.002). Both were indirectly correlated with age (R=-0.280, p<0.0001 and R=-0.179, p=0.0009, resp), and similar in men and women. Concordant results for both tests were achieved in 172 subjects (57.6%): Both were normal in 161 (53.3%), both showed accelerated GE in 10 (3.3%) and both delayed GE in 3 (1%) subjects. Discrepant results were observed in 128 subjects (42.4%), in the vast majority of these, one of the tests was normal, but in 7 subjects (2.3%), GE was accelerated in one test, delayed in the other. 67 patients (22.2%) had delayed GE in at least one of the tests. Only in this subgroup, GE time correlated significantly with GCSI (R=0.242, p=0.024), in particular with the nausea/vomiting subscale (p=0.009).

Conclusion

In a large group of dyspeptic patients, more than 45% had disturbances of liquid and/or solid GE. In less than 5% of the total group both tests were found to be either accelerated or delayed in the same patient. Instead, measurements of liquid and solid GE often differred. In patients with delayed GE in at least one of the tests, severity of gastroparesis symptoms was associated with GE time. Thus, measurements of liquid and solid GE may be complementary and identify patients with different pathomechanism leading to GE disturbances and symptoms.

Introduction

Gastroparesis (GP) is defined as symptomatic delayed gastric emptying. The most frequent etiologies are diabetes mellitus, after esophageal or gastric surgery and about a third of patients have idiopathic GP. The gastric emptying study by using a scintigraphy scintigraphy (GES) is considered as a principal diagnostic method. Endoscopic pyloromyotomy (G-POEM) is a method improving symptoms in about 60-70% of patients with GP. Its effect on gastric emptying remains controversial.

Aims & Methods

We performed a retrospective single-center analysis to assess the clinical efficicacy of G-POEM based on GES parameters. Between 2016 – 2024, a total of 72 patients with GP (confirmed by scintigraphy) underwent G-POEM and were later invited for clinical as well as scintigraphic assessment after 3, 12 and 36 months. Of these patients, 4 were excluded for missing data, incomplete follow-up data or non-standard testing meal. GES was always performed using the standardized 4 hours protocol with the standard testing meal mixed with 99Tc-DTPA. For this study, all GES were reanalyzed and the following parameters were established : residual activity after 2 hours, residual activity after 4 hours, biological halftimes of ingested activity and proximal-to-distal count ratio for time 0 (PDCR0).

Results

Mean value of GCSI before G-POEM was 3.1 and decreased to 1.6, 1.0 and 0.7 after 3, 12 and 36 months. Median value of GES after 2 hours was 60.2% before G-POEM and 38%, 32.6% and 24.2% after 3, 12 and 36 months. Median value of GES after 4 hours was 21.9% before G-POEM and 7.8%, 6.5% and 3.9% after 3, 12 and 36 months. Correlation index was weakly positive for GCSI and GES after 4 hours only for the first follow-up visit and negative for all remaining visits.
The residual activity after 2 hours and residual activity after 4 hours decreased after G-POEM during all follow-up visits (p<0,001). Mean decrease of residual activity after 4 hours was 12.89%, 15.13% and 6.7% after 3, 12 and 36 months.
Biological halftime also decreased after the procedure with statistically significant results with the mean halftime before G-POEM being 150 min and 86 min, 78.4 min and 65.8 min after 3, 12 and 36 months.
There was a difference between the diabetic and non-diabetic groups, with higher residual activity after 2 hours [median 29.6% before G-POEM, 9.0% after 3 months (p<0.001) and 11.0% after 12 months (p=0.005)] and 4 hours [median 64.8% before G-POEM, 39.4% after 3 months (p<0.001) and 37.7% after 12 months (p=0.012)] respectively in patients with diabetes.
The predictive value of PDCR0 for treatment success after G-POEM was only calculated for the first follow-up visit but was not statistically proved (p=0,712).

Conclusion

In our group of patients there is a weak correlation between the decrease of GCSI and GES early after G-POEM. The decrease in GES parameters tends to be lower in patients with diabetes compared to non-diabetic patients. Based on our data, predicting clinical success of G-POEM using PDCR0 cannot be recommended.

Introduction

Delayed gastric emptying (GE) is a necessary condition for the diagnosis of gastroparesis (1). Motor alterations leading to delayed GE remain poorly identified and are not assessed in routine care. High-resolution antroduodenal manometry (HR-ADM) allows precise characterization of antral, pyloric, and duodenal motility (2). However, HR-ADM has not been assessed in delayed GE.

Aims & Methods

We aimed to identify motility alterations related to delayed GE. Consecutive patients referred for HR-ADM for dyspeptic symptoms performed a concurrent GE breath test with 13C-octanoic acid. HR-ADM involved 36 sensors 1 cm apart placed across the pylorus, with a commercially available probe. Interdigestive and postprandial periods were identified. Antral, pyloric, and duodenal motor profiles were analyzed recording the frequency, amplitude, and propagative nature of contractions. The contractile integral was also measured for each period. Plots of patients with normal and delayed GE, based on the result of the breath test, were compared.

Results

Sixty patients underwent both HR-ADM and GE tests. Twenty-five and 35 patients had delayed and normal GE, respectively. Antral and duodenal motor profiles were not different between the two groups during the interdigestive period, whether during phase II or phase III of the migrating motor complex. The basal pyloric pressure was not different between patients with or without delayed GE. During the postprandial period, a lower frequency of antral contractions was associated with delayed GE (2.22 vs 1.39 contractions/min; p=0.002), but no difference in the amplitude of antral contractions was observed. No difference in duodenal contractions was observed. Finally, the pyloric region was identified in all the patients, and pylorospasms, defined as 3 min of repeated isolated pyloric contractions, were more frequent in patients with delayed GE (32.0% vs 5.7%; p=0.02) during the postprandial period. Manometric alterations in the postprandial period were observed in 72% of the patients with delayed GE, with a low frequency of antral contractions, defined as less than 1 contraction/min, in 56% of the patients.

Conclusion

Using HR-ADM, patients with delayed GE displayed different postprandial antro-pyloric motility as compared with patients with normal GE. HR-ADM could, therefore, be useful in the future to better select patients for treatments targeting the pylorus.

References

1. Camilleri M, Sanders KM. Gastroparesis. Gastroenterology 162: 68-87.e1, 2022. doi: 10.1053/j.gastro.2021.10.028.
2. Desipio J, Friedenberg FK, Korimilli A, Richter JE, Parkman HP, Fisher RS. High-resolution solid-state manometry of the antropyloroduodenal region. Neurogastroenterol Motil 19: 188–195, 2007. doi: 10.1111/j.1365-2982.2006.00866.x.