Seracam: characterisation of a new small field of view hybrid gamma camera for nuclear medicine.

BACKGROUND: Portable gamma cameras are being developed for nuclear medicine procedures such as thyroid scintigraphy. This article introduces Seracam® - a new technology that combines small field of view gamma imaging with optical imaging - and reports its performance and suitability for small organ imaging. METHODS: The count rate capability, uniformity, spatial resolution, and sensitivity for 99mTc are reported for four integrated pinhole collimators of nominal sizes of 1 mm, 2 mm, 3 mm and 5 mm. Characterisation methodology is based on NEMA guidelines, with some adjustments necessitated by camera design. Two diagnostic scenarios - thyroid scintigraphy and gastric emptying - are simulated using clinically relevant activities and geometries to investigate application-specific performance. A qualitative assessment of the potential benefits and disadvantages of Seracam is also provided. RESULTS: Seracam's performance across the measured characteristics is appropriate for small field of view applications in nuclear medicine. At an imaging distance of 50 mm, corresponding to a field of view of 77.6 mm × 77.6 mm, spatial resolution ranged from 4.6 mm to 26 mm and sensitivity from 3.6 cps/MBq to 52.2 cps/MBq, depending on the collimator chosen. Results from the clinical simulations were particularly promising despite the challenging scenarios investigated. The optimal collimator choice was strongly application dependent, with gastric emptying relying on the higher sensitivity of the 5 mm pinhole whereas thyroid imaging benefitted from the enhanced spatial resolution of the 1 mm pinhole. Signal to noise ratio in images was improved by pixel binning. Seracam has lower measured sensitivity when compared to a traditional large field of view gamma camera, for the simulated applications this is balanced by advantages such as high spatial resolution, portability, ease of use and real time gamma-optical image fusion and display. CONCLUSION: The results show that Seracam has appropriate performance for small organ 99mTc imaging. The results also show that the performance of small field of view systems must be considered holistically and in clinically appropriate scenarios.

Evaluation of the Effect of Thickeners in Enteral Formulas on the Gastric Emptying Rate of Proteins and Carbohydrates Using a Semi-Dynamic Gastric Model.

The emptying rate of specific nutrients in enteral formulas is poorly understood, despite the importance of controlling the emptying rate in tube-fed patients. Because of their viscosity, thickened formulas are widely used to avoid gastric reflux and reduce the burden on caregivers. This study examined how thickeners in enteral formulas affected the gastric emptying rates of proteins and carbohydrates. A semi-dynamic gastric model was used to prepare and digest test enteral formulas that contained either no thickeners or agar (0.2%). The amounts of protein and carbohydrates in each emptied aliquot were determined, and the emptying rate was calculated. We found that agar accelerated protein emptying, and an exploratory experiment with agar (0.5%) suggested the possibility of concentration dependence. Additionally, experiments using gellan gum (0.08%), guar gum (0.2%), or carrageenan (0.08%, 0.2%) suggested that protein emptying could vary depending on the thickener type and that carrageenan might slow it. These results could help with the appropriate selection of thickeners added to liquid foods based on the patient's metabolic profile to manage nutrition, not only for tube-fed patients but also for those with oropharyngeal dysphagia or diabetes.

Normative Data of Liquid Gastric Emptying and Small-bowel Transit: A Prospective Cross-sectional Study.

Purpose of the Study: The primary objective was to establish the reference values for liquid gastric emptying and small bowel. The secondary objectives encompassed comparing the anterior view and geometric mean methods, assessing gender differences, and exploring potential correlations with age. Materials and Methods: Thirty-five consecutive healthy participants (28 females and 7 males) with a mean age of 42 ± 11 years (median, 42; range, 23-65) underwent liquid gastric emptying scintigraphy at five intervals (0, 0.5, 1, 2, and 4 h), with optional additional imaging at 24 h. Liquid gastric emptying was evaluated using percent retention and half-time (T1/2). Small-bowel transit was assessed using the index of small-bowel transit (ISBT), calculated as the ratio of terminal ileal reservoir counts to total abdominal counts at 4 h. Reference values were established based on percentiles or mean and standard deviation (SD). Rapid small-bowel transit was determined through visual inspection. Statistical analysis involved paired Samples t-test or Wilcoxon signed-rank test for comparing imaging methods, independent Samples t-test or Mann-Whitney U-test for gender comparison, and Spearman's rank correlation for assessing age-related associations. A 2-tailed P < 0.05 indicated significance. Results: Rapid liquid gastric emptying based on the geometric mean method was defined as percent retention <8% at 30 min, while delayed emptying as percent retention >33%, >20%, and >4% at 1, 2, and 4 h, respectively. The reference range of T1/2 of gastric emptying was 10-60 min. The reference value for small-bowel transit using the geometric mean method was established as ISBT >30% at 4 h, while rapid small-bowel transit was defined as the first visualization of activity in the cecum-ascending colon within 1 h. Parameters for liquid gastric emptying and small-bowel transit were notably higher in the anterior view method compared to the geometric mean method (P ≤ 0.019), except for percent retention at 2 h (P = 0.510). Nevertheless, the obtained reference values, whether based on percentiles or mean and SD, showed no notable variance between the two methods to warrant clinical significance. Gender did not display an impact on liquid gastric emptying or small-bowel transit in either method (P ≥ 0.173), and age demonstrated no significant moderate or strong correlations (Spearman's ρ ≤ 0.397). Conclusion: The study determined reference values for liquid gastric emptying and small-bowel transit through a standard gastric emptying scintigraphy protocol, avoiding additional complex procedures or extended imaging sessions. The established normative data can apply to individuals of both genders aged ≥18 years. While advocating the geometric mean method as the primary choice, the study acknowledges that in busy centers handling multiple studies with limited resources and a single-head gamma camera catering to multiple studies, the anterior view method remains a feasible alternative.

Effect of sex on chronic stress induced alterations in hindbrain catecholaminergic system and autonomic dysfunction resulting in gastrointestinal dysmotility.

It has been reported that the clinical symptoms of functional dyspepsia (FD) exacerbate upon stress while the gender-related factors have been incompletely understood. This study aims to investigate the role of sex in chronic heterotypic stress (CHS)-induced autonomic and gastric motor dysfunction. For CHS, the rats were exposed to the combination of different stressors for 7 consecutive days. Subsequently, electrocardiography was recorded in anesthetized rats to evaluate heart rate variability (HRV) for the determination of autonomic outflow and sympathovagal balance. Solid gastric emptying (GE) was measured in control and CHS-loaded male and female rats. The immunoreactivities of catecholaminergic cell marker tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), corticotropin releasing factor (CRF), and estrogen receptor (ER-α/ß) were evaluated in medullary and pontine brainstem sections by immunohistochemistry. Compared with the controls, CHS significantly delayed GE in males but not in females. There was no significant sex-related difference in parasympathetic indicator HF under either control or CHS conditions. Sympathetic indicator LF was significantly higher in control females compared to the males. The higher sympathetic output in females was found to be attenuated upon CHS; in contrast, the elevated sympathetic output was detected in CHS-loaded males. No sex- or stress-related effect was observed on ChAT immunoreactivity in the dorsal motor nucleus of N.vagus (DMV). In males, greater number of TH-ir cells was observed in the caudal locus coeruleus (LC), while they were more densely detected in the rostral LC of females. Regardless of sex, CHS elevated immunoreactivity of TH throughout the LC. Under basal conditions, greater number of TH-ir cells was detected in the rostral ventrolateral medulla (RVLM) of females. In contrast, CHS remarkably increased the number of TH-ir cells in the RVLM of males which was found to be decreased in females. There was no sex-related alteration in TH immunoreactivity in the nucleus tractus solitarius (NTS) of control rats, while CHS affected both sexes in a similar manner. Compared with females, CRF immunoreactivity was prominently observed in control males, while both of which were stimulated by CHS. ER-α/ß was found to be co-expressed with TH in the NTS and LC which exhibit no alteration related to either sex or stress status. These results indicate a sexual dimorphism in the catecholaminergic and the CRF system in brainstem which might be involved in the CHS-induced autonomic and visceral dysfunction occurred in males.

Effect of Fasting Prior to Extubation on Prevalence of Empty Stomach in Enterally Fed and Mechanically Ventilated Patients.

BACKGROUND: Practice on fasting prior to extubation in critically ill patients is variable. Efficacy of fasting in reducing gastric volume has not been well established. The primary objective of this study was to assess the effect of 4 h of fasting on prevalence of empty stomach using gastric ultrasonography in critically ill subjects who are fasted for extubation. The secondary objectives were to evaluate the change in gastric volumes during 4 h of fasting and to determine factors associated with empty stomach after fasting. METHODS: This was a single-center, prospective, observational study on adult ICU subjects who were enterally fed for at least 6 h continuously and mechanically ventilated. Gastric ultrasound was performed immediately prior to commencement of fasting, after 4 h of fasting, and after nasogastric (NG) aspiration after 4 h of fasting. An empty stomach was defined as a gastric volume ≤ 1.5 mL/kg. RESULTS: Forty subjects were recruited, and 38 (95%) had images suitable for analysis. The prevalence of empty stomach increased after 4 h of fasting (25 [65.8%] vs 31 [81.6%], P = .041) and after 4 h of fasting with NG aspiration (25 [65.8%] vs 34 [89.5%], P = .008). There was a significant difference in median (interquartile range) gastric volume per body weight between before fasting and 4 h after fasting (1.0 [0.5-1.8] mL/kg vs 0.4 [0.2-1.0] mL/kg, P < .001). No patient factors were associated with higher prevalence of empty stomach after 4 h of fasting. CONCLUSIONS: Most mechanically ventilated subjects had empty stomachs prior to fasting for extubation. Fasting for 4 h further increased the prevalence of empty stomach at extubation to > 80%.

Food passage following proximal gastrectomy with double-tract reconstruction and its effect on nutritional status in early gastric cancer: a prospective single-center cohort study.

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) expectedly results in improved nutritional status and less body weight loss than conventional total gastrectomy in upper-third gastric cancer. This study aimed to investigate the food passage patterns following LPG-DTR and its effect on nutritional outcomes up to 1 year after surgery. Methods: This prospective cohort study recruited 10 patients with early gastric cancer scheduled for LPG-DTR. Nutritional indices and body composition were assessed every 3 months up to 12 months. Liquid and solid food transits were evaluated with fluoroscopic upper gastrointestinal study and radionuclide scintigraphy, respectively. Results: At 12 months, patients exhibited a body weight loss of 14.5% ± 3.6%. The main passage routes for liquid and solid foods differed, primarily via the interposed jejunum for liquids, whereas via both tracts for solids. The median half-life of solid food emptying from the remnant distal stomach was 105.1 minutes (range, 50.8-2,194.2 minutes), and duodenal passage of solid food was noted in 9 of 10 patients. Those with gastric half-emptying time >3 hours demonstrated greater weight loss (19.5% ± 1.4% vs. 12.5% ± 1.1%, P = 0.024) and more pronounced reduction in serum albumin levels (-0.5 ± 0.3 g/dL vs. 0.0 ± 0.2 g/dL, P = 0.024) after 12 months. Conclusion: LPG-DTR demonstrated varying food passage patterns depending on the food contents and delayed solid food emptying from the remnant stomach was associated with more substantial weight loss.

Gastric Emptying Scintigraphy Protocol Optimization Using Machine Learning for the Detection of Delayed Gastric Emptying.

PURPOSE: The purpose of this study is to examine the feasibility of a machine learning (ML) system for optimizing a gastric emptying scintigraphy (GES) protocol for the detection of delayed gastric emptying (GE), which is considered a primary indication for the diagnosis of gastroparesis. METHODS: An ML model was developed using the JADBio AutoML artificial intelligence (AI) platform. This model employs the percent GE at various imaging time points following the ingestion of a standardized radiolabeled meal to predict normal versus delayed GE at the conclusion of the 4 h GES study. The model was trained and tested on a cohort of 1002 patients who underwent GES using a 70/30 stratified split ratio for training vs. testing. The ML software automated the generation of optimal predictive models by employing a combination of data preprocessing, appropriate feature selection, and predictive modeling analysis algorithms. RESULTS: The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was employed to evaluate the predictive modeling performance. Several models were developed using different combinations of imaging time points as input features and methodologies to achieve optimal output. By using GE values at time points 0.5 h, 1 h, 1.5 h, 2 h, and 2.5 h as input predictors of the 4 h outcome, the analysis produced an AUC of 90.7% and a balanced accuracy (BA) of 80.0% on the test set. This performance was comparable to the training set results (AUC = 91.5%, BA = 84.7%) within the 95% confidence interval (CI), demonstrating a robust predictive capability. Through feature selection, it was discovered that the 2.5 h GE value alone was statistically significant enough to predict the 4 h outcome independently, with a slightly increased test set performance (AUC = 92.4%, BA = 83.3%), thus emphasizing its dominance as the primary predictor for delayed GE. ROC analysis was also performed for single time imaging points at 1 h and 2 h to assess their independent predictiveness of the 4 h outcome. Furthermore, the ML model was tested for its ability to predict "flipping" cases with normal GE at 1 h and 2 h that became abnormal with delayed GE at 4 h. CONCLUSIONS: An AI/ML model was designed and trained for predicting delayed GE using a limited number of imaging time points in a 4 h GES clinical protocol. This study demonstrates the feasibility of employing ML for GES optimization in the detection of delayed GE and potentially shortening the protocol's time length without compromising diagnostic power.

The goals for successful development of treatment in gastroparesis.

BACKGROUND: Gastroparesis is a motility disorder of the stomach characterized by cardinal symptoms and delayed gastric emptying of solid food in the absence of mechanical obstruction. There is significant unmet need in its management, and essentially there are no medications approved for its treatment over four decades. PURPOSE: The objectives of this review are to develop an understanding of the goals of treatment, the evidence-based criteria for treatment success based on the current scientific understanding of gastroparesis as well as patient response outcomes, and to propose evidence-based principles for the successful development of treatments for gastroparesis. Specifically, we discuss the pathophysiologic targets in gastroparesis, eligibility criteria for clinical trial participation based on validated gastric emptying studies, and the patient response outcome measures that have been validated to appraise effects of treatment on clinically relevant outcomes. These considerations lead to recommendations regarding eligibility, design, and duration of proof-of-efficacy studies, and to endorsing the American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index Daily Diary as a validated patient response outcome and to justification of the shortening of proof-of-efficacy, placebo-controlled clinical trials to 4 weeks treatment duration after a baseline period. We believe that such approaches will increase the likelihood of successful assessment of efficacy of novel approaches to treating patients with gastroparesis.

Modified One Anastomosis Gastric Bypass Following Sleeve Gastrectomy for Severe Reflux and Delayed Gastric Emptying: A Prospective Trial with Clinical and Physiological Outcome Measures.

BACKGROUND: Gastro-esophageal reflux (GORD) following sleeve gastrectomy (SG) is a central challenge, and precise indications for revisional surgery or the physiology have not been precisely defined. We aimed to determine whether OAGB performed for reflux post-SG (1) accelerates gastric emptying half-time, (2) reduces the frequency and severity of reflux events, and (3) improves reflux symptoms. METHODS: We undertook a prospective trial (ACTRN12616001089426). There were 22 participants who underwent measurement before and after revisional surgery with 29 optimal SG (patients with optimal outcome from their primary surgery) as controls. All participants underwent a protocolized nuclear scintigraphy, 24-h pH monitoring, and gastroscopy and completed objective questionnaires. RESULTS: Trial patients were 90.9% female, age 44.4 years. Conversion from SG to OAGB was at a median of 45.2 ± 19.6 months. Scintigraphy showed an increased rate of gastric emptying post-OAGB 34 (IQR 14) vs 24 (IQR 10.3) min, p-value 0.008, with decreased number of reflux events post-prandially (39 (IQR 13) vs 26 (IQR 7), p-value 0.001). This data correlated with the pH analysis; total acid events substantially reduced post-OAGB 58.5 (IQR 88) vs 12 (IQR 9.4) events, p-value 0.017. Endoscopic findings indicated a reduction in incidence of bile stasis 72.7% vs 40.9% post-OAGB, p-value < 0.00010. Post-OAGB, patients experienced less frequent regurgitation (12 ± 4.1 vs. 5.5 ± 3, p-value 0.012) and reflux (37.1 ± 15.7 vs. 16.8 ± 12.6, p-value 0.003). CONCLUSIONS: We found OAGB is an effective treatment for reflux associated with delayed gastric emptying post-SG. The likely mechanisms is by, an increase in the rate of gastric clearance and reduced reflux events and overall esophageal acid exposure. This suggests that some forms of post-SG reflux are driven by slower emptying of the residual stomach and are amenable to treatment with drainage above the incisura.

The influence of delayed gastric emptying on quality of life after partial duodenopancreatectomy.

PURPOSE: Quality of life (QoL) is temporarily compromised after pancreatic surgery, but no evidence for a negative impact of postoperative complications on QoL has been provided thus far. Delayed gastric emptying (DGE) is one of the most common complications after pancreatic surgery and is associated with a high level of distress. Therefore, the aim of this study was to analyse the influence of DGE on QoL. METHODS: This single-centre retrospective study analysed QoL after partial duodenopancreatectomy (PD) via the European Organization for Research and Treatment of Cancer core questionnaire (QLQ-C30). The QoL of patients with and without postoperative DGE was compared. RESULTS: Between 2010 and 2022, 251 patients were included, 85 of whom developed DGE (34%). Within the first postoperative year, compared to patients without DGE, those with DGE had a significantly reduced QoL, by 9.0 points (95% CI: -13.0 to -5.1, p < 0.001). Specifically, physical and psychosocial functioning (p = 0.020) decreased significantly, and patients with DGE suffered significantly more from fatigue (p = 0.010) and appetite loss (p = 0.017) than patients without DGE. After the first postoperative year, there were no significant differences in QoL or symptom scores between patients with DGE and those without DGE. CONCLUSION: Patients who developed DGE reported a significantly reduced QoL and reduced physical and psychosocial functioning within the first year after partial pancreatoduodenectomy compared to patients without DGE.

Heat Treatment and Homogenization Influence the Gastric Digestion of Bovine Milk Protein in Growing Pigs as an Adult Human Model.

BACKGROUND: Bovine milk processing influences the structure of the curd formed during gastric digestion, which may alter gastric protein hydrolysis and impact amino acid (AA) release into the small intestine. OBJECTIVES: This study aimed to determine the influence of heat treatment and homogenization on the gastric protein digestion and AA emptying of bovine milk. METHODS: Nine-wk-old pigs (n = 144) consumed either raw, pasteurized nonhomogenized (PNH), pasteurized homogenized (PH), or ultra-high-temperature homogenized (UHT) bovine milk for 10 d. On day 11, fasted pigs received the milk treatment (500 mL) before gastric contents were collected at 0, 20, 60, 120, 180, and 300 min postprandially. The apparent degree of gastric protein hydrolysis (based on the release of free amino groups), apparent gastric disappearance of individual proteins [based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel band intensity], and the gastric emptying of digested protein and AA were determined. RESULTS: During the first 60 min, the rate of apparent gastric protein hydrolysis was fastest in pigs fed UHT milk (0.29%/min compared with on average 0.07%/min in pigs fed raw, PNH, and PH milk). Differences in the apparent degree of gastric protein hydrolysis and emptying were reflected in the rate of digested protein entering the small intestine. The AA gastric emptying half-time was generally shorter in pigs fed PH and UHT milk than in pigs fed raw and PNH milk. For example, the gastric release of total essential AA was >2-fold faster (P < 0.01) in pigs fed PH or UHT milk than that in pigs fed raw or PNH milk (i.e., homogenized compared with nonhomogenized milk). CONCLUSIONS: Heat treatment and homogenization increased the apparent gastric degree of protein hydrolysis and the release of digested protein into the small intestine. However, the rate of AA entering the small intestine was mainly increased by homogenization.

Consensus practice recommendations for management of gastrointestinal dysfunction in Parkinson disease.

BACKGROUND: Gastrointestinal (GI) dysfunction is a common non-motor feature of Parkinson disease (PD). GI symptoms may start years before the onset of motor symptoms and impair quality of life. Robust clinical trial data is lacking to guide screening, diagnosis and treatment of GI dysfunction in PD. OBJECTIVE: To develop consensus statements on screening, diagnosis, and treatment of GI dysfunction in PD. METHODS: The application of a modified Delphi panel allowed for the synthesis of expert opinions into clinical statements. Consensus was predefined as a level of agreement of 100 % for each item. Five virtual Delphi rounds were held. Two movement disorders neurologists reviewed the literature on GI dysfunction in PD and developed draft statements based on the literature review. Draft statements were distributed among the panel that included five movement disorder neurologists and two gastroenterologists, both experts in GI dysmotility and its impact on PD symptoms. All members reviewed the statements and references in advance of the virtual meetings. In the virtual meetings, each statement was discussed, edited, and a vote was conducted. If there was not 100 % consensus, further discussions and modifications ensued until there was consensus. RESULTS: Statements were developed for screening, diagnosis, and treatment of common GI symptoms in PD and were organized by anatomic segments: oral cavity and esophagus, stomach, small intestine, and colon and anorectum. CONCLUSIONS: These consensus recommendations offer a practical framework for the diagnosis and treatment of GI dysfunction in PD.

An observational study of gastric contents in pediatric patients with long bone fracture using gastric ultrasound.

BACKGROUND: The retention of gastric contents at surgery presentation is a risk factor for perioperative aspiration. A preoperative fasting (nil per os; NPO) interval is widely used to reduce this risk, but this approach is based on assumptions about the prevalence of typical gastric emptying rates. We assessed NPO guidelines' reliability with ultrasound (US) imaging and suction in pediatric patients presenting for single long-bone fracture repair after appropriate NPO intervals, when nearly all should have had empty stomachs. AIMS AND METHODS: This prospective cross-sectional observational study comprised 200 pediatric surgical patients. As their NPO times varied by food/drink type, we defined "weighted NPO units" as the lowest multiple of elapsed recommended NPO times between consumption and surgery for each type of food or drink. We used US to image the stomach and its contents before anesthesia induction, followed by gastric suction. We evaluated the relationships between weighted NPO units, US gastric contents grade, opioid analgesic dosage and timing, and suctioned volume. RESULTS: Despite meeting typical NPO standards (median 14 h fasting), many patients retained nontrivial quantities of gastric contents at surgery. Weighted NPO units did not exhibit statistically-significant relationships with either suctioned volume or US grade. However, suctioned volume did correspond well to US grade. CONCLUSION: NPO status may be a less reliable predictor of gastric contents at anesthesia induction in this patient population than has been assumed. Bedside US screening appears to provide more useful information for the planning of airway management.

Postoperative delayed emptying after total, subtotal, or distal gastrectomy for gastric cancer: a population-based study.

BACKGROUND: This study aimed to examine the rate of delayed emptying and other 90-day postoperative complications after total, subtotal, and distal gastrectomies for gastric adenocarcinoma in a population-based setting. METHODS: This study included all patients who underwent total, subtotal, or distal gastrectomy for gastric cancer in Finland in 2005-2016, with follow-up until December 31, 2019. Logistic regression provided the odds ratios with 95% CIs of 90-day mortality. The results were adjusted for age, sex, year of surgery, comorbidities, pathologic stage, and neoadjuvant therapy. RESULTS: A total of 2058 patients underwent total (n = 1227), subtotal (n = 450), or distal (n = 381) gastrectomy. In the total, subtotal, and distal gastrectomy groups, the rates of 90-day delayed emptying were 1.7%, 1.3%, and 2.1% in the whole cohort and 1.6%, 1.8%, and 3.5% in the subgroup analysis of R0 resections, respectively. The resection type was not associated with the risk of delayed emptying. Subtotal gastrectomy was associated with a lower risk of major complications and reoperations, whereas distal gastrectomy was associated with a lower risk of anastomotic complications. CONCLUSION: The extent of resection did not affect delayed emptying, whereas fewer postoperative complications were observed after subtotal or distal gastrectomy than after total gastrectomy.

Safe Continuation of Glucagon-like Peptide 1 Receptor Agonists at Endoscopy: A Case Series of 57 Adults Undergoing Endoscopic Sleeve Gastroplasty.

PURPOSE: Glucagon-like receptor agonists (GLP1-RAs) have raised peri-procedural concerns due to their potential to delay gastric emptying. The American Association of Anesthesiologists has advised pausing a single dose before elective endoscopy. However, a subsequent directive from multiple gastroenterology societies underscored the need for further assessment to substantiate this practice. We aimed to evaluate the frequency of serious adverse events and retained gastric products during endoscopic sleeve gastroplasty (ESG) with uninterrupted GLP1-RA use. MATERIALS AND METHODS: We conducted a retrospective evaluation of all patients undergoing ESG while on GLP1-RAs at three centers from August 2022 to February 2024. Per standard protocol, all patients had refrained from solid foods for at least 24 h and maintained nil per os for 12 h preceding their ESG. Records were reviewed for patient characteristics and medication type and doses. Primary outcomes included serious adverse events and retained gastric products based on patient records, procedure reports, and procedural videos. RESULTS: Fifty-seven consecutive adults (89.5% women, mean age of 44 ± 9 years, mean BMI of 40.1 ± 8.1 kg/m2, 35.1% with T2DM, and 26.3% with pre-T2DM) underwent ESG without stopping GLP1-RAs, which included semaglutide (45.6%), liraglutide (19.3%), dulaglutide (22.8%), and tirzepatide (12.3%). During intubation, endoscopy, and recovery, there were no instances of retained gastric solids, pulmonary aspiration, gastroesophageal regurgitation, or hypoxia. CONCLUSION: A ≥ 24-h pre-endoscopy liquid-only diet with ≥ 12-h pre-endoscopy fast may negate the need for GLP1-RA interruption for routine upper endoscopy in adults with native gastric anatomy.

Gastric emptying in newly diagnosed, treatment-naïve Han Chinese with type 2 diabetes and the impact of 4-week insulin pump therapy.

AIM: To evaluate gastric emptying (GE) and the glycaemic response to a 75-g oral glucose load in newly diagnosed, treatment-naïve Han Chinese with type 2 diabetes (T2D) before insulin pump therapy, after 4 weeks of insulin pump therapy, and 12-15 months after insulin pump therapy. MATERIALS AND METHODS: Twenty participants with T2D (baseline glycated haemoglobin [± SD] 10.7% [± 1.2%] 93 [± 10] mmol/mol) ingested a 75-g glucose drink containing 150 mg 13C-acetate, to determine the gastric half-emptying time, and underwent assessment of plasma glucose and serum insulin, C-peptide and glucagon-like peptide-1 (GLP-1) over 180 min before and after 4 weeks of insulin pump therapy (discontinued for 48 h before re-assessment). Data were compared to those in 19 healthy participants matched for sex and age. After 12-15 months, GE was re-measured in 14 of the T2D participants. RESULTS: At baseline, participants with T2D exhibited substantially augmented fasting and post-glucose glycaemia, diminished insulin secretion, and more rapid GE (p < 0.05 each), but comparable GLP-1, compared to healthy participants. Following insulin pump therapy, insulin secretion increased, GLP-1 secretion was attenuated, fasting and post-glucose glycaemia were lower, and GE was slowed (p < 0.05 each). The slowing of GE in T2D participants was sustained over 12-15 months of follow-up. CONCLUSIONS: In newly diagnosed Han Chinese with T2D, GE is often accelerated despite poor glycaemic control and is slowed by short-term insulin pump therapy. The effect on GE is maintained for at least 12 months.

Gastric emptying is slower in women than men with type 2 diabetes and impacts on postprandial glycaemia.

AIM: To evaluate sex differences in gastric emptying and the glycaemic response to a glucose drink and a high carbohydrate meal in type 2 diabetes (T2D). METHODS: In cohort 1, 70 newly diagnosed, treatment-naïve Chinese patients with T2D (44 men) recruited from a diabetes outpatient clinic ingested a 75-g glucose drink containing 150 mg 13C-acetate. In cohort 2, 101 Australian patients with T2D (67 male) recruited from the community, managed by diet and/or metformin monotherapy, ingested a semi-solid mashed potato meal, labelled with 100 µl 13C-octanoic acid. Breath samples were collected over 3 and 4 h, respectively, for assessment of gastric emptying, and venous blood was sampled for evaluation of glycaemia (with and without adjustment for each participant's estimated total blood volume). RESULTS: Gastric emptying was slower in female than male subjects in both cohorts (both p < .01). Multiple linear regression analyses revealed that gastric emptying was independently associated with sex (both p < .05). Without adjustment for blood volume, the glycaemic responses to oral glucose and the mixed meal were greater in female subjects (both p < .001). However, after adjustment for blood volume, the glycaemic responses were greater in men (both p < .05). CONCLUSIONS: Gastric emptying is slower in women than men with T2D, associated with a reduced blood volume-adjusted glycaemic response to oral glucose and a mixed meal in women. These observations highlight the sex difference in postprandial glucose handling, which is relevant to the personalized management of postprandial glycaemia in T2D.

Risks of peri- and postoperative complications with glucagon-like peptide-1 receptor agonists.

AIM: To assess whether adults with diabetes on oral hypoglycaemic agents undergoing general endotracheal anaesthesia during nine common surgical procedures who are glucagon-like peptide-1 receptor agonist (GLP1-RA) users, compared with non-users, are at increased risk of six peri- and post-procedure complications. MATERIALS AND METHODS: A retrospective observational cohort analysis of over 130 million deidentified US adults with diabetes (defined as being on oral hypoglycaemic agents) from a nationally representative electronic health dataset between 1 January 2015 and 1 April 2023 was analysed. Cohorts were matched by high-dimensionality propensity scoring. We compared the odds of six peri- and postoperative complications in GLP1-RA users and non-users. A sensitivity analysis compared these odds in GLP1-RA users to non-users with diabetes and obesity. We measured the odds of (a) a composite outcome of postoperative decelerated gastric emptying, including antiemetic use, ileus within 7 days post-procedure, gastroparesis diagnosis, gastric emptying study; (b) postoperative aspiration or pneumonitis; (c) severe respiratory failure; (d) postoperative hypoglycaemia; (e) inpatient mortality; and (f) 30-day mortality. RESULTS: Among 13 361 adults with diabetes, 16.5% were treated with a GLP1-RA. In the high-dimensionality propensity score-matched cohort, GLP1-RA users had a lower risk of peri- and postoperative complications for decelerated gastric emptying and antiemetic use compared with non-users. The risk of ileus within 7 days, aspiration/pneumonitis, hypoglycaemia and 30-day mortality were not different. A sensitivity analysis showed similar findings in patients with diabetes and obesity. CONCLUSION: No increased risk of peri- and postoperative complications in GLP1-RA users undergoing surgery with general endotracheal anaesthesia was identified.

Drug dissolution and transit in a heterogenous gastric chyme after fed administration: Semi-mechanistic modeling and simulations for an immediate-release and orodispersible tablets containing a poorly soluble drug.

Mathematical models that treat the fed stomach content as a uniform entity emptied with a constant rate may not suffice to explain pharmacokinetic profiles recorded in clinical trials. In reality, phenomena such as the Magenstrasse or chyme areas of different pH and viscosity, play an important role in the intragastric drug dissolution and its transfer to the intestine. In this study, we investigated the data gathered in the bioequivalence trial between an immediate-release tablet (Reference) and an orally dispersible tablet (Test) with a poorly soluble weak base drug administered with or without water after a high-fat high-calorie breakfast. Maximum concentrations (Cmax) were significantly greater after administering the Reference product than the Test tablets, despite similar in vitro dissolution profiles. To explain this difference, we constructed a novel semi-mechanistic IVIVP model including a heterogeneous gastric chyme. The drug dissolution in vivo was modeled from the in vitro experiments in biorelevant media simulating gastric and intestinal fluids in the fed state (FEDGAS and FeSSIF). The key novelty of the model was separating the stomach contents into two compartments: isolated chyme (the viscous food content) that carries the drug slowly, and aq_chyme open for rapid Magenstrasse-like routes of drug transit. Drug distribution between these two compartments was both formulation- and administration-dependent, and recognized the respective drug fractions from the clinical pharmacokinetic data. The model's assumption about the nonuniform mixing of the API with the chyme, influencing differential drug dissolution and transit kinetics, led to simulating plasma concentration profiles that reflected well the variability observed in the clinical trial. The model indicated that, after administration, the Reference product mixes to a greater extent with aq_chyme, where the released drug dissolves better and transfers faster to the intestine. In conclusion, this novel approach underlines that diverse gastric emptying of different oral dosage forms may significantly impact pharmacokinetics and affect the outcomes of bioequivalence trials.

Glucagon-like peptide-1 receptor agonists: a narrative review of clinical pharmacology and implications for peri-operative practice.

BACKGROUND: Glucagon-like peptide-1 receptor agonists are used increasingly in the management of patients living with type 2 diabetes mellitus and obesity. In patients using glucagon-like peptide-1 receptor agonists, a key concern in the peri-operative period is the increased risk of pulmonary aspiration due to delayed gastric emptying. This review provides an overview of the pharmacodynamic and pharmacokinetic properties of glucagon-like peptide-1 receptor agonists and the risk of delayed gastric emptying and aspiration. METHODS: We conducted searches of MEDLINE and EMBASE databases of articles published before January 2024 using the keywords and medical subject headings: incretins; glucagon-like peptide-1; GLP-1; glucagon-like peptide-1 receptor agonists; GLP-1 RA; peri-operative period; perioperative; peri-operative; stomach emptying; gastric emptying; pulmonary aspiration; aspiration; food regurgitation; and regurgitation. The evidence was analysed, synthesised and reported narratively. RESULTS: A total of 1213 articles were located after duplicates were removed. Two authors screened the titles and abstracts to identify those studies which assessed specifically the risk of delayed gastric emptying and pulmonary aspiration or regurgitation in the peri-operative period. We searched manually the reference lists of relevant studies to identify any additional case reports. Ten studies were identified. Available evidence was limited to case reports, case series and observational work. CONCLUSIONS: There is insufficient evidence to put forward definitive guidance regarding the ideal cessation period for glucagon-like peptide-1 receptor agonists before elective surgery. Precautionary practice is required until more evidence becomes available. We suggest an individualised, evidence-based approach. In patients living with type 2 diabetes mellitus, there is concern that prolonged cessation before surgery will have a detrimental effect on peri-operative glycaemic control and discussion with an endocrinologist is advised. For patients taking glucagon-like peptide-1 receptor agonists for weight management, these drugs should be withheld for at least three half-lives before an elective surgical procedure.