Intragastric Pressure Research Articles

Elevation and adhesion properties of injectable hydrogels based on catechol/boronic acid-modified Alaska pollock gelatin for endoscopic submucosal dissection

Elevation of early-stage gastrointestinal cancer using submucosal injection materials (SIMs) and postoperative wound care with adhesive materials are crucial for preventing complications arising from endoscopic submucosal dissection (ESD). Several types of SIMs have been developed; however, they often provide insufficient tissue elevation and fail to adequately adhere to the defect following the removal of early-stage gastrointestinal cancer. In this study, we present the development of injectable Cat-PBA-ApGltn hydrogels, which are based on catechol group-modified Alaska pollock gelatin (Cat-ApGltn) and phenylboronic acid-modified Alaska pollock gelatin (PBA-ApGltn), serving as multifunctional SIMs. A Cat-ApGltn/PBA-ApGltn mixed solution formed a hydrogel within 3 seconds. The resulting Cat-PBA-ApGltn hydrogels were easily injected manually through a 23 G needle due to their shear-thinning properties. Additionally, 10 w/v% Cat-PBA-ApGltn hydrogels demonstrated a 2.3-fold increase in mucosal elevation (7.2 ± 0.4 mm) compared with a commercially available SIM (3.1 ± 0.7 mm). The 10 w/v% Cat-PBA-ApGltn hydrogel, when adhered to porcine gastric submucosa, exhibited a burst strength 7 times greater than the average human intragastric pressure. Furthermore, the Cat-PBA-ApGltn hydrogels demonstrated biodegradability without inducing severe inflammation upon implantation in rat subcutaneous tissue. These Cat-PBA-ApGltn hydrogels hold promise as multifunctional SIMs, boasting injectability, excellent elevation, adhesion capabilities, and biodegradability.

Development of novel rectal/uterine clamping device

We developed a novel clamping device for laparoscopic surgery, free from conventional pinch structure, capable of uniformly occluding any ductal organ. This study aimed to evaluate performance of the new clamper compared to the pinch-type clamper. The new clamper consists of two metal bars with ties at each end, which enables parallel clamping. A resected porcine stomach was used, with an infusion tube at the anal end to increase intra-luminal pressure. The oral side of the stomach was clamped with either the new clamper or the pinch-type clamper, and their performances were evaluated in qualitative and semi-quantitative manner. Qualitative evaluation involved imaging the clamping site at intra-gastric pressures from 0 to 15 mmHg using microfocus computed tomography. The new clamper showed no gap even under increased intra-luminal pressure, while the pinch-type clamper showed a gap on the distal side. Quantitative evaluation measured bursting pressure under continuous air insufflation. Air leakages were observed in the new clamper at higher intra-luminal pressures than in the pinch-type clamper (46.1 mmHg vs. 13.6 mmHg, P < 0.01). Our new clamping device showed superior performance in preclinical setting compared to the conventional pinch-type clamper. We are currently working on its design freezing and aiming for early commercialization.

Normative high resolution esophageal manometry values in asymptomatic patients with obesity.

Surgical bariatric interventions, while highly effective, can be associated with post-operative esophageal symptoms, gastroesophageal reflux disease and esophageal dysmotility. Whether pre-operative physiology impacts this risk is unknown, in part because expected values on esophageal manometry in patients with obesity are not well understood. This study seeks to establish normative values on esophageal high resolution manometry (HRM) and the prevalence of esophageal dysmotility in the asymptomatic patient with obesity. This retrospective study included adult patients with body mass index (BMI) ≥35 kg m-2 without esophageal symptoms undergoing preoperative bariatric surgical evaluation, including HRM, at a single tertiary care center between February, 2019 and February, 2020. Of 104 asymptomatic patients with obesity, HRM identified normal esophageal motility in 94 (90.4%) with the remaining 10 having ineffective esophageal motility (3.8%), manometric esophagogastric junction outflow obstruction (3.8%), distal esophageal spasm (1.0%), and hypercontractile esophagus (1.0%). Mean of median lower esophageal sphincter integrated relaxation pressure (LES IRP) was 10.6 mmHg supine (95th percentile 21.5 mmHg) and 8.5 mmHg upright (95th percentile 21.3 mmHg). 86% of patients had intragastric pressure above 8 mmHg. Mean of mean distal contractile integral (DCI) was 2261.6 mmHg cm s-1 (95th percentile 5889.5 mmHg cm s-1). The vast majority of asymptomatic patients with obesity had normal manometry. LES IRP and DCI were higher than that observed in non-obese cohorts. Additionally, BMI correlated to increased intragastric pressure. These data suggest that normative values in patients with obesity should be adjusted to prevent overdiagnosis of EGJOO or hypercontractile esophagus.

Current state of rumination syndrome.

Rumination syndrome (RS) is an underdiagnosed behavioral disorder of recurrent regurgitation. Regurgitation occurs in RS due to increased gastric pressure achieved by subconscious contraction of the abdominal musculature wall, reversing the pressure gradient between the esophagus and the stomach. RS is mainly diagnosed clinically by the Rome Criteria with symptoms of regurgitation without retching of recently ingested food into the mouth and subsequent spitting or re-mastication. When the diagnosis is unable to be made clinically, supportive testing including fed impedance manometry can be considered. RS occurs worldwide, affecting patients of all ages, races, and genders with a prevalence of 3.1-5.8%. There is significant overlap with RS and disorders of a gut-brain interaction and upright gastroesophageal reflux driven by aerophagia and supragastric belching. There is also an association with mood disorder, fibromyalgia, and eating disorders. RS may be misdiagnosed as a variety of other syndromes including gastroesophageal reflux disease, gastroparesis, achalasia, and bulimia nervosa. Once RS is diagnosed, the mainstay of treatment is diaphragmatic breathing to lower the intragastric pressure and increase the lower esophageal pressure. Diaphragmatic breathing can be supported with biofeedback and cognitive behavioral therapy as well as medication options for more refractory cases. Response to therapy overtime and changes in symptoms overtime can now be tracked with a validated questionnaire.

Incorporating body mass index into esophageal manometry metrics and mean nocturnal baseline impedance for the evaluation of gastro-esophageal reflux disease

This study aims to enhance the effectiveness of high resolution manometry (HRM) and pH-impedance monitoring metrics in distinguishing between gastro-esophageal reflux disease (GERD) and non-GERD. A retrospective propensity score matching (PSM) study was conducted on 643 patients with GERD symptoms. PSM matched 134 GERD patients with 134 non-GERD controls. Body mass index (BMI), intra-esophageal pressure (IEP) and intra-gastric pressure (IGP) were significantly higher in the GERD group compared to the non-GERD group. BMI was correlated with IEP and IGP positively. IGP was positively correlated with esophagogastric (EGJ) pressure (EGJ-P) in participants with EGJ type 1 and 2, but not in participants with EGJ type 3. BMI was correlated with distal MNBI negatively. Logistic regression showed BMI as an independent risk factor for GERD. Receiver operating characteristic curve (ROC) and decision curve analysis (DCA) showed that BMI adjusted EGJ contractile integral (EGJ-CI) and BMI adjusted MNBI were superior to the corresponding original ones in predicting GERD susceptibility. According to the findings, BMI and IGP are the main factors contributing to the development of GERD. BMI affects IEP through the adaptive response of EGJ-P to IGP. Incorporating BMI into the calculations of EGJ-CI and MNBI can improve their ability in predicting GERD susceptibility.

The combination of L-menthol and caraway oil does not affect gastric function but increases hunger in healthy subjects.

The heterogeneous character of functional gastrointestinal disorders, recently renamed into disorders of gut-brain interaction, makes finding effective treatment options challenging. Compared to synthetic drugs, phytotherapy can have broader pharmacological effects and is often better tolerated. This study aimed to investigate the effect of peppermint oil and caraway oil (POCO) on gastric function and symptom levels in 32 healthy subjects in a single-blinded, placebo-controlled, randomized, parallel design. Gastric emptying rate was assessed using a 13C-breath test. Intragastric pressure was measured using high-resolution manometry in fasted state and during intragastric infusion of a nutrient drink (350 mL or until full satiation). GI symptoms were rated on a 100 mm VAS. Data were analyzed using linear mixed models. POCO had no effect on intragastric pressure in fasted or fed state (p > 0.08 for all). No significant differences in gastric emptying rate were observed (p = 0.54). In the fasted state, a stronger increase in hunger and decrease in satiety were observed following POCO (p = 0.016 and p = 0.008, respectively). No differences in hunger and satiety were observed in the fed state (p > 0.31 for all). POCO induced less epigastric burning, bloating, and fullness (p < 0.05 for all). Acute POCO administration did not affect gastric function in healthy subjects, but increased fasted hunger ratings. The effects of POCO on gastric function and hunger sensations in patients with disorders of gut-brain interaction, and the contribution to symptom improvement, needs to be elucidated in future studies.

Impact of peroral endoscopic myotomy on the endoscopic pressure study integrated system.

The endoscopic pressure study integrated system (EPSIS) is an endoscopic diagnostic system utilized for evaluation of lower esophageal sphincter function. Although previous studies have determined that EPSIS was effective as a tool for the diagnosis of achalasia, it remains uncertain if EPSIS can detect significant changes before and after peroral endoscopic myotomy (POEM), which is the premier treatment for achalasia. This study aimed to evaluate the effectiveness of EPSIS as an objective diagnostic tool for assessing the clinical effect of POEM. We conducted a retrospective analysis of patients who underwent POEM from January 2022 to December 2023. The patients underwent EPSIS preoperatively and 2 months postoperatively. Intragastric pressure (IGP) parameters, including the maximum IGP, IGP difference, and waveform gradient were compared pre- and post-POEM. These parameters also were compared between two groups: the postoperative gastroesophageal reflux disease (GERD) group and the non-GERD group. A total of 50 patients were analyzed. The mean maximum IGP was significantly lower postoperatively than preoperatively (15.0 mmHg vs. 19.8 mmHg, P < 0.001). The mean IGP difference and waveform gradient were also significantly lower postoperatively than preoperatively (8.0 mmHg vs. 12.2 mmHg, P < 0.001; and 0.26 mmHg/s vs. 0.43 mmHg/s, P < 0.001, respectively). The mean postoperative waveform gradient was significantly lower in the GERD group (17 patients, 34%) than in the non-GERD group (33 patients, 66%) (0.207 mmHg vs. 0.291 mmHg, P = 0.034). The results supported the use of EPSIS as an effective diagnostic tool for assessing the effect of POEM.

Surface mapping of gastric motor functions using MRI: a comparative study between humans and rats.

The stomach's ability to store, mix, propel, and empty its content requires highly coordinated motor functions. However, current diagnostic tools cannot simultaneously assess these motor processes. This study aimed to use magnetic resonance imaging (MRI) to map multifaceted gastric motor functions, including accommodation, tonic and peristaltic contractions, and emptying, through a single noninvasive experiment for both humans and rats. Ten humans and 10 Sprague-Dawley rats consumed MRI-visible semisolid meals and underwent MRI scans. We used a surface model to analyze MRI data, capturing the deformation of the stomach wall on ingestion or during digestion. We inferred muscle activity, mapped motor processes, parcellated the stomach into functional regions, and revealed cross-species distinctions. In humans, both the fundus and antrum distended postmeal, followed by sustained tonic contractions to regulate intragastric pressure. Peristaltic contractions initiated from the distal fundus, including three concurrent wavefronts oscillating at 3.3 cycles/min and traveling at 1.7 to 2.9 mm/s. These motor functions facilitated linear gastric emptying with a 61-min half-time. In contrast, rats exhibited peristalsis from the midcorpus, showing two wavefronts oscillating at 5.0 cycles/min and traveling at 0.4 to 0.9 mm/s. For both species, motility features allowed functional parcellation of the stomach along a midcorpus division. This study maps region- and species-specific gastric motor functions. We demonstrate the value of MRI with surface modeling in understanding gastric physiology and its potential to become a new standard for clinical and preclinical investigations of gastric disorders at both individual and group levels.NEW & NOTEWORTHY A novel MRI technique can visualize how the stomach accommodates, mixes, and propels food for digestion in humans and animals alike. Digital models of gastric MRI reveal the functional maps, organization, and distinction of the stomach across individuals and species. This technique holds the unique potential to advance basic and clinical studies of functional gastric disorders.

Endoscopic pressure study integrated system using an ultrathin gastroscope for the functional assessment of the lower esophageal sphincter.

The endoscopic pressure study integrated system (EPSIS) represents an innovative approach for evaluating lower esophageal sphincter function by monitoring intragastric pressure using diagnostic gastroscopes. This study aimed to assess the feasibility and validity of employing ultrathin gastroscopes for EPSIS. A retrospective analysis was conducted on a database of consecutive patients who underwent EPSIS using both ultrathin and regular gastroscopes between September 2021 and October 2023. The study compared EPSIS parameters between the two gastroscope types to evaluate the correlation of key metrics. Thirty patients underwent EPSIS with both ultrathin and regular gastroscopes. Significant positive correlations were observed in the pressure waveform: maximum intragastric pressure (mmHg) (ρ = 0.82, P < 0.001) and intragastric pressure gradient (mmHg/s) (ρ = 0.80, P < 0.001) when comparing the two gastroscopes. Maximum intragastric pressure (15.5 [5.3-20.3] vs. 18.5 [3.4-21.6], P < 0.001) and pressure gradient (0.16 [0.013-0.41] vs. 0.24 [0.0039-1.13], P < 0.001), (median [range]) were significantly lower with ultrathin gastroscopes. This study establishes that EPSIS parameters obtained with an ultrathin gastroscope exhibit a significant correlation with those obtained using a regular gastroscope, with each EPSIS parameter consistently lower. These findings support the viability of EPSIS for ultrathin gastroscopy and highlight its potential as a diagnostic tool for assessing lower esophageal sphincter function.

Gastric accommodation: pathogenetic role and clinical significance

The article presents a literature review of modern Russian and foreign publications devoted to the study of gastric accommodation. It has been shown that accommodation of the proximal stomach plays an important role in its adaptation to food intake. This process is carried out in two stages with the participation of parasympathetic and paracrine regulation; the effects of nutrients when they enter the duodenum also play an important role. Methods for assessing gastric accommodation include gastric barostat, gastric scintigraphy with food load, drinking tests, single-photon emission computed tomography, magnetic resonance imaging and ultrasound examination of the stomach, intragastric manometry. Violation of gastric accommodation leads to an excessive increase in intragastric pressure and the occurrence of symptoms most often found in functional dyspepsia, gastroesophageal reflux disease and diabetic gastropathy. Approaches to the treatment of gastric accommodation disorders are at the development stage, the possibilities of diet therapy, pharmacological and non-drug correction are being discussed.

A Highly Distensible, Cable Loop-Driven Soft Robotic Gastric Simulator for Endoscopy Training

With the increased demand for endoscopic diagnosis in the upper gastrointestinal (GI) tract, gastric simulators have been developed for endoscopy training. However, most of them remain nonideal due to their static and nondistensible nature. This paper presents a new soft robotic gastric simulator, comprising mainly of a silicone-based stomach model that mimics the size and inner surface condition of a human stomach. It also features peristaltic effect on its stomach wall via five cable loop-driven mechanisms, sphincter mechanisms at two ends of the stomach model, and structural pathology phantoms that can be magnetically controlled for multi-location deployment. Finite element simulation of the stomach behavior was performed under different insufflation pressures to determine the cable loop mechanism design parameters. During the simulator evaluation, the performances of the sphincters and cable loop mechanisms were first characterized. The simulator was then actuated to provide sequential contraction across the stomach model at different contraction ratios, leading to intragastric pressures similar to those reported in the literature. Finally, a preliminary user study was performed to face validate the simulator in terms of its realism, usability, and usefulness for endoscopy training. It is envisioned that the soft robotic gastric simulator could be adopted in endoscopy training programs to replace the use of animal models.

Intragastric pressure and peristalsis analysis of the sleeve gastric tube after laparoscopic sleeve gastrectomy

IntroductionLaparoscopic sleeve gastrectomy (LSG) is a procedure that is being increasingly recommended. However, LSG can worsen gastroesophageal reflux disease (GERD) and cause vomiting, and consequently impact the quality of life (QOL) of patients. Abnormal motility of the sleeve gastric tube has been linked to the onset of GERD and vomiting. Hence, this study investigated the peristalsis of the sleeve gastric tube after LSG and its relationship with gastroesophageal reflux. There are only a few reports on the peristalsis of the sleeve gastric tube after LSG. MethodsWe measured the motility function of the sleeve gastric tube using high-resolution manometry (HRM) within 2–4 weeks after LSG. The manometry catheter was positioned in the antrum using fluoroscopy. ResultsThis analysis included 18 patients. Postoperative HRM measurement of the sleeve gastric tube was characterized by the absence of gastric body peristalsis in at least 90% of swallows and contractions of the antrum. Furthermore, reverse peristalsis was observed from the pyloric antrum toward the stomach body although the frequency was low. ConclusionsLSG was associated with characteristic of pressure and peristalsis in sleeve gastric tube. HRM was able to detect and visualize intragastric pressure and peristalsis of the sleeve gastric tube.

Intraoesophageal pressure in patients receiving proximal gastrectomy with hinged double flap method for gastric cancer: a retrospective cohort study

Background: Objective functional assessment of esophagogastric anastomosis in patients who underwent proximal gastrectomy with the hinged double flap method for gastric cancer has not been well investigated. This study aimed to perform a functional analysis of reconstruction using high-resolution impedance manometry (HRIM). Materials and methods: The authors enroled 25 patients who underwent proximal gastrectomy for gastric cancer between May 2015 and April 2020 and subsequently underwent HRIM postoperatively. Eligible questionnaires [Postgastrectomy Syndrome Assessment Scale-37 (PGSAS-37)] were retrieved from 16 patients. The association between HRIM data and PGSAS-37 was analyzed. Results: The amplitudes of distal oesophageal peristaltic waves, contractile front velocity, and distal latency assessed by HRIM were almost normal after surgery. Most patient’s lower oesophageal sphincter (LES) resting pressure created by the hinged double flap was within normal limits. Conversely, LES residual pressure values during swallowing-induced relaxation were abnormally high in most patients, and the lower the values, the more severe the reflux and diarrhoea symptoms (P=0.038, P=0.041, respectively). In addition, even when the integrated relaxation pressure (IRP) was normal, lower values corresponded to more severe reflux symptoms (P=0.020). The required LES pressure may be higher after proximal gastrectomy because of the relatively higher intragastric pressure due to the reduced volume of the remnant stomach. This also suggests that swallowing-induced relaxation of the LES was considered a trigger for oesophageal reflux in post-proximal gastrectomy patients. Conclusion: LES residual pressure and IRP values in HRIM correlated with reflux symptoms in patients after proximal gastrectomy.

Effect characteristics of electroacupuncture at the acupoints of different regions in regulating gastric motility of the rats: response time.

To observe the effect of electroacupuncture (EA) at "Zhongwan" (CV 12) and "Zusanli" (ST 36) on gastric motility and explore the response time of the acupoints at different regions for regulating gastric motility and its neuromechanism. Thirty-three SD rats were randomly divided into a normal group, a vagectomy group and a splanchnicotomy group, 11 rats in each one. Vagectomy and splanchnicotomy were operated in the rats of the vagectomy group and the splanchnicotomy group, respectively. In each group, EA was delivered at "Zhongwan" (CV 2) and "Zusanli"(ST 36) on the left successively (with disperse-dense wave, 2 Hz/15 Hz in frequency and 2 mA in intensity); and it was performed at one acupoint for 1 min. Using multiple physiological signal collecting system, the intragastric pressure was measured 1 min before EA and in 0 s to 60 s, 0 s to 30 s and 30 s to 60 s of EA in the rats of each group, separately. The change rate of intragastric pressure was calculated to compare the effect size among groups. 1) Compared with that before intervention, in the normal group, the intragastric pressure was dropped in 0 s to 60 s, 0 s to 30 s and 30 s to 60 s of EA at "Zhongwan" (CV 12) (P<0.01); and it was elevated in 0 s to 60 s and 30 s to 60 s of EA at "Zusanli" (ST 36) (P<0.01). 2) In 0 s to 60 s, 0 s to 30 s and 30 s to 60 s of EA at "Zhongwan" (CV 12), the intragastric pressure decreased when compared with that before intervention in both the vagectomy group and the splanchnicotomy group (P<0.01, P<0.05); and it increased in 0 s to 60 s, 0 s to 30 s and 30 s to 60 s of EA at "Zusanli" (ST 36) in the splanchnicotomy group (P<0.05). 3) Compared with the normal group, the inhibition effect size was reduced in 30 s to 60 s of EA at "Zhongwan" (CV 12) in the vagectomy group (P<0.01), and in 0 s to 30 s and 30 s to 60 s of EA at "Zhongwan" (CV 12) in the splanchnicotomy group (P<0.01). During EA at "Zhongwan" (CV 12) for 0 s to 30 s and 30 s to 60 s, the inhibition effect size was declined more obviously in the splanchnicotomy group when compared with that in the vagectomy group (P<0.01). The excitation effect size was dropped in the vagectomy group when EA at "Zusanli" (ST 36) for 30 s to 60 s compared with the normal group (P<0.01), while it increased during 0 s to 30 s in the splanchnicotomy group (P<0.05). Compared with that of the vagectomy group, the excitation effect size increased more remarkably in the splanchnicotomy group when EA at "Zusanli" (ST 36) for 0 s to 30 s and 30 s to 60 s (P<0.01). Electroacupuncture at the acupoints of different regions differ in the response time and neuromechanism for regulating gastric motility of normal rats. The response time at "Zhongwan" (CV 12) is short and the effect of this acupoint works fast within 30 s; while that at "Zusanli" (ST 36) is prolonged and the effect starts 30 s later. In 0 s to 30 s of EA, the effect of "Zhongwan" (CV 12) and "Zusanli" (ST 36) is predominated by the splanchnic nerve; and in 30 s to 60 s, the effect of "Zhongwan" (CV 12) may be co-innervated by the splanchnic nerve and the vagus nerve, and that of "Zusanli" (ST 36) only by the vagus nerve.

When symptoms are more than reflux.

45 year-old male patient with history of heartburn and regurgitation of non-acid food in the immediate postprandial period, with no symptomatic improvement after anti-acid treatment. The patient underwent an upper endoscopy that was unremarkable. A high-resolution impedance manometry (HRIM) was performed according to Chicago Protocol 4.0, as well as an additional solid test meal, with findings of rumination syndrome (RS) (figure 1). The study was completed with a 24-hour impedance pH monitoring that showed, in the immediate postprandial period, episodes of reflux that reached the proximal sensor followed by a normal swallow (figure 2). Abdominophrenic biofeedback was started with clinical improvement and anti-acid treatment was maintained at once a day. Discussion: RS is diagnosed by a complete clinical history, using the Rome IV or DSM-5 criteria (figure 3). Due to lack of knowledge of the disease and the fact that regurgitation can be present in other conditions including gastroesophageal reflux disease and achalasia, most patients undergo multiple tests and visit several physicians before reaching the diagnosis1. The gold standard investigation for RS, in cases where there are diagnostic doubts, is HRIM with solid meal administration, that shows a sudden increase in intragastric pressure > 30 mmHg concurrent with a drop in impedance and both simultaneous lower and upper esophageal sphincter relaxation, that may or may not be followed by re-swallowing food2. Rumination episodes can appear spontaneously (type 1) or may be preceded by a reflux episode (type 2) or a supragastric belch (type 3)3. 24-hour impedance pH monitoring cannot confirm de diagnosis, but during rumination, in the majority of episodes, the refluxed material reaches the proximal esophagus2.

Assessment of the Smartpill, a Wireless Sensor, as a Measurement Tool for Intra-Abdominal Pressure (IAP).

Background: The SmartPill, a multisensor ingestible capsule, is marketed for intestinal motility disorders. It includes a pressure sensor, which could be used to study intra-abdominal pressure (IAP) variations. However, the validation data are lacking for this use. Material and Methods: An experimental study was conducted on anesthetized pigs with stepwise variations of IAP (from 0 to 15 mmHg by 3 mmHg steps) generated by laparoscopic insufflation. A SmartPill, inserted by endoscopy, provided intragastric pressure data. These data were compensated to take into account the intrabdominal temperature. They were compared to the pressure recorded by intragastric (IG) and intraperitoneal (IP) wired sensors by statistical Spearman and Bland-Altmann analysis. Results: More than 4500 pressure values for each sensor were generated on two animals. The IG pressure values obtained with the SmartPill were correlated with the IG pressure values obtained with the wired sensor (respectively, Spearman ρ coefficients 0.90 ± 0.08 and 0.72 ± 0.25; bias of -28 ± -0.3 mmHg and -29.2 ± 0.5 mmHg for pigs 1 and 2). The intragastric SmartPill values were also correlated with the IAP measured intra-peritoneally (respectively, Spearman ρ coefficients 0.49 ± 0.18 and 0.57 ± 0.30; bias of -29 ± 1 mmHg and -31 ± 0.7 mmHg for pigs 1 and 2). Conclusions: The SmartPill is a wireless and painless sensor that appears to correctly monitor IAP variations.

Endoscopic versus laparoscopic bariatric procedures: A computational biomechanical study through a patient-specific approach

Background and ObjectivesWithin the framework of computational biomechanics, finite element models of the gastric district could be seen as a potential clinical tool not only to study the effects apported by bariatric surgery, but also to compare different surgical techniques such as the new emerging Endoscopic Sleeve Gastroplasty (ESG) with respect to well-established ones (such as the Laparoscopic Sleeve Gastrectomy, LSG). MethodsThis work realized a fully computational comparison between the outcomes obtained from 10 patient-specific stomach models, which were used to simulate ESG, and the complementary results obtained from models representing the post-LSG of the same subjects. Specifically, once the ESG was simulated, a mechanical stimulus was applied by increasing an intragastric pressure up to a maximum of 5 kPa, in order to replicate the process of food intake, as well as for post-LSG models. Results: Results revealed non negligible differences between the techniques also within the same subject. In particular, not only LSG could lead to a greater reduction in the stomach volume (about 77 % at baseline, which is strictly linked to weight loss), but also influence the gastric distension (12 % less than pre-operative models). On the contrary, if ESG would be performed, a more similar pre-operative mechanical stimulation of the gastric walls may be seen (difference of about 1 %), thus preserving the mechanosensation, but the detriment of the volume reduction (about 56 % at baseline, and even decreases with increasing pressure). Moreover, since results suggested ESG may be more influenced by the pre-operative gastric cavity than LSG, a predictive model was proposed to support the surgical planning and the estimation of the volume reduction after ESG. Conclusions: ESG and LSG have substantial differences in their protocols and post-surgical effects. This work pointed out that variations between the two procedures may be observed also from a computational point of view, especially when including patient-specific geometries. These insights support gastric modelling as a valuable tool to evaluate, design and critically compare emerging bariatric surgical procedures, not only from empirical aspects and clinical outcomes, but also from a mechanical point of view.

Endoscopic pressure study integrated system for the diagnosis of achalasia.

The endoscopic pressure study integrated system (EPSIS) is a novel diagnostic tool used to evaluate lower esophageal sphincter (LES) function. EPSIS allows the measurement of intragastric pressure (IGP) during gastric insufflation through esophagogastroduodenoscopy (EGD) and records its pressure waveform. This study aimed to assess the usefulness and applicability of EPSIS as an adjunct diagnostic modality for achalasia. This case-control study was conducted using a database of patients who underwent EGD, barium swallow (BS), high-resolution manometry (HRM), and EPSIS between January 2022 and December 2022. The achalasia (experimental) group (n = 35) consisted of patients with a definitive diagnosis of achalasia. The control group (n = 34) consisted of patients with no abnormalities in EGD, BS, or HRM and no abnormal acid reflux confirmed with 24-h pH-impedance monitoring. EPSIS findings were compared between the two groups and characterized by the waveform pattern (uphill or flat), maximum IGP (IGP-Max), pressure difference, and the gradient of the waveform. All patients in the achalasia group showed an uphill pattern, in contrast to 21 patients (61.8%) in the control group. IGP-Max demonstrated the best diagnostic accuracy for achalasia, with a cut-off value of 15.8 mmHg (100% sensitivity, 58.8% specificity, and area under the curve [AUC] 0.78). The pressure gradient also demonstrated good diagnostic accuracy, with a cut-off value of 0.40 mmHg/s (80% sensitivity, 61.8% specificity, and AUC 0.76). This study demonstrated that EPSIS can be applied as a diagnostic modality in patients with achalasia.

Gastro‑oesophageal reflux disease in liver cirrhosis: Possible pathogenesis and clinical intervention (Review).

Oesophageal variceal bleeding is a common complication of decompensated liver cirrhosis (LC). Some studies have reported that reflux oesophagitis (RE) is a risk factor for upper gastrointestinal bleeding, and greatly impacts the quality of life. However, the frequency and mechanism of gastro-oesophageal reflux disease (GERD) in LC remain unclear. The present review explored the possible pathogenesis, and analysed the advantages and disadvantages of the interventional measures and the need for implementation of these measures. By combining the comprehensive terms associated with LC, GERD and RE, EMBASE, Medline/PubMed and the Cochrane Library were systematically searched. The underlying pathological mechanism of GERD in LC was summarized: Transient relaxation of the lower oesophageal sphincter, delayed gastric emptying, increased intra-abdominal pressure, increased intragastric pressure and excessive nitric oxide production destroyed the 'anti-reflux barrier', causing gastric content reflux. Proton pump inhibitors (PPIs) have been widely used empirically to lower the risk of oesophageal venous rupture and bleeding. However, long-term use of acid inhibitors in patients with LC may induce complications, such as spontaneous bacterial peritonitis. The metabolic half-life of PPIs is prolonged in patients with severe liver function impairment. Therefore, the indications for using acid inhibitors lack clarity. However, after endoscopic oesophageal variceal eradication, additional benefits may be gained from the long-term use of PPIs in small doses.

Proximal Gastric Pressurization After Sleeve Gastrectomy Associates With Gastroesophageal Reflux.

Sleeve gastrectomy (SG) results in persistent or de novo reflux more often than Roux-en-Y gastric bypass (RYGB). We investigated pressurization patterns in the proximal stomach on high-resolution manometry (HRM) to determine associations with reflux after SG. Patients undergoing HRM and ambulatory pH-impedance monitoring after SG and RYGB over a 2-year period (2019-2020) were included. For each included patient, 2 symptomatic control patients with HRM and pH-impedance monitoring for reflux symptoms were identified within the same time frame; 15 asymptomatic healthy controls with HRM studies were also studied. Concurrent myotomy and preoperative diagnosis of obstructive motor disorders were exclusions. Conventional HRM metrics, esophagogastric junction (EGJ) pressures, contractile integral (EGJ-CI), acid exposure time (AET), and reflux episode numbers were extracted. Intragastric pressure was sampled at baseline, during swallows, and with straight leg raise maneuver, and compared with intraesophageal pressure and reflux burden. Patient cohorts included 36 SG patients, 23 RYGB patients, 113 symptomatic controls, and 15 asymptomatic controls. While both SG and RYGB patients pressurized the stomach during swallows and straight leg raise, SG patients had higher AET (median 6.0% vs 0.2%), reflux episode numbers (median 63.0 vs 37.5), and baseline intragastric pressure (median 17.3 mm Hg vs 13.1 mm Hg) ( P < 0.001). SG patients also had lower trans-EGJ pressure gradients when reflux episodes were >80 or AET was >6.0% ( P = 0.018 and 0.08, respectively, compared with no pathologic reflux). On multivariable analysis, SG status and low EGJ-CI independently associated with AET and reflux episode numbers ( P ≤ 0.04). Impaired EGJ barrier function and proximal gastric pressurization after SG are associated with gastroesophageal reflux, especially during strain maneuvers.