Intragastric Pressure Measurement Research Articles

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.

Continuous intra-gastral monitoring of intra-abdominal pressure in critically ill children: a validation study

BackgroundIn critically ill children, detection of intra-abdominal hypertension (IAH > 10 mmHg) and abdominal compartment syndrome (ACS = IAH + organ dysfunction) is paramount and usually monitored through intra-vesical pressures (IVP) as current standard. IVP, however, carries important disadvantages, being time-consuming, discontinuous, with infection risk through observer-dependent manipulation, and ill-defined for catheter sizes. Therefore, we sought to validate air-capsule-based measurement of intra-gastric pressure (ACM-IGP).MethodsWe prospectively compared ACM-IGP with IVP both in vivo and in vitro (water column), according to Abdominal-Compartment-Society validation criteria. We controlled for patient age, admission diagnosis, gastric filling/propulsive medication, respiratory status, sedation levels and transurethral catheters, all influencing intra-abdominal pressure (IAP).ResultsIn tertiary care PICU setting, finally, n = 97 children were enrolled (median age, 1.3 years [range 0 days–17 years], LOS-PICU 8.0 [1–332] days, PRISM-III-Score 13 [0–35]). In n = 2.770 measurements pairs, median IAP was 6.7 [0.9–23.0] mmHg, n = 38 (39%) children suffered from IAH > 10 mmHg, n = 4 from ACS. In vitro against water column, ACM-IGP correlated perfectly (r2 0.99, mean bias − 0.1 ± 0.5 mmHg, limits of agreement (LOA) − 1.1/+ 0.9, percentage error [PE] 12%) as compared with IVP (r2 0.98, bias + 0.7 ± 0.6 mmHg, LOA − 0.5/+ 1.9, PE 15%). With larger IVP catheters at higher pressure levels, IVP underestimated pressures against water column. In vivo, agreement between either technique was strong (r2 0.95, bias 0.3 ± 0.8 mmHg, LOA − 1.3/+ 1.9 mmHg, PE 23%). No impact of predefined control variables on measurement agreement was observed.ConclusionsIn a large PICU population with high IAH prevalence, ACM-IGP agreed favourably with IVP. More widespread usage of ACM-IGP may improve detection rates of ACS in critically ill children.Trial registration WHO-ICTRP-No. DRKS00006556 (German Clinical Trial Register). Registered 12th September 2014, URL: https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00006556

Measurement of intragastric pressure: an objective method to ascertain whether gastric wall extension is sufficient for assessment of the non-extension sign.

Background and study aims The optimal intragastric pressure (IP) for strong gastric wall extension is unclear. We aimed to develop an accurate method to measure IP using endoscopy and determine the pressure required for strong gastric wall extension. Methods An in vitro experiment using an endoscope with a rubber attached at its tip was conducted. The process of inserting the pressure measurement probe into the forceps channel was skipped, and the tube of the pressure measurement device was directly connected to the forceps channel. In vivo, the pressure in 51 consecutive patients at the time of strong gastric wall extension was measured. Strong extension of the gastric wall was defined as when the folds in the greater curvature were flattened as a result of sufficient extension of the gastric wall by insufflated air during upper gastrointestinal endoscopy. The IP at that time was measured. Results In vitr o , 20 mL of tap water was injected once into the forceps channel and then aspirated for 10 seconds. Pressure measurement after irrigation of the forceps channel as well as the measurement by inserting the probe procedure were accurately performed. In vivo, among the 51 included patients, the mean IP (range) was 14.7 mmHg (10–23). Strong extension of the gastric wall was obtained in 96.1 % of patients when the IP was 20 mmHg. Conclusions We developed an accurate method to measure IP using upper gastrointestinal endoscopy. Strong extension of the gastric wall was obtained in almost all patients when the IP was 20 mmHg.

The effect of prucalopride on gastric sensorimotor function and satiation in healthy volunteers.

Gastric motor function alterations have been implicated in the pathogenesis of functional dyspepsia with postprandial distress syndrome (PDS). Prucalopride, a 5-TH4 agonist, is known to stimulate gastrointestinal motility. We aimed to evaluate the effect of prucalopride on gastric sensorimotor function in healthy subjects (HV). Barostat and intragastric pressure (IGP) measurements were performed in 17 HV (59% females, age 29.4±2.7y) after treatment with placebo or prucalopride (2mg) (single-blind cross-over). Isobaric stepwise distensions and gastric sensations were assessed to determine gastric compliance and sensitivity. Gastric accommodation (GA) with the barostat was quantified before and after ingestion of 200ml of a nutrient drink (ND). GA measured by IGP was quantified as the drop of IGP from baseline during the intragastric infusion of ND until maximal satiation (60ml/min). Prucalopride did not affect barostat assessed gastric compliance or sensitivity. No differences were observed in GA after prucalopride. During the barostat study, 10min after the meal, 7 HVs reported significantly higher ratings for nausea after prucalopride (p<0.001), and vomiting was induced in 4 of the HVs. A positive correlation was observed between the delta mean perception of nausea with the delta mean increase of intra-balloon volume before and after meal ingestion (r=0.37, p=0.03). During IGP measurements, no effect on nutrient tolerance was observed and increased cramp severity scores were observed which were associated with a significant increase of distal IGP (r=0.78, p<0.0001). Prucalopride does not enhances gastric accommodation but it might increase sensitivity to gastric distention. Furthermore, the increase in sensitivity seems to be related to an increase in nausea with distension. Clinicaltrials.gov: NCT04429802.

Duodenal acidification induces gastric relaxation and alters epithelial barrier function by a mast cell independent mechanism

Duodenal hyperpermeability and low-grade inflammation in functional dyspepsia is potentially related to duodenal acid exposure. We aimed to evaluate in healthy volunteers the involvement of mast cell activation on the duodenogastric reflex and epithelial integrity during duodenal acidification. This study consisted of 2 parts: (1) Duodenal infusion of acid or saline during thirty minutes in a randomized, double-blind cross-over manner with measurement of intragastric pressure (IGP) using high resolution manometry and collection of duodenal biopsies to measure epithelial barrier function and the expression of cell-to-cell adhesion proteins. Mast cells and eosinophils were counted and activation and degranulation status were assessed. (2) Oral treatment with placebo or mast cell stabilizer disodiumcromoglycate (DSCG) prior to duodenal perfusion with acid, followed by the procedures described above. Compared with saline, acidification resulted in lower IGP (P < 0.01), increased duodenal permeability (P < 0.01) and lower protein expression of claudin-3 (P < 0.001). Protein expression of tryptase (P < 0.001) was increased after acid perfusion. Nevertheless, an ultrastructural examination did not reveal degranulation of mast cells. DSCG did not modify the drop in IGP and barrier dysfunction induced by acid. Duodenal acidification activates an inhibitory duodenogastric motor reflex and, impairs epithelial integrity in healthy volunteers. However, these acid mediated effects occur independently from mast cell activation.

The effect of rikkunshito on gastrointestinal symptoms and gastric motor function: The first study in a Belgian functional dyspepsia population.

Rikkunshito, a traditional Kampo medicine, has shown efficacy to treat functional dyspepsia (FD) in controlled trials in Japan. Its putative benefit for European patients and mechanism of action has not been established. This study examined the effect of rikkunshito on gastric motility and GI symptom perception in FD-PDS patients in a randomized, placebo-controlled, cross-over study. After a 2-week run-in period, patients received rikkunshito or matching placebo (2.5g t.i.d.) for 4weeks, separated by a 4-week washout period. Symptoms were assessed by the Leuven Postprandial Distress Scale (LPDS) diary throughout the study. At baseline and after both treatment arms, intragastric pressure (IGP) was measured to evaluate gastric accommodation and gastric motility. Simultaneously, GI symptoms were scored on a 100mm visual analogue scale. Validated symptom questionnaires (PAGI-SYM, VSI, DSS, and PHQ) were completed each study visit. Twenty-three patients completed the study (33±14years, 22.7±3.22kg/m2 ). Intragastric pressure was numerically, but not significantly, lower after rikkunshito compared with baseline and placebo (P=.14). No differences were found in gastric accommodation, nutrient volume tolerance, and symptoms assessed during IGP measurements. Early satiation and postprandial fullness (daily diary) decreased after rikkunshito compared with baseline (P<.041 for both). Placebo also improved most other symptoms assessed. No significant changes in VSI scores occurred. No adverse reactions occurred. Rikkunshito did not alter gastric motility. Treatment with rikkunshito improved upper GI symptoms in FD patients but similarly high placebo effects were observed using the LPDS diary, PAGI-SYM, SF-NDI, and DSS scores. Rikkunshito was safe and well-tolerated.

The Intragastric Pressure Measurement: A Novel Method to Assess Gastric Accommodation in Functional Dyspepsia Children.

Impaired gastric accommodation (GA) is proposed as a main pathophysiological mechanism for functional dyspepsia (FD). At present, the gastric barostat is the criterion standard to measure GA. Hence, this procedure is invasive and it may alter gastric physiology. Recently, we proposed the measurement of intragastric pressure (IGP) by means of high-resolution manometry during nutrient intake as a potential alternative for assessing GA in adults. Our aim was first to study the feasibility of the IGP measurement with nutrient tolerance in children with FD and second to compare these results with young healthy adults. A high-resolution manometry probe and a feeding tube were positioned in the proximal stomach. The IGP was measured before and during intragastric infusion of a nutrient drink (ND, 300 kcal, 60 mL/min). Subjects were asked to score their satiation and epigastric symptoms. The test ended when the subjects scored maximal satiation. A total of 15 healthy volunteers (HVs, 21.7 ± 4.7 years, 21.1 ± 0.3 kg/m) and 17 patients with FD (14.4 ± 0.7 years, 19.6 ± 0.7 kg/m) participated. Patients with FD experienced mainly from postprandial fullness (86%), epigastric pain (71%), and bloating (62%). In both groups, intragastric infusion of ND induced a drop in IGP (area above the IGP curve FD: -15.5 ± 3.5 mmHg vs HVs: -18.0 ± 8.7 mmHg; P = 0.57). Patients showed impaired nutrient tolerance compared with HVs (587.6 ± 80.2 vs 936 ± 66.2 kcal; P = 0.003). All patients and HVs tolerated the catheters and could finalize the study. The measurement of IGP during intragastric ND infusion was well tolerated in children. Nutrient tolerance was reduced in children with FD compared with HVs. In the future, this may be a useful tool to assess GA accommodation and nutrient tolerance in children.

Sa1612 - Impaired Gastric Distribution of a Meal is Associated with Impaired Intragastric Pressure Measurement and Satiation In FD

Sa1612 - Impaired Gastric Distribution of a Meal is Associated with Impaired Intragastric Pressure Measurement and Satiation In FD

OP‐6 INTRAGASTRIC PRESSURE MEASUREMENT DURING NUTRIENT INTAKE

Background:Functional dyspepsia (FD) in pediatrics is defined as the presence of upper abdominal symptoms for at least 2 months in the absence of organic or metabolic disease likely to explain the symptoms. The main proposed pathophysiological mechanisms are visceral hypersensitivity,impaired gastric accommodation (GA) and delayed gastric emptying. At present, the gastric barostat is the gold standard to measure GA. However, this procedure is perceived as very invasive and it might alter the normal gastric physiology. Recently, we proposed the intragastric pressure (IGP) measurement during nutrient intake as a potential alternative for assessing GA in adults. This technique uses a thin manometry catheter that measures the IGP over the entire length of the stomach. By means of this study we aim to introduce the HRM as new minimally invasive technique to measure GA and nutrient tolerance in children.Methods:After the manometry probe and a second infusion catheter were positioned through the nose into the stomach, the IGP was measured 30 minutes before and during intragastric infusion of nutrient drink (300 Kcal, 60 ml per minute). The patients were asked to score hunger and satiation and 6 epigastric symptoms (fullness, nausea, belching of air, cramps in the abdomen, bloating and pain) at 5‐minute intervals. The experiment ended when the volunteers scored maximal satiation at 1‐minute intervals by using a graphic rating scale that combines verbal descriptors on a scale graded from 0–5 (1, threshold; 5, maximum satiety).Results:For this study 13 FD pediatric patients (92% female, 14.8 ± 0.8 years old, BMI: 19.5 ± 0.8) and 12 young adult volunteers (100% female, 22.2 ± 0.4 years old, BMI: 21.2 ± 0.3) were recruited. The Rome III questionnaire showed that FD patients suffered mainly from postprandial fullness (75%), epigastric pain (58%), bloating (50%), nausea (50%) and early satiation (42%). In both groups, intragastric infusion of nutrient drink induced a rapid drop in proximal stomach IGP. The average AUC change from baseline was ‐44.7 ± 11.0 mmHg in patients and ‐48.4 ± 25.2 mmHg in healthy subjects. Patients tended to score maximal satiation at lower volumes compared healthy subjects (433.8 ± 64.2 ml and 600.0 ± 67.6 mL respectively, p = 0.1). All FD patients and healthy subjects tolerated the catheters and could finalize the study.Conclusions:The IGP measurement during intragastric nutrient drink infusion is a promising minimally invasive alternative to the gastric barostat method to assess GA and nutrient tolerance. Future studies need to increase the patient numbers and compare the measurements in different subsets of pediatric FD (e.g. weight loss vs. no weight loss, present or absent early satiation, etc.).

Pressure Measurement Techniques for Abdominal Hypertension: Conclusions from an Experimental Model.

Introduction. Intra-abdominal pressure (IAP) measurement is an indispensable tool for the diagnosis of abdominal hypertension. Different techniques have been described in the literature and applied in the clinical setting. Methods. A porcine model was created to simulate an abdominal compartment syndrome ranging from baseline IAP to 30 mmHg. Three different measurement techniques were applied, comprising telemetric piezoresistive probes at two different sites (epigastric and pelvic) for direct pressure measurement and intragastric and intravesical probes for indirect measurement. Results. The mean difference between the invasive IAP measurements using telemetric pressure probes and the IVP measurements was −0.58 mmHg. The bias between the invasive IAP measurements and the IGP measurements was 3.8 mmHg. Compared to the realistic results of the intraperitoneal and intravesical measurements, the intragastric data showed a strong tendency towards decreased values. The hydrostatic character of the IAP was eliminated at high-pressure levels. Conclusion. We conclude that intragastric pressure measurement is potentially hazardous and might lead to inaccurately low intra-abdominal pressure values. This may result in missed diagnosis of elevated abdominal pressure or even ACS. The intravesical measurements showed the most accurate values during baseline pressure and both high-pressure plateaus.

In Vivo Measurement of Intragastric Pressure with a Rubber Balloon in the Anesthetized Rat

The protocols described in this unit are designed to measure the intragastric pressure in anesthetized rats by a water-filled low-compliance rubber balloon. The balloon is introduced into the stomach either orally (by passing the balloon down the esophagus) or directly via a small incision of the fundus after laparotomy. The effects of both stimulatory (e.g., carbachol) and inhibitory (e.g., oxymetazoline) agents can be evaluated on the gastric tone and phasic contractions. The model allows the evaluation of dose-response curves and also the time-course of the effects. Furthermore, by combining centrally or peripherally acting agents the site of action can also be determined.

Effect of acute peppermint oil administration on gastric sensorimotor function and nutrient tolerance in health

Menthol reduces intestinal motility in animal studies, an effect that is probably mediated by transient receptor potential channels. Peppermint oil (PO), with menthol as a major constituent, is widely used as a spasmolytic agent in irritable bowel syndrome. In the current study, we investigated the effect of acute PO administration on intragastric pressure (IGP) profiles and gastric sensorimotor functions in health. Healthy volunteers underwent IGP measurement before and during continuous intragastric infusion of a nutrient drink (n = 13), and gastric barostat studies (n = 13). A single capsule of PO (182 mg) or placebo was administered during the studies in a randomized controlled crossover design. Throughout the studies, healthy volunteers scored 11 epigastric symptoms on a visual analogue scale (VAS); satiation was scored on a 6-point Likert scale during intragastric infusion. During fasting, IGP and motility index (MI) of the proximal stomach decreased significantly after PO administration compared with placebo (P < 0.0001 and <0.05, respectively). In contrast, during intragastric infusion of the nutrient drink, no significant differences were detected between PO and placebo in IGP profiles, MI, satiation scores, and epigastric symptoms. The maximum infused volume, gastric compliance or sensitivity to balloon distention did not differ between both treatment arms. However, reduced appetite scores were seen during fasting after PO treatment, as compared with placebo (P = 0.01). Postprandial VAS scores were similar between PO and placebo. Peppermint oil reduces IGP, proximal phasic contractility, and appetite, with negligible effects on gastric sensitivity, tone, accommodation, and nutrient tolerance in health.

Su1621 Intragastric Pressure Measurement Using Air Insufflation During Gastroscopy to Assess the Effect of Glucagon or Prifinium Bromide on Functional Dyspepsia

Su1621 Intragastric Pressure Measurement Using Air Insufflation During Gastroscopy to Assess the Effect of Glucagon or Prifinium Bromide on Functional Dyspepsia

A validation study of a new nasogastric polyfunctional catheter

Pleural and abdominal pressure are clinically estimated by measuring the esophageal and bladder or intragastric pressure (IGP), respectively. A new nasogastric polyfunctional catheter is now commercially available, equipped with two balloons in the lower and distal part; this catheter allows simultaneous esophageal pressure (Pes) and IGP measurements and can be also used to feed the patient. We compared the Pes and IGP measured using this new device with those obtained with a standard balloon catheter taken as gold standard. Twenty-four intubated patients requiring ventilator support (mean age 64.3 ± 16.8 years, body mass index 25.3 ± 3.0 kg/m(2), and PaO(2)/FiO(2) 280.8 ± 123.4 mmHg) were enrolled. Esophageal pressure and IGP were measured with the new nasogastric polyfunctional catheter (Nutrivent, Sidam, Italy) and with a standard balloon catheter (Smart Cath Viasys, USA). The Smart Cath was first inserted in the stomach and then retracted to the esophagus to measure IGP and Pes, respectively. In each patient two paired measurements were averaged. In the Bland-Altman analysis, the bias and agreement bands for Pes, ΔPes (computed as the difference of esophageal pressure between end-inspiration and expiration), and IGP were -0.25 (-2.65 to +2.15), 0.0 (-0.9 to +0.9), and -0.45 (-2.85 to + 1.95) cmH(2)O, respectively. No side effects or complications were recorded. The new polyfunctional catheter showed a clinically acceptable validity in recording esophageal and intragastric pressure. This device should help physicians to better individualize the clinical patient management.

The use of intra‐gastric pressure measurements via esophageal manometry catheters to determine Pabd in urodynamic investigations

The use of intra‐gastric pressure measurements via esophageal manometry catheters to determine Pabd in urodynamic investigations

Validation of continuous intragastric pressure measurement and correlation with intramucosal pH in a pig model

The aim of this study was the validation of continuous intragastric pressure (IGP) measurement and correlation with intramucosal pH (pHi) in a pig model of intra-abdominal hypertension (IAH).

Response to Air Insufflation in Patients with Non-Erosive Gastro-Oesophageal Reflux Disease (NERD)

This study compared changes in intragastric pressure (IGP) in response to a gastric distension stimulus caused by air insufflation in 25 patients with non-erosive gastro-oesophageal reflux disease (NERD) and 34 healthy volunteers (controls). In four NERD patients, IGP responses were also measured before and after oral treatment with 10 mg rabeprazole daily for 2 weeks. The rate of increase in IGP at the start of insufflation was significantly higher in NERD patients than in controls. The time to appearance of symptoms (i.e. time to threshold) was significantly shorter in NERD patients than in controls. Direct measurement of IGP showed that visceral hypersensitivity and impaired fundal relaxation are both characteristic of NERD. Administration of rabeprazole led to a marked prolonging of time to threshold, indicating that treatment could alleviate this hypersensitivity.

Failure of experimental acute intra-gastric gas and fluid accumulation to produce gastric dilatation-volvulus in unanaesthetized dogs

The stomachs of 6 mongrel dogs were cannulated with a simple assemblage of cannula and sphygmomanometer for direct and rapid administration of gas and combination of gas and fluid, respectively, to investigate the role of intra-gastric accumulation of gas and fluid in the stomach in development of acute gastric dilatation-volvulus in the animals. In all the experiments, the stomach of each dog was fully distended at a consistent intra-gastric pressure of 31.73 ± 0.43 mmHg. The mean intra-gastric pressure of the empty stomach in fasted unanaesthetized animals was 4.17 ± 0.63 mmHg, while in animals that received 500 ml of water, the mean intra-gastric pressure was 14.2 ± 2.4 mmHg. The animals successfully evacuated the distended stomach at the peak of the intra-gastric pressure by eructation and/or vomition in 1.31 ± 0.43 min. There were no clinical and radiological evidence of the classical acute gastric dilatation-volvulus syndrome in any of the animals. The experiments failed to show that rapid accumulation of gas and fluid in the stomach primarily caused the condition in the clinically normal animals. There was apparent intra-gastric pressure threshold at which the cardiac orifice of the stomach of the animals opened for evacuation. The assemblage was functionally efficient for direct and rapid administration of gas and fluid into the stomach and simultaneous measurement of intra-gastric pressure in unanaesthetized dogs.

LOCALISED ABDOMINAL COMPARTMENT SYNDROME: BLADDER-OVER-GASTRIC PRESSURE RATIO (B/G RATIO) AS A CLUE TO DIAGNOSIS

Introduction: Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) have been identified as a cause of organ dysfunction and mortality in critically ill patients. The diagnosis of IAH/ACS depends on accurate intra-abdominal pressure (IAP) measurement, which is usually performed via the bladder or the stomach. The aim of this study was to describe cases where intragastric pressure (IGP) and intrabladder pressure (IBP) were measured simultaneously.Patients and methods: After review of medical records, four patients admitted to our ICU department where both IGP and IBP were measured, could be identified. IGP was measured using the Spiegelberg catheter and IBP was measured using the FoleyManometer LV. In all patients, the bladder-over-gastric pressure ratio (B/G ratio) was calculated.Results: In two of four patients, IGP and IBP differed significantly. In one patient the B/G ratio was lower than 1 suggesting a diagnosis of epigastric ACS and in one patient B/G ratio was greater than 1 leading to a diagnosis of pelvic ACS. The latter patient was spared a decompressive laparotomy due to the additional IGP measurement and the subsequent diagnosis of localized ACS.Conclusion: The preferred methods for IAP measurement are via the bladder and via the stomach. In some patients, IGP and IBP may differ significantly and this may have clinical implications. Clinicians should be aware of the possibility of localized ACS. In order to identify risk factors and to recommend treatment for localized ACS, further study of simultaneous IGP and IBP measurements are needed.

Leaks and endoscopic assessment of break of integrity after NOTES gastrotomy: the LEAKING study, a prospective, randomized, controlled trial

Gastric leak testing after natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure may help reduce the risk of leaks after transgastric procedures. To develop a novel endoscopy-based system to determine the presence of a leak after NOTES gastrotomy and to compare this system prospectively with radiographic leak testing. Prospective, randomized, controlled trial. Academic Medical Center laboratory. Fifty swine. During the pretrial phase, an endoscopic system for the measurement of intragastric pressure was developed. In the trial phase, swine with a NOTES gastrotomy were randomized to endoscopic versus radiographic leak testing. If a leak was demonstrated, the gastrotomy was reclosed by using a second-generation prototype T-anchor system. The primary outcome was leak detection after gastrotomy closure. The secondary outcome variables included necropsy findings, peritoneal fluid analysis, histologic examination, and clinical outcome. Fourteen swine were included in the pretrial phase and 36 in the randomized trial. Swine were survived for a mean of 9 days postoperatively. Endoscopic pressure monitoring demonstrated a reproducible change in intragastric pressure with insufflation; r = 0.735, P = .001 and r = 0.769, P < or = .000 for the total and maximum pressures, respectively. Post-peritoneoscopy, there was a detectable and significant decrease in the mean total and mean maximum pressures versus baseline (P = .006 and P = .009). There was no significant difference between the radiologic and endoscopic arms in leak detection rate (4/18 vs 3/18, respectively, P = .500). Clinical outcomes and mean weight gain were equivalent. There was 1 operative abdominal wall injury and no deaths. Animal study. Endoscopic pressure monitoring was reproducible, demonstrated the presence of gastric leak, and was as reliable as contrast-based radiographic leak testing.