Gastric yield pressure and gastric yield volume to assess anti-reflux barrier in a porcine model.

Anti-reflux barrier (ARB) resistance may be useful to test new treatments for gastroesophageal reflux (GER). The ARB has been estimated by increasing gastric yield pressure (GYP) and gastric yield volume (GYV) in animal models but has not been validated. This study aimed to develop an experimental model suitable for assessing the ARB resistance to increasing intragastric pressure and volume and its reproducibility in a seven-day interval. Ten two-month-old female Large-White swine were studied. Intragastric pressure and volume were recorded using a digital system connected to a Foley catheter inserted through gastrostomy into the stomach. GYP and GYV were defined as the gastric pressure and volume able to yield gastric contents into the esophagus detected by esophageal pH. A sudden pH drop below 3 sustained during 5 min was considered diagnostic for gastric yield. Animals were studied again after seven days. On days 0 and 7, there were no significant differences for GYP (mean ± SD = 7.66 ± 3.02 mmHg vs. 7.07 ± 3.54 mmHg, p = .686) and GYV (636.70 ± 216.74 ml vs. 608.30 ± 276.66 ml; p = .299), respectively. Concordance correlation coefficient (ρc) was significant for GYP (ρc = 0.634, 95% CI = 0.141-0.829, p = .006), but not for GYV (ρc = 0.291, 95% CI = -0.118 to 0.774, p = .196). This study demonstrated an experimental model, assessing the ARB resistance. GYP seems to be a more reliable parameter than GYV for assessment of ARB resistance.

Endoscopic augmentation of the esophagogastric junction with polymethylmethacrylate: durability, safety, and efficacy after 6 months in mini-pigs.

BACKGROUND AND AIMS: Endoscopic augmentation of the esophagogastric junction (EGJ) with polymethylmethacrylate (PMMA) has been reported in an experimental short-term study. We assessed whether endoscopic augmentation of the EGJ with PMMA is durable, safe, and efficacious after 6 months in mini-pigs. METHODS: Ten mini-pigs were studied under anesthesia. After a pilot study in two animals, eight mini-pigs underwent lower esophageal sphincter (LES) manometry and gastrostomy with measurement of gastric yield volume (GYV) and gastric yield pressure (GYP). Endoscopic implantation of PMMA was performed aiming for the submucosa of the EGJ. Six months later, LES manometry and GYV and GYP measurements were repeated and animals were sacrificed, followed by microscopic analyses of the EGJ. RESULTS: Out of 32 implants (four per animal), 29 (91%) were identified as submucosal nodules postmortem. PMMA deposits were found at microscopic analysis in all animals and located as follows [mean (range)]: submucosa 61.5% (37.5-91%), muscularis propria 21.5% (0-58%), mucosa 11% (0-25%), and subserosa 6% (0-17%). Neither esophageal perforation nor death was observed. A significant increase in GYV (1,404 versus 905 ml; p = 0.02) and a borderline increase in GYP (8.1 versus 6.5 mmHg; p = 0.057) were detected 6 months later. CONCLUSIONS: Endoscopic augmentation of the esophagogastric junction with PMMA was durable and had no complications after 6 months. However, the occurrence of implants in the subserosa requires technical refinement before use in clinical trials.

Acalasia na doença de Chagas é diferente de acalasia idiopática? Experiência do Hospital de Clínicas de Porto Alegre / Is achalasia in Chagas'disease different from idiopathic achalasia? Experience of the Hospital de Clínicas de Porto Alegre

O presente trabalho tem como objetivo avaliar as diferenças entre a acalasia chagásica e a idiopática em pacientes do Hospital de Clínicas de Porto Alegre, através da análise de achados epidemiológicos, clínicos, radiológicos e manométricos. Foram estudados pacientes encaminhados ao Hospital de Clínicas de Porto Alegre, entre novembro de 1996 e dezembro de 2001, com suspeita de acalasia, posteriormente, confirmada por manometria esofágica. Além das características manométricas e radiológicas, os pacientes foram avaliados quanto a idade, sexo, sintomas e tempo de evolução. Entre 51 pacientes, nove (18 por cento) tiveram sorologia positiva para doença de Chagas e 42 (82 por cento) sorologia negativa. Indivíduos com sorologia negativa foram considerados portadores de acalasia idiopática. Pacientes com acalasia chagásica tinham média de idade de 62 mais ou menos 15 anos e os com idiopática 43 mais ou menos 18 anos (P<0,02). O período de evolução dos sintomas em pacientes com acalasia chagásica foi de 74 mais ou menos 47 meses e nos idiopáticos 49 mais ou menos 35 meses (P<0,05). Disfagia, regurgitação, dor torácica e emagrecimento, valores do esfíncter esofágico inferior (pressão basal, pressão e duração de relaxamento pós-deglutição e comprimento total) e do corpo esofágico (amplitude e duração das ondas pós-deglutição) foram similares em ambos os grupos). As únicas diferenças estatisticamente significativas encontradas entre os dois grupos foram a média de idade e o período de evolução dos sintomas, maiores nos pacientes chagásicos. Esses dados permitem especular sobre uma maior tolerância aos sintomas nos pacientes com idade mais avançada.