The relationship between esophageal peristalsis and in vivo intraband pressure measurements in gastric banding patients.

Intraband pressure (IBP) measurement may be a less invasive method to assess esophageal motility response to band adjustment and restrictive integrity of the device in Swedish adjustable gastric band (SAGB) patients. However, the relationship between IBP and esophageal function is not yet established. Our aim was to characterize in vivo IBP-peristalsis associations in SAGB patients. Ten patients in their second postoperative year were prospectively recruited. IBP was measured via percutaneous port, and concurrent esophageal manometry was performed using an 8-channel catheter. Contraction length and amplitude were measured with both methods. The IBP-peristalsis correlation was computed using the R-square of the regression analysis (R (2)) for band volumes ranging from 4 to 9 mL. One hundred ten swallows were studied. Excellent IBP-peristalsis correlation was observed in 6 of 10 patients (267 contractions): contraction length R (2) = 0.8537 and amplitude R (2) = 0.7365 (p-value of slope < 0.001). Mean contraction length was 17 +/- 7 (4-42) s for manometry and 18 +/- 7 (5-43) s for IBP. Mean amplitude was 55 +/- 55 (9-209) mm Hg for manometry and 67 +/- 47 (7-190) mm Hg for IBP. A weak IBP-peristalsis correlation was observed in the remaining four patients: two had impaired lower sphincter relaxation, one had band slippage, and one had disruption of the port needle connection. In vivo IBP measurement may be reliable in the assessment of esophageal peristalsis in response to band adjustments and the restrictive integrity of the device in patients with intact esophageal function. More studies are warranted to completely assess the potential for IBP to be indicative of the presence of band-related complications.

Effect of hydrochloric acid, pepsin, or taurocholate on bioelectric properties of gastric squamous mucosa in horses.

OBJECTIVE: To determine the effect of pH with or without pepsin or taurocholic acid on the bioelectric properties of gastric squamous mucosa in horses. SAMPLE POPULATION: Gastric tissues obtained from 16 adult horses that did not have evidence of gastric disease. PROCEDURE: Bioelectric properties of squamous mucosa were determined, using modified Ussing chambers. Tissues then were exposed to mucosal pepsin (1 mg/ml) or taurocholic acid (2.5 mM) under neutral (pH 74) or acidic (pH 1.7) conditions. RESULTS: Exposure of mucosal sheets to an acidic pH resulted in an immediate and sustained decrease in transmembrane potential difference and calculated tissue resistance. Pepsin or taurocholic acid did not significantly affect bioelectric variables when added to a mucosal bath solution of pH 7.4. A synergistic effect between pepsin or taurocholic acid and mucosal acidification was not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Mucosal acidification with or without pepsin or taurocholic acid resulted in reduced tissue resistance. These data support the contention that squamous erosions or ulcers in horses are mediated, in part, by prolonged exposure of gastric squamous mucosa to luminal acid.