Organization of antral, pyloric and duodenal motility in patients with gastroparesis

The motor mechanisms associated with delayed gastric emptying are poorly understood, and the contribution of abnormal patterns of gastroduodenal motility to gastroparesis is unknown. Limited data suggest an increased frequency of localized pyloric contractions contributes to delayed gastric emptying. Antropyloroduodenal pressures and gastric emptying of ^99mTc chicken liver/ground beef were recorded simultaneously for 60 min in 16 patients with gastroparesis and 26 healthy subjects using a sleeve/sidehole manometric assembly and a scintigraphic technique. Manometric recordings were analysed for localized pyloric contractions (isolated pyloric pressure waves), basal pyloric pressure (tone), antral and duodenal pressure waves and the number of associated antropyloroduodenal contractions ≥ 6 cm in length. There was no significant difference in median pyloric tone (1.1 (interquartile range 0.3-2.1) vs 0.5 (0-1.8)mmHg), number of isolated pyloric pressure waves (15 (4.5-25) vs 25 (12-37)) or antral pressure waves (47 (16-62) vs 46 (17-76) between the patients with gastroparesis and the healthy controls. The number of duodenal pressure waves was significantly less in the gastroparetics (54 (41-80) vs 102 (63-116), P < 0.05) as was the number of antropyloroduodenal pressure waves ≥ 6 cm (5 (0.5-6) vs 12.5 (4-24), P < 0.05). There was no difference in the lag time for solid gastric emptying but there was a reduction in the amount emptied after 60 min (1 (0-10) vs 10 (0-14)%, P < 0.01). These results suggest that abnornmal patterns of antropyloroduodenal contractions contribute to slow gastric emptying in patients with gastroparesis. Localized pyloric contractions are not a major pathogenetic mechanism.