OBJECTIVETo explore the impact of abnormal myoelectricity at gastroduodenal anastomosis on gastric emptying in rats.

METHODSRats were randomly divided into experimental group (n=16) and control group (n=16). Pylorectomy and end-to-end gastroduodenal anastomosis were performed in the experimental group and electrodes were implanted in the serosal surface adjacent to the anastomosis. Slow waves were recorded by the implanted electrode in vivo. Gastric emptying was examined by scintigraphy.

RESULTSAt the first week after surgery, antral slow-wave frequency was significantly lower in the experimental group (0.8±1.4 vs. 3.3±1.2, P<0.01), as was the duodenal slow-wave frequency (2.1±0.6 vs. 11.1±0.7, P<0.01). There was no consecutive slow-waves transduction across the pylorus or the anastomosis. Within 12-16 weeks after operation, antral slow-wave frequency in the experimental group and the control group were (8.7±0.6) cpm and (4.0±0.4) cpm, respectively (P<0.01), and duodenal slow-wave frequency were (11.1±0.8) cpm and (10.8±0.7) cpm, respectively (P>0.05). Retrograde and antegrade myoelectricity transduction through the anastomosis were detected. The mean semi-emptying time in the proximal stomach was 14.7 min in the experimental group and 13.6 min in the control group (P>0.05). Radionuclide retention rate was 25.4% in the experimental group and 39.4% in the control group (P>0.05). The mean semi-emptying time in the distal stomach was 25.3 min in the experimental group and 10.5 min in the control group (P<0.01). Radionuclide retention rate was 46.4% in the experimental group and 18.7% in the control group (P<0.01).

CONCLUSIONThe abnormal myoelectricity in the region of gastroduodenal stoma may delay liquid gastric emptying in pylorectomy rats.