Complete resection of the gastric antrum decreased incidence and severity of delayed gastric emptying after pancreaticoduodenectomy

Background: Delayed gastric emptying(DGE) is the main complication after pancreaticoduodenectomy(PD), but the mechanism is still unclear. The aim of this study was to elucidate the role of complete resection of the gastric antrum in decreasing incidence and severity of DGE after PD. Methods: Sprague-Dawley rats were divided into three groups: expanded resection(ER group), complete resection(CR group), and incomplete resection(IR group) of the gastric antrum. The tension(g) of remnant stomach contraction was observed. We analyzed the histological morphology of the gastric wall by different excisional methods after distal gastrectomy. Moreover, patients underwent PD at our department between January 2012 and May 2016 were included in the study. These cases were divided into IR group and CR group of the gastric antrum, and the clinical data were retrospectively analyzed. Results: The ex vivo remnant stomachs of CR group exhibited much greater contraction tension than others( P < 0.05). The contraction tension of the remnant stomach increased with increasing acetylcholine concentration, while remained stable at the concentration of 10 × 10-5mol/L. Furthermore, 174 consecutive patients were included and retrospectively analyzed in the study. The incidence of DGE was significantly lower(3.5% vs. 21.3%, P < 0.01) in CR group than in IR group. In addition, hematoxylin-eosin staining analyses of the gastric wall confirmed that the number of transected circular smooth muscle bundles were higher in IR group than in CR group(8.24 ± 0.65 vs. 3.76 ± 0.70, P < 0.05). Conclusions: The complete resection of the gastric antrum is associated with decreased incidence and severity of DGE after PD. Gastric electrophysiological and physiopathological disorders caused by damage to gastric smooth muscles might be the mechanism underlying DGE.