Effect of antecolic or retrocolic reconstruction of the gastro/duodenojejunostomy on delayed gastric emptying after pancreaticoduodenectomy: a meta-analysis

DGE after PD is a frequent complication, which is usually managed by nasogastric drainage and nutritional support by parenteral or enteral routes, with or without prokinetics. Many efforts for reducing the incidence of DGE have been attempted; these include pyloric dilation [18], preservation of the left gastric vein [19], preoperative use of erythromycin [20], and prophylactic octreotide [21]. Other studies evaluated the clinical efficacy of reconstruction procedure of gastric emptying. As compared with Billroth II reconstruction, both Roux-en-Y and Billroth-I reconstructions were found to be associated with higher incidence of DGE [22, 23]. Two routes are usually used for Billroth II reconstruction after PD: the antecolic route or the retrocolic route. A meta-analysis reported the superiority of the antecolic route compared with the retrocolic route concerning the reduction of DGE [3]. However, a significant proportion of data in this meta-analysis came from nonrandomized studies, which may introduce confounding and selection bias that often distort the findings.

The present updated meta-analysis pooled five RCTs and provided clearly the best available evidence on the effect of reconstruction route concerning DGE. In contrast with previously published meta-analysis, the main finding is that the two routes after PD were equally efficient concerning DGE. There is wide variation definition of a DGE in the pancreatic surgery literature. In 2007, the ISGPS proposed a standardized definition of DGE [17]. Three of 5 RCTs used the ISGPS criteria and consistently found that the route of gastro/duodenojejunostomy reconstruction had no significant impact on the incidence and severity of DGE. The pooled data is also in concordance with these RCTs.

The pathogenesis of DGE after pancreatoduodenectomy has been proposed to be multifactorial: disruption of the vagal nerve system; ischemic injury to the antropyloric mechanism; and decreased plasma motilin stimulation caused by resection of the duodenum [20]. From a mechanical point of view, some researchers observed that a transient torsion or angulation of the reconstructed alimentary tract might contribute to DGE [24]. With antecolic reconstruction, the duodenal stump or distal stomach and the descending jejunal loop are set in a straight line. Torsion or angulation of the reconstructed alimentary tract can thus be avoided [25]. However, in case of retrocolic reconstruction, the risk of torsion or angulation can be diminished by suturing the duodenum or distal stomach to the transverse mesocolon [12]. Thus, one can understand that the reconstruction route has no measurable impact on the incidence and severity of DGE.

Regarding the operative technique, it has been suggested that DGE more likely occurs in patients who underwent pylorus-preserving pancreaticoduodenectomy (PPPD) (in comparison with classic Whipple PD). However, a recent meta-analysis of six RCTs showed an overall comparable rate of DGE for both techniques. [26] Also, the type of pancreatic anastomosis (pancreaticogastrostomy and pancreaticojejunostomy) was not significantly associated with DGE [27]. By contrast, there are growing evidences that other intraabdominal complications, such as pancreatic fistula, biliary fistula, intraabdominal collections or abscesses, have a critically influence on DGE. Park et al [28] found that DGE was significantly more frequent among patients with postoperative intraabdominal complications (41.7 % versus 8.8 %; P<0.0001). Similarly, in another report by Horstmann et al [29], DGE almost exclusively occurs as a consequence of other postoperative complications. These findings are supported by those of other reports [21, 30]. Hence, prevention of such complications might reduce the incidence of DGE.

This present analysis has some limitations. First, considerable heterogeneity was detected between studies regarding primary endpoint. The presence of heterogeneity is due to paper by Tani et al [7] in which incidence of DGE of 5 % in their antecolic group compared to 50 % in the retrocolic group (P<0.001). Apart from the fact that there were only 20 patients in each arm in this study, a total of 12/20 patients in the retrocolic group had at least one postoperative complication as compared to 3/20 in the antecolic group might have influenced their results [10]. Second, the number of studies included in this meta-analysis is small. Indeed, randomised trials in surgery are difficult to conduct [31]. Finally, funnel plot analysis suggested the possibility of publication biases. This may relate to our inclusion of English only studies.