Does the Ileal Brake Contribute to Delayed Gastric Emptying After Pancreatoduodenectomy?

Abstract

Delayed gastric emptying (DGE) represents a significant cause for morbidity following pancreatoduodenectomy (PD). At a time when no specific and universally effective therapy exists to treat these patients, elucidating other potential (preventable or treatable) mechanisms for DGE is important. The aim of the manuscript was to test the hypothesis that ileal brake contributes to DGE in PD patients receiving jejunal tube feeding by systematically reviewing experimental and clinical literature. A series of clinically relevant questions were framed related to the potential role of the ileal brake in development of DGE post-PD and formed the basis of targeted literature searches. A comprehensive search of major reference databases from January 1980 to June 2015 was carried out which included human and animal studies. The ileal brake is a feedback loop neurally mediated by the vagus and sympatho-adrenergic pathways and hormonally by gut peptides including glucagon-like peptide-1, peptide YY (PYY), and neurotensin. The most potent stimulus for this inhibitory reflex is intra-ileal fat. There is evidence to indicate the role of an inhibitory reflex (on gastric emptying) mediated by PYY and CCK which, in turn, are stimulated by nutrient delivery into the distal small intestine providing indirect support to the role of ileal brake in post-PD DGE. The ileal brake is a likely factor contributing to DGE post-PD. While there has been no study to directly test this hypothesis, there is compelling indirect evidence to support it. Designing a trial that would answer such a question appears to be the most appropriate way forward.

Impact of gastric resection and enteric anastomotic configuration on delayed gastric emptying after pancreaticoduodenectomy: a network meta-analysis of randomized trials

“…The route of gastro-or duodenojejunostomy (antecolic vs retrocolic), anastomotic reconfiguration method (Billroth II vs Roux-en-Y), and addition of Braun enteroenterostomy have been commonly investigated for their role in DGE 18,66 , but there is a paucity of physiological literature justifying specific mechanisms. Some hypothesise excess torsion or poor angulation of the gastro-enteric anastomosis may contribute to DGE through mechanical obstruction, but this requires further exploration in future studies 67 . The poor performance of approaches that use retrocolic gastro-enteric anastomosis for DGE in our study may support this hypothesis, potentially due to the possibility of mechanical obstruction through a tight transmesocolic window 47 .…”

Impact of gastric resection and enteric anastomotic configuration on delayed gastric emptying after pancreaticoduodenectomy: a network meta-analysis of randomized trials

“…The various anatomical differences that result from the resection and reconstruction configurations for PD have been widely examined in relation to their roles in DGE 16 , 67 . Some hypothesize excess torsion or poor angulation of the gastroenteric anastomosis may be mechanical factors that contribute to DGE 68 . Mechanical obstruction caused by a tight transmesocolic window 44 might be reflected in the poor performance of approaches that use retrocolic gastroenteric anastomosis for DGE in the present study.…”

High temporal resolution gastric emptying breath tests in mice

“…The occurrence of a second peak in gastric emptying curves likely reflects intestinal feedback to the stomach; however, the rate of gastric emptying is not influenced by the presence or absence of two peaks. Therefore, intestinal feedback, manifest as two‐phase gastric emptying, may not contribute to diabetic gastroparesis, but may contribute to delayed gastric emptying in other conditions, for example, following pancreatoduodectomy …”