State-of-the-art colorectal disease: postoperative ileus

Abstract

Purpose: Postoperative Ileus (POI) remains an important complication for patients after abdominal surgery with an incidence of 10-27% representing an everyday issue for abdominal surgeons. It accounts for patients' discomfort, increased morbidity, prolonged hospital stays, and a high economic burden. This review outlines the current understanding of POI pathophysiology and focuses on preventive treatments that have proven to be effective or at least show promising effects.

Methods: Pathophysiology and recommendations for POI treatment are summarized on the basis of a selective literature review.

Results: While a lot of therapies have been researched over the past decades, many of them failed to prove successful in meta-analyses. To date, there is no evidence-based treatment once POI has manifested. In the era of enhanced recovery after surgery or fast track regimes, a few approaches show a beneficial effect in preventing POI: multimodal, opioid-sparing analgesia with placement of epidural catheters or transverse abdominis plane block; μ-opioid-receptor antagonists; and goal-directed fluid therapy and in general the use of minimally invasive surgery.

Conclusion: The results of different studies are often contradictory, as a concise definition of POI and reliable surrogate endpoints are still absent. These will be needed to advance POI research and provide clinicians with consistent data to improve the treatment strategies.

Keywords: Enhanced recovery; Fast-track; Perioperative management; Postoperative ileus; Prevention.

Fig. 1

Current hypothesis of the complex orchestrated immunomodulatory effects on POI: Enteric glia are activated by purinoceptor (P2XR2) response to ATP and a IL-1 receptor type 1 (IL1R1) mediated response to IL-1α released after the trauma and IL-1ß that is dependent on the absent in melanoma 2 (AIM2) inflammasome. This and the activation of resident macrophages with consecutive leukocyte infiltration and release of nitric oxide (NO), reactive oxygen species (ROS), and prostaglandins contribute to POI development and provide potential new targets in POI prevention