Post‐operative ileus: definitions, mechanisms and controversies

Abstract

Post‐operative ileus (POI) is a syndrome of impaired gastrointestinal transit which occurs following abdominal surgery. There are few effective targeted therapies for ileus, and research has been limited by inconsistent definitions and an incomplete understanding of the underlying pathophysiology. Despite considerable effort, there remains no widely‐adopted definition of ileus, and recent work has identified variation in outcome reporting is a major source of heterogeneity in clinical trials. Outcomes should be clearly‐defined, clinically‐relevant, and reflective of the underlying biology, impacts on hospital resources and quality of life. Further collaborative efforts will be needed to develop consensus definitions and a core outcome set for postoperative gastrointestinal recovery. Investigation into the pathophysiology of POI has been hindered by use of low‐resolution techniques and difficulties linking cellular mechanisms to dysmotility patterns and clinical symptoms. Recent evidence has suggested the common assumption of post‐operative GI paralysis is incorrect, and that the distal colon becomes hyperactive following surgery. The post‐operative inflammatory response is important in the pathophysiology of ileus, but the time course of this in humans remains unclear, with the majority of evidence coming from animal models. Future work should investigate dysmotility patterns underlying ileus, and identify biomarkers which may be used to diagnose, monitor and stratify patients with ileus.

From Postoperative Ileus to Palliative Care: A Case Report

“…Inflammatory cells get activated and autonomic dysfunction occurs, resulting in the modulation of gastrointestinal hormone activity. Therefore, older patients and patients with comorbidities who have undergone long and difficult open surgeries requiring transfusion or excessive fluid support are at higher risk (7)(8)(9). N.Ö.…”

Muscularis Macrophages in Healthy and Diseased Gut

“…Extrinsic innervation by the vagus nerve plays an important role in regulating acetylcholine signaling [44] and counterbalancing sympathetic neuro-inflammatory interaction [42]. Finally, recent experimental evidence has illustrated the paramount importance of MMs as intermediate factors in motility disorders of the gastrointestinal tract, such as gastroparesis [13], post-operative ileus [72] and intestinal ischemia-reperfusion injury [13], leading to interesting etiopathogenic and treatment-implicative considerations.…”

“…This results in prolonged hospitalization and recovery time, reducing patient quality of Phagocytosis -Main Key of Immune System life and increasing healthcare expenditure. Although the pathophysiology of POI is complex, it seems to be arising in a background of neurogenic and inflammatory deregulation, mediated by corticotropin-releasing factor, which promotes central and autonomic nervous system response [72]. The resulting inflammatory response is characterized by sustained expression of intercellular adhesion molecule-1 (ICAM-1) and P-selectin, which both facilitate circulating monocyte extravasation [73].…”

Right colectomy from open to robotic — a single-center experience with functional outcomes in a learning-curve setting

“…The pathophysiology of prolonged postoperative bowel dysfunction is uncertainly multifactorial but currently not fully understood [ 58 ]. Although the literature previously suggests that intracorporal anastomoses are beneficial regarding the duration of postoperative bowel recovery, our data give some important insights in the pathophysiology of prolonged gastrointestinal dysfunction: neither duration of surgery nor extent of CME with central lymph node harvesting but greater extent of ileo-colic manipulation, higher trauma to the abdominal cavity, and more severe systemic inflammatory response, both might trigger opioid-based pain therapy, contribute to prolonged gastrointestinal dysfunction in the COS and ECA groups ( p = 0.0009 and p = 0.020 versus ICA, respectively) [ 33 , 57 , 59 ]. Furthermore, regression analyses clearly demonstrate the harmful effect of gastrointestinal dysfunction on patient outcome: delayed postoperative bowel dysfunction contributes to longer postoperative in-hospital stay especially in patients who underwent COS ( r 2 = 0.187, p = 0.045) for oncologic RC.…”