Postoperative ileus—An ongoing conundrum

Abstract

Postoperative ileus refers to an arrest of gastrointestinal motility that complicates the recovery of up to 30% of patients undergoing gastrointestinal surgery. 1,2 It is distressing to the patient and surgeon and is expensive to manage. [3][4][5][6][7] This disruption of gut motility has its origins in the handling and resection of the gut during surgery. In brief, this activates mast cells in the gut wall and triggers subsequent infiltration by leukocytes. 8,9 This inflammatory process then causes long-term sensitization of visceral afferent nerve fibers which project to the spinal cord. These activate preganglionic and then postganglionic sympathetic motor neurons which inhibit gut motility for many hours to days. 10 Currently, treatment of patients with ileus is largely supportive. Many measures have been tried to prevent ileus 7 but, in most cases, randomized controlled trials (RCTs) have shown them to be either ineffective or minimally effective. There is a gap in understanding between the short-term arrest of gut activity seen in experimental animals and the condition in humans. | WHAT IS ILEUS?Postoperative ileus, recognized and investigated for over 100 years, 11 is a common condition and major clinical problem that occurs soon after surgery. It is largely associated with gastrointestinal surgery but can also manifest from other retroperitoneal pathology such as aortic or urinary disorders. It is characterized by a transient interruption of normal gut motor activity. Usually, postoperative ileus has relatively little impact on patient recovery and hospital discharge.

Sympathetic Pathways Target Cholinergic Neurons in the Human Colonic Myenteric Plexus

“…The specific details of these connections may be important in helping us to understand the causes of functional colonic disorders in humans. For instance, post-operative ileus, the temporary cessation of GIT motility following surgery, has a significant sympathetic component ( Behm and Stollman, 2003 ; Bauer and Boeckxstaens, 2004 ; Wattchow et al, 2020 ). Slow transit constipation is a debilitating disorder with a largely unknown aetiology, however, extrinsic sympathetic inputs running in the extrinsic nerves have been implicated ( Dinning et al, 2016 ).…”

Extra Loading Dose of Dexmedetomidine Enhances Intestinal Function Recovery After Colorectal Resection: A Retrospective Cohort Study

“…Surgical operation activated the neurogenic stage of POGD from skin incision to 3–6 h postoperatively, in which the inhibition of vagus nerve tone widely inhibited gastrointestinal motility ( Bauer and Boeckxstaens, 2004 ; Bragg et al, 2015 ; Stakenborg et al, 2017 ; Wattchow et al, 2021 ). The extra loading dose of Dex had a 4.9-fold higher peak concentration than without this dose at the end of the surgery, and its effects lasted longer up to 8 h postoperatively, which covered the neurogenic stage of POGD.…”

“…Continuous intestinal inflammation prolongs the excessive excitement of the intestinal sympathetic nerve and inhibits gastrointestinal peristalsis ( Bauer and Boeckxstaens, 2004 ; Wattchow et al, 2021 ). The inflammatory stage of POGD covers from 3 to 4 h intraoperatively to 72 h postoperatively ( Stakenborg et al, 2017 ).…”

“…The occurrence of POGD prolongs hospitalization time and increases treatment costs enormously ( Vather et al, 2013 ; Murphy et al, 2016 ; Gao et al, 2021 ). Various strategies have been used to prevent POGD, including early postoperative feeding, avoidance of nasogastric tube use, limitation of fluid infusion, the use of minimally invasive surgery, and the use of symptomatic treatment drugs and chewing gum, but their effectiveness is limited because of the lack of pathogenesis-related targeted therapies ( Bragg et al, 2015 ; Wolthuis et al, 2016 ; Wang et al, 2020 ; Wattchow et al, 2021 ).…”

The human enteric nervous system. Historical and modern advances. Collaboration between science and surgery

“…While intramural enteric neural pathways play a crucial role in gut function, the gut is also innervated by extrinsic neural pathways. Sensory and motor nerves extrinsic to the bowel wall exert powerful influences upon intestinal motor function and secretion, shown by the cessation of intestinal motor activity seen in ileus 32 . This is a fertile area for surgical research as ileus represents a major problem in recovery from gut surgery.…”