Colon Myoelectric Activity Measured After Open Abdominal Surgery with a Noninvasive Wireless Patch System Predicts Time to First Flatus

J Gastrointest Surg. 2019 May;23(5):982-989. doi: 10.1007/s11605-018-4030-4. Epub 2018 Nov 2.


Background: Passage of flatus after abdominal surgery signals resolution of physiological postoperative ileus (POI) and often, particularly after complex open surgeries, serves as the trigger to initiate oral feeding. To date, there is no objective tool that can predict time to flatus allowing for timely feeding and optimizing recovery. In an open, prospective study, we examine the use of a noninvasive wireless patch system that measures electrical activity from gastrointestinal smooth muscles in predicting time to first flatus.

Methods: Eighteen patients who underwent open abdominal surgery at El Camino Hospital, Mountain View, CA, were consented and studied. Immediately following surgery, wireless patches were placed on the patients' anterior abdomen. Colonic frequency peaks in the spectra were identified in select time intervals and the area under the curve of each peak times its duration was summed to calculate cumulative myoelectrical activity.

Results: Patients with early flatus had stronger early colonic activity than patients with late flatus. At 36 h post-surgery, a linear fit of time to flatus vs cumulative colonic myoelectrical activity predicted first flatus as much as 5 days (± 22 h) before occurrence.

Conclusions: In this open, prospective pilot study, noninvasive measurement of colon activity after open abdominal surgery was feasible and predictive of time to first flatus. Interventions such as feeding can potentially be optimized based on this prediction, potentially improving outcomes, decreasing length of stay, and lowering costs.

Keywords: Colon myoelectrical activity; First flatus; Ileus; Noninvasive wireless patch; Open abdominal surgery; Postoperative recovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdomen / surgery
  • Adult
  • Aged
  • Aged, 80 and over
  • Colon / physiopathology*
  • Female
  • Flatulence / physiopathology
  • Humans
  • Ileus / physiopathology*
  • Male
  • Middle Aged
  • Muscle, Smooth / physiopathology*
  • Pilot Projects
  • Postoperative Complications / physiopathology
  • Predictive Value of Tests
  • Prospective Studies
  • Recovery of Function
  • Time Factors
  • Wireless Technology*