Human colonic smooth muscle electrical activity during and following recovery from postoperative ileus. Condon, Robert E., Verne E. Cowles, Alvaro A. B. Ferraz, Senol Carilli, Mark E. Carlson, Kirk Ludwig, Ercument Tekin, Kenan Ulualp, Fikret Ezberci, Yutaka Shoji, Philip Isherwood, Constantine T. Frantzides, William J. Schulte. Department of Surgery, the Digestive Disease Research Center, and the Clinical Research Center, Medical College of Wisconsin, and the Surgical Research Service, Zablocki Veterans Administration Medical Center, Milwaukee, Wisconsin, 53226
APStracts 2:0091G, 1995.
Colon smooth muscle electrical control (ECA) and response (ERA) activities were recorded for up to 4 weeks postoperatively from 48 patients following major abdominal operations. Bipolar electrodes were implanted into right and left colon circular muscle, exteriorized through the flanks, and signals tape-recorded for 2-24 hrs daily beginning on the first postoperative day. A computer program was used for data reduction and analysis. Recorded signals were digitized and filtered. The ECA frequency components were identified by fast Fourier transformation, and their relative tenancy in low, mid and high frequency ranges determined. Short and long ERA burst duration and frequency, and number and velocity of propagating long ERA bursts, were determined. ECA was omnipresent and exhibited a downshift of the dominant frequency from the mid to the low range as recovery from postoperative ileus progressed. Concurrently, first in the right and then in the left colon, the frequency of long ERA bursts increased followed by the appearance of propagating long ERA. After the sixth postoperative day, no further significant changes in parameters of colon electrical activity occurred with time.

Received 17 May 1994; accepted in final form 29 March 1995.
APS Manuscript Number G184-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 16 May 1995.