Long-Term Effects on Pressure and Electromyography in a Rat Model of Anal Sphincter Injury

Abstract

Anal pressures recover significantly after sphincterotomy. Pudendal nerve transection caused atrophy of the external anal sphincter that was reflected by decreased pressures and electromyography. The results of this study can contribute to a better understanding of the mechanisms that lead to fecal incontinence and can be used to test the efficacy of therapies.

Functional Outcome of Human Adipose Stem Cell Injections in Rat Anal Sphincter Acute Injury Model

“…Salcedo et al stated that rat anal pressures tend to return to baseline after sphincterotomy at 4 weeks even without intervention, but this does not occur after pudendal nerve transection 42. In our results, both resting and contraction anal pressures were significantly lower in both control groups at 2 and 4 weeks compared with the hASC treatment groups.…”

Electromyography of Pelvic Floor Muscles in Rats

“…Several muscles in or close to the pelvic floor have been studied in rats, including the pubococcygeus, iliococcygeus, EUS, and external anal sphincter (EAS) muscles Salcedo et al 2010;Thor & de Groat 2010). EUS EMG in female rats has been investigated more often than EMGs of the other pelvic or perineal muscles www.intechopen.com because of the clinical relevance to stress incontinence and urodynamic testing (Jiang et al 2009b;Kerns et al 2000;Peng et al 2006;Thor & de Groat 2010).…”

“…In addition, the motoneurons innervating the EUS and EAS in rats are anatomically separated in the spinal cord (McKenna & Nadelhaft 1986). Nonetheless, EAS EMG has been studied in rats for specific purposes (Holmes et al 1998;Salcedo et al 2010), such as for development of an animal model of fecal incontinence (Zutshi et al 2009). EAS EMG is recorded using a 30 G concentric monopolar needle after inserting it into the EAS.…”

“…The signals are then rectified ( Figure 7) and mean amplitude is calculated. To calculate mean firing rate of the EMG signal (previously termed "mean frequency" in Jiang et al 2009aJiang et al , 2009bSalcedo et al 2010;Steward et al 2010), a threshold for differentiating noise from neuromuscular activity is set at a certain voltage (such as 0.25 µV), depending on the amplitude of noise in a particular situation. The mean firing rate is calculated by counting the number of peaks above the threshold per second (Steward et al 2010).…”

A novel animal model of long-term sustainable anal sphincter dysfunction

“…However, these 7 7 studies were based on the hypotheses that these models had complete fecal incontinence. Since then, several conventional anal dysfunction animal models were reported, such as the sphincterotomy model (19)(20)(21)(22), cryoinjured anal sphincter model (23) and pudendal nerve transection model (19,20).…”