Electrophysiological study of the rectosigmoid canal: evidence of a rectosigmoid sphincter

Abstract

Previous studies strongly suggest the presence of a sphincter at the rectosigmoid junction, an area with a mean length of 2.8 cm in adults, called the rectosigmoid canal (RSC). To find supporting evidence of a sphincteric function for the RSC, two recording electrodes were applied to each of the sigmoid colon (SC), RSC and rectum (R) in 11 subjects during operative repair of huge incisional hernias. The RSC, SC and R were individually stimulated by a further electrode and their pressures monitored by a three-channel microtip catheter. The variables of the slow waves or pacesetter potentials, recorded at rest from the RSC and R, were significantly higher than those of the SC. While the frequency and conduction velocity of pacesetter potentials of the RSC and R were similar, the potential pacesetter amplitude of the RSC was significantly higher. The increase of the electrical activity and pressure upon electrostimulation was significantly greater in the RSC than that of the SC or R. Electrostimulation led to an increase in pressure of all three areas, the RSC increase being significantly the greatest. The greater increase of the electrical activity and pressure of the rectosigmoid canal upon electrostimulation, compared to that of the SC or R, strongly supports the presence of a rectosigmoid sphincter.

Electrical stimulation induces propagated colonic contractions in an experimental model

“…Peristaltic and antiperistaltic pressure waves were observed following electrical stimulation, as described previously in animals29 and humans23. Pressure waves were related to displacement of the magnet, but a pressure increase was not always related to faecal movement22, 23, 30, 31. Segmental colonic shortening, associated with mass movement, induced lower changes in intraluminal pressure than radial contractions32.…”

Transvaginal rigid-hybrid natural orifice transluminal endoscopic surgery technique for anterior resection treatment of diverticulitis: a feasibility study

“…The rectum was retracted upward so the loose areolar plane between the mesorectum and the presacral fascia could be identified. The proximal rectum was mobilized to completely resect the high-pressure zone of the rectosimoid junction [19]. Thereby, the right and the left hypogastric nerves were clearly visualized and preserved from damage.…”

Onset of Ischemic Colitis Following Use of Electrical Muscle Stimulation (EMS) Exercise Equipment

“…In this case, the onset of ischemic colitis immediately followed the use of an EMS device, although the causal relationship is uncertain. The effect of one muscular contraction at a voltage of 1.20 V and current of 2.40 mA on the colorectal mucosa is small (9). Electrical and mechanical stimulation of the lower abdomen by the EMS equipment was thought to either induce colonic or vascular spasm, leading to ischemia, or dislodge thrombi associated with atrial fibrillation or atherosclerosis, causing embolisation and ischemia.…”