Role of the Enteric Nervous System in the Elongated Sigmoid Colon of Patients With Sigmoid Volvulus

Abstract

To clarify the physiologic function of the enteric nervous system (ENS) in the elongated sigmoid colon (ESC) of patients with sigmoid volvulus (SV), we examined the enteric nerve responses in lesional and normal longitudinal muscle strips (LMS) derived from patients with ESC and patients who underwent colon resection for colonic cancers. Thirty preparations of LMS were taken from the lesional sigmoid colons of 10 ESC patients with SV (8 men and 2 women, aged 53 to 80 years, mean 66.2 years). Forty preparations of LMS were taken from the normal sigmoid colons (NSC) of 20 patients with colonic cancer (12 men and 8 women, aged 55 to 76 years, mean 62.3 years). A mechanographic technique was used to evaluate in vitro muscle responses to electrical field stimulation (EFS) before and after treatment with various autonomic nerve blockers. Response to EFS before blockade of the adrenergic and cholinergic nerves was as follows: NSC and ESC significantly demonstrated relaxation reaction rather than contraction reaction (P ¼ 0.0253, P , 0.0001, respectively). ESC showed relaxation reaction more than NSC (P ¼ 0.1138). Response to EFS after blockade of the adrenergic and cholinergic nerves was as follows: NSC and ESC significantly demonstrated relaxation reaction via nonadrenergic noncholinergic (NANC) inhibitory nerves rather than contraction reaction via NANC excitatory nerves (P , 0.0001, P , 0.0001, respectively). ESC with SV significantly showed relaxation reaction more than NSC (P ¼ 0.0092). An increased response of relaxation mediated NANC inhibitory nerves may play a role in impaired motility in the ESC of patients with SV.

Clinical Features and Colonic Motor Disturbances in Chronic Megacolon in Adults

“…The following disturbances have been documented in the literature in idiopathic chronic megacolon: a relative increase in non-adrenergic, non-cholinergic (NANC) inhibitory neuronal input to smooth muscle with a concomitant relative decrease in excitatory cholinergic and NANC nerves [21] or a reduction in ICCs [22]. Connective tissue disorders predisposing to megacolon have been less well characterized.…”

Should we recommend PEC and when?

“…Indeed, from an anatomical point of view, 2 subtypes of sigmoid volvulus can be characterized using computerized tomography or (less and less frequently) by barium enema: 1) a twist of the sigmoid colon over its mesenteric axis, which is the most well-known subtype, resulting in the endoscopic aspect of “closed-loop” with 2 spiral stenosis; and 2) a twist of the sigmoid colon over its longitudinal axis, which was only discovered in 1992 but might account for up to 70 % of occlusions 11 and results endoscopically in a single spiral stenosis. Whether these anatomical differences play a significant role regarding disease evolution and PEC efficacy remains unknown, as does the role of other parameters such as colonic dysmotility or enteric nerves alterations 12 .…”