Purpose: Although sigmoid volvulus (SV) causes acute obstruction, its pathogenesis and mechanism of torsion are unknown, and few reports have described its pathological findings. Here, we evaluated the clinicopathological characteristics of volvulus and factors contributing to volvulus of the sigmoid colon.
Methods: We compared 14 patients with SV (10 men and 4 women; median age, 78.5 years) with 14 age- and sex-matched control patients for differences in clinical characteristics, focusing on dysmotility (enteric visceral myopathy, neuropathy, and mesenchymopathy).
Results: Of the 14 SV patients, 7 had recurrent volvulus, 11 had an associated condition, and 5 required emergency surgery. Atrophy and fibrosis of the inner muscle were more prevalent in the SV than control patients (p = 0.041). Median extent (per centimeter of muscularis propria) of the myenteric plexus (12.5 versus 17.5, p < 0.001) and submucous plexus (15.0 versus 25.5, p < 0.001) was lower in the SV patients, as were the median numbers of myenteric (9.7 versus 30.4, p < 0.001) and submucous ganglion cells (10.0 versus 23.2, p < 0.001). Inflammatory neuropathy was more prevalent in the SV than control patients (p = 0.046); whereas, the prevalence of mesenchymopathy did not differ (p = 0.481).
Conclusions: A decrease in the extent of enteric plexus and ganglion cells precedes the clinical manifestation of SV. Although further elucidation is needed, this decrease may play an important role in the diagnosis of SV and in identifying the mechanism leading to torsion in SV.