Stereoscopic Quantitative Analysis of Enteric Nervous System in Patients With Slow Transit Constipation

In previous studies, abnormal changes in the enteric nervous system (ENS) were often found in intestinal specimens from patients with slow transit constipation (STC). However, there are no clear pathological diagnostic criteria for STC due to the lack of accurate quantitative data references. The association of ENS alterations with STC remains unanswered. Full-thickness colon specimens were obtained from 10 STC patients who underwent subtotal colectomy and 20 colon cancer patients who underwent radical colectomy. Using stereoscopic imaging combined with tissue clearing, immunohistochemistry, and confocal imaging techniques, the differences in ENS quantitative data between STC patients and controls were observed, and the correlation between this change and the clinical symptoms of STC was analyzed. Quantitative analysis demonstrated significant reductions in both myenteric plexus density (descending: control: Mean ± SD = 27.0% ± 3.0% vs. STC: 22.2% ± 3.5%, p = 0.004; sigmoid: 26.1% ± 5.6% vs. 20.3% ± 4.1%, p = 0.018) and ganglion density (descending: 8.7% ± 2.6% vs. 5.9% ± 2.1%, p = 0.015; sigmoid: 11.5% ± 2.3% vs. 8.7% ± 3.3%, p = 0.042) in STC patients compared to controls. After stretch correction, we observed significant decreases in both neuronal populations (descending: 205.2 ± 23.2 vs. 180.3 ± 18.6, p = 0.016; sigmoid: 168.3 ± 20.0 vs. 137.2 ± 18.0, p = 0.002) and ganglion volumes (descending: 1.53 ± 0.42 vs. 1.19 ± 0.24, p = 0.045; sigmoid: 1.74 ± 0.42 vs. 1.36 ± 0.30, p = 0.031) in STC patients compared to controls. Furthermore, the proportion of neuronal subtypes in STC patients was significantly altered. Notably, several of these neuropathological changes correlated significantly with STC symptom severity. This study revealed abnormal changes in colonic ENS in STC patients through three-dimensional imaging and quantitative analysis of ENS. There was a certain correlation between ENS changes and constipation symptoms in STC patients, and further studies of other components of ENS are needed to clarify the correlation between STC and ENS.