Background: The large intestine is a derivative of the midgut and the hindgut. It is extending from the caecum to the anal canal. The quantitative values of biopsy segments of a particular part of the colon especially the rectum was published but the normal morphometric values of sigmoid colon studies were minimal.
Aim: The present study was designed to determine the quantitative analysis of the myenteric plexus of the sigmoid segment of the large intestine.
Materials and Methods: A Descriptive study was carried out at Pondicherry Institute of Medical Sciences, Pondicherry from the year 2014 to 2022 and the aborted human foetuses samples were collected from Rajiv Gandhi Govt. Women and Children Hospital, Pondicherry, and from Obstetrics and Gynaecology department, Pondicherry Institute of Medical Sciences, Pondicherry. The total sample size was 50 human aborted foetuses. The age of aborted human foetuses was confined to Biparietal diameter, Crown-rump length and correlated with clinical history The aborted human fetuses were assigned into two groups. Group A was from 13 weeks of gestation to 20 weeks of gestation. Group B was from above 20 weeks of gestation to 36 weeks of gestation. The NADPH diaphorase histochemistry, an enzyme histochemistry technique was used to study the tissue preparations. A para median incision over the abdomen was given and exposed the entire large intestine. The entire large intestine was divided into seven segments i.e. A1- caecum, A2- ascending colon, A3- transverse colon, A4 – descending colon, A5- sigmoid colon, A6- rectum and A7 -anal canal. The aborted human foetuses were assigned into two groups (group A (n = 29), ≤ 20 Weeks of Gestation and group B (n= 21) ≥ 20 Weeks of Gestation.
Statistical analysis: The images were captured by using camera attached binocular microscope and the images were analyzed for various parameters of the myenteric plexus of the sigmoid colon by using Image J software. The data were expressed as mean± standard deviation (SD). The independent sample t-test was done for parametric analysis. The SPSS software package version 20.0 was used for statistical analysis.
Results: The foetuses were assigned into two groups. Group A (n = 29), ≤ 20 WG and Group B (n= 21) ≥ 20 WG. The present study reported that the number of nerve cells in a ganglion and the area occupied by nerve cells was increased in group A than the group B.
Conclusion: The total area, perimeter, diameter, muscular area, inter ganglion distance, neurons per ganglion, myenteric fraction and numerical density were compared between the two groups. The normal measurements of the myenteric plexus of the sigmoid colon will be suggestive for denoting the pathological stage of the sigmoid colon in motility disorders.