A Histomorphometric Analysis of Interganglionic Distance in the Myenteric Plexus of the Entire Large Intestine of Aborted Human Foetuses: A Cross-sectional Study

Abstract

Introduction: The Enteric Nervous System (ENS) contributes to the innervation of the gut and is considered the second brain in the gut. It is a part of the peripheral nervous system and the ganglionated plexus (GP) of enteric neurons, present in the layers of the digestive tract, is more complex than any other structure of the peripheral nervous system. The establishment of a valid standard method for quantitative analysis of the myenteric plexus has been a topic of debate among enteric neuropathologists and is essential for better characterisation of patients with gut dysmotility. Aim: To determine the histomorphometric analysis of the interganglion distance of the myenteric plexus in the entire large intestine of aborted human foetuses. Materials and Methods: A cross-sectional descriptive study was carried out in the Department of Anatomy at Pondicherry Institute of Medical Sciences, Pondicherry, India. The study duration was eight years and seven months, from October 2014 to May 2022. A total of 50 aborted human foetus samples were collected from Rajiv Gandhi Government Women and Children’s Hospital, Puducherry, India, from the Department of Obstetrics and Gynaecology. The age of the aborted human foetuses was determined based on Biparietal Diameter (BPD) and Crown Rump Length (CRL) and correlated with clinical history. The aborted human foetuses were assigned to two groups: group A (n=29), ≤20 Weeks of Gestation (WG), and group B (n=21), ≥20 WG. Nicotinamide Adenine Dinucleotide Phosphate (NADPH) diaphorase histochemistry, an enzyme histochemistry technique, was used to study the tissue preparations. Statistical significance was determined using Statistical Package for Social Sciences (SPSS) version 20.0, International Business Machines (IBM) corporation. The independent sample t-test was conducted for parametric analysis. Results: The interganglion distance was measured from the caecum (A1 segment) to the anal canal (A7 segment) in aborted foetuses of less than 20 WG. The mean values ranged from 78.86±38.09 μm to 126.94±23.87 µm in foetuses of less than 20 WG. The mean values ranged from 66.41±8.05 μm to 107.67±30.17 µm in aborted human foetuses of more than 20 WG. Conclusion: The anal canal showed a long interganglion distance. The average reference values were found to be helpful as a diagnostic tool for identifying disorders related to gut innervation and motility.

Keywords

• aganglionosis
• enteric neurons
• ganglionated plexus
• nervous system