A study on the congruence and proximity of the sling and clasp fibres at the cardio-esophageal junction of the stomach

Abstract

Background and Aim: The cardio-esophageal sphincter that is located in close longitudinal proximity to the origin of the lesser curvature of the stomach has a unique pattern of external muscle bres whose inner oblique layer would normally form an elongated sling and the middle partially circular layer would form a projecting clasp into the already existing muscular sling of the former congruently, which would result in the formation of an anatomical sphincter in that area that would normally be devoid of the external longitudinal muscle layer coat. Certain authors have disagreed with the notion of this standard literature and have proposed that the clasp and sling bres need not necessarily be congruent and may even remain independent of each other with partial contributions from the longitudinal muscle layers as well that may arise tangentially in different populations, which may in turn contribute to re ux esophagitis in that population. Hence, the clasp and sling bre muscular patterns were observed in six formalin-embalmed cadavers at the department of anatomy in a tertiary care institute as part of routine dissections in series, and the ndings were then reported.Findings: At the junction of the lesser curvature of the stomach with the oesophagus, all 6 cadavers showed a longitudinal sling pattern as opposed to the conventional oblique sling. The circular muscle layer was found to be merged with the outer longitudinal muscle layer to form the sling that pulled away from the clasp, resulting in a loss of congruency for the same. The clasp bres, however, were found to be contributed by the inner oblique muscle layer. The conventional perpendicular or tangential merging of the clasp with the sling was not observed; instead, an obtuse, blunt angular merging of the clasp with the sling was observed.Discussion -The deviation of the sling from the clasp could indicate a lack of a proper t between them at the cardioesophageal sphincter. The lack of robustness in the attachment of the clasp to the sling may possibly contribute to the diminished taut pull of the clasp in this subset of the population. These would be signi cant determinants for a predisposition to re ux esophagitis and Barrett's oesophagus.