Morphological Study of the Thebesian Valve in Fresh Autopsied Adult Human Hearts.

Background The coronary sinus (CS) and its tributaries have been used to perform various electrophysiological and cardiac interventional procedures which require cannulation. The Thebesian valve (TV) guarding the coronary sinus orifice (CSO) exhibits morphological variations which might make cannulation unsuccessful leading to the failure of invasive cardiac procedures. This study aimed to analyze in detail the morphological features of the TV in fresh autopsied human hearts which were representative of the adult population of this region owing to its practical implications in invasive cardiac procedures. Methodology This was a cross-sectional, descriptive study conducted in the Department of Anatomy in collaboration with the Department of Forensic Medicine and Toxicology at Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry. A total of 104 fresh adult heart specimens were collected during the autopsy. The CSO was located, and the characteristic shape, composition, position, and extent of coverage of the CSO by the TV were observed and analyzed. Results The TV was present in 65% of heart specimens. The most common shape was remnant (33%), and the most common site of origin was inferior (63%). The valve composition was thin and membranous in 63% of heart specimens. In 7% of heart specimens, the TV covered more than 75% of the CSO diameter, of which in 4% of heart specimens, the CSO was completely closed and found to be obstructive. Conclusions This study highlights the variability in the morphological structure of the TV in adult human hearts and its potential implications in unsuccessful CS cannulation and failure of invasive cardiac procedures. Thus, prior imaging of the TV should be an integral part of CS cannulation procedures to avoid unsuccessful cannulation and complications related to repeated forceful cannulation.