Morphology and Topography of Fossa Ovalis, Limbus Fossa Ovalis, and Probe Patency of Foramen Ovale in Formalin-fixed Hearts

Introduction: Understanding the location and morphology of the fossa ovalis (FO) is crucial for radiographic and interventional cardiac procedures. Objective: The aim was to explore the morphology and topography of FO and limbus FO and to correlate them with the dimensions of the heart. The objective was to determine the frequency of congenital disabilities of the interatrial septum (IAS) in our sample population. Materials and Methods: The study included 57 formalin-fixed adult cadaveric hearts. The topography and morphological variants of different shapes of FO and limbus FO were noted. Pearson’s correlation test was performed to assess the association between the dimensions of FO and the heart. Results: In our study, 33 hearts (57.89%) had oval-shaped FO, round in 20 hearts (35.1%), and in 4 hearts (7.01%), it was elliptical in shape. The limbus FO was raised in 46 hearts (80.7%) and this had flat in morphology in 11 hearts (19.3%). The probe patency of the foramen ovale was observed in 10 hearts (17%). The atrial septal defect (ASD) was observed in 12 hearts (21.05%) and one among them had an ostium secundum defect. The length of IAS was 52.5 ± 7.2 mm and the distance between the left margin of the superior vena caval opening and limbus FO was 22.7 ± 5.4 mm. Conclusion: This study provided additional information about the morphological and topographical variations of FO and limbus FO. This knowledge is helpful to cardiologists for diagnosing and correlating the embryological basis of ASDs.