Morphometric study of fossa ovale in human cadaveric hearts: embryological and clinical relevance

Abstract

Atrial septal defect (ASD) is the 5th common congenital abnormality at birth. Secundum atrial defect and patent foramen ovale (PFO) are the most common atrial septal defects. In this setting, the anatomical functional characterization of the interatrial septum seems to be of paramount importance not only for device selection but also for therapeutic intervention. This study was carried out to evaluate the morphometric parameters of fossa ovale (FOv) in the human adult cadaveric hearts. For this study, 50 normal cadaveric human hearts available in the department of Anatomy over the period of 3 years were used where size, position, shape, nature of the FOv was noted. The size of the fossa was measured and prominence, location, and extent of the limbus fossa ovalis were observed. The probe patency of foramen ovale (FO) was confirmed. In most specimens, the fossa was oval (80%), the average transverse diameter was 24.21 mm, and the vertical diameter 26.84 mm. In 84% rim was raised. In 56% of cases, the fossa was present at the middle of the interatrial septum. The patency of foramen was observed in 3%. The findings of the present study provide pertinent information on the morphology of the FOv, which may be useful for device selection in treating ASDs and PFO. This would definitely help the clinicians in a deeper understanding of the region as very few cadaveric studies are available in the literature at present.

Keywords: Atrial septal defect; Cadaver; Foramen ovale; Heart; Patent foramen ovale.

Fig. 1

Normal formation of IAS. (A) SP a sickle-shaped crest that descends from the roof of the primitive atrium. Opening between SP and ECC is OP. (B) SP fusing with ECC, perforation in the upper part of SP forms OS. New fold appears from roof as SS. (C) Opening between lower end of SS and upper end of SP is FO. ECC, endocardial cushion; FO, foramen ovale; IAS, inter atrial septum; OP, ostium primum; OS, ostium secundum; SP, septum primum; SS, septum secundum.

Fig. 2

Developmental defects of IAS formation showing. (A) Excessive resorption of SP. (B): Absence of SS. (C) Absence of both SP and SS, leading to a common atrium or Cor triloculare biventriculare. (D) Showing large FO. (E) Showing ASD. ASD, atrial septal defect; IAS, inter atrial septum;O, foramen ovale; PV, pulmonary veins; RV, right ventricle; SP, septum primum; SS, septum secundum.

Fig. 3

Elliptical shape of FOv. (A) Showing raised margin in whole circumference AFO. In upper part shows slit like recess or pouch (white arrows). In lower part a deep recess present (red arrows). (B) Raised margin is present only in upper and anterior part of FO with slit like recess or pouch (white arrows). Blue double headed arrow showing S and I view. AFO, annulus fossa ovalis; CSO, coronary sinus opening; FO, foramen ovale; FOv, fossa ovale; RV, right ventricle; I, inferior; S, superior.

Fig. 4

Showing Position of FOv in the interatrial septum in cadaveric hearts (n=50). FOv, fossa ovale; IVC, inferior vena cava; SVC, superior vena cava.

Fig. 5

Showing different shapes of FOv in the interatrial septum in cadaveric hearts (n=50). FOv, fossa ovale.

Fig. 6

Showing extent and location of Limbus fossa ovalis in the interatrial septum in cadaveric hearts (n=50).

Fig. 7

Large FOv. (A) Showing deep recess in the superior margin (two white arrows), redundancy present in the middle part (asterisk). (B) Showing redundancy in the right part of FOv. In the right part showing bulging towards left atrium. Red arrow is showing vertical diameter, Yellow arrow is showing transverse diameter. Blue double headed arrow showing S and I view. FO, foramen ovale; FOv, fossa ovale; I, inferior; LFO, limbus fossa ovalis; S, superior.

Fig. 8

(A) Showing fibrous brands in the inferior part (yellow arrows). (B) Showing a membrane (red asterisk) in antero superior part of FOv. Blue double headed arrow showing S and I view. FO, foramen ovale; FOv, fossa ovale; I, inferior; S, superior.

Fig. 9

Showing shapes of FOv. (A) Oval shape, (B) Round. Red arrow is showing vertical diameter, Yellow arrow is showing transverse diameter. Double-headed red arrow indicates the long axis and yellow arrow indicates width. Blue double headed arrow showing S and I view. CSO, coronary sinus opening; FO, foramen ovale; FOv, fossa ovale; I, inferior; RV, right ventricle; S, superior; TCV, tricuspid valve.

Fig. 10

Right surface of the interatrial septum. (A) Showing presence of a foramen (yellow asterik). (B) Showing deep recess (red arrow). Blue double headed arrow showing S and I view. FO, foramen ovale; I, inferior; S, superior.