Ventricular Septal Crypts: Remnants of Spontaneous Interventricular Defect Closure?

Background: Ventricular crypts are quite a common finding during cardiac imaging, but their etiology is unclear. A possible final result of a spontaneous ventricular septal defect closure has been supposed but never investigated in earlier studies. Method: From January 1997 to December 2020, all newborns diagnosed to have a ventricular septal defect were prospectively entered in our database and those with an isolated defect were included in the study. Ventricular septal defects were classified into four types: perimembranous, trabecular muscular, inlet and outlet. A long-term follow up was performed in order to visualize the possible residual formation of a septal myocardial crypt. Results: A total of 376 isolated ventricular septal defects (314 muscular and 54 perimembra-nous, 4 inlet, 4 outlet) were detected. Follow up ranged from 1 to 23 years and showed that, among muscular type, a spontaneous closure occurred in 284 (91%), 26 did not close (8,28%), 2 required surgical intervention (0,63%), 3 were lost at follow up (0,95%). During this period, after spontaneous defect closure closure, 20 crypts were found (6,4%). Conclusion: This study shows that a muscular ventricular septal defect may evolve in the 6.4% of cases in a residual septal crypt. Although septal crypts occur more frequently in patients affected by hypertrophic and hypertensive cardiomyopathy, they may also represent the evolution of a spontaneous closure of a muscular interventricular defect.