Persistent Eustachian Valve Causing Abdominal and Pelvic Venous System Dilation in a 44-Year-Old Male: A Case Report.

This case report presents a rare incidence of a persistent Eustachian valve (EV) causing notable venous dilation in the abdominal and pelvic regions of a 44-year-old healthy male. Initially presenting with left flank pain, diagnostic evaluations identified a 4.8-mm calculus in the distal left ureterovesical junction. Incidentally, imaging also revealed unexplained venous distensions, subsequently attributed to a prominent EV obstructing the inferior vena cava (IVC). The EV, an embryological structure in fetal circulation that helps divert blood from the IVC to the left atrium via the foramen ovale, typically regresses postnatally. Its persistence into adulthood is uncommon and often does not necessitate intervention. However, a persistent EV is often associated with other cardiac findings, especially a patent foramen ovale (PFO) of an atrial septal defect (ASD). There were some reports demonstrating that persistent EV may play a role in an increased risk of paradoxical cerebral embolism in such cases. Therefore, the case underscores the importance of considering such embryological remnants in the differential diagnoses of unexplained venous distension and cryptogenic stroke. It also highlighted the need for a personalized approach to management, especially during the preparation phase before interventional procedures, such as an ASD closure, to minimize the risks during the operation. Furthermore, it also contributed to a broader understanding of the clinical implications of persistent embryological structures and emphasized the value of meticulous diagnostic processes in identifying the underlying causes of observed anomalies.