Congenital systemic arteriovenous fistulas

Background: Data on congenital systemic arteriovenous fistulas are largely based on individual case reports. A true systemic arteriovenous fistula needs to be differentiated from other vascular malformations like capillary or venous hemangiomas, which are far more common. Objectives: We sought to identify the varied symptoms, diagnostic challenges, describe interventional treatment options, and postulate an embryological basis for this uncommonly described entity. Methods: This is a descriptive study of a cohort of systemic arteriovenous fistulas seen in the department of pediatric cardiology at a tertiary cardiac institute from 2010 to 2020, with prospective medium-term follow-up. A total of seven cases were identified. The diagnosis was confirmed by computed tomographic imaging, magnetic resonance angiography, or conventional angiography. Results: All were successfully closed using duct occluders or embolization coils with no recurrence in six cases over a median duration of follow-up of 48 months (interquartile range: 16; 36–52 months). Four of the seven cases underwent follow-up imaging using echocardiography or ultrasound. Conclusion: The incidence of congenital systemic arteriovenous fistulas is low and accounted for 0.009% of pediatric outpatients seen over 10 years at our institute. The spectrum of clinical presentation varies from an innocuous swelling or a pulsating mass to frank heart failure. Strong clinical suspicion and advanced imaging modalities have helped identify some hitherto undescribed connections. Large malformations with multiple communications may persist or recur despite transcatheter closure.