RESUMEN
Abstract Background: Fontan circulation can be associated with significant morbidity, especially Protein-Losing Enteropathy (PLE). Echocardiographic parameters can provide valuable diagnostic information about a patient's risk of developing PLE after Fontan surgery. Objectives: To describe echocardiographic/ultrasonographic parameters associated with PLE in patients after Fontan surgery through a systematic review with meta-analysis. Methods: A literature search was performed in electronic databases to identify relevant studies about echocardiographic parameters and PLE prediction in children after Fontan surgery. The search terms used were: "echocardiography", "ultrasonography", "Fontan," and "protein-losing enteropathy". A p < 0.05 was considered statistically significant. Results: A total of 653 abstracts were obtained from electronic databases and bibliographic references. From these, six articles met criteria to be included in the qualitative analysis and three in the quantitative (meta-analysis). The resistance index in the superior mesenteric artery was described in three studies, and the quantitative analysis showed statistical significance (p < 0.001). Other echocardiographic and ultrasonographic parameters were also described, albeit in single studies not allowing a meta-analysis. Conclusion: This systematic review with meta-analysis identified echocardiographic and ultrasonographic parameters related to PLE in patients with Fontan physiology. Vascular ultrasonography seems to play a prominent role in this aspect, but additional studies are needed to increase the degree of evidence.