A comprehensive review of the anatomical variations in the right atrium and their clinical significance

Two cases of catheters inserted from the femoral vein straying into the hepatic vein, possibly owing to a Eustachian valve: a case report

Background

In minimally invasive cardiac surgery (MICS) and extracorporeal membrane oxygenation (ECMO), a guidewire is inserted from the femoral vein (FV) into the right atrium. However, rarely, the guidewire or catheter strays into the hepatic vein (HV) because of the inferior vena cava (IVC)-HV angle. We report two cases in which a guidewire and venous cannula from the FV strayed into the HV, likely owing to a Eustachian valve.

Case presentation

Both patients were women who underwent transesophageal echocardiography-guided FV cannulation. In case 1, a guidewire from the FV strayed into the HV owing to a Eustachian valve. In case 2, ECMO was established postoperatively. Transthoracic echocardiography confirmed the venous cannula had strayed into the HV. Computed tomography indicated IVC-HC angles of 129° (case 1) and 102° (case 2).

Conclusion

A Eustachian valve can impede devices inserted from the FV and even allow them to stray into the HV.

Polygonal surface processing and mesh generation tools for the numerical simulation of the cardiac function

In order to simulate the cardiac function for a patient-specific geometry, the generation of the computational mesh is crucially important. In practice, the input is typically a set of unprocessed polygonal surfaces coming either from a template geometry or from medical images. These surfaces need ad-hoc processing to be suitable for a volumetric mesh generation. In this work we propose a set of new algorithms and tools aiming to facilitate the mesh generation process. In particular, we focus on different aspects of a cardiac mesh generation pipeline: (1) specific polygonal surface processing for cardiac geometries, like connection of different heart chambers or segmentation outputs; (2) generation of accurate boundary tags; (3) definition of mesh-size functions dependent on relevant geometric quantities; (4) processing and connecting together several volumetric meshes. The new algorithms-implemented in the open-source software vmtk-can be combined with each other allowing the creation of personalized pipelines, that can be optimized for each cardiac geometry or for each aspect of the cardiac function to be modeled. Thanks to these features, the proposed tools can significantly speed-up the mesh generation process for a large range of cardiac applications, from single-chamber single-physics simulations to multi-chambers multi-physics simulations. We detail all the proposed algorithms motivating them in the cardiac context and we highlight their flexibility by showing different examples of cardiac mesh generation pipelines.