A rare case of left hepatic vein anomalous drainage to the coronary sinus.

The left hepatic vein (LHV) anomalous drainage into the coronary sinus (CS) is an extremely rare congenital vascular abnormality. It is usually asymptomatic, but it has surgical implications if the patient undergoes cardiac, vascular or hepatic procedures. We report a case of a 90-year-old man who had an isolated LHV anomalous drainage diagnosed on a computed tomography performed to evaluate fatigue. The diagnosis of LHV drainage into the CS during preoperative evaluation can avoid intraoperative complications and may determine the preferred surgical approach.

Introduction

The left hepatic vein (LHV) anomalous drainage into the coronary sinus (CS) is an extremely rare congenital abnormality involving the CS [1]. It is characterized by a single vessel that arises from the left hepatic lobe and passes through the diaphragm to drain directly into the CS in the right atrium [2]. Most cases are incidentally diagnosed by imaging exams or during surgery and their incidence are limited to case reports. The patients are usually asymptomatic, but have surgical implications if the patient is undergoing cardiac, vascular, or hepatic procedures [3]. The objectives of this study are to describe a case of LHV anomalous drainage into the CS as a solitary cardiovascular malformation and to review the current literature.

Case Report

A 90-year-old man was admitted in the emergency room with fatigue that started 5 days before his admission. He was previously diagnosed with systemic hypertension, pulmonary hypertension, and coronary artery disease. A thoracic and abdominal contrast-enhanced computed tomography using a 256-sliced multidetector and dual-energy scanner was performed. It showed enlargement of the right atrium and ventricle and an anomalous drainage of the LHV into the CS (Fig. 1, Fig. 2). The inferior vena cava (IVC) received the middle and right hepatic veins, with normal connection to the right atrium.

Fig. 1

Maximum intensity projection (MIP) contrast-enhanced CT images of the thorax and abdomen in axial (A), coronal (B) and sagittal (C) planes: the left hepatic vein (arrow) communicates directly with the coronary sinus (dotted arrow) in the right atrium; the middle and right hepatic veins drained normally into the inferior vena cava (arrowhead).

Fig. 2

Coronal oblique three-dimensional reconstructed image demonstrating the left hepatic vein (arrow) draining directly into the coronary sinus (dotted arrow) of the right atrium.

The patient received proper care, medication dose adjustment and was discharged from the hospital 2 days after admission.

Discussion

The LHV anomalous drainage into the CS is an extremely rare congenital abnormality usually reported as an incidental finding in imaging exams. To the best of our knowledge, this is the fourth reported case of an isolated LHV anomalous drainage [4], [5], [6]. Table 1 summarizes those case reports. Most cases reports describe this anomalous drainage with other cardiovascular malformations, such as persistent left superior vena cava [7], duplication of the superior or IVC [3], IVC continuing with the azygos vein [3], subaortic valve stenosis [8], anomalous pulmonary venous drainage [1], atrial and ventricular septal defect [2].

Table 1

Summary of cases of isolated LHV anomalous drainage into the coronary sinus described in the literature.

Author, Year	Gender	Age (years)	Diagnostic method	Clinical or surgical implications
Uraz et al., 2007	Female	48	Doppler USCTA	Living donor for liver transplantation. Patient underwent right hepatectomy without complications.
Lee et al., 2013	Female	61	CT	None (incidental finding).
Morshuis et al., 2015	Female	76	Intraoperative finding	None.

CT, computed tomography; CTA, computed tomography angiography; US, ultrasound.

The vitelline (omphalomesenteric), umbilical and cardinal veins are the 3 types of vessels composing the venous system in the fifth gestational week that lead blood to the sinus venosus [3,8]. The presence of an anomalous drainage of the LHV directly into the CS may be explained by the persistence of the left omphalomesenteric vein connection with the left horn of the sinus venosus during the fetal period [5]. The left horn of the sinus venosus eventually becomes the CS [8].

This anatomical abnormality should have no clinical or hemodynamic consequences. However, it has been suggested that it may be associated with atrial arrhythmias [1]. Radiologists should report the LHV anomalous drainage because of its surgical implications, including inability to be a living donor liver transplantation [6], technical difficulties during trans-CS interventions [5] and Fontan procedures [4], impairment of venous return during cardiac surgery using extracorporeal bypass [4], and impossibility to use the CS for retrograde cardioplegia [4].

Computed Tomography angiography (CTA) with multiplanar reconstruction is the “gold standard” in diagnostic imaging because it's noninvasive and faster when compared to conventional angiography. CTA provides a complete evaluation of the great vessels and can detect some of the other systemic venous maldevelopments that may come along with the LHV anomalous drainage [8]. The echocardiography can also detect this anatomical abnormality [5] and is particularly useful in patients with contraindications to CTA, but it has limited spatial resolution and limited windows with narrow fields of view.

In conclusion, the diagnosis of LHV drainage into the CS during preoperative evaluation can avoid intraoperative complications and may determine the preferred surgical approach. The best diagnostic imaging method is the CTA because it provides detailed anatomic characterization with the advantage of 3D reconstruction.