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Case report
A 75-year-old female was referred to our hospital with a history of
dedifferentiated acinic cell carcinoma of the left parotid gland treated
with total parotidectomy and lymphadenectomy followed by radiation
therapy.
For pulmonary metastases a chemotherapy with carboplatin and taxol was
started. This treatment was suspended after three months for the
occurrence of severe neutropenia and the identification of mild
myelodysplastic syndrome. Computed tomography (CT) scan of the chest
with iodinated contrast was performed for staging and a partial filling
defect of the right superior pulmonary vein (RSPV) related to a large
thrombotic formation (50 x 20 mm) protruding in left atrium (LA) and
connected with pathological tissue of the pulmonary hilum (Figure 1) was
found. She then started an anticoagulant therapy with Edoxaban 60 qd.
Four months later she started suffering from headache, diplopia and
bilateral scotoma. During the evaluation in our emergency department,
she was on sinus rhythm and the echocardiography showed heart chambers
with normal function and dimensions without significant valvopathies.
Her blood tests were within normal limits, except for a slight elevation
of serum creatinine (1.15 mg/dl, estimated GFR 46 ml/min). Plasma
Edoxaban dosage (188 ng/ml (RV 19.0 – 62.0 ng/ml) confirmed the
therapeutic range of the drug. Brain CT and MRI scan indicated multiple
cerebral ischemic lesions (Figure I in Data Supplement).
In order to reassess the Pulmonary Vein Thrombus (PVT) after the
anticoagulant therapy Transesophageal Echocardiography (TEE) was
performed. The TEE confirmed a large RSPV thrombus protruding in LA as
an oscillating shaggy hypoechoic mass of 50 x 12 mm (Figure 2a and
Figure II in Data Supplement).
The Three-dimensional echocardiography clearly showed the thrombus
origin from RSPV, its relationship with the other structures of LA and
its multi-lobular aspect with “papillary-like” shape (Figure 3,Figure III and Video I-III in Data supplement). These characteristics
proved the high embolic potential of the thrombus.
A direct comparison of the thrombus between the TEE and the CT scan
performed four months earlier was performed thought reconstruction of
the transesophageal projection from the CT dataset (Figure 2b,2c).
This comparison demonstrated that the thrombus was not reduced after
four months of anticoagulant therapy.
Thrombus removal with surgical intervention was excluded due to the
patient’s overall conditions. The anticoagulation therapy was switched
from Edoxaban 60 mg qd to Dabigatran 150 mg bid, which demonstrated the
greatest absolute reduction in risk of stroke compared to warfarin in
atrial fibrillation. After two weeks of hospitalization, the patient was
discharged with complete neurological recovery.
Discussion
Pulmonary vein thrombosis (PVT) is a rare and insidious condition in
which most patients are usually asymptomatic or with non-specific
symptoms [1-4]. Its real incidence is unknown, as literature
includes only case report and case series.
The most frequent risk factors are primary and metastatic lung carcinoma
[5-7], major lung surgery and chest trauma [1]. PVT was also
described in association with atrial fibrillation [2,6], polycitemia
vera, treatment of asthma with omalizumab, autonomic nervous system
dysfunction and various kind of neoplasia [1,3,4]. Sporadic cases
were described as idiopathic [1].
The effect of a PVT on pulmonary circulation could be similar to that
caused by a mitral stenosis, but it depends on the number of veins
involved, the obstruction severity and the pulmonary vessels compliance.
The clinical presentation of PVT is a triad of cough, dyspnea and
hemoptysis [1]. When the disease involves more than one pulmonary
vein patients arrive at medical attention for pulmonary edema [1]
and if only one side is affected a unilateral pulmonary edema can be
observed.
To the best of our knowledge, this is the first case in which a PVT
evolution was investigated using comprehensive TEE associated with CT
scan and multimodality post-processing tools.
The PVT was identified as an incidental finding in a staging CT scan of
the chest and after four months she had a stroke despite anticoagulant
therapy.
After multidisciplinary consultation it was decided to re-evaluate the
patient with TEE to better characterize the suspected thrombus after
four months with anticoagulant therapy [3,7].
The multimodality imaging approach is helpful to evaluate intracardiac
masses. In particular, the CT scan with the ability to image in any
plane allows full visualization of the heart and mediastinum that is
crucial to identify origin, extension, relationship of the masses with
nearby structures [6,8].
The Real-time three-dimensional Echocardiographic assessment is useful
to analyze the consistency, mobility and hemodynamic effects of masses
[3,7].
Furthermore, the possibility of reconstructing TEE projection directly
from CT imaging allows a direct comparison between the two techniques.
In this case this reconstruction enabled the comparison between the TEE
images and the previous CT scan confirming that the thrombus was almost
unchanged. This finding showed that anticoagulant therapy was
ineffective and the stroke had cardioembolic origin.