A 63-year-old woman was referred to hospital for symptomatic hypoxemia of several days duration. She had no symptoms in a supine position, but  experienced severe dyspnoea  in an upright or standing position, Her medical history noted treated systolic hypertension ,chronic obstructive bronchitis with mild pulmonary hypertension (40 mmHg.and  left pneumonectomy for lung cancer (one year ago) however she was not limited in her daily activities until recentlyThere were no signs of congestive heart failure. Various tests were performed (routine lab,ECG, chest radiograph, thoracic computed tomography and bronchial fibroscopy) didn’t reveal any other pulmonary disease that could explain the new onset of dyspnoea. Oxygen saturation decreased from 93% when recumbent to 85 % when upright. After breathing pure oxygen for 30 minutes, The right to left shunt was 18% in the supine and 28% in the upright position.

Transthoracic echocardiography showed an important shift of the heart towards upper and left direction leading to modification of the heart chambers and especially of the atria. Bientricular function was preserved There was a mild dilatation of the right cavities and no congenital heart disease. The tricuspid regurgitant flow permitted the estimation of a pulmonary artery pressure of 40 mmHg,   After injection of contrast (saline-air) into the right cubital vein revealed a very small right to left shunting across the atrial septum (less than 10 microbubbles). Transesophageal echocardiography (TEE)  showed a flask atrial septum with a 10 mm excursion. On the Valsalva manoeuvre and in the upright position, the patent foramen ovale opened largely and there was a massive increase in  shunting with the presence of a clear signal on colour Doppler across the septum secundum. This confirmed the platypnea-othodeoxia syndrome in relation to the re-opening of a large patent foramen ovale in upright position.

We used the StarFLEX device (Nitinol Medical Technical Inc., Boston, Massachusetts). It is a double umbrella device that developed from the Clamshell occluder.. After positioning a long sheath in  the left atrium across the patent foramen ovale, the device was attached to its delivery system and advanced within the sheath until the distal umbrella was deployed in the left atrial cavity. Both the sheath and delivery system were then slowly withdrawn towards the atrial septum. At that time the adequate position of the distal umbrella is confirmed onTEE , and then the proximal disc umbrella was opened on the right side of the atrial septum by withdrawing the sheath alone. Thanks to TEE, interference of the device with caval or pulmonary veins or with atrioventricular valves was excluded. Once the deployment was complete, the 28 mm StarFlex device was released...The following day,  right to left shunt was measured. ( 16% in supine and 18.6% in upright position). There was no hypoxemia in an upright position. At three months, the patient had   no complaints of dyspnoea in supine or upright position. The echocardiography with microbubbles contrast showed no more passage at rest or under Valsalva manoeuvre.

In this patient, the mechanism of right to left shunting is certainly due to the relative change in the position of the two atria and the mechanical distortion of the atrial septum due to pneumonectomy. Thus, the blood flow is preferentially directed towards the patent foramen ovale. Also, the inferior vena cava orifice may come closer to the patent foramen ovale due to the rightwards displacement of the interatrial septum.  TEE shows the flow directed towards the fossa ovalis and the opening of the foramen ovale during Valsalva manoeuvre (Figure 1).

Until recently, the method of choice for the management of patent foramen ovale closure in the setting of platypnea-orthodeoxia syndrome was the surgical approach..  TEE allows the best choice of the device’s size and an excellent control of the position of the two umbrellas  In this case, it was of  particular interest not to come into  conflict with the superior vena cava despite  the atrial septum deformation.  TEE is the golden standard for size selection and aids optimal application of the device according to individual anatomical configuration. (Figure 2 )

So far, the method of choice for the closure of patent foramen ovale has become the percutaneous way.