Discussion
To the best of our knowledge, this is the first case in which partial anomalous pulmonary venous return (PAPVR) anomaly, iatrogenic ASD and rheumatic mitral stenosis were found together. Anomalous pulmonary venous return (APVR) is a rare congenital anomaly seen between 0.4% and 0.7% in the autopsy series (3). The main pathophysiologic problem in APVR is the direct or indirect opening of the pulmonary veins into the right atrium (1,4). While one or more pulmonary veins are defective in the partial type, all of the pulmonary veins are unrelated to the left atrium in total anomaly (5). PAPVR is most commonly encountered in the supracardiac form in which the right upper pulmonary vein drains into the right atrium or superior vena cava (6), as in our case. The abnormal pulmonary venous return may be supracardiac, cardiac, infracardiac, or mixed type. Although an anomaly in the drainage of a single vein usually does not cause hemodynamic problems, an anomaly in more than one vein or other congenital or acquired diseases may cause the symptoms to occur (4,7). PAPVR is often accompanied by atrial septal defect, which has been reported to be 82% in some publications (8). There are also some publications on its association with rheumatic mitral stenosis (9,10).
PAPVR usually has a silent clinical course and varies depending on the degree of left-to-right shunt and other associated cardiac anomalies (11,12). The clinical problem in our patient was accompanying mitral stenosis. Diagnosis of PAPVR was missed during the evaluation period for mitral stenosis, and therefore the treatment was determined as percutaneous mitral balloon valvuloplasty. However, with the effect of iatrogenic ASD due to PBMV, unfortunately, the volume load in the right chambers increased. Thus, the patient’s symptoms continued as before PBMV, although mitral stenosis was treated.
The incidence of ASD following PBMV ranges from 4% to 53% (13). This high variability is related mainly to the diagnostic method used. In a study by Arora et al., in which TOE was used in the assessment, the rate of ASD was observed as 92% immediately after PBMV, 80% after 72 hours, and 10% in the evaluation 3 months later. So, most of the iatrogenic ASD close spontaneously (14).
In our case, the iatrogenic atrial septal defect was too large to be associated with only transseptal puncture. Most likely, the inappropriate withdrawn of the percutaneous mitral balloon delivery system damaged aneurysmatic septum and caused it to tear. Otherwise, such a large atrial septal defect was unlikely to be overlooked in TOE assessment before PBMV. The abnormally connected pulmonary vein was drained to the superior region of SVC, so it cannot be clearly detected with TOE. Also, the presence of diastolic D-sign has forced us to find the cause of a volume load other than iatrogenic ASD. As a matter of fact, while the diastolic d-sign indicates a significant volume load, it was not possible to explain this with only 2-monthly iatrogenic ASD. however, we would expect to see systolic D-sign secondary to pressure increase in patients with severe mitral stenosis diagnosed late.
The crucial question to be answered in our case was which strategy should be chosen in a patient with diastolic-D sign, dilatation in the right heart cavities, mild mitral stenosis, and especially planning pregnancy. Cardiac MRI and CT demonstrated a partial pulmonary venous return anomaly associated with an isolated single vein located superiorly. In cardiac catheterization, significant left-right shunt was observed, and pulmonary capillary wedge pressure was within normal limits. These findings proved that mitral stenosis was not serious and the main problem was left-to-right shunt. It was decided by the heart team to perform PAPVR and ASD repair with robotic method. Close follow-up was planned for mitral valve stenosis. Thus, the patient would have the chance to be treat with PMBV or mitral valve replacement after pregnancy. In addition, a treatment without sternotomy would have reduced the risk of cardiac surgery that could be performed in the follow-up. After all, the patient was successfully treated with the robotic surgery (da-Vinci system), and normalization was observed in the right heart chambers and pulmonary artery pressure in the second month control TTE.
The take-home messages that we want to give in our patient, who was a very important example of the individualized treatment option:
1- It should never be forgotten in clinical practice that an acquired disease such as rheumatic mitral stenosis may be accompanied by a congenital disease.
2- Even if the partial pulmonary venous return anomaly is isolated, it should always be kept in mind in the causes of volume overload and pulmonary hypertension in adults.
3- Iatrogenic atrial septal defect sizes can sometimes be much higher than expected. The operation team should definitely check the IAS just after the procedure.
4- Some individual indications such as pregnancy request may force the physician to completely review patient management, surgical indications and methods.
5- The optimum treatment option for each patient should be evaluated in their own circumstances.