Transcatheter closure of congenital and acquired VSDs is a procedure that has gained widespread use in the recent years. Initially, VSD closure was performed using devices designed for atrial septal defects (ASD), but eventually special devices intended for closure of muscular and perimembranous defects were developed [6, 7]. Although there has been remarkable progress in production of specifically designed occlusion devices, demand for off-label or custom-made devices suitable for various types of defects remains high [2, 3, 8].
Transcatheter closure of postinfarction, traumatic or residual postoperative VSDs is mainly performed using ASOs [3, 9]. As ECHO and angiocardiographic measurements showed a large defect size in our patient, we elected to use a 24 mm ASO, a device 2–3 mm larger than the defect. The defect could have been closed using a 24 mm muscular VSD occluder or a post-myocardial infarction muscular VSD occluder as well; however, we preferred the ASO as it would allow for more convenient manual fenestration.
Long-term pulmonary hypertension may lead to a fixed increase in pulmonary vascular resistance. In some patients that have undergone VSD closure, pulmonary hypertension may persist or regress very slowly, in which case there may be hypertensive crisis-like exacerbations requiring long-term ventilation and specific treatment. In VSD cases with high pulmonary resistance, post-operative pulmonary hypertensive crises as well as acute congestive heart failure and respiratory failure may prove fatal. For these reasons, surgeons nowadays are instructed to leave an opening in the VSD patch or to use a flap patch that allows for left-to-right shunt . For the same reasons, fenestration is now performed on transcatheter occluder devices. Home-made fenestrated devices have been safely used in cases of ASD with severe PHT under the assumption that fenestrated occluders reduce left-to-right shunt and in the long run, lower pulmonary arterial pressure . Bruch et al. reported using a home-made fenestrated ASO that allowed for a minor to moderate bidirectional shunt in elderly patients with PHT and/or right heart failure. While the authors did not see any deterioration of right or left heart failure in their patient group, they observed an impressive symptomatic benefit .
As our patient was an 18-year-old with a large VSD and severe PHT, we performed a vasoreactivity test in order to assess whether the defect could be closed. The patient’s left heart cavities were found to be enlarged, the pulmonary artery flow velocity was high and the response to the vasoreactivity test was positive, so the patient was deemed a suitable candidate for transcatheter closure. However, as the patient was a young adult with bidirectional shunt and an enlarged right ventricle and pulmonary artery, we debated whether or not to fenestrate the device.
A review of literature did not reveal any cases with manually fenestrated devices used for closure of VSDs in patients with severe PHT. However, based on the Bruch study mentioned above and others that used fenestrated ASOs, we assumed that such a device in our case would allow for bidirectional shunt and could possibly reduce PHT in the long run. While no satisfactory reduction in pulmonary artery pressure was seen immediately after the procedure, transthoracic ECHO performed 24 hours later showed left-to-right gradient of 35–40 mmHg through the fenestration.
In the follow-up examination 1 month later, the gradient value was the same, average aortic pressure was 75 mmHg, average pulmonary artery pressure was 30 mmHg and PVR/SVR was 0.2.
Both minor and major complications such as hemolysis, cardiac perforation, device malposition, thromboembolism, temporary or permanent rhythm disorders, endocarditis and death may occur during, immediately after or in the follow-up of transcatheter defect closure [4, 12]. In our case, a nodal rhythm started 12 hours after the procedure and spontaneously reverted to normal 9 days later. Temporary junctional rhythms following closure of muscular VSDs have also been reported in the literature [12, 13].
Heart block occurring after placement of an oversized device can be attributed to the expansion of the device against the conducting tissue. Even if the device is not oversized, it may cause an inflammatory reaction or formation of scarring in the conduction tissue, in which case steroid therapy may be useful . The nodal rhythm in our patient can be attributed to the fact that an ASO has a larger left disc and a narrower gap between the discs than a VSD device, which may have put pressure on the conduction system or the neighboring tissues.