Author`s Reply

To the Editor,

We would like to thank the authors of the letter for their interest about our paper entitled “Transcatheter closure of antegrade pulmonary blood flow with Amplatzer muscular VSD occluder after Fontan operation.”, published in the September issue of The Anatolian Journal of Cardiology 2014; 14: 565 (1). In 1971, Fontan and Baudet described a surgical procedure for repair of tricuspid atresia that built on experimental and clinical research from the 1940s. Today, the Fontan procedure is the most commonly performed staged palliative surgical procedure in patients with single ventricle physiology to ultimately create a circulatory system driven by a single ventricle without passing the right ventricle (2). It has been performed to treat several complex congenital heart diseases, including tricuspid atresia, hypoplastic left heart syndrome, pulmonary atresia with intact ventricular septum, and double-inlet ventricle.

At the time of the Fontan procedure, it is necessary to remove all origins of supplemental pulmonary blood flow to avoid volume loading of the heart. However, this can result in acute reduction in ventricular preload and diastolic dysfunction in the early postoperative period (3). In addition, some studies reported that non-pulsatile pulmonary blood flow decreased capillary flow and increased vascular resistance (2). On the other hand, there is a risk of persistent pleural effusions or progressive ventricular failure in patients having forward flow from the ventricle to the pulmonary arteries after Fontan procedure (3). As a result, it is controversial as to whether additional sources of systemic to pulmonary artery flow are beneficial or not.

Transcatheter closure of accessory antegrade pulmonary blood flow is an alternative to surgery, because it is less invasive, easy to perform, reliable, and more comfortable (4, 5). Numerous kinds of devices are now commercially available for the closure. Petko et al. (4) showed that the off-label use of Amplatzer Septal or Ductal Occluders or an Amplatzer Vascular Plug for the closure was effective for the reduction of ventricular volume load and resolution of the pleural effusions, which can occur as a complication after cavopulmonary shunt or Fontan procedure. Desai et al. (3) also reported that the use of a Raskind Umbrella Occluder or Amplatzer Septal or ductal occluder for the closure was a safe and effective technique after cavopulmonary shunt or Fontan procedure.

In my opinion, an issue that is worthy of discussion may be the thrombotic problems in the author’s case. Devices can be placed to the pulmonary artery band or pulmonary valve tissue or above the pulmonary valve (4). The place and approach for occlusion can be modified by patient anatomy and technical ease. By the way, if there is room between the pulmonary valve and device, the stasis of blood in the room can lead to formation of a thrombus. The thrombus is also possible for patients who have undergone surgical ligation of main pulmonary artery distally to the pulmonary valve, creating a pulmonary artery stump (6). In conclusion, we think that patients with a risk of thrombosis over time should be followed up more often in clinical practice, and anticoagulation may be considered in these cases.