Atrial septostomy as a palliative intervention for the treatment of PAH has been performed for almost 30 years since the initial report by Rich and Lam in 1983 [8]. However, the proper appreciation of its role in the management of PAH has been limited mainly by the lack of a controlled clinical trial demonstrating its efficacy and safety. Most of our knowledge regarding the procedure has been derived from small series or case reports. In addition, the relative success of the current pharmacologic treatment regimens as well as the fear of a previously reported high procedure-related mortality [9] have limited a more widespread use of this valuable intervention.

Here we review the worldwide literature regarding the use of BAS in the setting of severe PAH. There have been approximately about 352 procedures performed in 304 patients reported as series [10–32], and 20 additional procedures have been published as single case reports [33–52] (Table 20.1). Atrial septostomy has been performed in young patients (~30 years), mostly women (72 %), and most of them at an advanced stage of the disease (functional classes III and IV). Regarding the etiology of pulmonary hypertension, the procedure has been performed mostly in patients with idiopathic PAH (77 %), however, it has also been performed in patients with PAH associated with collagen vascular disease (15 %) or with corrected congenital heart disease (9 %), and in a few cases of distal chronic thromboembolic pulmonary hypertension (5 %). RVF alone (50 %) or combined with syncope (19.8 %) have been the main indications for the procedure. In many of these patients atrial septostomy had been performed after the failure of pharmacologic treatment.

As shown in Table 20.2, BDAS has been by far the preferred technique for the procedure [7]. BDAS has the advantage of a better control of the desired size of the defect which is not easily obtained with a blade septostomy. The final size of the defect has varied in the different series but there is a tendency to create small defects (~10 mm) in a step-by-step fashion, rather than large orifices, which probably accounts for the reduction in procedure-related deaths noticed in the last few years. In this global experience analysis there have been 27 immediate (first 24 h) procedure-related deaths (~7 %), most of them related to acute and refractory hypoxemia. If we also take into account the deaths occurring within 1-month (although not necessarily related to the procedure itself) the global procedure mortality for atrial septostomy is about 12 %.