This category includes closure of atrial and ventricular septal defects, closure of pervious ductus arteriosus, and closure of ventricular pseudoaneurysms (Figure 32.1). Beyond standard cardiac catheterization competency, additional knowledge base includes a full understanding of atrial and ventricular anatomy, understanding of indications and contraindications for closure, knowledge of occluder devices, specialized guidewires, and arterial sheath, and the development of technical skills needed for access to ventricular septal defects and ventricular pseudoaneurysm. Details on techniques and indications are listed in Chapters 35 and 45.

The pioneering work done in the 1950s by Rubio-Alvarez on tricuspid and pulmonic valvuloplasty²,³ was followed 30 years later by the development of percutaneous mitral and aortic balloon valvuloplasty. The long-term results with mitral valvuloplasty were encouraging and were confirmed in headto-head comparisons with surgical commissurotomy. Thus, today mitral valvuloplasty is considered a valid alternative to surgical commissurotomy (see Chapter 33). In contrast, the initial enthusiasm for aortic valvuloplasty in the adult was met by disappointing intermediate- and long-term results, leading to a class IIb indication for aortic valvulopasty in the
2008 focused update of the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease⁴ “Class IIb. 1. Aortic balloon valvotomy might be reasonable as a bridge to surgery in hemodynamically unstable adult patients with AS who are at high risk for AVR. (Level of Evidence: C) 2. Aortic balloon valvotomy might be reasonable for palliation in adult patients with AS in whom AVR cannot be performed because of serious comorbid conditions.” The recent introduction of transcatheter aortic valve replacement has created a revolution in the management of patients with aortic stenosis,⁵,⁶ and it has resulted in a resurgence of aortic valvuloplasty as a key component of transcatheter aortic valve replacement (Chapter 33). Similar developments are occurring for the management of mitral valve disease through percutaneous mitral valve repair and replacement⁷,⁸ (see Chapter 33), and also for the pulmonic valve (see Chapters 33 and 35). Thus, percutaneous valve interventions are emerging as an alternative to surgery in high-risk patients, and as a new option for patients who otherwise are not surgical candidates.

The growth of percutaneous valve interventions has been paralleled by a growth in interventions for the management of paravalvular leaks.⁹, ¹⁰, ¹¹, ¹², ¹³, ¹⁴, ¹⁵, ¹⁶ It has been estimated that paravalvular leaks can occur in 5% to 17% of patients following surgical valve replacement. In addition, paravalvular leaks are a recognized occurrence following transcatheter aortic valve replacement.¹⁷ The clinical spectrum varies from asymptomatic status to heart failure and/or severe hemolysis. Reoperation in these patients is associated with high morbidity and mortality. Thus, there has been a large body of work attempting to address this problem with transcatheter techniques, and using a variety of devices from vascular coils to vascular plugs (Figures 32.2 and 32.3). Additional interventional skills required for the management of paravalvular leaks include proficiency in transseptal catheterization, access to the left ventricle through direct apical puncture, the ability to evaluate 3D echocardiographic and CT reconstructions of the defect (Figure 32.4), and familiarity with guidewire snaring and exteriorization techniques (Figure 32.5).¹¹,¹⁸ Currently, there are no devices that have been developed specifically for the management of paravalvular leaks. It is hoped that the growing experience will lead to the development of dedicated devices.

This group includes alcohol septal ablation and the new field of interventions with cell therapies. Transcatheter ablation
of the septum with ethanol was first reported by Sigwart in 1995.¹⁹ The procedure entails inducing a controlled myocardial infarction by injecting absolute ethanol in the septal perforator branch supplying the area of the septum participating in the creation of left ventricular outflow tract (LVOT) obstruction. Confirmation of selection of the proper septal branch can be obtained by injecting in the septal artery echocardiographic contrast²⁰,²¹ (Figure 32.6). The procedure has been shown to reduce the LVOT gradient and to provide symptomatic relief in patients with LVOT obstruction and with symptoms refractory to medical therapy. Criteria for selection of patients for septal reduction therapy with either surgical myectomy or alcohol ablation are shown in Table 32.2.²² Significant controversy still exists regarding the long-term risk of sudden death in patients undergoing alcohol septal ablation, although a recent meta-analysis has suggested that the benefits of alcohol septal ablation are similar to the benefits of surgical myectomy.²³ Thus, the most recent 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic Cardiomyopathy include alcohol septal ablation as a class IIa indication in patients with refractory symptoms who are not surgical candidates, and as a class IIb
indication for “eligible adult patients with hypertrophic cardiomyopathy (HCM) with severe drug-refractory symptoms and LVOT obstruction when, after a balanced and thorough discussion, the patient expresses a preference for alcohol septal ablation”.²² Given the complexity of HCM and the fact that alcohol ablation has a steep learning curve and unusual complications²⁴ (Table 32.3), it has been recommended that alcohol ablation should be performed only by experienced operators within a multidisciplinary program, and in centers offering comprehensive care for patients with HCM. The
guidelines for the management of patients with HCM further define an experienced operator as “individual operator with a cumulative case volume of at least 20 procedures or an individual operator who is working in a dedicated HCM program with a cumulative total of at least 50 procedures.”²²