Bilateral Branch Pulmonary Artery Melody Valve Implantation for Treatment of Complex Right Ventricular Outflow Tract Dysfunction in a High-Risk Patient

Abstract

P ercutaneous pulmonary valve replacement is one of the most important advancements in the field of interventional cardiology in the past decade. 1,2 However, currently available technologies are not applicable to patients with oversized right ventricular outflow tracts (RVOTs), especially when there is concomitant proximal branch pulmonary artery (PA) stenosis. This combination commonly is encountered in clinical practice. Our group has a longstanding interest in these complex patients, and we have recently published preclinical studies describing the feasibility and short-term effects of implanting 2 Melody valves-1 into each proximal branch PA-in an ovine model of postoperative pulmonary insufficiency and dilated RVOT. 3 This report describes bilateral branch PA Melody valve implantation to treat complex RVOT dysfunction in a high-risk patient. HistoryAt presentation, the patient was a 27-year-old woman with a complex medical history. Her cardiac condition was doubleoutlet RV with pulmonary stenosis and interrupted inferior vena cava with azygos continuation to a left-sided superior vena cava. She was status post-Waterston shunt as an infant, with subsequent closure of the ventricular septal defect and patch augmentation of the RVOT. Three months before catheterization, the patient presented to her cardiologist with symptoms of progressive activity intolerance over the past year. She was oxygen dependent and on long-term continuous positive airway pressure therapy. Comorbidities included VATER and Klippel-Feil syndromes, renal agenesis, Mülle-rian agenesis, gout, and obesity. The patient had undergone multiple spinal fusion and Harrington rod procedures as well as repair of tracheoesophageal fistula. An echocardiogram was obtained but was nondiagnostic because of her body habitus. A limited cardiac CT scan obtained at an outside hospital revealed dilated RV and left ventricle (LV). The RVOT was large, and there were complex stenoses involving the origins of both the right and left branch PAs. Pulmonary function studies revealed severe restrictive and obstructive lung disease.After discussion at our multidisciplinary rounds, we decided to bring the patient to our combined MRI-catheterization suite for a diagnostic cardiac MRI followed by invasive assessment. Because of her comorbidities, the patient was deemed at excessive risk for surgical intervention; thus we determined that if diagnostic data warranted, the patient was to be considered for possible bilateral branch PA Melody valve implantation.

Use and Performance of the Melody Transcatheter Pulmonary Valve in Native and Postsurgical, Nonconduit Right Ventricular Outflow Tracts

“…All patients had prestenting and Melody implantation within the RVOT, without unconventional measures to ensure RVOT stent stability (eg, deliberate branch pulmonary artery jailing with extension into the RVOT, implantation of Melody valves into the branch pulmonary arteries, etc.). 2,7 The majority of valves were deployed on a 22-mm delivery system. Postdilation of the implanted Melody valve was performed in 5 (16%) patients with balloons ranging from 22 to 24 mm.…”

“…Under this rubric, Melody TPVs have been placed in a number of off-label clinical situations and anatomic locations. [2][3][4][5][6] Among these, placement in nonconduit RVOTs likely presents the greatest opportunity to extend this therapy to the largest population and has the potential to significantly modify our approach to postsurgical RVOT dysfunction. Although several investigators have described innovative and potentially useful methods of implanting the Melody valve in unconventional ways in patients with large native RVOTs, these are unlikely to be broadly applicable.…”

“…Although several investigators have described innovative and potentially useful methods of implanting the Melody valve in unconventional ways in patients with large native RVOTs, these are unlikely to be broadly applicable. 2,7 Otherwise, there are several small series of Melody valve implantations into the native RVOT, [7][8][9] and cases have been included in other large series, 10 but there is limited information on outcomes in this population.…”

The future of transcatheter pulmonary valvulation

“…Other reports described advanced techniques to make these patients suitable for the transcatheter technique (i.e. the use of two Melody valves implanted in respective pulmonary arteries in a single patient; jailing and/or Russian doll techniques) [9,[15][16][17]. Cheatham et al showed that PPVI using a 24 mm balloon catheter for the deployment of the Melody valve was feasible, without impairment of valvular function (RVOT diameter of 26 mm) [18].…”

Recent Progress in the Understanding and Management of Postoperative Right Ventricular Outflow Tract Dysfunction in Patients With Congenital Heart Disease

“…For example, experimental studies and case reports have demonstrated the feasibility and physiological efficacy of implanting a TPV in each proximal branch pulmonary artery when complex anatomy precludes seating a device within the RVOT per se. 45,46 Extending this concept, TPV implantation into only a single branch pulmonary artery might be beneficial in certain circumstances, given the finding that PR often arises with considerable asymmetry from the left and right pulmonary arteries. 47 The clinical incentive to extend TPV therapy beyond the approved indications is further evidenced by other creative, off-label approaches to TPV replacement in patients with a large RVOT such as seating the Melody valve in a scaffold of bare metal stents that are anchored in the branch pulmonary arteries and extend proximally into the outflow tract.…”