Derize Boshoff

Infective endocarditis of a transcatheter pulmonary valve in comparison with surgical implants

Background Melody valved stents (Medtronic Inc, Minneapolis, Minnesota, USA) have become a very competitive therapeutic option for pulmonary valve replacement in patients with congenital heart disease. After adequate prestenting of the right ventricular outflow tract (RVOT) Melody valved stents have a good medium term functional result but are exposed to infective endocarditis (IE). Patients and methods Retrospective study of tertiary centre Congenital Heart Disease database; to compare incidence of IE in three different types of valved conduits in RVOT: Melody valved stent, cryopreserved homograft (European Homograft Bank) and Contegra graft (Medtronic Inc). Results Between 1989 and 2013, 738 conduits were implanted in 677 patients. 107 Melody valved stents were implanted in 107 patients; IE occurred in 8 (7.5%) patients during a follow-up of 2.0 years (IQR 2.4 years, range 0.3–7.8 years). 577 Homografts were implanted in 517 patients; IE occurred in 14 patients (2.4%) during a median follow-up of 6.5 years (IQR 9.2 years; range 0.1–23.7 years). Finally, 54 Contegra grafts were implanted in 53 patients; 11 patients (20.4%) had IE during a follow-up of 8.8 years (IQR 7.7 years; range 0.2–3.5 years). Survival free of IE by Kaplan–Meier for homografts was 98.7% at 5 years and 97.3% at 10 years; for Contegra 87.8% at 5 years and 77.3% at 10 years and for Melody 84.9% at 5 years (log-rank test; p<0.001). Conclusions The Contegra conduit and Melody valved stents have a significantly higher incidence of IE than homografts. IE is a significant threat for long-term conduit function.

Transapical left ventricular access for difficult to reach interventional targets in the left heart

Objective: Interventional targets may be virtually “excluded” due to vascular access problems or complex previous surgical procedures. This study reviews our experience using transapical ventricular puncture to gain direct access to the systemic ventricle. Patients: Patient 1 (74 years, 2 previous sternotomies), patient 2 (66 years, 5 previous sternotomies), and patient 5 (69 years, 3 previous sternotomies) with prosthetic valves had paravalvular mitral valve leaks. Patient 3 (6.3 years, 2 previous sternotomies) with an extracardiac Fontan conduit, had a significant residual leak after two previous surgical attempts of patch closure of a severely regurgitant right atrioventricular valve. Patient 4 (10 months) had failure of standard ablation of the posteroseptal region of the mitral valve with persistent life‐threatening episodes of ventricular tachycardia. Methods: Procedures were performed under general anesthesia. Entry site was percutaneous in three patients and in two (and one conversion) a mini‐thoracotomy was used. Sheaths were placed (6 F) using standard Seldinger technique, followed by the procedure as required. Direct surgical closure of the puncture site was done in 4 patients and in patient 3, a percutaneous vascular occlusion device was used. Results: Easy and immediate access was obtained in all patients. The paravalvular leaks were crossed within seconds and completely closed with Amplatzer occluders. In patient 3 the valve was crossed using a Brokenbrough needle and a 12‐mm Amplatzer device was placed in the patch leak. Patient 4 was successfully ablated using a 7‐F irrigated catheter endo‐ and epicardially. Complications were in the percutaneous puncture group: in one patient a coronary artery was punctured and in one a hemothorax developed. Conclusion: Direct left ventricular puncture offers a very useful alternative access site in selected patients to reach “inaccessible” targets for certain percutaneous interventions in patients where standard approaches may be impossible or difficult.

Off-label use of percutaneous pulmonary valved stents in the right ventricular outflow tract: time to rewrite the label?

Percutaneous pulmonary valve implantation is now considered feasible and safe. “Native” right ventricular outflow tract (RVOT), small diameter conduits (<16 mm) and relatively large RVOT with a dynamic outflow aneurysm are currently considered off‐label uses. Extending indications creates concerns of safety, ethics, reimbursement, and liability.

Transcatheter closure of secundum atrial defect in small children

Objective: To assess safety and efficacy of transcatheter atrial septal defect (ASD) closure in small children. Background: Percutaneous closure of ASD is a well accepted alternative to surgery. Reported experience in small children remains, however, scarce. Methods: Fifty‐two children underwent percutaneous ASD closure at a weight ≤15 kg, in four Belgian tertiary referral paediatric cardiology centers. Indication for treatment, device implantation rate, procedural details, complication rate, residual shunt on echocardiography, and impact of procedure on symptoms were retrospectively analyzed. Results: Mean age at procedure was 36 months (7–60), mean weight 13 kg (4.7–15). Associated cardiac lesions were seen in 21% of the patients and noncardiac in 32.7%. Most patients (69.2%) were symptomatic. Mean ASD size was 12 mm (range 5–20 mm). A device could be inserted in 49 patients (94%). No major complications occurred. Minor complications occurred in 8 patients (15.4%) including device embolization in 2, successfully treated with transcatheter retrieval and second device insertion. Mean follow‐up reached 27 months (0.03–61.2). Residual shunt was absent, trivial, or small in 93% (n = 42) at latest follow‐up. Clinical improvement was noted in 91.7% of the symptomatic patients. Minor complications were more frequent in the presence of large ASDs (>15 mm) but not in smaller babies (<10 kg). Conclusion: Patients ≤15 kg requiring ASD closure form a special population with high incidence of associated anomalies and medical conditions. For this particular set of patients, percutaneous closure is a valid alternative. Asymptomatic or mildly symptomatic children should be treated at a later age.

Percutaneous pulmonary valve implantation for free pulmonary regurgitation following conduit-free surgery of the right ventricular outflow tract

INTRODUCTION Pulmonary regurgitation (PR) following surgery of the right ventricular outflow tract (RVOT) is not innocent and leads to significant right heart dysfunction over time. Recent studies have demonstrated that percutaneous valves can be implanted in conduit free outflow tracts with good outcomes. OBJECTIVES To evaluate in patients with severe PR--anticipated to require future pulmonary valve replacement--the feasibility and safety of pre-stenting dilated non-stenotic patched conduit-free right ventricular outflow tracts before excessive dilation occurs, followed by percutaneous pulmonary valve implantation (PPVI). PATIENTS AND METHODS Twenty seven patients were evaluated, but only 23 were deemed suitable based on the presence of an adequate retention zone ≤ 24 mm defined by semi-compliant balloon interrogation of the RVOT. A 2 step procedure was performed: first the landing zone was prepared by deploying a bare stent, followed 2 months later by valve implantation. RESULTS RVOT pre-stenting with an open cell bare metal stent (Andrastent XXL range) was performed at a median age of 13.0 years (range: 6.0-44.9) with a median weight of 44.3 kg (range: 20.0-88.0). Ninety six percent (22/23) of patients proceeded to PPVI a median of 2.4 months (range: 1.4-3.4) after initial pre-stent placement. Twenty one Melody valves and one 26 mm Edwards SAPIEN™ valve were implanted. Complications consisted of embolization of prestent (n = 1), scrunching (n = 4) and mild stent dislocation (n = 2). During follow-up, no stent fractures were observed and right ventricular dimensions decreased significantly. CONCLUSIONS Post-surgical conduit-free non-stenotic RVOT with free pulmonary regurgitation can be treated percutaneously with a valved stent if anatomical (predominantly size) criteria are met. In experienced hands, the technique is feasible with low morbidity.

A review of the options for treatment of major aortopulmonary collateral arteries in the setting of tetralogy of Fallot with pulmonary atresia

with pulmonary atresia when combined with aventricular septal defect is frequently unifocalvia the arterial duct. In more complex cases, it can bemultifocal. This can be through bilaterally patentarterial ducts, but more typically is through majoraortopulmonary collateral arteries. In patients withsuch major aortopulmonary collateral arteries, estab-lishing the source and arrangement of the pulmonaryarterial supply is fundamental to management andprognosis.

Dilatable pulmonary artery banding in infants with low birth weight or complex congenital heart disease allows avoidance or postponement of subsequent surgery

OBJECTIVE This study evaluated the efficiency and feasibility of dilatable bands in selected patients. METHODS Two types of dilatable handmade bands were retrospectively evaluated and divided into two groups: main pulmonary artery bands and bilateral branch pulmonary artery bands (hybrid stage I palliation). Stepwise balloon angioplasty (BA) was performed, increasing the diameter either to completely dilate with total release of the band, or in others, to partially dilate the bands in order to improve flow and/or saturation. PATIENTS AND RESULTS Balloon angioplasty was performed in 20 patients (median birth weight 2.9 kg, range: 1.3-4.5 kg). Main pulmonary artery: Partial dilation: Six patients: Large ventricular septal defects (VSDs) and complex lesions requiring additional surgery. Progressive dilation allowed postponement of surgery in four children and allowed percutaneous VSD closure in one. Complete dilation: Eight patients: Spontaneous restriction of VSDs occurred in six patients; the bands were subsequently percutaneously completely released after a median of 39 weeks (7-91 weeks). The median gradient decreased from 90 to 38 mmHg (p<0.0001). Bilateral branch pulmonary artery: An average 8.5% increase in saturations was achieved in five patients, and in one patient, a hybrid procedure with borderline left ventricle, complete dilation allowed successful percutaneous biventricular repair. CONCLUSIONS Dilation of both main and bilateral branch pulmonary artery bands is possible, effective and safe. Dilatable main pulmonary artery bands allow for progressive dilation with postponement of surgery or complete release of the bands. Bilateral dilatable branch pulmonary bands offer palliative benefit, especially in hybrid cases where pulmonary blood flow may be limited by the bands before the ideal conditions for a stage II procedure exist.

Volume load paradox while preparing for the Fontan: not too much for the ventricle, not too little for the lungs

Ventricular dysfunction is frequently encountered in Fontan patients. Cardiologists and cardiac surgeons have, therefore, mainly focused on preservation of cardiac function, limiting the early volume overload as much as possible both in magnitude and duration. This resulted in improved cardiac function but, in some patients, also in poor pulmonary artery (PA) growth which in turn resulted in a poor final Fontan circuit. The volume requirements for optimal growth and development of the ventricle and the lungs are different and divergent. Avoiding overload of the ventricle is important, but excessive protection from volume overload may not be necessary and may result in PA hypoplasia, which in turn will severely affect the Fontan circuit.

Hybrid approach as bridge to biventricular repair in a neonate with critical aortic stenosis and borderline left ventricle

A newborn presented with severe aortic valve stenosis and a borderline hypoplastic left ventricle due to disproportionate left ventricular hypertrophy (maternal diabetes). The aortic valve was balloon dilated and the infant tolerated a biventricular circulation. However, severe retrograde pulmonary hypertension and mitral regurgitation developed, indicating that biventricular circulation was not possible at that stage. A hybrid approach with ductal stenting, atrial septostomy and bilateral dilatable pulmonary artery band placement was followed on day 25. This allowed the left ventricle several months to adapt to lower pressure and normoglycemic conditions. At re-evaluation after 8 months biventricular repair appeared possible: the ductus was closed with Amplatzer occluders and the pulmonary artery bands were opened up with bilateral balloon angioplasty of the dilatable bands. At the age of 3 years, the infant is doing well with a biventricular circulation and normal pulmonary artery pressure. The hybrid approach allowed adequate time (months) for careful consideration and acted as a bridge to biventricular repair in this infant.

Stenting the neonatal arterial duct

Ductal stenting in neonates with either duct-dependent pulmonary or systemic circulation has become a good alternative for the initial palliation of complex congenital heart disease. Changes of stent and catheter technology (low profile, flexible, premounted stents with good scaffolding), better patient selection and preparation, optimal interventional access and covering the complete length of the duct have significantly improved results.