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Transcatheter Right Ventricular Outflow Tract Intervention: The Risk to the Coronary Circulation
Abstract
A 14-year-old male with degeneration of his right ventricular to pulmonary artery homograft conduit was referred to us for percutaneous pulmonary valve implantation (PPVI).1 Magnetic resonance imaging indicated close proximity of the left anterior descending coronary artery to the homograft (Figure, A). To test whether PPVI would compress the …
... This procedure can be performed with excellent short-and mid-term results, with low morbidity and mortality [3][4][5]. One of the most serious potential complications is coronary arterial compression [6,7]. Preprocedural imaging (computed tomography (CT) or cardiovascular magnetic resonance (CMR)), careful patient selection, and a patient-modified approach during the procedure can guide a safe and successful intervention [4]. ...
... The large variation in anatomy that exists amongst patients who require RVOT conduits leads to significant diversity in the relationship between the outflow anatomy and the coronary arterial course [8]. Coronary arterial compression, a potentially fatal compli-cation, may occur during PPVI [3,4,6,9]. To minimise the risk of this major adverse event we suggest noninvasive imaging followed by meticulous biplane visualisation of the coronary anatomy. ...
... This procedure can be performed with a low morbidity and mortality and excellent medium-term results [3][4][5]. Along with conduit rupture, coronary compression remains a major potential complication [6][7][8]. Careful patient selection should include preprocedural imaging (CT and or CMR imaging), with angiographic coronary assessment in selected cases. Balloon interrogation of the conduit with concomitant selective biplane coronary arteriography is invaluable in some cases, but the aggression of the balloon interrogation needs to be balanced by the risk of conduit rupture during this diagnostic step. ...
Despite advances in surgical techniques, right ventricular outflow tract (RVOT) conduits are prone to fail over time. Percutaneous pulmonary valve implantation was introduced to expand the lifetime of these conduits and to decrease the number of open heart operations during a patient's lifetime. The procedure can be performed with excellent results; however, serious complications such as coronary arterial compression and conduit rupture have been reported. We present percutaneous treatment of a patient after Ross-Konno operation with RVOT conduit dysfunction and a potentially problematic course of the left anterior descending artery.
... The course of the left main and descending anterior coronary artery in proximity to the RVOT as well as a take-off angle ≤90 • of the left main and right coronary arteries may increase the PPVI failure rate or even contraindicate it ( Figure 2) [29]. Final invasive evaluation during cardiac catheterization is performed to cross-check data with a selective coronary angiography during balloon inflation in the RVOT to evaluate possible coronary compression during valve placement [30]. ...
... The course of the left main and descending anterior coronary artery in proximity to the RVOT as well as a take-off angle ≤90° of the left main and right coronary arteries may increase the PPVI failure rate or even contraindicate it ( Figure 2) [29]. Final invasive evaluation during cardiac catheterization is performed to cross-check data with a selective coronary angiography during balloon inflation in the RVOT to evaluate possible coronary compression during valve placement [30]. ...
Performance of cardiovascular magnetic resonance (CMR) in the planning phase of percutaneous pulmonary valve implantation (PPVI) is needed for the accurate delineation of the right ventricular outflow tract (RVOT), coronary anatomy and the quantification of right ventricular (RV) volume overload in patients with significant pulmonary regurgitation (PR). This helps to find the correct timings for the intervention and prevention of PPVI-related complications such as coronary artery compression, device embolization and stent fractures. A defined CMR study protocol should be set for all PPVI candidates to reduce acquisition times and acquire essential sequences that are determinants for PPVI success. For correct RVOT sizing, contrast-free whole-heart sequences, preferably at end-systole, should be adopted in the pediatric population thanks to their high reproducibility and concordance with invasive angiographic data. When CMR is not feasible or contraindicated, cardiac computed tomography (CCT) may be performed for high-resolution cardiac imaging and eventually the acquisition of complementary functional data. The aim of this review is to underline the role of CMR and advanced multimodality imaging in the context of pre-procedural planning of PPVI concerning its current and potential future applications.
... In patients with a conduit-free RVOT, balloon-interrogation at low-pressure was performed using a flexible, semicompliant, mildly oversized balloon (typically Tyshak V R balloon; NuMED, NY) to delineate the potential zone of retention (careful observation of the balloon during submaximal inflation and deflation). Simultaneous coronary angiography was performed to exclude coronary compression [8]. Prestenting was performed in all patients; in the large RVOT, we typically used a bare stent with a hybrid open cell design to provide sufficient anchoring at the retention zone. ...
... Inflation was typically done by hand using a 20 ml syringe; this automatically limits the inflation pressure. As in group 1 patients, a standard coronary angiography with simultaneous balloon inflation at the target implantation site was performed to assess the danger for coronary artery compression; full dilation to the final anticipated size was typically not performed to avoid graft tearing or rupture [8]. To allow a controlled expansion without blood extravasation , prestenting was performed typically with covered Cheatham Platinum stents TM (CCP stent TM , NuMED, NY); we aimed to cover the full length of the conduit overlapping the proximal and distal anastomosis. ...
Introduction
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.
Aim of study
To report the safety and feasibility of off‐label application of percutaneous pulmonary valve implantation.
Design
Retrospective analysis of prospectively collected data.
Patients and Methods
Off‐label indications: conduit‐free RVOT or patients with an existing but undersized conduit.
Results
Twenty‐one Melody® valves and two Sapien® valves were successfully implanted in 23 patients (16.9 years; range 6.1–80.5 years). In 22 patients, prestenting was performed 4.8 months (range 0–69.2) before valve implantation (15 covered and 13 bare stents). Stent endothelial ingrowth was allowed for at least 2 months prior to implantation of the percutaneous valve if stent stability or sealing by the covering was presumed to be insufficient. Group 1 patients ( n = 8) had a “conduit‐free” RVOT after transannular/infundibular patch and after prestenting underwent percutaneous pulmonary valve implantation (PPVI), with a final RVOT diameter of 21.5 mm (range 16–26 mm). Group 2 patients consisted of two elderly patients with pulmonary valve stenosis and severe RVOT calcifications. Group 3 ( n = 13) had an existing conduit (nominal 15.9 ± 3.2 mm; range 10–20 mm). The conduit was augmented from 14.7 ± 3.5 to 20 ± 1.6 mm with PPVI. The RVOT preparation and valve implantations were uneventful.
Conclusions
PPVI is safe and feasible in selected patients with an off‐label indication. Creating an adequate “landing zone” by prestenting makes the procedure safe and predictable. Updating the indications for PPVI should be considered. © 2013 Wiley Periodicals, Inc.
... If there is no evidence of CA compression, tPVR is performed. If there is any question of potential CA compression, either from study of the angiograms or electrocardiographic changes, tPVR is aborted [26,27]. Pre-stenting of the conduit with a bare metal or a covered stent has several advantages. ...
Introduction: Right ventricular outflow tract (RVOT) dysfunction is common among individuals with congenital heart disease (CHD). Surgical intervention often carries prohibitive risks due to the need for sequential pulmonary valve (PV) replacements throughout their life in the majority of cases. Transcatheter pulmonary valve replacement (tPVR) is one of the most exciting recent developments in the treatment of CHD and has evolved to become an attractive alternative to surgery in patients with RVOT dysfunction. Areas covered: In this review, we examine the pathophysiology of RVOT dysfunction, indications for tPVR, and the procedural aspect. Advancements in clinical application and valve technology will also be covered. Expert opinion: tPVR is widely accepted as an alternative to surgery to address RVOT dysfunction, but still significant numbers of patients with complex RVOT morphology deemed not suitable for tPVR. As the technology continues to evolve, new percutaneous valves will allow such complex RVOT patient to benefit from tPVR. ARTICLE HISTORY
... 18 When in doubt, concomitant balloon inflation inside the homograft and contrast injection into the LMCA is useful to determine the risk of coronary compression. [37][38][39] In this series, a transcatheter approach was attempted in 1 patient despite a homograft to LMCA distance of 2 mm, and expectedly, there was confirmed coronary compression, which led to aborting the procedure. In patients deemed high risk for coronary obstruction, open surgery remains the gold standard to treat symptomatic homograft stenosis. ...
OBJECTIVES
Pulmonary homograft dysfunction is a limitation after the Ross procedure. Decellularized pulmonary homografts can potentially mitigate this complication. The aim of this study was to examine the incidence, predictors, progression and morphology of pulmonary homograft dysfunction using data from the Canadian Ross Registry.
METHODS
From 2011 to 2019, 466 consecutive patients (mean age: 47±12 years, 73% male) underwent a Ross procedure using a decellularized cryopreserved pulmonary homograft (SynerGraft SG, Cryolife, Kennesaw, USA). Pulmonary homograft dysfunction was defined as any of the following: peak pulmonary gradient ≥30mmHg, pulmonary regurgitation >2 or pulmonary homograft reintervention. Patients meeting ≥1 of these criteria (n=30) were compared to the rest of the cohort (n=436). Median follow-up is 2.2 years (maximum= 8.5 years) and 99% complete (1176 patient-years).
RESULTS
The cumulative incidence of pulmonary homograft dysfunction was 11±2% at 6 years. Pulmonary homograft stenosis was the most frequent presentation (n=28 patients, 93%). Morphologically, stenosis occurred most often along the conduit (59%). Overall, 4 patients required homograft reintervention. At 6 years, the cumulative incidence of homograft reintervention was 3±1%. The instantaneous risk rate was greatest in the first year after surgery (3.5%/year) and decreased to <1%/year thereafter. Patient age <45 was the only independent risk factor associated with pulmonary homograft dysfunction (HR= 3.1, 95% CI= 1.1-8.6, p=0.03).
CONCLUSIONS
Use of decellularized cryopreserved pulmonary homografts results in a low incidence of dysfunction and reintervention after the Ross procedure. The risk is higher in the first postoperative year. Younger age is the only independent risk factor for pulmonary homograft dysfunction.
... If there is no evidence of CA compression, tPVR is performed. If there is any question of potential CA compression, either from study of the angiograms or electrocardiographic changes, tPVR is aborted [26,27]. Pre-stenting of the conduit with a bare metal or a covered stent has several advantages. ...
Introduction: Right ventricular outflow tract (RVOT) dysfunction is common among individuals with congenital heart disease (CHD). Surgical intervention often carries prohibitive risks due to the need for sequential pulmonary valve (PV) replacements throughout their life in the majority of cases. Transcatheter pulmonary valve replacement (tPVR) is one of the most exciting recent developments in the treatment of CHD and has evolved to become an attractive alternative to surgery in patients with RVOT dysfunction.
Areas covered: In this review, we examine the pathophysiology of RVOT dysfunction, indications for tPVR, and the procedural aspect. Advancements in clinical application and valve technology will also be covered.
Expert opinion: tPVR is widely accepted as an alternative to surgery to address RVOT dysfunction, but still significant numbers of patients with complex RVOT morphology deemed not suitable for tPVR, As the technology continues to evolve, new percutaneous valves will allow such complex RVOT patient to benefit from tPVR.
... For risk-stratification of coronary-artery-compression, an invasive test was described which requires simultaneous inflation of a balloon catheter within the RVOT and injection of contrast medium through a second catheter placed in the aortic root [16]. If this test shows an occlusion of the coronaries by the balloon, PPVI should not be attempted. ...
To compare contrast-enhanced magnetic resonance angiography (ceMRA) and 3D steady-state free precession (SSFP) during systole and diastole for assessment of the right ventricle outflow tract (RVOT) in patients considered for percutaneous pulmonary valve implantation (PPVI) after tetralogy of Fallot (TOF) repair. We retrospectively evaluated 89 patients (male: 45, mean age 19 ± 8 years), who underwent cardiac-MRI after surgical TOF-repair. Datasets covering the whole heart in systole and diastole were acquired using ECG-gated 3D SSFP and non-gated ceMRA. Measurements were performed in SSFP-sequences and in ceMRA in the narrowest region of the RVOT to obtain the minimum, maximum and effective diameter. Invasive balloon sizing as the gold standard was available in 12 patients. The minimum diameter in diastolic SSFP, systolic SSFP and ceMRA were 21.4 mm (± 6.1 mm), 22.6 mm (± 6.2 mm) and 22.6 mm (± 6.0 mm), respectively. Maximum diameter was 29.9 mm (± 9.5 mm), 30.0 mm (± 7.0 mm) and 28.8 mm (± 8.1 mm) respectively. The effective diameter was 23.2 mm (± 5.7 mm), 27.4 mm (± 6.7 mm) and 24.4 mm (± 6.2 mm), differing significantly between diastole and systole (p < 0.0001). Measurements in ECG-gated SSFP showed a better inter-and intraobserver variability compared to measurements in non-ECG-gated ceMRA. Comparing invasive balloon sizing with our analysis, we found the highest correlation coefficients for the maximum and effective diameter measured in systolic SSFP (R = 0.99 respectively). ECG-gated 3D SSFP enables the identification and characterization of a potential landing zone for PPVI. The maximum and effective systolic diameter allow precise sizing for PPVI. Patients with TOF-repair could benefit from cardiac MRI before PPVI.
... Coronary artery compression during PPVI has been reported in multiple case series with outcomes varying from symptomatic acute coronary syndrome to cardiac arrest [5,6,7,8,9,10,11]. Morray and colleagues retrospectively evaluated coronary artery testing in 404 patients referred for PPVI in a multi-institutional study [4]. ...
... Critically, this treatment is also possible for patients after TOF patch surgery, a large group of patients with congenital heart diseases. Patients at risk of coronary artery compression were excluded from the procedure [16][17][18]. Standard indications for TPVR require circumferential conduit in the pulmonary position. ...
Background:
Transcutaneous pulmonary valve replacement (TPVR) has become an alternative to heart surgery for patients after previous right ventricular outflow tract (RVOT) or pulmonary artery (PA) surgical interventions. The objective was to present immediate and long-term outcomes of transcutaneous pulmonary valve replacement.
Methods:
Between 06/2009 and 06/2016, 46 patients underwent TPVR. Initial diagnoses included tetralogy of Fallot, common arterial trunk, transposition of great arteries post Rastelli correction, left ventricle outflow obstruction after Ross operation, pulmonary atresia, and isolated dysplastic pulmonary valve stenosis. Thirty eight patients (78%) had previously implanted conduits in the pulmonary position, the rest had either RVOT patch reconstruction (n = 6; 13%) or biological valve implantation (n = 2; 4%). They presented primarily with pulmonary stenosis (n = 18; 39%) or regurgitation (n = 28; 60%).
Results:
All procedures were successful - 44 Melody and 2 Edwards-Sapien valves were implanted. Before each procedure exclusion of potential coronary compression and RVOT prestenting was performed. Significant RVOT systolic gradient reduction (from 35.3 ± 19.5 to 13.5 ± 7.1 mm Hg; p < 0.001) and decrease of right to left ventricle systolic pressure ratio from 0.58 ± 0.18 to mean 0.37 ± 0.1 (p < 0.001) was achieved. Also, in every patient PA-RVOT competence was restored, with minor incompetence in only a few patients. Post procedure follow-up ranged from 2 to 86 (mean 35.2) months. Follow-up fluoroscopy or chest X-ray revealed 6 stent fractures (2 stent defragmentation - with only one significant valve stenosis).
Conclusions:
TPVR is a safe procedure with encouraging results, it also enables deferring surgical reintervention in the majority of patients.
... If coronary compression is documented, the procedure has to be aborted. 25 Pre-stenting of the conduit with a bare metal stent has several advantages. It is required in almost all cases (for Edwards valve) to provide a landing zone for the stented valve, to reduce the risk of stent fracture (for Melody valve), to maintain a circular configuration of the valve in the long term, and in case of the SAPIEN valve to allow greater margin of safety when positioning the relatively short valve prosthesis (14-19 mm) which would not cover the whole length of conduit or pulmonary trunk obstruction. ...
Percutaneous pulmonary valve implantation (PPVI) is one of the most exciting recent developments in the treatment of structural heart disease and has evolved as an attractive alternative to surgery in patients with dysfunctional right ventricle-pulmonary artery conduits. Although surgical pulmonary valve replacement is associated with low morbidity and mortality rates, there are many instances when operative risks are high or surgery is prohibitive.1 Patients requiring RVOT reconstruction require multiple sternotomies and cardiac surgical procedures throughout their lives due to the limited lifespan of such conduits (∼10 years).2 Patient management strategies have, therefore, been based on delaying surgical intervention for as long as possible, in order to minimize the number of surgical procedures. However, this approach carries the risk of delaying surgery beyond a point of irreversible right ventricular (RV) dysfunction. A balance between the deleterious effects of RVOT dysfunction and the need to minimize the total number of lifetime surgeries for a given patient is a clinically challenging task prompting the need to develop minimally invasive valve therapies. Since the introduction of PPVI in 2000,3 the learning curve with this technology lead to significant improvements in both valve design and procedural approach, with several clinical trials demonstrating the safety and efficacy in restoring valvular competence with excellent short to medium term outcomes;4–6 transforming this technique from its early pioneering nature into routine clinical care at specialized centers. Evolving data from these studies have shown beneficial effects of PPVI in right ventricular volume reduction,7 left ventricular filling properties,8 exercise capacity9 and electrical remodeling.10
This review discusses the evolution, indications, and technical aspects of PPVI using the Melody and Edwards SAPIEN transcatheter heart valve as non-surgical treatment options for dysfunctional RVOT/pulmonary trunk.
... In some cases there is relevant proximity of one or more of the relevant coronary artery branches to the main PA. This exposes patients who undergo interventions of the RVOT to the risk for fatal coronary artery obstruction due to expansion of the RVOT [31,32] . Therefore, it is essential to assess the course of proximal coronary arteries in relation to the RVOT prior to PPVI deployment. ...
The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an "interdisciplinary challenging", heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions.
... Since the first, pioneering human PPVI in 2000 by Bonhoeffer et al, 7 the technique has gained acceptance, with >4000 procedures performed to date. Several studies have now demonstrated the short-term efficacy of PPVI [8][9][10][11][12][13] and defined the potential complications of the procedure, including device migration and fractures, 14 coronary compression, 15 and infective endocarditis. Sustained relief from stenosis and regurgitation has also been demonstrated in the medium term, with freedom from reoperation of 93%, 86%, 84%, and 70% at 10, 30, 50, and 70 months, respectively, with similar freedom from redo interventions 95%, 87%, 73%, and 73% at the same intervals. ...
In contrast to the 50 000+ transcatheter aortic valve replacements to date since 2002, PPVI has enjoyed a more gradual, but nonetheless measured success. Dynamic RVOT characteristics pose greater technical challenges, and preimplantation 3D imaging can be considered the mandatory gold standard for safe patient selection for PPVI. Currently available percutaneous valve sizes remain the rate-limiting step to increasing the number of patients eligible for PPVI, but characterization of RV morphology may also play an important role for designing new devices. Finally, a patient-specific approach (preimplantation 4D imaging, hybrid FEM, and 3D physical prototyping) can be used to improve safety and accuracy in selection of borderline cases. Preimplantation modeling and prototyping is vital to assess morphological suitability with 3D imaging for reintervention to predict stent fracture risk to generate patient-specific physical models in dilated RVOTs and to measure RV function and structure for accurate serial follow-up. The practicalities of designing a clinical service to deliver the above benefits require a truly multidisciplinary team approach involving surgeons, imagers, interventional cardiologists, and engineers incorporating a multimodality imaging protocol and integrated software and manufacturing tools. Despite the promise of this integrated approach, patients and their caregivers need to understand that although percutaneous therapies prolong conduit life span and delay future surgical procedures, stent fracture and redo interventions remain a real possibility.
... Angiography of the coronary arteries is performed to assess the risk of compression from the valve implantation. If the risk of compression remains unclear, then coronary angiography is done with simultaneous inflation of angioplasty balloon at the implantation site (65,67,68). The site for implantation is determined from angiographic studies and hemodynamic assessment of RVOT to identify the position and extent of obstruction and regurgitation (56,63,69). ...
Echocardiographic guidance has an important role in percutaneous cardiovascular procedures and vascular access. The advantages include real time imaging, portability, and availability, which make it an effective imaging modality. This article will review the role of echocardiographic guidance for diagnostic and therapeutic percutaneous procedures, specifically, transvenous and transarterial access, pericardiocentesis, endomyocardial biopsy, transcatheter pulmonary valve replacement, pulmonary valve repair, transcatheter aortic valve implantation, and percutaneous mitral valve repair. We will address the ways in which echocardiographic guidance provides these procedures with detailed information on anatomy, adjacent structures, and intraprocedural instrument position, thus resulting in improvement in procedural efficacy, safety and patient outcomes.
... If the RVOT conduit passes directly over a major coronary branch, the coronary artery can be compressed because of rigid stent expansion. Sridharan et al.24) and Biermann et al.25) reported a significant coronary artery compression, which was demonstrated by balloon inflation within homograft to maximum diameter and simultaneous selective coronary angiography. If there are suspicions of coronary artery compression, selective coronary angiography with simultaneous ballon inflation in the RVOT is the key procedure to assess the spatial relationship between the coronary artery and stent. ...
Pulmonary regurgitation (PR) is a frequent sequelae after repair of tetralogy of Fallot, pulmonary atresia, truncus arteriosus, Rastelli and Ross operation. Due to patient growth and conduit degeneration, these conduits have to be changed frequently due to regurgitation or stenosis. However, morbidity is significant in these repeated operations. To prolong conduit longevity, bare-metal stenting in the right ventricular outflow tract (RVOT) obstruction has been performed. Stenting the RVOT can reduce the right ventricular pressure and symptomatic improvement, but it causes PR with detrimental effects on the right ventricle function and risks of arrhythmia. Percutaneous pulmonary valve implantation has been shown to be a safe and effective treatment for patients with pulmonary valve insufficiency, or stenotic RVOTs.
Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.
Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease, occurring in 1 in 3600 live births. Complete repair of TOF was devised over 50 years ago (first reported by Lillehei in 1954) and can result in complete intracardiac repair in early infancy. There are excellent short- and medium-term survival rates, and 25-year actuarial survival for patients repaired before their fifth birthday is now greater than 90% of the expected survival rate, though the annualized risk of death triples in the third postoperative decade. Late morbidity and mortality related to pulmonary incompetence have been observed in many patients long after total repair. Cardiovascular magnetic response imaging forms an essential part of the long-term follow-up of repaired TOF, guiding when to perform pulmonary valve replacement (PVR), selecting which patients should undergo surgical or percutaneous PVR, and helping to risk assess patients for adverse events.
Patients with surgically repaired congenital right ventricular (RV) outflow anomalies face reintervention due to RV to pulmonary artery (PA) conduit dysfunction in adulthood. Conduit regurgitation, valvular stenosis, and conduit stenosis with calcification are all mechanisms of failure that if untreated lead to deterioration in RV function. Re-operation is associated with high risks and subsequently percutaneous pulmonary valve implantation (PPVI) has been developed as a less invasive alternative. PPVI is established as a safe and effective option for patients with dysfunctional surgical RV-PA conduits. This chapter demonstrates real-life examples of PPVI in clinical practice and reviews the current landscape in RV-PA conduit intervention.KeywordsPulmonary valveConduitCongenital heart diseaseTranscatheterRight ventricular outflow tractPercutaneous valve replacement
The majority of patients with congenital heart disease who have undergone open heart surgery during childhood are possible candidates for additional transcatheter or surgical interventions. One fifth of these conditions usually involve the right ventricular outflow tract (RVOT). Percutaneous pulmonary valve replacement (PPVR) has been widely established as an alternative, less invasive option to surgical pulmonary valve replacement (SPVR). The variability of RVOT anatomy and size, the relative course of the coronary arteries and the anatomy of the pulmonary artery branches are factors that determine the success of the intervention as well as the complication rates. Careful and reliable pre-interventional imaging warrants the selection of suitable candidates and minimizes the risk of complications. 2D and 3D fluoroscopy have been extensively used during pre- and peri-interventional assessment. Established imaging techniques such as Cardiovascular Magnetic Resonance (CMR) and Computed Tomography (CT), as well as newer techniques, such as fusion imaging, have proved to be efficient and reliable tools during pre-procedural planning in patients assessed for PPVR.
Background
Standardization of perioperative care can reduce resource utilization while improving patient outcomes. We sought to describe our outcomes after the implementation of a perioperative clinical pathway for pediatric patients undergoing elective surgical pulmonary valve replacement and compare these results to previously published national benchmarks.
Methods
A retrospective single-center descriptive study was conducted of all pediatric patients who underwent surgical pulmonary valve replacement from 2017 through 2020, after the implementation of a clinical pathway. Outcomes included hospital length of stay and 30-day reintervention, readmission, and mortality.
Results
Thirty-three patients (55% female, median age 11 [7, 13] years, 32 [23, 44] kg) were included in the study. Most common diagnosis and indication for surgery was Tetralogy of Fallot (61%) with pulmonary valve insufficiency (88%). All patients had prior cardiac surgery. Median hospital length of stay was 2 [2, 2] days, and longest length of stay was three days. There were no 30-day readmissions, reinterventions, or mortalities. Median follow-up time was 19 [9, 31] months.
Conclusions
Formalization of a perioperative surgical pulmonary valve replacement clinical pathway can safely promote short hospital length of stay without any short-term readmissions or reinterventions, especially when compared with previously published benchmarks. Such formalization enables the dissemination of best practices to other institutions to reduce hospital length of stay and limit costs.
Background:
Transcatheter valves provide a safe and effective alternative to surgery for treating dysfunctional right ventricular outflow tracts (RVOTs). We present our early multicenter experience of percutaneous pulmonary valve implantation (PPVI) using Melody valve (Medtronic Inc., Minneapolis, MN).
Methods:
Patients with stenosed conduits or degenerated bioprosthetic valves in RVOT with combined stenosis and regurgitation were evaluated for suitability of Melody valve implantation. After undergoing an initial structured training, PPVI using Melody transcatheter pulmonary valve (TPV) was guided by an approved proctor. Conduits were serially dilated and prestented with careful coronary interrogation, and bioprosthetic valves were dilated with high-pressure balloons. Clinical and echocardiographic follow-up was performed at 6 monthly intervals.
Results:
Fifteen patients (three females) aged 23.1 ± 9.5 years in NYHA Class II-III underwent Melody TPV implantation in four Indian centers. The underlying anatomy comprised surgically implanted bioprosthetic valves for pulmonary regurgitation (n= 5), conduit repair for pulmonary atresia (n = 4), Rastelli repair (n = 3), truncus (n = 1), and Ross procedure (n = 2). Twelve patients had more than one previous surgery. Doppler gradient decreased from 74.2 ± 21.5 mmHg to 10.2 ± 4.5 mmHg after the PPVI. At a median follow-up of 14 months (1-39 months), all the patients were in NYHA Class I with echocardiographic gradients of 8 ± 5.7 mmHg with no evidence of pulmonary regurgitation. There were no major procedural adverse events or deaths.
Conclusions:
Our early experience shows encouraging results of the PPVI program in India with proctored case selection and meticulous planning. It also confirms the safety and efficacy of Melody TPV for treating dysfunctional RVOT in postoperative patients.
Introduction
Cardiac magnetic resonance (CMR) has expanded its role in the diagnosis and management of congenital heart disease and acquired heart disease in children. However, there are few studies evaluating the role of cardiac magnetic resonance delineating the anatomy of coronary arteries along with assessment of first pass myocardial perfusion in children. The purpose of this study is to evaluate the extensive use of CMR for delineating coronary anatomy, evaluating first pass myocardial perfusion and late gadolinium enhancement in children with acquired and congenital heart disease.
Methods
A retrospective review of 81 consecutive CMR Whole Heart T2 Prep coronary angiography studies of patients with congenital and acquired heart disease that were performed from December 2013 to May 2015. Results of first pass myocardial perfusion study (at rest and with adenosine stress) and Late Gadolinium enhancement imaging findings were also reviewed.
Results
The median age at the time of CMR was 14 years with range of 2 months to 35 years of age with 46 male and 35 female subjects. Tetralogy of Fallot was the most common pre CMR diagnosis with almost 30% (24/81) of all subjects, followed by suspected coronary artery anomaly in 18.5% (15/81) of all subjects. First pass myocardial perfusion defects were identified in 2.5% (2/81) of subjects. Delayed myocardial enhancement study was performed in 83% (67/81) of all patients, with an abnormal result identified in 28.3% (19/67) of these subjects. The left coronary origin, proximal course and proximal branches were visualized in 94% (76/81) of the subjects. The right coronary origin and proximal course was visualized in about 89% (72/81) of subjects. We found good diagnostic quality images in 90% (73/81) of the subjects. Abnormal coronary artery origin was observed in about 9% of all subjects (7/81). Coronary aneurysmal malformations were identified in 6% of all subjects (5/81). We were unable to visualize either one of the coronary arteries in about 9% of subjects (7/81) either due to patient movement during the study, metallic artifacts or extremely fast heart rate.
Conclusions
Cardiac magnetic resonance imaging can reliably evaluate the coronary anatomy, first pass myocardial perfusion defect and myocardial scar in a diverse group of patients with acquired and congenital heart diseases.
Objective
To evaluate the reliability of balloon coronary compression testing during percutaneous pulmonary valve implantation.
Background
Despite the widespread use of the ‘balloon coronary test’ as the preferable method to rule out the risk of coronary compression, this adverse event has been described after pulmonary valve implantation where coronary balloon test suggested no risk or low risk, calling into question the accuracy of the test.
Methods
We performed a retrospective chart review of 84 patients who underwent pulmonary valve implantation between January 2018 and December 2019 and selected 36 patients whose archived imaging was suitable to perform quantitative analysis of the ‘balloon coronary test’. We focused on the spatial disparity between the right ventricular outflow tract position defined by the inflated testing balloon and the eventual implanted valve position, to classify the test as inaccurate or accurate.
Results
In total, 36.1% of cases were classified as having an inaccurate coronary balloon test. Among the baseline characteristics, right ventricular outflow tract substrate was identified as a significant predictor of test accuracy. Related to this characteristic, the type of testing balloon used and the size of the eventually implanted valve were found to be associated with test accuracy.
Conclusions
Based on our findings, balloon coronary testing is not an accurate method of predicting final valve position with respect to fixed structures in the thorax. This may translate to a high false positive rate for the likelihood of coronary compression in pulmonary valve implantation.
Percutaneous pulmonary valve implantation (PPVI) has the distinction of being the first percutaneous valve replacement in humans, writing a new chapter in cardiac therapeutics with the development of transcatheter valve technologies. This innovation has evolved as an attractive alternative to surgery and has allowed treatment of a growing patient population with congenital heart disease, minimizing the number of lifetime sternotomies and extending the life of previously implanted conduits. Since the introduction of this technology in 2000, several clinical trials have demonstrated effective restoration of valvular competence with excellent outcomes; transforming this technology from its early pioneering nature into routine clinical care at specialized centers.
Aims:
The post-approval MELODY Registry aimed to obtain multicentre registry data after transcatheter pulmonary valve implantation (TPVI) with the Melody™ valve (Medtronic plc.) in a large-scale cohort of patients with congenital heart disease (CHD).
Methods and results:
Retrospective analysis of multicentre registry data after TPVI with the Melody™ valve. Eight hundred and forty-five patients (mean age: 21.0 ± 11.1 years) underwent TPVI in 42 centres between December 2006 and September 2013 and were followed-up for a median of 5.9 years (range: 0-11.0 years). The composite endpoint of TPVI-related events during follow-up (i.e. death, reoperation, or reintervention >48 h after TPVI) showed an incidence rate of 4.2% per person per year [95% confidence interval (CI) 3.7-4.9]. Transcatheter pulmonary valve implantation infective endocarditis (I.E.) showed an incidence rate of 2.3% per person per year (95% CI 1.9-2.8) and resulted in significant morbidity and in nine deaths. In multivariable Cox proportional hazard models, the invasively measured residual right ventricle (RV)-to-pulmonary artery (PA) pressure gradient (per 5 mmHg) was associated with the risk of the composite endpoint (adjusted hazard ratio: 1.21, 95% CI 1.12-1.30; P < 0.0001) and the risk of TPVI I.E. (adjusted hazard ratio: 1.19, 95% CI 1.07-1.32; P = 0.002). Major procedural complications (death, surgical, or interventional treatment requirement) occurred in 0.5%, 1.2%, and 2.0%, respectively. Acutely, the RV-to-PA pressure gradient and the percentage of patients with pulmonary regurgitation grade >2 improved significantly from 36 [interquartile range (IQR) 24-47] to 12 (IQR 7-17) mmHg and 47 to 1%, respectively (P < 0.001 for each).
Conclusion:
The post-approval MELODY Registry confirms the efficacy of TPVI with the Melody™ valve in a large-scale cohort of CHD patients. The residual invasively measured RV-to-PA pressure gradient may serve as a target for further improvement in the composite endpoint and TPVI I.E. However, TPVI I.E. remains a significant concern causing significant morbidity and mortality.
Experience with cardiac magnetic resonance to evaluate coronary arteries in children and young adult patients is limited. Because noninvasive imaging has advantages over coronary angiography, we compared the effectiveness of these techniques in patients who were being considered for percutaneous pulmonary valve implantation.
We retrospectively reviewed the cases of 26 patients (mean age, 12.53 ± 4.85 yr; range, 5–25 yr), all of whom had previous right ventricular-to-pulmonary artery homografts. We studied T2-prepared whole-heart images for coronary anatomy, velocity-encoded cine images for ventricular morphology, and function- and time-resolved magnetic resonance angiographic findings. Cardiac catheterization studies included coronary angiography, balloon compression testing, right ventricular outflow tract, and pulmonary artery anatomy.
Diagnostic-quality images were obtained in 24 patients (92%), 13 of whom were considered suitable candidates for valve implantation. Two patients (8%) had abnormal coronary artery anatomy that placed them at high risk of coronary artery compression during surgery. Twelve patients underwent successful valve implantation after cardiac magnetic resonance images and catheterization showed no increased risk of compression. We attempted valve implantation in one patient with unsuitable anatomy but ultimately placed a stent in the homograft.
Magnetic resonance imaging of coronary arteries is an important noninvasive study that may identify patients who are at high risk of coronary artery compression during percutaneous pulmonary valve implantation, and it may reveal high-risk anatomic variants that can be missed during cardiac catheterization.
Purpose of review:
The past couple of decades have brought tremendous advances to the field of pediatric and adult congenital heart disease (CHD). Percutaneous valve interventions are now a cornerstone of not just the congenital cardiologist treating patients with congenital heart disease, but also-and numerically more importantly-for adult interventional cardiologists treating patients with acquired heart valve disease. Transcatheter pulmonary valve replacement (tPVR) is one of the most exciting recent developments in the treatment of CHD and has evolved to become an attractive alternative to surgery in patients with right ventricular outflow tract (RVOT) dysfunction. This review aims to summarize (1) the current state of the art for tPVR, (2) the expanding indications, and (3) the technological obstacles to optimizing tPVR.
Recent findings:
Since its introduction in 2000, more than ten thousands tPVR procedures have been performed worldwide. Although the indications for tPVR have been adapted earlier from those accepted for surgical intervention, they remain incompletely defined. The new imaging modalities give better assessment of cardiac anatomy and function and determine candidacy for the procedure. The procedure has been shown to be feasible and safe when performed in patients who received pulmonary conduit and or bioprosthetic valves between the right ventricle and the pulmonary artery. Fewer selected patients post trans-annular patch repair for tetralogy of Fallot may also be candidates for this technology. Size restrictions of the currently available valves limit deployment in the majority of patients post trans-annular patch repair. Newer valves and techniques are being developed that may help such patients. Refinements and further developments of this procedure hold promise for the extension of this technology to other patient populations.
Introduction: Right ventricular outflow tract (RVOT) dysfunction is a common hemodynamic challenge for adults with congenital heart disease (ACHD), including patients with repaired tetralogy of Fallot (TOF), truncus arteriosus (TA), and those who have undergone the Ross procedure for congenital aortic stenosis and the Rastelli repair for transposition of great vessels. Pulmonary valve replacement (PVR) has become one of the most common procedures performed for ACHD patients.
Areas covered: Given the advances in transcatheter technology, we conducted a detailed review of the available studies addressing the indications for PVR, historical background, evolving technology, procedural aspects, and the future direction, with an emphasis on ACHD patients.
Expert commentary: Transcatheter pulmonary valve implantation (TPVI) is widely accepted as an alternative to surgery to address RVOT dysfunction. However, current technology may not be able to adequately address a subset of patients with complex RVOT morphology. As the technology continues to evolve, new percutaneous valves will allow practitioners to apply the transcatheter approach in such patients. We expect that with the advancement in transcatheter technology, novel devices will be added to the TPVI armamentarium, making the transcatheter approach a feasible alternative for the majority of patients with RVOT dysfunction in the near future.
During the last 10 years, there have been major technological achievements in pediatric interventional cardiology. In addition, there have been several advances in cardiac imaging, especially in 3-dimensional imaging of echocardiography, computed tomography, magnetic resonance imaging, and cineangiography. Therefore, more types of congenital heart diseases can be treated in the cardiac catheter laboratory today than ever before. Furthermore, lesions previously considered resistant to interventional therapies can now be managed with high success rates. The hybrid approach has enabled the overcoming of limitations inherent to percutaneous access, expanding the application of endovascular therapies as adjunct to surgical interventions to improve patient outcomes and minimize invasiveness. Percutaneous pulmonary valve implantation has become a successful alternative therapy. However, most of the current recommendations about pediatric cardiac interventions (including class I recommendations) refer to off-label use of devices, because it is difficult to study the safety and efficacy of catheterization and transcatheter therapy in pediatric cardiac patients. This difficulty arises from the challenge of identifying a control population and the relatively small number of pediatric patients with congenital heart disease. Nevertheless, the pediatric interventional cardiology community has continued to develop less invasive solutions for congenital heart defects to minimize the need for open heart surgery and optimize overall outcomes. In this review, various interventional procedures in patients with congenital heart disease are explored.
Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. In developed countries, almost all patients with this cardiac malformation are repaired in childhood. Innovations in the diagnosis and management of tetralogy of Fallot have led to dramatic improvements in early survival. As a result, the population of tetralogy of Fallot repair survivors is growing rapidly. Surgical management of tetralogy of Fallot leaves anatomic and functional abnormalities in the majority of patients. This chapter will discuss the different issues related to the most important problems (as chronic pulmonary-valve insufficiency and obstruction of the right ventricular outflow tract, right ventricular outflow tract aneurysm, pulmonary branch artery stenosis, dilated ascending aorta, aortic regurgitation, residual ventricular septal defect, arrhythmic problems) that physicians can face in managing these patients.
Some other important aspects of the postoperative management of the right ventricular function will also be proposed.
The dilemma of when to treat patients who have right ventricular outflow tract (RVOT) dysfunction presenting late after repair of various congenital heart diseases, such as those with repaired tetralogy of Fallot, is one that faces all congenital heart disease clinicians. Surgical pulmonary valve replacement lacks longevity as conduit dysfunction usually occurs within 10-15 years and exposes patients to multiple risky operations over their lifetime. The recent availability of a percutaneous approach to treat RVOT dysfunction, therefore, offers an attractive solution, as it permits earlier intervention without the problems associated with surgery and cardiopulmonary bypass. Initial midterm results are promising and the technique has been proven safe and has provided efficacious relief of pressure and/or volume overload. Following percutaneous pulmonary valve implantation (PPVI), there is a significant remodeling of biventricular volumes with improvement in biventricular systolic function. These results are associated with improvement of symptoms and objective exercise capacity. However, PPVI is not free from possible complications. These have been reduced by improving the implantation technique (learning curve) and the valve design (hammock effect). Due to anatomical (size and morphology) and dynamic reasons, with the current device, only 15 % of patients with RVOT dysfunction are eligible for such a treatment, but future valve design and advances in four-dimensional imaging techniques will most likely broaden its applica bility, thus making PPVI an even better alternative to surgery.
The assessment of valvular heart disease by cardiac MRI has changed little over the last decade. However, with the increasing use and development of percutaneous valve interventions (transcatheter and minimally-invasive surgery), there is an increasing need to use cardiac MRI to define which patients will benefit from treatment, which patients are suitable for a specific treatment and how patients will respond to their treatments. As cardiac MRI is the best available in-vivo test to define great vessel flow and ventricular volumes, whilst at the same time providing beautiful, high-resolution 3D/4D anatomical images of the heart, it may become the imaging modalities of choice for these assessments. Importantly, as long-term outcome data is acquired, this ability of cardiac MRI to accurately measure physiological parameters will help us define when to treat patients, in particular asymptomatic patients with valvular regurgitation. Finally, the development and increasing use of high spatio-temporal real-time data for acquiring flow and function information will enable MR scans to be performed over a short time period (e.g. 15 mins) comparable to the time it takes to perform a full echocardiogram!
To date, transcatheter valve replacement for congenital heart disease has focused on the treatment of the dysfunctional right ventricular outflow tract. Following congenital heart disease surgery, the right ventricular outflow tract is often subject to pulmonary regurgitation and/or stenosis, which has been shown to lead to insidious dilation and progressive risk of irreversible systolic dysfunction, arrhythmia, and sudden death. The Melody transcatheter pulmonary valve and the Edwards transcatheter valve have both demonstrated excellent rates of technical success and safety in right ventricle to pulmonary artery conduits. Short-term safety and efficacy are comparable to those reported following operative pulmonary valve replacement. Technical concerns during deployment in conduits include coronary compression and conduit rupture. Expanding indications for the transcatheter pulmonary valve replacement include implantation within a failed bioprosthetic valve and in the native right ventricular outflow tract. A major challenge is that a large proportion of subjects with dysfunctional right ventricular outflow tracts are dilated with a tremendous variation in anatomy. Several methods that adjust current technology to address the dilated RVOT are described, while a device designed to address such dilated outflow tracts is in clinical trials at the present time.
The anatomy of tetralogy of Fallot (TOF), together with the pathophysiological consequences, was first described by Etienne-Louis Fallot in 1888. The tetrad of overriding aorta, right ventricular (RV) outflow tract obstruction, ventricular septal defect (VSD) and consequent RV hypertrophy is all due to antero-cephalad deviation of the outlet septum during fetal development. TOF is the most common cyanotic congenital heart disease (CHD), accounting for 10 % of CHD patients and occurring in 1 in 3,600 births (Shinebourne et al., Heart 92:1353-1359, 2006). It carries a recurrence risk of 3 % in siblings. There is genetic microdeletion in 22q11 in 15-25 % of TOF patients in whom TOF is part of DiGeorge syndrome. There is a spectrum of morphology, despite the four features that comprise 'tetralogy', and the severity of the RV outflow tract (RVOT) obstruction is the major determinant of first clinical presentation. Surgical palliation was achieved using the Blalock-Taussig shunt (subclavian artery to ipsilateral pulmonary artery connection) in 1944, a landmark event as these patients underwent the first cardiac surgery. Subsequently, surgical repair was described in the 1950s with the advent of cardiopulmonary bypass. Primary surgical repair involves patch closure of the VSD and intervention to the RVOT to relieve obstruction. RV muscle bundles are resected. Depending on the size of the outflow tract, pulmonary valve and pulmonary arteries; an RVOT patch, transannular patch and/or pulmonary artery (PA) patch may be required for RVOT reconstruction. In the variants with anomalous coronary arteries or in pulmonary atresia-type Fallot, an RV to PA conduit may be used. © 2014 Springer Science+Business Media New York. All rights reserved.
Purpose of review:
Transcatheter pulmonary valve replacement has only been both approved and widely available for most congenital heart disease centers for a few years; its use and familiarity for interventionalists have greatly expanded our knowledge of its applicability to a multitude of clinical situations. Expanded worldwide use and longer time from implant have both served to better understand procedural limits and uncommon late adverse events.
Recent findings:
Although currently approved for implantation in the USA only in dysfunctional and circumferential right ventricle to pulmonary artery conduits, with expanded experience operators have been able to adapt the delivery of this valve in a large number of additional clinical scenarios. Rare technical limitations of the procedure, most importantly coronary compression, are now being better defined. Although not frequent, a significant number of infective endocarditis episodes have been reported, but more recently several studies have deepened our understanding of this late adverse event for the most commonly implanted transcatheter pulmonary valve prosthesis.
Summary:
Expanded and widened use has extended our understanding of who may benefit from transcatheter pulmonary valve implantation (TPVI), the current limits of TPVI, and uncommon but important late issues following TPVI.
Tetralogy of Fallot (ToF) and its surgical treatment frequently lead to dysfunction of the pulmonary valve. A common surgical approach to this is to implant a right ventricle to pulmonary artery valved conduit. Many conduits are available and their nature is important when considering a transcatheter valve. Pulmonary or aortic homografts (human donor valves) have been successfully used as a right ventricle to pulmonary artery conduit [1]. These conduits can fail causing progressive stenosis, or regurgitation, which can present at an early stage. Homografts are prone to calcification as well as endocarditis. Other conduits have been used including pericardial valves mounted in a prosthetic tube, such as a Hancock conduit (porcine) and a valved conduit of bovine jugular vein (Contegra). When a conduit is not needed some surgeons use stented bioprosthetic valves with pericardial leaflets to achieve a competent pulmonary valve [2].
Improved surgical and medical therapy have prolonged survival in patients with congenital heart disease (CHD) such that general medical conditions like coronary artery disease (CAD) are now the main determinants of mortality. A summary of the association of CAD with CHD, as well as a discussion of the radiologic evaluation of the coronary arteries in adults with CHD is described herein. Cross sectional imaging to evaluate CAD in adults with CHD should follow the same appropriateness criteria as gender and aged matched patients without CHD. Coronary CT imaging may be particularly valuable in evaluating the coronary arteries in this patient population as invasive coronary angiography may prove challenging secondary to complicated or unconventional anatomy of the coronary arteries. Further, typical methods for evaluating CAD such as stress or echocardiography may be impractical in adults with CHD. Finally, delineating the anatomic relationship of the coronary arteries and their relationship with the sternum, chest wall, conduits, grafts, and valves is highly recommended in patients with CHD prior to reintervention to avoid iatrogenic complications.
Cardiac MRI has expanded its role in the diagnosis and management of congenital heart disease in both children and adults. Ongoing technological advancements in both data acquisition and data presentation have enabled cardiac MRI to be integrated into clinical practice with increasing understanding of the advantages and limitations of the technique by cardiologists and congenital heart surgeons. Importantly, the combination of exquisite 3D anatomy with functional physiological data enables cardiac MRI to provide a unique perspective for the management of many patients with congenital heart disease. Cardiac MRI can be challenging in this setting, in particular in neonates and small children, and this chapter will review the technical requirements, imaging protocols and application of cardiac MRI in these complex cardiac conditions.
Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease, occurring in 1 in 3,600 live births [1]. Complete repair of TOF was devised over 50 years ago (first reported by Lillehei in 1954) and can result in complete intra-cardiac repair in early infancy [2]. However, despite excellent short- and medium-term survival rates, the 30 year actuarial survival for patients repaired before their 5th birthday is 90 % of the expected survival rate and the annualized risk of death triples in the third postoperative decade [2, 3]. Late morbidity and mortality, in particular related to pulmonary incompetence, has been observed in many patients long after total repair.
Over the last several decades there has been a remarkable change in the therapeutic strategy of congenital heart disease. Development of new tools and devices, accumulations of experience, technical refinement have positively affected the outcome of interventional treatment. Many procedures including atrial septostomy, balloon valvuloplasty, balloon dilation of stenotic vessel with or without stent implantation, transcatheter occlusion of abnormal vascular structure, transcatheter closure of patent arterial duct and atrial septal defect, are now performed as routine interventional procedures in many institutes. In diverse conditions, transcatheter techniques also provide complementary and additive role in combination with surgery. Intraoperative stent implantation on stenotic vessels, perventricular device insertion, and hybrid stage 1 palliative procedure for hypoplastic left heart syndrome have been employed in high risk patients for cardiac surgery with encouraging results. Transcatheter closure of ventricular septal defect has been performed safely showing comparable result with surgery. Investigational procedures such as percutaneous valve insertion and valve repair are expected to replace the role of surgery in certain group of patients in the near future. Continuous evolvement in this field will contribute to reduce the risk and suffering from congenital heart disease, while surgery will be still remained as a gold standard for significant portion of congenital heart disease.
We present the first in Poland, and among the first in Europe, cases of transcatheter implantation of the biological Sapien Edwards valve in the pulmonary position. The valves were implanted successfully without periprocedural complications in 2 patients with post-operative right ventricular outflow tract dysfunction.
Percutaneous pulmonary valve implantation is one of the most significant advances in catheter interventional treatment of patients with congenital heart disease within the last 10 years. The lifetime of biological conduits in the right ventricular outflow tract can be expanded and, hence, patients may have fewer open heart surgeries during their lifetime. Careful patient selection is mandatory. The correct timing of percutaneous pulmonary valve implantation, especially in the presence of prevailing pulmonary regurgitation, is still a matter of debate. Prestenting ensures a good hemodynamic result, lowers the incidence of stent fractures and enables the treatment of patients with a 'native' right ventricular outflow tract. Coronary arterial compression and conduit rupture are the major periprocedural hazards. The only fatalities occurred after coronary arterial compression. Further studies are needed to demonstrate the excellent short time results are sustained over time. The intervention should only be carried out by an experienced interventionalist.
We report a case of a 29-year-old man who developed exercised-induced myocardial infarction 3 months post Melody valve implantation. We introduce the concept of ruling out dynamic coronary artery compression by simulating transcatheter pulmonary valve implant while increasing cardiac output and thus aortic dimensions in the catheterization laboratory. © 2014 Wiley Periodicals, Inc.
Objectives
Evaluate the incidence, diagnosis, and outcome of coronary compression (CC) during right-ventricular outflow tract interventions. Background
The incidence, risk factors, diagnosis, and outcomes of CC during percutaneous pulmonary valve implantation are poorly defined. Methods
One-hundred consecutive patients (May 2008 to January 2012) undergoing transcatheter right-ventricular outflow tract treatment in two institutions were studied. ResultsCC occurred in six patients (6%) with a right ventricular outflow conduit stenosis, at a median age of 24.5 (13-49) years. It involved the left main coronary artery in four and the right coronary artery originating from the left anterior descending coronary artery in two patients. Conduit types were homograft (n=3), bioprosthesis (n=2), and a pericardial patch (n=1). Median diameter was 23 (17-24) mm at surgical implantation. CC was diagnosed through a selective coronary angiogram during balloon dilation of the conduit in the first three patients and through an aortic root angiogram for the three next cases because we recognized that proximal compression could be masked during coronary artery cannulation. It was suspected on pre-procedure imaging (magnetic resonance imaging and/or computed tomography) in three cases. Patients with abnormal coronary anatomy tend to be at increased risk of CC (P=0.0504). One institution had a higher incidence of CC (P=0.04). CC resolved after balloon deflation. No patient underwent conduit stenting. Four patients underwent surgical reconstruction of right ventricular outflow tract. ConclusionsCC is accurately diagnosed during right-ventricular outflow tract interventions. We recommend an aortic root angiogram during dilation with a non-compliant balloon matching the diameter and length of the intended conduit implant. (c) 2014 Wiley Periodicals, Inc.
As increasing numbers of patients with congenital heart disease enter adulthood, there is a growing need for minimally invasive percutaneous interventions, primarily to minimize the number of repeated surgeries required by these patients. The use of percutaneous devices is commonplace for the treatment of simple lesions, such as atrial septal defect, patent foramen ovale, patent duct arteriosus, and abnormal vascular connections. There is also substantial experience with device closure of membranous and muscular ventricular septal defects, as well as more complex shunts such as baffle leaks after atrial switch repair and ventricular pseudoaneurysms. An increasing use of covered stents has improved the safety of aortic coarctation, conduit, and branch pulmonary stenosis interventions. Percutaneous pulmonary valve implantation now has an established role in the setting of dysfunctional right ventricle-pulmonary artery conduits or failing bioprosthetic pulmonary valves. Many patients remain unsuitable for percutaneous pulmonary valve implantation because of large diameter "native" outflow tracts, however, various techniques have emerged and multiple devices are in development to provide solutions for these unique anatomic challenges. Hybrid approaches involving use of surgical and transcatheter techniques are increasingly common, serving to optimize efficacy and safety of certain procedures; they depend on a collaborative and collegial relationship between cardiac surgeons and interventionalists that is primarily patient-centred.
Background:
The Melody transcatheter pulmonary valve (TPV) was approved for implantation in obstructed right ventricular outflow tract conduits in 2010 after a multicenter trial demonstrating improvements in conduit obstruction, regurgitation, and right ventricular pressure. A recognized risk and contraindication to TPV implantation is the demonstration of coronary artery (CA) compression during balloon angioplasty or stent placement in the overlying conduit. This study is the first to characterize the risk of CA compression in this population.
Methods and results:
From 2007 to 2012, 404 patients underwent 407 catheterizations for potential TPV implantation (median age, 18 years) at 4 centers. Three hundred forty-three patients (85%) underwent valve implantation. Twenty-one patients (5%) had evidence of CA compression with simultaneous right ventricular outflow tract angioplasty and CA angiography. Sixty-eight patients (17%) had abnormal CA anatomy. Fifteen of 21 (71%) patients with CA compression had abnormal CA anatomy. Eight patients with tetralogy of Fallot and 7 patients with transposition of the great arteries demonstrated compression. Of the 34 patients with tetralogy of Fallot and abnormal CA, 7 (21%) demonstrated CA compression.
Conclusions:
CA compression following TPV implantation can be catastrophic. CA compression was observed in 5% of patients during test balloon angioplasty. No patients in this study developed clinically apparent CA compression after TPV implantation. CA compression was significantly associated with the presence of abnormal CA anatomy, especially in patients with tetralogy of Fallot or transposition of the great arteries. Preimplantation coronary angiography with simultaneous test angioplasty is an important step to evaluate for the presence of CA compression during TPV implantation.
Right ventricular outflow tract (RVOT) dysfunction with pulmonary regurgitation or obstruction is a common postsurgical consequence in congenital heart disease.
Magnetic resonance imaging (MRI) is widely accepted as standard method of imaging in congenital heart disease. It provides anatomical and functional information without radiation exposure and is therefore well suited for serial examinations.
Percutaneous pulmonary valve implantation (PPVI) has been shown to be a safe and effective treatment option for patients with pulmonary valve insufficiency or stenosis. Correct patient selection for PPVI is crucial. It is important to be familiar with the indications and anatomical requirements for stent placement and to tailor imaging protocols.
Imaging the RVOT, assessment of right ventricular volumes and function and calculation of pulmonary flow and regurgitation are core elements of the MRI examination prior to PPVI. Low interobserver and intraobserver variation allows even small changes to be detected.
Imaging provides relevant information for correct patient selection for PPVI and is part of postinterventional follow-up. Imaging is an important tool for documentation of success and for detection of complications.
Several imaging modalities are used for evaluation of RVOTs; however, MRI can provide answers to most questions without radiation exposure.
Expanded surgical options and improved outcomes for children born with structural heart defects have ushered a greater clinical interest in the normal and abnormal development of the coronary circulation. Anatomic variations of the coronary system may impact surgical candidacy or operative technique during neonatal life, while others may impact long-term clinical management and planning for subsequent interventions. This review aims to characterize coronary artery anatomy in symptomatic congenital heart disease, emphasizing the clinical consequence of these variations and anomalies.
Right ventricular outflow tract (RVOT) reconstruction with valved conduits in infancy and childhood leads to reintervention for pulmonary regurgitation and stenosis in later life.
Patients with pulmonary regurgitation with or without stenosis after repair of congenital heart disease had percutaneous pulmonary valve implantation (PPVI). Mortality, hemodynamic improvement, freedom from explantation, and subjective and objective changes in exercise tolerance were end points. PPVI was performed successfully in 58 patients, 32 male, with a median age of 16 years and median weight of 56 kg. The majority had a variant of tetralogy of Fallot (n=36), or transposition of the great arteries, ventricular septal defect with pulmonary stenosis (n=8). The right ventricular (RV) pressure (64.4+/-17.2 to 50.4+/-14 mm Hg, P<0.001), RVOT gradient (33+/-24.6 to 19.5+/-15.3, P<0.001), and pulmonary regurgitation (PR) (grade 2 of greater before, none greater than grade 2 after, P<0.001) decreased significantly after PPVI. MRI showed significant reduction in PR fraction (21+/-13% versus 3+/-4%, P<0.001) and in RV end-diastolic volume (EDV) (94+/-28 versus 82+/-24 mL.beat(-1).m(-2), P<0.001) and a significant increase in left ventricular EDV (64+/-12 versus 71+/-13 mL.beat(-1).m(-2), P=0.005) and effective RV stroke volume (37+/-7 versus 42+/-9 mL.beat(-1).m(-2), P=0.006) in 28 patients (age 19+/-8 years). A further 16 subjects, on metabolic exercise testing, showed significant improvement in VO2max (26+/-7 versus 29+/-6 mL.kg(-1).min(-1), P<0.001). There was no mortality.
PPVI is feasible at low risk, with quantifiable improvement in MRI-defined ventricular parameters and pulmonary regurgitation, and results in subjective and objective improvement in exercise capacity.