Left coronary artery occlusion after percutaneous pulmonary valve implantation. Ann Thorac Surg. 2012;94:e7-e9. [PMID: 22735024 DOI: 10.1016/j.athoracsur.2012.01.022]

Technical recommendations for computed tomography guidance of intervention in the right ventricular outflow tract: Native RVOT, conduits and bioprosthetic valves:: A white paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of Cardiovascular Computed Tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits, and Bioprosthetic Valves

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital heart disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons, and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multimodality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits and Bioprosthetic Valves: A White Paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Pediatric Surgical Pulmonary Valve Replacement Outcomes After Implementation of a Clinical Pathway

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.

Cardiac Magnetic Resonance to Predict Coronary Artery Compression in Transcatheter Pulmonary Valve Implantation Into Conduits

OBJECTIVES

The aim of this study was to evaluate the accuracy of cardiac magnetic resonance (CMR) in predicting coronary artery (CA) compression during transcatheter pulmonary valve implantation (TPVi).

BACKGROUND

TPVi is a widely available option to treat dysfunctional right ventricle (RV)-to-pulmonary artery (PA) conduits, but CA compression is an absolute contraindication. CMR can evaluate coronary anatomy, but its utility in predicting CA compression is not well established.

METHODS

After Institutional Review Board approval was obtained, all patients at 9 centers with attempted TPVi in RV-PA conduits and recent CMR (≤12 months) were analyzed. A core laboratory reviewed all CMR studies for the shortest orthogonal distance from a CA to the conduit, the shortest distance from a CA to the most stenotic area of the conduit, and subjective assessment of CA compression risk.

RESULTS

Among 231 patients, TPVi was successful in 198 (86%); in 24 (10%), balloon testing precluded implantation (documented CA compression or high risk). Distance to the RV-PA conduit ≤2.1 mm (area under the curve [AUC]: 0.70) and distance to most stenotic area ≤13.1 mm (AUC: 0.69) predicted CA compression. Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with CA compression when controlling for abnormal coronary anatomy or degree of conduit calcification.

CONCLUSIONS

CMR can help predict the risk for CA compression during TPVi in RV-PA conduits but cannot completely exclude CA compression. CMR may assist in patient selection and counseling families prior to TPVi, although balloon testing remains essential.

Aortic Root Distortion During Balloon Angioplasty of Right Ventricular Outflow Tract Prior to Transcatheter Pulmonary Valve Implantation

We describe our experience with aortic root distortion in transcatheter pulmonary valve implantation (TPVI). Aortic root distortion (AD) can be observed with balloon angioplasty of the right ventricular outflow tract (RVOT), but its long-term significance is unknown. This has been a common finding in our institution, though not fully appreciated in our early experience. Retrospective review of procedural angiograms prior to TPVI and follow up imaging was performed. Between June 2012 and October 2017, 47 patients underwent catheterization to attempt TPVI. Five patients had coronary compression which precluded TPVI (one with significant AD as well). Four patients had significant AD and did not receive TPVI. Of the remaining 38 successful TPVI, 20 had adequate imaging to assess the aortic root. Four patients had severe AD, 7 had mild AD, and 9 with no AD. Severity of AI did not correlate with degree of AD. Median follow up after TPVI was 46 months (IQR 21-67). Of the 4 patients with severe AD who received TPVI, 1 has new mild AI with 78 months follow up. Of the 18 patients who received TPVI without adequate arch imaging, 2 patients have new mild AI with 86 and 75 months follow up. AD during RVOT angioplasty is a relatively common finding. In our early experience, some patients who were retrospectively identified to have severe AD received TPVI. These patients have done well, though further data is needed before considering severe AD a benign finding.

Transcatheter pulmonary valve replacement in pediatric patients

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.

Utility of CT Angiography for the Prediction of Coronary Artery Compression in Patients Undergoing Transcatheter Pulmonary Valve Replacement

Objectives:

We aimed to evaluate the utility of computed tomography angiography (CTA) for coronary compression (CC) prediction in patients with congenital heart disease undergoing balloon-expandable transcatheter pulmonary valve replacement (TPVR).

Background:

Coronary compression is a serious complication of TPVR, but the value of preprocedural CTAs to assess CC risk is largely unexplored.

Methods:

In all, 586 patients underwent TPVR between January 2009 and July 2018. Adults with a pre-TPVR CTA and children with a CTA performed less than one year prior to TPVR were included. Patients with poor CTA image quality or with aborted cases due to reasons other than CC were excluded. Sixty-six patients were finally included. Cardiac anatomy was assessed via multiplanar reconstruction of CTAs.

Results:

Coronary compression occurred in 9 (14%) of the 66 patients who underwent TPVR. Most CC cases (seven of nine) occurred in patients with conduits. Proximity of the right ventricular outflow tract (RVOT) landing zone to the coronary arteries and to the chest wall was a significant risk factor for compression ( P < .001 and P = .019, respectively). Compression risk increased significantly if patients had an RVOT to coronary artery distance of ≤3 mm ( P < .001) and an RVOT to chest wall distance of ≤8 mm ( P = .026). Anomalous course of coronary arteries was another significant univariate risk factor ( P = .003).

Conclusions:

Right ventricular outflow tract landing zone distance of ≤3 mm to a coronary artery, landing zone distance of ≤8 mm to the chest wall, and anomalous coronary arteries are associated with increased CC risk. Electrocardiogram gating may not be necessary if coronary arteries are opacified on CTAs. Larger studies are needed to explore and confirm these coronary artery compression risk factors.

3D-assessment of RVOT dimensions prior percutaneous pulmonary valve implantation: comparison of contrast-enhanced magnetic resonance angiography versus 3D steady-state free precession sequence

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.

Percutaneous pulmonary valve implantation in patients after Ross procedure: role of intravascular ultrasound

Coronary compression exclusion during right ventricle outflow tract stenting is recommended and potential oversight may be fatal. Balloon inflation in right ventricle outflow tract with simultaneous aortography can be inconclusive or falsely negative. We present a case of 27-year-old male post Ross operation qualified for percutaneous pulmonary valve implantation. Neither of the conventional views obtained provided a definite exclusion of coronary compression, therefore an intravascular ultrasound of the left coronary artery before and during balloon inflation in right ventricle outflow tract was performed. Acquired images allowed excluding potential constriction, thus a covered stent and pulmonary valve were implanted and the procedure was concluded. Two hours later, the patient complained of chest pain. Transthoracic echocardiography demonstrated a significant pericardial effusion. Retrospective analysis of the final angiogram revealed a possibility of subtle extravasation at the distal part of the homograft. A hybrid procedure consisting of additional covered stent implantation, pericardial drainage, and second pulmonary valve implantation was performed with an acceptable result. To conclude, in case of doubtful or unconvincing images obtained from aortography or selective angiography during balloon inflation in right ventricle outflow tract, intravascular ultrasound might be a feasible and useful technique. Signs of homograft rupture may be subtle, whereas symptoms of cardiac tamponade delayed. In selected patients percutaneous treatment of homograft rupture is achievable and beneficial.

Transcatheter Pulmonary Valve Replacement: Current State of Art

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.

Recent advances in transcatheter pulmonary valve delivery

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.

Aortic Root Distortion and Aortic Insufficiency During Balloon Angioplasty of the Right Ventricular Outflow Tract Prior to Transcatheter Pulmonary Valve Replacement

OBJECTIVE

To describe the significance of aortic root distortion (AD) and/or aortic valve insufficiency (AI) during balloon angioplasty of the right ventricular outflow tract (RVOT) performed to rule out coronary artery compression prior to transcatheter pulmonary valve (TPV) implantation.

METHODS

AD/AI was assessed by retrospective review of all procedural aortographies performed to evaluate coronary anatomy prior to TPV implantation. AD/AI was also reviewed in all pre-post MPV implant echocardiograms to assess for progression.

RESULTS

From 04/2007 to 3/2015, 118 pts underwent catheterization with intent for TPV implant. Mean age and weight were 24.5 ± 12 years and 64.3 ± 20 kg, respectively. Diagnoses were: TOF (53%), D-TGA/DORV (18%), s/p Ross (15%), and Truncus (9%). Types of RV-PA connections were: conduits (96), bioprosthetic valves (14), and other (7). Successful TPV implant occurred in 91 pts (77%). RVOT balloon angioplasty was performed in 43/118 pts (36%). Aortography was performed in 18/43 pts with AD/AI noted in 6/18 (33%); 2 with D-TGA (1 s/p Lecompte, 1 s/p Rastelli), 2 with TOF, 1 Truncus and 1 s/p Ross. Procedure was aborted in the 2 who developed severe AD/AI. TPV was implanted in 3/4 patients with mild AD/AI. Review of pre-post TPV implantation echocardiograms in 83/91 pts (91%) revealed no new/worsened AI in any patient.

CONCLUSION

AD/AI is relatively common on aortography during simultaneous RVOT balloon angioplasty. Lack of AI progression by echocardiography post-TPV implant suggests these may be benign findings in most cases. However, AD/AI should be carefully evaluated in certain anatomic subtypes with close RVOT/aortic alignments.

Injectable tissue engineered pulmonary heart valve implantation into the pig model: A feasibility study

Background

Transcatheter pulmonary valve replacement is currently performed in clinical trials, but is limited by the use of glutaraldehyde-treated bioprostheses. This feasibility study was performed to evaluate delivery-related tissue distortion during implantation of tissue-engineered (TE) heart valves.

Material/Methods

The injectable TE heart valve was mounted on a self-expanding nitinol stent (n=7) and delivered into the pulmonary position in 7 pigs, (weight 26 to 31 kg), performing a sternotomy or limited lateral thoracotomy. Prior to implantation, the injectable TE heart valves were crimped and inserted into an applicator. Positioning of the implants was guided by fluoroscopy, and after careful deployment, angiographic examination was performed to evaluate the correct delivered position. Hemodynamic measurements were performed by epicardial echocardiography. Finally, the animals were sacrificed and the injectable TE heart valves were inspected by gross examination and histological examination.

Results

Orthotopic deliveries of the injectable TE heart valves were all successful performed, expect in 1 where the valve migrated due to a discrepancy between pulmonary valve annulus size and injectable TE valve size. Angiographic evaluation (n=6) showed normal valve function, supported by epicardial echocardiography in which no increased flow velocity was measured, neither trans- nor paravalvular regurgitation. Histological evaluation demonstrated absence of tissue damage from the delivery process.

Conclusions

Transcatheter implantation of an injectable TE heart valve seems to be possible without tissue distortion due to the delivery system.

Percutaneous pulmonary and tricuspid valve implantations: An update

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.

Current status of right ventricular outflow tract reconstruction: complete translation of a review article originally published in Kyobu Geka 2014;67:65-77

Right ventricular outflow tract (RVOT) reconstruction is becoming more prevalent as the number of adult patients who require repeated surgery long after definitive repair of congenital heart defects during childhood has increased. Early primary repair and annulus-preserving surgery have been the two current strategies of RVOT reconstruction from the viewpoint of timing and indications for surgical intervention; however, the long-term outcomes of both procedures remain unknown. Although various materials have been used for pulmonary valve replacement during RVOT reconstruction, deficient durability due primarily to immunological rejection frequently arises, particularly when implanted into young patients. A multicenter study in Japan showed that the clinical outcomes of expanded polytetrafluoroethylene (ePTFE) valved patches/conduits that we developed and manufactured comprised an excellent alternative material for RVOT reconstruction. Such enhanced outcomes might have partly been attributable to the biocompatibility and low antigenicity of ePTFE, and also to the fluid dynamic properties arising from the structural characteristics of a bulging sinus and a fan-shaped valve. However, numerous issues concerning RVOT reconstruction, such as indications for and the timing of definitive repair, as well as the choice of materials for pulmonary valve replacement, must be resolved to achieve better patient prognoses and quality of life. This review describes recent surgical strategies and outstanding issues associated with RVOT reconstruction.

One-year follow-up of the Melody transcatheter pulmonary valve multicenter post-approval study

OBJECTIVES

This study sought to confirm that the short-term hemodynamic effectiveness of the Melody transcatheter pulmonary valve (TPV) (Medtronic, Inc., Minneapolis, Minnesota) achieved by real-world providers is equivalent to the historical results established in the initial 5-center Investigational Device Exemption trial.

BACKGROUND

TPV replacement has been used to treat right ventricular outflow tract (RVOT) conduit dysfunction for >10 years. The Melody TPV received U.S. Food and Drug Administration approval in 2010 as a Humanitarian Use Device.

METHODS

Patients with dysfunctional RVOT conduits were entered in this prospective, nonrandomized study at 10 centers. The primary endpoint was acceptable hemodynamic function at 6 months post-implantation, defined as a composite of RVOT echocardiographic mean gradient ≤30 mm Hg, pulmonary regurgitation less than moderate as measured by echocardiography, and freedom from conduit reintervention and reoperation.

RESULTS

Cardiac catheterization was performed in 120 patients for potential implantation of the Melody TPV; of these, 100 patients were implanted, with a 98.0% procedural success rate. There were no procedure-related deaths. Acceptable hemodynamic function at 6 months was achieved in 96.7% of patients with evaluable data (87.9% of the entire implanted cohort), with results maintained through 1 year. No patient had moderate or severe pulmonary regurgitation after implantation. No patient required catheter reintervention in the first year after implantation, and 2 patients required reoperation for conduit replacement. The rate of freedom from TPV dysfunction was 96.9% at 1 year.

CONCLUSIONS

This first prospective, real-world experience with the Melody TPV in the United States demonstrates continued high procedural success, excellent short-term TPV function, and low reintervention and reoperation rates at 1 year. (Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692).

[Minimally invasive pulmonary valve replacement in pediatric patients: importance of imaging]

CLINICAL/METHODICAL ISSUE

Right ventricular outflow tract (RVOT) dysfunction with pulmonary regurgitation or obstruction is a common postsurgical consequence in congenital heart disease.

STANDARD RADIOLOGICAL METHODS

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.

METHODICAL INNOVATIONS

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.

PERFORMANCE

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.

ACHIEVEMENTS

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.

PRACTICAL RECOMMENDATIONS

Several imaging modalities are used for evaluation of RVOTs; however, MRI can provide answers to most questions without radiation exposure.

Left Main Coronary Artery Compression following Melody Pulmonary Valve Implantation: Use of Impella Support as Rescue Therapy and Perioperative Challenges with ECMO

The purpose of this case is to describe the complex perioperative management of a 30-year-old woman with congenital heart disease and multiple resternotomies presenting with pulmonary homograft dysfunction and evaluation for percutaneous pulmonary valve replacement. Transvenous, transcatheter Melody valve placement caused left main coronary artery occlusion and cardiogenic shock. An Impella ventricular assist device (VAD) provided rescue therapy during operating room transport for valve removal and pulmonary homograft replacement. ECMO support was required following surgery. Several days later during an attempted ECMO wean, her hemodynamics deteriorated abruptly. Transesophageal and epicardial echocardiography identified pulmonary graft obstruction, requiring homograft revision due to large thrombosis. This case illustrates a role for Impella VAD as bridge to definitive procedure after left coronary occlusion and describes management of complex perioperative ECMO support challenges.

Transcatheter pulmonary valve insertion, expanded use and future directions

Transcatheter pulmonary valve replacement with the Melody® valve is an accepted alternative to surgical replacement of the pulmonary valve for some patients and therefore a complementary strategy in the long-term management of several groups of patients with congenital heart disease. It allows at least extending the time between sternotomies and possibly improving late outcomes. With a combined surgical and percutaneous approach, late morbidity for some of these patients will likely be diminished. This manuscript will review the current expanded applications for this technology, demonstrate several examples of its use and discuss future directions for this evolving equipment.

Risk of coronary artery compression among patients referred for transcatheter pulmonary valve implantation: a multicenter experience

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.

Percutaneous pulmonary valve implantation

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.