Pulmonary Valve Insertion Research Articles

Myocardial fibrosis affects outcome of pulmonary valve insertion after tetralogy repair

Myocardial fibrosis affects outcome of pulmonary valve insertion after tetralogy repair

Time-Related Risk of Pulmonary Conduit Re-replacement: A Congenital Heart Surgeons’ Society Study

BackgroundPatients receiving a right ventricle to pulmonary artery conduit (PC) in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically placed PC (PC2). MethodsFrom 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons’ Society member institutions survived to discharge after initial valved PC insertion (PC1) at age ≤ 2 years. Of those, 355 underwent surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI. ResultsOf 355 PC2 patients (median follow-up, 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (hazard ratio [HR] 1.6, P < .001), concomitant aortic valve intervention (HR 7.6, P = .009), aortic allograft (HR 2.2, P = .008), younger age (HR 1.4, P < .001), and larger Z score of PC1 (HR 1.2, P = .04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, P = .006), porcine unstented conduit (HR 4.7, P < .001), and older age (HR 2.3, P = .01). ConclusionsAortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Procedural technique for hybrid pulmonary valve replacement in infants and small children.

Hybrid approach to pulmonary valve replacement (PVR) in the paediatric population has been reported, although data in infants and small children are limited. Several strategies are now possible. The aim of this study is to review our hybrid PVR strategy in a complex patient cohort, outlining a variety of approaches employed in our centre. We performed a retrospective review of infants and small children who underwent hybrid PVR between May 2017 and April 2019 in a single tertiary cardiology centre. Medical records were reviewed to ascertain demographic, clinical and outcome data. Ten patients with a median (interquartile range) age of 1.5 years (1.1-1.9) and weight of 8.8 kg (8-10.6) were managed with hybrid pulmonary valve insertion. Eight patients had perventricular approach (4 sternotomy and 4 subxiphoid) and 2 patients had surgically sutured valve. Six patients underwent cardiopulmonary bypass for associated lesions. Three had insertion of the valve into conduits and 7 were deployed into native right ventricular outflow tracts. The pulmonary valve was successfully inserted in all 10 patients with no mortality. Postprocedural complications included paravalvar leak in 2 patients, suspected endocarditis in 1 patient who developed early valve regurgitation and wound infection in 1 patient. Several approaches to hybrid PVR may be employed in small children with a high success rate. Follow-up studies are required to evaluate longer term durability of these approaches compared to standard surgical replacement.

Right Ventricular Outflow Tract Reintervention in the Transcatheter Era: Outcomes and Cost Analysis.

Surgical pulmonary valve insertion (SPVI) for re-entry right ventricular outflow tract intervention (RVOTI) remains an established and reproducible approach. Fast-track in patients undergoing RVOTI of the comprehensive valve program targets early ICU and hospital discharge (Hd). Feasibility study for outcome and cost analysis was undertaken. Between January 2015 and December 2016, 34 patients underwent re-entry RVOTI. Seventeen had SPVI and 17 transcatheter PVI (TPVI). Surgical perioperative fast-track protocol was used. Echocardiographic evaluation preoperatively (TTE-1), after RVOTI (TTE-2), at hospital discharge (TTE-3), and follow-up (TTE-4) were obtained. Cost Analysis included procedural and hospital costs. Mean follow-up period was 11.3 ± 6.9months. All patients were extubated prior to ICU arrival. Mean age was 8.5 ± 7.8 for SPVI [vs 28.5 ± 8.6years for TPVI] (p < 0.05). There was no hospital mortality or 30-day readmission for SPVI (versus 1 for TPVI).Mean hospital length of stay (LOS) was 4.1 ± 1.1days for SPVI [vs 1.1 ± 0.7days for TPVI] (p < 0.05). Number of prior sternal re-entry had no influence on outcome. RV systolic pressure referenced to LVSP (rRVSP, %) and diastolic dimension (RVEDDi, z score) showed sustainable improvement (TTE-2, TTE-3, TTE-4) in both groups compared to TTE-1 (p < 0.05). Mean total hospital cost was $5475.86 ± 2503.91 lower after SPVI (p=0.09), 21.7% procedural cost reduction. Patients undergoing RVOTI can be safely stratified, based on a customized concept, towards SPVI or TPVI. Standardized strategy can advocate a fast-track path. SPVI is associated with comparable mid-term outcomes to TPVI although SPVI is delivered in younger patients. Despite longer LOS SPVI is associated with reduced hospital cost. Multisite studies might help determine suitability for each strategy on cost containment/quality of life basis.

Ventricle Stress/Strain Comparison Between Models Using Different Zero-Load Diastole and Systole Morphologies and Models Using Only One Zero-Load Morphologies

Ventricle mechanical stress and strain calculations play an important role in cardiovascular investigations. Patients with repaired tetralogy of Fallot (TOF) account for the majority of cases with late onset right ventricular (RV) failure. The current surgical approach, including pulmonary valve replacement(PVR), has yielded mixed results with some patients recover RV function after pulmonary valve insertion with or without concomitant RV remodeling surgery but some do not[Therrien, Siu and McLaughlin (2000);]. Cardiac magnetic resonance (CMR) data were collected from 6 healthy volunteers and 12 Tetralogy of Fallot (TOF) patients before PVR with consent obtained. 12 patients were divided into two groups depending on right ventricle post-surgery recover( 6 for each group). 3D patient-specific CMR-based ventricle models with different zero-load diastole and systole geometries were constructed to qualify right ventricle (RV) stress and strain values at begin-filling, end-filling, begin-ejection, and end-ejection, respectively. The models are solved with ADINA. Our new models (called 2G models) could provide end-diastole and end-systole stress/strain values which the old models with only one zero-load geometries (called 1G models) could not provide[Tang, Del Nido, Yang, et al., 2016]. Logistic regression with 5-fold cross validation was adopted to predict pulmonary valve replacement outcome. The results showed 2G mean end-ejection stress value from the 18 participants was 321.4% higher than that from 1G models (p=0.0002). 2G mean strain values was 230% higher than that of 1G models (p=0.0002). TOF group (TG) end-ejection mean stress value was 105.4% higher than that of healthy group (HG) (17.54±7.42kPa vs. 8.54±0.92kPa, p=0.0245). Worse outcome group (WG) begin-ejection mean stress was 57.4% higher than that of better outcome group (BG, 86.94±26.29 vs. 52.93±22.86 kPa; p=0.041). Among 7 chosen parameters (stress, strain, age, gender, right volume end-diastole volume index, right volume end-systole volume index and ejection fracture), end-filling stress was the best predictor to differentiate BG patients from WG patients with prediction accuracy = 0.8208. 2G models may provide more accurate stress/strain results than 1G models and be applied in clinical situation, potentially. Large scale studies are still needed for validation.

The impact of pulmonary valve-sparing techniques on postoperative early and midterm results in tetralogy of Fallot repair

In this study, we analyzed the impact of pulmonary valve-sparing techniques on early and midterm postoperative results of tetralogy of Fallot repair. A total of 64 patients diagnosed with tetralogy of Fallot, who underwent total correction operation by the same surgeon between November 2010 and September 2015 were included in this retrospective study. Mean age of the patients was 20.0±14.2 months (5.5-96 months). Forty patients (62.5%) were male. Thirty two of the patients (50%) were under one year of age. Pulmonary valve-sparing techniques were performed in 29 patients (Group 2), while transannular patch was applied in the remaining 35 patients (Group 1). Pericardial monocusp valve was constructed in 15 patients in Group 1. In Group 2, pulmonary valve-sparing techniques were transatrial repair in nine patients; transatrial-transpulmonary in eight, infundibular patch in eight, and infundibular-pulmonary patch in four patients. There was no early postoperative mortality in Group 2. Five patients (14.2%) in Group 1 died in the early postoperative period (p=0.058). Pulmonary monocusp insertion was performed in 2 (13.3%) of these patients (p=1). The causes of mortality were sudden cardiac arrest (n=2), multiorgan failure (n=1), low cardiac output (n=1), and neurological complications (n=1). Five patients in Group 1 required extracorporeal membrane oxygenation support (ECMO). Three of them were separated from ECMO and two of the patients that were separated were discharged uneventfully. Total postoperative morbidity rate was significantly higher in Group 1 (51.4% vs. 6.8%) (p=0.0001). Morbidity rate was significantly lower in patients with pulmonary monocusp insertion than patients in the same group without a monocusp (p=0.0176). Forty nine (83%) of the patients were followed up for a median of 6.5 (1-24) months. While free pulmonary regurgitation was detected in all non-monocusp patients in Group 1, pulmonary regurgitation was absent or mild in Group 2. Twelve (80%) of the patients in Group 1 who had monocusp insertion were followed up. Only two of these patients had free pulmonary regurgitation (16.6%). The rest of them had mild (n=6) or mildmoderate pulmonary regurgitation (n=4). Mortality and morbidity rates are lower when pulmonary valvesparing techniques are used in repair of tetralogy of Fallot. Monocusp pulmonary valve insertion may improve results in patients who require transannular patch repair. It is suggested that every effort should be made to achieve a competently working pulmonary valve during repair.

Transcatheter pulmonary valve insertion, expanded use (beyond large conduits from the right ventricle to pulmonary artery), and future directions.

Transcatheter pulmonary valve insertion is the most important advance in congenital interventional cardiology since atrial septal defect devices became commonly available 15 years ago. It has changed the way we look at a number of diverse diagnoses and changes how we plan, diagnose, operate, and follow-up patients. It has changed how we counsel families expecting a child that may benefit from it. Expanded use of the Melody® valve, outside its United States Food and Drug Administration approved indications, has helped numerous additional patients. The use of transcatheter pulmonary valve insertion in selected patients following surgical Gore-tex® bileaflet in valve right ventricular outflow tract reconstruction and those with a history of prior small homograft conduits will be discussed.

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.

Surgical pulmonary valve insertion

Pulmonary valve replacement is being performed with increasing frequency in patients with various congenital heart diseases. Chronic pulmonary regurgitation after repair of tetralogy of Fallot is a typical situation that requires pulmonary valve replacement. Chronic pulmonary regurgitation after repair of tetralogy of Fallot can lead to right ventricular dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias, and sudden death. Although pulmonary valve replacement can lead to improvement in functional class and a substantial decrease or normalisation of right ventricular volumes, the optimal timing of pulmonary valve replacement in patients with chronic pulmonary regurgitation is still unknown. There are several options for surgical pulmonary valve replacement. However, no ideal pulmonary valve substitute exists currently and most of the surgically implanted pulmonary valves will eventually require re-replacement. This article will review options and timing of surgical pulmonary valve insertion in patients with chronic pulmonary regurgitation after repair of tetralogy of Fallot.

Pulmonary Valve Preservation Strategies for Tetralogy of Fallot Repair

was affirmed in a significant number of patients who tolerated the persistent effects of right ventricular volume overload for many years. In a significant number of postoperative patients, however, long-term complications of pulmonary regurgitation, residual ventricular septal defects (VSD), distal pulmonary artery stenosis, right ventricular dysfunction, atrial or ventricular arrhythmias, and exercise intolerance 2-5 required further operative intervention to address the residual defects, perform concomitant arrhythmia surgery, and pulmonary valve insertion.

Transcatheter pulmonary valve insertion: when, how, and why

Transcatheter pulmonary valve replacement is fast becoming an accepted alternative to repeat surgical pulmonary valve replacement for selected patients and therefore a complementary strategy in the long-term management of those requiring surgical pulmonary valve replacement. With a combined surgical and percutaneous approach, late morbidity for some of these patients may be diminished. This manuscript will review the current indications for this procedure, its limitations, and its benefits.

Surgical pulmonary valve insertion – when, how, and why

Relief of right ventricular outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation. The resultant chronic volume overload can lead to right ventricular dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias, and sudden death. Although pulmonary valve replacement can lead to improvement in functional class and a substantial decrease or normalisation of right ventricular volumes, the optimal timing of pulmonary valve replacement is not well defined. Benefits of pulmonary valve replacement have to be weighed against the risks of this procedure, including subsequent reoperation. This article will review the benefits and risks of pulmonary valve replacement, options for pulmonary valve substitute, and timing of pulmonary valve replacement in patients with chronic pulmonary regurgitation after relief of right ventricular outflow tract obstruction.

286 – Percutaneous right outflow tract valve implantation: substrate matters

Percutaneous pulmonary valve insertion has been recently introduced in clinical setting. Patient selection is widely accepted. These candidates are however heterogeneous, in regard of heart defects, and type of surgical right ventricular outflow tract (RVOT) reconstruction. It is presently unclear in the literature if type of surgical reconstruction matters for the success of the pulmonary valve insertion. Our goal was to compare the hemodynamic results of percutaneous pulmonary valve in patients with homografts, prosthetic conduit or RVOT reconstructed with patch. We reviewed patients included over the last 6 months in the prospective study (REVALV) for patients undergoing RVOT intervention for severe stenosis and/or insufficiency. Only valved stent group is analyzed here. All patients undergoing valved stent implantation are previously pre-stented with a bare metal stent according to present recommendations. Thirty-seven patients were included, distributed in three groups according to type of RVOT reconstruction (homograft REVALV is a multicentric prospective study for patients undergoing RVOT intervention for severe stenosis and/or insufficiency. Patients are distributed in three groups according to type of RVOT reconstruction (homograft, n = 10; prosthetic conduit, n = 20; RVOT enlargement by patch, n = 7). Overall, all groups were similar in RV to AP gradient improvement (after pre-stenting mean 30,79 vs 28 p = NS; final result mean 23,71 vs 28,17, p = NS), RV to aorta pressures ratio (after pre-stenting 0,187 vs 0,3117 p = NS; final result man 0,315 vs 0,317, p = NS). If considering non-extensible synthetic tubes we observe that RV-to-AP improvement is significantly worst to the rest of the group (mean 7,07 vs 0,17, p = 0,005). When focusing on outflow tract diameter, results did not differ in homograft group and patch group. In contrast, diameter did play a role in those patients having a synthetic tube, with a cut-off at 20 mm diameter. Below 20 mm, relieve of outflow tract gradient was significantly worse than for bigger conduits. Pulmonary valve insertion is efficient in all type of RVOT reconstruction at least in the short term. The diameter of the conduits did not play a role in RVOT obstruction relief as long as surgical substrates are homografts or patch enlargement. In patients with prosthetic conduits, size matters. In non-extensible synthetic tubes results are worst. Reduced distensibility and progressive diameter reduction may lead to not consider these patients as good candidates for this procedure.

287 Extension of indications for percutaneous pulmonary valve implantation in native right ventricle outflow tract: should all patients be considered?

Patient selection for percutaneous pulmonary valve insertion PPVI is widely accepted, being limited to patients having a right ventricle to pulmonary artery conduit. Little data has been reported regarding PPVI on patients having a native RVOT. We present our data regarding percutaneous PPVI in native RVOT and discuss the specific requirements to make this technique safe and durable. We review patients included over the last 12 months in the prospective study (REVALV) for patients undergoing RVOT intervention for severe stenosis and/or insufficiency. Only valved stent on native RVOT group is analyzed here. 10 patients were included. We perform MRI, balloon calibration and angiography of the RVOT to all patients in order to define the RVOT morphology, and to establish a personalized technique for each patient in order to implant a valved stent on the native RVOT. All patients undergoing valved stent implantation are previously pre-stented with a bare metal stent according to present recommendations. Initial dimensions for these patients were on the upper limit for the established criteria. 2 had a diameter above 24 mm. Decision for implanting valved stent was taken based on the fact that pre-stenting reduces RVOT diameter acchieving 22 mm, and giving the native outflow track the stability to prevent valved-stent fractures. For one patient, left pulmonary branch was stented down to the pulmonary trunk in order to have an appropriate diameter for valved-stenting. Pulmonary valve was placed successfully in all cases. All but one had been pre-stented at same procedure than valvulation. Of those, one freshly implanted bare metal stent dislodged to the right pulmonary artery when tenting to place the delivery system for the percutaneous valve. Two extra bare metal stents were implanted in order to cover the branch to the trunk, and finally valved stent was placed with no further problems. Percutaneous pulmonary valve implantation can be performed on patients having native RVOT with success. Pre-stenting should be performed in a previous intervention in order to ensure stabilization of the bare metal stent and to avoid dislodgements. MRI, angiography and balloon calibration are not discriminating criteria for discarding candidates if personalized techniques are established for each patient. Pulmonary branches can be used as anchors for PPVI.

316 Percutaneous right outflow tract valve implantation: when should we pre-stent?

Percutaneous pulmonary valve insertion has been recently introduced in clinical setting. Patient selection is widely accepted. Initial results demonstrated early and differed stent fractures that make consider pre-stenting as a previous step for the procedure. To date, differed or intra-procedure pre-stenting are both accepted techniques. We reviewed patients included over the last 6 months in the prospective study (REVALV) for patients undergoing RVOT intervention for severe stenosis and/or insufficiency. Only valved stent group is analyzed here. All patients undergoing valved stent implantation are previously pre-stented with a bare metal stent according to present recommendations. Thirty-seven patients were included, distributed in two gropus according moment of pre-stenting: differed pre-stenting (bare metal stent implantation several days before valved stent implantation -20 patients-) and same procedure pre-stenting (bare metal stent implantation at the same procedure of valved stent implantation-17 patients-). For analytical purposes, we considered RVOT anatomy (homograft, synthetic tube, patch-extended RVOT or native outflow tract). Overall, no differences were found regarding mean procedure times (77,35 vs 96,88, p = NS) and time of hospitalization (2,95 vs 3,63, p = NS). Mean delay time from pre-stenting to valvulation was 196,5 + −68 days. Rv to Ao ratio improvement from basal to valvulation was significantly better in intra-procedure pre-stenting group (0,172 vs 0,373, p = 0,009). Concerning complications, bare metal stent mobilization happened just after implantation while trying to place valved stent delivery gain. Two pelvic hematomas were observed (one of each group). Intra-procedure pre-stenting influences final result when considering RV-to-Ao ratio improvement, probably related to increase radial strength. The risk, however, remains higher as freshly implanted bare metal stent can mobilize, especially in native RVOT. Stratification of patient should be considered while choosing candidates for valved stent implantation.

The Performance of Hancock Porcine-Valved Dacron Conduit for Right Ventricular Outflow Tract Reconstruction

The surgical reconstruction of right ventricle outflow tract (RVOT) often requires the implantation of a valved conduit. Homografts are lacking availability and are associated with limited durability in children. Our experience with the Hancock porcine-valved Dacron (DuPont, Wilmington, DE) conduit (Medtronic, Minneapolis, MN) was retrospectively assessed. Follow-up was studied in 214 survivors who underwent 247 conduit implants between January 1990 and January 2007. Pulmonary atresia/ventricular septal defect was present in 86 (40.2%) and truncus arteriosus in 62 (29%). Conduit implantation was associated with anatomic repair in 136, conduit replacement in 96, and secondary pulmonary valve insertion in 15. Median age at operation was 62.5 months (range, 1 week to 50 years), including 14 neonates (6%). Median conduit size was 17.4 mm because of routine over-sizing. Pulmonary bifurcation patch augmentation was necessary in 26 patients. Periodic echocardiography studies were performed for a median follow-up of 98 months (range, 13 to 142 months). Three (1.4%) late deaths occurred. No conduit-related deaths or complications occurred. Conduit degeneration was associated with increase in valvular gradient. Valve regurgitation was absent or mild. Higher RVOT systolic pressure gradient at discharge did not influence conduit longevity. Conduit reoperation was delayed due to percutaneous balloon dilatation in 14 patients, associated with stenting in 7. Survival with freedom from conduit reoperation was 98% (95% confidence interval [CI], 97% to 100%) at 1 year, 81% (95% CI, 75% to 87%) at 5 years, and 32% (95% CI, 22% to 42%) at 10 years. The Hancock valved conduit is a safe and reliable alternative to homografts. It appears to be appropriate in patients with limited pulmonary vascular bed and high pulmonary artery pressures. Caution is required in neonates because of the rigidity of the Dacron housing. Initial results with secondary percutaneous procedures are encouraging.

Transcatheter valve insertion in a model of enlarged right ventricular outflow tracts

Transcatheter pulmonary valve insertion has recently emerged as an alternative to surgery. To extend its indications to patients with a large right ventricular outflow tract, we previously developed an intravascular device that reduces the diameter of the main pulmonary artery, allowing the insertion of available valved stents. Here we report its use in a model of animals with an enlarged right ventricular outflow tract and pulmonary valve incompetence. The study comprised 33 sheep that first underwent surgical enlargement of the main pulmonary artery. We then intended to implant a filler percutaneously, followed later by the insertion of a valve. Three animals died during the intermediate stage. The remainder were humanely killed either immediately (group 1, n = 6) or after a mean follow-up of 1 (group 2, n = 12) or 2 months (group 3, n = 12). Animals from groups 2 and 3 were equally divided into 2 subgroups according to the difference between diameters of the device inserted and the main pulmonary artery (A < 5 mm, B > or = 5 mm). Fillers were all inserted successfully (n = 30), although one embolized after its insertion (group 3A). A valved stent was implanted in all animals, but in 1 case a balloon ruptured during inflation of the stent leading to incomplete expansion and the death of the animal. Six animals, 5 of which were from group A, had pulmonary regurgitation after valve insertion. Pulmonary valve insertion is possible through a transcatheter technique using a pulmonary artery filler. Oversizing the device reduces the risk of embolization and paraprosthetic leak.

Percutaneous pulmonary and aortic valve insertion in Belgium: Going for conditional reimbursement or waiting for further evidence?

The aim of this study was to assess current evidence supporting the use of percutaneous heart valves (PHV) in degenerative aortic valve and congenital pulmonary outflow tract disease, as compared to conservative medical therapy or traditional surgical valve replacement. A systematic review of the literature on PHV was performed. No randomized controlled trials (RCT) on PHV have been published so far. Only observational data from series and data presented at cardiology meetings are available. Both percutaneous aortic valve (PAV) and percutaneous pulmonary valve (PPV) seem feasible in the hands of an experienced team. Safety, however, seems to be a problem in PAV, as shown by the high 30-day and 6-month mortality rates. Due to safety concerns, PAV reimbursement is not recommended and patients should only be subjected to PAV insertion within the boundaries of an RCT. In contrast, PPV implantation seems to be a safe and promising technology for which reimbursement under strict conditions may be recommended.

Clinical Summaries

Clinical Summaries

Abstract 2611: Transcatheter Valve Insertion A Model Of Enlarged Right Ventricular Outflow Tracts

Background: Transcatheter pulmonary valve insertion has recently emerged as an alternative to surgery. To extend the indications to patients with large right ventricular outflow tract (RVOT), we previously developed an intravascular device that reduces the diameter of the main pulmonary artery (MPA) allowing the insertion of available valved stents. We report its use in a model of animals with enlarged RVOT and pulmonary valve incompetence (PVI). Methods and Results: 33 sheep were included. They first underwent surgical MPA enlargement. We then intended to implant percutaneously a reducer followed by the insertion of a valve. Three animals died during interstage. The remaining were sacrificed acutely (group 1, n=6), after a mean follow-up of 1 (group 2, n=12) and 2 months (group 3, n=12). Animals from chronic groups were equally divided into 2 subgroups according to the difference between diameters of the device inserted and MPA (A: &lt; 5-mm, B: ≥ 5-mm). Reducers were inserted successfully (n=30). One embolized after its insertion (Group 3A). A valved stent could be implanted in all animals but one which experienced a balloon ruptured during its inflation leading to incomplete expansion and death of the animal. Six animals had pulmonary regurgitation after valve insertion. Five of them (Group A, n=5; Group B, n=1) had downsizing of the reducer. Conclusion: Pulmonary valve insertion is possible through a transcatheter technique using a PA reducer. Oversizing of this device reduces the risk of embolisation and paraprosthetic leak.