Percutaneous Pulmonary Valve Implantation

3D Modeling of Self-Expandable Valves for PPVI in Distinct RVOT Morphologies

Tetralogy of Fallot often requires transannular patch repair, leading to pulmonary insufficiency. Percutaneous pulmonary valve implantation (PPVI) with self-expandable valves offers a promising alternative, especially for enlarged right ventricular Queryoutflow tracts (RVOT). Five RVOT types identified in patients with Tetralogy of Fallot reflect anatomical variations due to disease and prior surgeries. This study assesses the Pulsta THV® valve's in vitro hemodynamic performance across these RVOT morphologies using 3D-printed models. Five RVOT morphologies were recreated as 3D models from patient-specific imaging data. The Pulsta THV® valves, available in 28, 30, and 32 mm sizes, were evaluated using the ViVitro Pulse Duplicator System at three cardiac outputs (2, 3.5, and 5 L/min). Hemodynamic performance was assessed by measuring regurgitation rates and pressure gradients in the left and right pulmonary arteries. The Pulsta THV® performed optimally in RVOT Types 1 and 2, demonstrating lower regurgitation rates and pressure gradients, particularly with larger valve sizes. Conversely, RVOT Types 3 and 5 showed increased pressure gradients and hemodynamic variability, indicating less favorable outcomes. The results highlighted the critical role of precise anatomical compatibility, with larger valve sizes proving more effective in enlarged RVOT geometry. Valve sizes tailored to specific RVOT morphologies can enhance PPVI outcomes. Types 1 and 2 are ideal for PPVI, while Types 3 and 5 present challenges due to hemodynamic variability. This study supports 3D modeling and in vitro testing for pre-procedural planning to reduce complications, with future research exploring dynamic imaging and materials mimicking tissue properties.

Rupture of a calcified right ventricle to pulmonary artery homograft by balloon dilation- emergency rescue by venus P-Valve

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) is a recognized alternative treatment to surgery for patients with dysfunctional right ventricular outflow tracts. Patient selection is essential to avoid serious complications from attempted treatment, such as rupture or dissection, especially of the calcified outflow tracts. We describe a case with an unexpected rupture of a calcified homograft valve and main pulmonary artery, which was treated successfully by emergency implantation of a self-expanding Venus P-Valve (Venus MedTech, Hangzhou, China) without the need for pre-stenting with a covered stent.

CASE DETAILS

A 13-year-old boy had two previous operations of tetralogy of Fallot, one a total repair and the other a homograft valved conduit for pulmonary regurgitation. He presented with dyspnea and severe right ventricular outflow tract obstruction (RVOTO) and had a calcified outflow tract and main pulmonary artery. In the catheter laboratory, a non-compliant balloon dilation resulted in a contained rupture of the conduit. The patient remained hemodynamically stable, and the rupture was treated with a self-expandable Venus P-Valve without the need for a covered stent combined with a balloon-expandable valve or a further surgical procedure.

DISCUSSION

Preprocedural evaluation with an inflating balloon is necessary to examine tissue compliance and determine suitability for PPVI. However, this condition is accompanied by a risk of conduit rupture. Risk factors of this complication are calcification and homograft use. These ruptures are mostly controlled with a prophylactic or therapeutic covered stent, with a low rate of requiring surgery. However, there are severe ruptures which lead to hemothorax and death. In the available literature, there was no similar reported case of conduit rupture, which a self-expandable Pulmonary valve stent has managed. It seems that fibrosis and collagen tissue around the heart, formed after open surgeries, can contribute to the control of bleeding in these cases.

CONCLUSION (CLINICAL LEARNING POINT)

The suitability of patients for the PPVI procedure should be examined more carefully, specifically patients with homograft and calcification in their conduit. Furthermore, conduit rupture might be manageable with self-expandable artificial pulmonary valves, specifically in previously operated patients, and the applicability of this hypothesis is worth examining in future research.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

BACKGROUND

Due to the wide variety of morphology, size, and dynamics, selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation (PPVI). This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional (3D)-printed models for planning PPVI with the Venus P-valve.

METHODS

Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.

RESULTS

3D model bench testing altered treatment strategy in all patients (100%). One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly. In the remaining 14 patients, valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery. In four patients, it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract (RVOT) ( n = 2) or risk of compression coronary artery ( n = 2). Concerning sizing, we found that an oversize of 2-5 mm suffices. Anchoring of the valve was dictated by the flaring of the in- and outflow portion in the pulmonary artery. PPVI was successful in all 14 patients (absence of valve migration, no coronary compression, and none-to-mild residual pulmonary regurgitation [PR]). The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group (36 [2] vs. 32 [4], Z = -3.77, P <0.001).

CONCLUSIONS

In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique, as 2-5 mm sufficed.

Finite element modeling with patient-specific geometry to assess clinical risks of percutaneous pulmonary valve implantation

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) is a non-surgical treatment for right ventricular outflow tract (RVOT) dysfunction. During PPVI, a stented valve, delivered via catheter, replaces the dysfunctional pulmonary valve. Stent oversizing allows valve anchoring within the RVOT, but overexpansion can intrude on the surrounding structures. Potentially dangerous outcomes include aortic valve insufficiency (AVI) from aortic root (AR) distortion and myocardial ischemia from coronary artery (CA) compression. Currently, risks are evaluated via balloon angioplasty/sizing before stent deployment. Patient-specific finite element (FE) analysis frameworks can improve pre-procedural risk assessment, but current methods require hundreds of hours of high-performance computation.

METHODS

We created a simplified method to simulate the procedure using patient-specific FE models for accurate, efficient pre-procedural PPVI (using balloon expandable valves) risk assessment. The methodology was tested by retrospectively evaluating the clinical outcome of 12 PPVI candidates.

RESULTS

Of 12 patients (median age 14.5 years) with dysfunctional RVOT, 7 had native RVOT and 5 had RV-PA conduits. Seven patients had undergone successful RVOT stent/valve placement, three had significant AVI on balloon testing, one had left CA compression, and one had both AVI and left CA compression. A model-calculated change of more than 20% in lumen diameter of the AR or coronary arteries correctly predicted aortic valve sufficiency and/or CA compression in all the patients.

CONCLUSION

Agreement between FE results and clinical outcomes is excellent. Additionally, these models run in 2-6 min on a desktop computer, demonstrating potential use of FE analysis for pre-procedural risk assessment of PPVI in a clinically relevant timeframe.

Percutaneous pulmonary valve implantation in a patient with congenitally corrected transposition of the great arteries: a case report

BACKGROUND

Percutaneous pulmonary valve implantation has become an attractive method of dysfunctional right ventricle outflow tract treatment.

CASE PRESENTATION

We describe a unique case of a 20-year-old Caucasian male patient with a complex cyanotic heart defect, namely pulmonary atresia, with congenitally corrected transposition of the great arteries and ventricular septal defect after Rastelli-like surgery at the age of 5 years with homograft use. At the age of 20 years, the patient needed percutaneous pulmonary valve implantation owing to homograft dysfunction. Despite unusual course of the coronary arteries, balloon testing in the landing zone of the right ventricle outflow tract excluded potential coronary artery compression. Then, after presentation, a Melody valve was implanted successfully in the pulmonary valve position. The 8-year follow-up was uneventful.

CONCLUSION

This is likely the first description of a percutaneous pulmonary valve implantation in such anatomy. Such a procedure is feasible; however, it requires exceptional caution owing to the anomalous coronary arteries course, which can be the reason for their compression.

Early results of Pulsta® transcatheter heart valve in patients with enlarged right ventricular outflow tract and severe pulmonary regurgitation due to transannular patch

OBJECTIVE

The purpose of this study is to assess the feasibility, effectivity, and safety of a novel self-expandable valve system, Pulsta® transcatheter heart valve in patients with tetralogy of fallot and severe pulmonary regurgitation after transannular patch repair.

BACKGROUND

Severe pulmonary regurgitation after tetralogy of fallot repair is a life-threatening problem and should be treated by pulmonary valve implantation. Although percutaneous pulmonary valve implantation has been ever increasingly used for this purpose, available balloon-expandable valves have limitations and cannot be used by most patients. Pulsta® transcatheter heart valve is a new self-expandable valve system and offers a new solution to be used in patients with different types of native right ventricular outflow tract geometry.

PATIENTS AND METHODS

Ten patients with severe regurgitation after tetralogy of fallot repair with a transannular patch have been enrolled in the study according to echocardiographic examination. MRI was used in asymptomatic patients to delineate the indication and the right ventricular outflow tract geometry. Pulsta® transcatheter heart valve implantation was performed in ten patients, and preprocedural, procedure, and 6 months follow-up findings of the patients were evaluated.

RESULTS

Pulsta® pulmonary valve implantation was performed in ten patients successfully without any severe complications. Valve functions were perfect in six of ten patients, while the others had insignificant regurgitation by echocardiographic examination at the end of 6 months follow-up.

CONCLUSIONS

This study showed that Pulsta® transcatheter heart valve is a feasible, effective, and safe method in the treatment of severe pulmonary regurgitation due to transannular patch repair in patients with tetralogy of fallot.

Infective Endocarditis Risk with Melody versus Sapien Valves Following Transcatheter Pulmonary Valve Implantation: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

BACKGROUND

Transcatheter pulmonary valve implantation (TPVI) is an effective non-surgical treatment method for patients with right ventricle outflow tract dysfunction. The Medtronic Melody and the Edwards Sapien are the two valves approved for use in TPVI. Since TPVI patients are typically younger, even a modest annual incidence of infective endocarditis (IE) is significant. Several previous studies have shown a growing risk of IE after TPVI. There is uncertainty regarding the overall incidence of IE and differences in the risk of IE between the valves.

METHODS

A systematic search was conducted in the MEDLINE, EMBASE, PubMed, and Cochrane databases from inception to 1 January 2023 using the search terms 'pulmonary valve implantation', 'TPVI', or 'PPVI'. The primary outcome was the pooled incidence of IE following TPVI in Melody and Sapien valves and the difference in incidence between Sapien and Melody valves. Fixed effect and random effect models were used depending on the valve. Meta-regression with random effects was conducted to test the difference in the incidence of IE between the two valves.

RESULTS

A total of 22 studies (including 10 Melody valve studies, 8 Sapien valve studies, and 4 studies that included both valves (572 patients that used the Sapien valve and 1395 patients that used the Melody valve)) were used for the final analysis. Zero IE incidence following TPVI was reported by eight studies (66.7%) that utilized Sapien valves compared to two studies (14.3%) that utilized Melody valves. The pooled incidence of IE following TPVI with Sapien valves was 2.1% (95% CI: 0.9% to 5.13%) compared to 8.5% (95% CI: 4.8% to 15.2%) following TPVI with Melody valves. Results of meta-regression indicated that the Sapien valve had a 79.6% (95% CI: 24.2% to 94.4%, p = 0.019; R2 = 34.4) lower risk of IE incidence compared to the Melody valve.

CONCLUSIONS

The risk of IE following TPVI differs significantly. A prudent valve choice in favor of Sapien valves to lower the risk of post-TPVI endocarditis may be beneficial.

Percutaneous Transcatheter Closure of Congenital Ventricular Septal Defects

Ventricular septal defects (VSDs) are the most common kind of congenital heart disease and, if indicated, surgical closure has been accepted as a gold-standard treatment. However, as less-invasive methods are preferred, percutaneous device closure has been developed. After the first VSD closure was performed percutaneously by Lock in 1988, both techniques and devices have developed consistently. A perventricular approach for closure of muscular VSD in small patients and the closure of perimembranous VSD using off-label devices are key remarkable developments. Even though the Amplatzer membranous VSD occluder (Abbott) could not be approved for use due to the high complete atrioventricular conduction block rate, other new devices have shown good results for closure of perimembranous VSDs. However, the transcatheter technique is slightly complicated to perform, and concerns about conduction problems after VSD closure with devices remain. There have been a few reports demonstrating successful closure of subarterial-type VSDs with Amplatzer devices, but long-term issues involving aortic valve damage have not been explored yet. In conclusion, transcatheter VSD closure should be accepted as being as effective and safe as surgery but should only be performed by experienced persons and in specialized institutes because the procedure is complex and requires different techniques. To avoid serious complications, identifying appropriate patient candidates for device closure before the procedure is very important.

Staged Percutaneous Management of Pulmonary Atresia and Intact Interventricular Septum: Stretching the Limits

Aims

Pulmonary atresia with intact ventricular septum (PA/IVS) can be treated by catheter-based interventions and complemented by various surgical procedures. We aim to determine a long-term treatment strategy to enable patients to be surgery free, depending solely on percutaneous interventions.

Methods and Results

We selected five patients from among a cohort of patients with PA/IVS treated at birth with radiofrequency perforation and dilatation of the pulmonary valve. Patients had reached a pulmonary valve annulus of 20 mm or larger on their biannual echocardiographic follow-up, with right ventricular dilatation. The findings, together with the right ventricular outflow tract and pulmonary arterial tree, were confirmed by multislice computerised tomography. Based on the angiographic size of the pulmonary valve annulus, all patients were successfully implanted with either Melody® or Edwards® pulmonary valves percutaneously, regardless of their small weights and ages. No complications were encountered.

Conclusion

We managed to stretch the age and weight limitations for performing percutaneous pulmonary valve implantation (PPVI): interventions were attempted whenever a pulmonary annulus size of >20 mm was reached, which was rationalised by the prevention of progressive right ventricular outflow tract dilatation and accommodating valves between 24 and 26 mm, which is enough to sustain a normal pulmonary flow in adulthood.

Isolated pulmonary valve endocarditis with pulmonary annular abscess in a patient of Noonan syndrome

Right-sided endocarditis is a rare entity, with various series reporting an incidence of 5%–10%. Pulmonary valve (PV) is not only the least commonly involved valve in infective endocarditis (IE), with an incidence of 1.5%–2%, but ‘isolated’ pulmonic valve endocarditis (PVE) without tricuspid valve involvement is even rarer with limited published data. We report a middle-aged man with Noonan syndrome and a dysplastic PV with severe pulmonary stenosis. He presented with a large isolated mobile PV vegetation with moderate pulmonary regurgitation (PR). Initially, he was managed conservatively, but due to persistent fever, pulmonary regurgitation and evidence of pulmonary annular abscess extending into the right ventricular outflow tract, he required surgical intervention. Considering the low incidence of isolated PVE, it poses a challenge for physicians in prompt diagnosis and timely management of the infection.

Coronary Artery Anomalies and Their Impact on the Feasibility of Percutaneous Pulmonary Valve Implantation

One of the major obstacles preventing successful percutaneous pulmonary valve implantation (PPVI) is related to the close proximity of coronary artery branches to the expected landing zone. The aim of this study was to assess the frequency of coronary artery anomalies (CAAs) especially those associated with major coronary branches crossing the right ventricular outflow tract (RVOT) and to describe their relevance for the feasibility of percutaneous pulmonary valve implantation (PPVI). In our retrospective single-center study 90 patients were evaluated who underwent invasive testing for PPVI in our institution from 1/2010 to 1/2020. CAAs were identified in seven patients (8%) associated with major branches crossing the RVOT due to origin of the left anterior descending (LAD) or a single coronary artery from the right aortic sinus. In 5/7 patients with CAAs balloon testing of the RVOT and selective coronary angiographies revealed a sufficiently large landing zone distal to the coronary artery branch. While unfavorable RVOT dimensions prevented PPVI in one, PPVI was performed successfully in the remaining four patients. The relatively short landing zone required application of the "folded" melody technique in two patients. All patients are doing well (mean follow-up 3 years). CAAs associated with major coronary branches crossing the RVOT can be expected in about 8% of patients who are potential candidates for PPVI. Since the LAD crossed the RVOT below the plane of the pulmonary valve successful distal implantation of the valve was possible in 4/7 patients. Therefore these coronary anomalies should not be considered as primary contraindications for PPVI.

Repositioning an embolised stent during a percutaneous pulmonary valve implantation

Percutaneous pulmonary valve implantation is a less invasive procedure to treat right outflow tract dysfunction related to surgical procedures such as repair of Tetralogy of Fallot. Despite the lower risks, complications have been reported, namely embolisation of the pre-stent. We report a case of a 16-year-old boy, whose procedure was complicated by embolisation of the pre-stents and the strategy used to reimplant them, prior to the successful implantation of a pulmonary valve.

Pulmonary percutaneous valve implantation in large native right ventricular outflow tract with 32 mm Myval transcatheter heart valve

Pulmonary percutaneous valve implantation (PPVI) is feasible with satisfactory mid-term results in patients with native right ventricular outflow tract (RVOT) and has been increasingly used instead of surgically implantable pulmonary valves. Creating a stable landing zone with a diameter less than the largest commercially available valve (previously available 29 mm and currently available 32 mm) is crucial for technical success of the procedure, limiting the number of suitable candidates for PPVI. We report the case of PPVI with a 32 mm Myval transcatheter heart valve in a patient with a large native RVOT (pre-stented with AndraStent XXL mounted on a 35 × 60 mm valve balloon catheter) lesion who had Tetralogy of Fallot surgically corrected. The post-procedural outcomes of this case were satisfactory with no complications reported during the hospital stay.

[First serial transcatheter implantation of pulmonary valve using MedLab-KT prosthesis]

BACKGROUND

Surgical treatment of 'blue' congenital heart defects frequently implies various interventions on the outlet portion of the right ventricle or pulmonary artery trunk. Most often used are various conduits, reconstructing the outlet portion of the right ventricle and pulmonary artery. Most patients having previously endured the mentioned interventions, would in the remote terms require repeat operative procedures for stenosis or insufficiency on the pulmonary valve or the implanted conduit. Taking into account complexity and the risk of open interventions, the current trends are towards more frequent use of transcatheter implantation of the pulmonary valve.

AIM

The purpose of this work is to present the first serial experience with hybrid transventricular implantation of an original Russian-made valve into the position of the pulmonary artery.

PATIENTS AND METHODS

We retrospectively studied a series of 5 clinical cases who from July 2019 to May 2020 at the Federal Centre of Cardiovascular Surgery (Penza) had underwent hybrid transventricular implantation of the first Russian-made valve-containing stent (MedLab-KT) into the position of the pulmonary valve, with the stent's closing component consisting of leaflets made of polytetrafluoroethylene.

RESULTS

3 patients underwent implantation of valve # 25 and 2 subjects received valve # 23, with all cases yielding good immediate results. The haemodynamic parameters of the implanted prosthesis were optimal. In all cases, the significant gradient was absent and regurgitation did not exceed grade I. There was no in-hospital mortality. The method of hybrid prosthetic repair of the pulmonary valve via the transapical right-ventricular access from the left lateral mini-thoracotomy was aimed at reducing potential risks of artificial circulation, also contributing to a significant decrease in the traumatic nature of surgical treatment of patients requiring a repeat intervention for pulmonary valve pathology.